Behavior of the reconstructed Wolf Creek culvert
by Gerald Anson Willett
A thesis submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE in Civil Engineering
Montana State University
© Copyright by Gerald Anson Willett (1967)
Abstract:
The failure of an 18.5 foot diameter structural-plate culvert under 83 feet of cover led to its
reconstruction using the "imperfect trench" type of construction as well as other changes , This paper
reports the findings of a research project that was initiated to study the behavior of the reconstructed
culvert, The study was sponsored by the Montana State Highway Commission and the Bureau of
Public Roads and was performed by the Department of Civil Engineering and Engineering Mechanics
at Montana State University.
The reconstructed culvert was instrumented to study its behavior. Instrumentation consisted of: SR-4
strain gages placed on the culvert walls at approximately mid-height; Carlson Soil Stress Meters,
placed on the outside walls of the culvert and in the fill; rubber pressure cells, which were commercial
hot water bottles , placed in the fill; and settlement cells, which were placed in the fill oh each side of
the culvert „ Also, measurements that were taken included: levels on the culvert invert, vertical and
horizontal diameters, and levels of the roadway profile.
Computer programs were developed to determine stresses and earth pressure from data obtained by
periodic readings of the instruments .
Overall, the instrumentation performed satisfactorily. Results from strain gages, stress meters, and
rubber pressure cells, correlated well and demonstrated that the vertical load on the culvert was much
less than the weight of the overlying column of earth - a highly favorable load condition which the
"imperfect trench" method of construction was expected to produce. The SR-4 strain gages, which
measured bending strains in addition to circumferential compression, showed that significant residual
bending stresses were induced in the plates during erection. They also monitored bending stress
changes that occurred at the strain gage sites during and after the backfilling operation. The vigorous
compaction of the backfill on each side of the culvert, during the early stages of backfilling, produced a
bending stress pattern in the side walls that persisted throughout the embankment construction period
and thereafter.
There was no measurable differential settlement of the pavement attributable to the "imperfect trench"
type of construction. /V ffZ fBEHAVIOR OF THE RECONSTRUCTED
WOLF CREEK CULVERT
by
GERALD ANSON WILLETT, JR.
A th e s i s s u b m itte d to th e G ra d u a te F a c u lty in p a rtia l
fu lfillm e n t of th e re q u ire m e n ts for th e d e g re e
of
MASTER OF SCIENCE
in
C iv il E n g in ee rin g
A pproved:
H e a d , M ajo r D e p a rtm e n t
C h a irm a n , E xam ining C o m m ittee
D e a n , G ra d u a te D iv is io n
MONTANA STATE UNIVERSITY
B o zem an , M o n tan a
A u g u st, 1967
iii
ACKNOWLEDGEMENTS
The A uthor w is h e s to sh o w h is a p p r e c ia tio n b y th a n k in g th o s e w ho ■
h a v e h e lp e d in m a k in g th is t h e s i s p o s s i b l e .
T h an k s go to th e th e s i s
c o m m itte e , e s p e c i a l l y to P ro fe s s o r A. C . S c h e e r , M a jo r A d v iso r for th e
A u th o r.
The s tu d y an d r e s e a r c h for th e L arg e C u lv e rt R e s e a rc h P ro je c t w a s
m ad e p o s s ib le by th e B ureau o f P u b lic R oads a g d th e M o n ta n a .S ta te H ig h ­
w a y C o m m is s io n , w ho
a n d R e s e a rc h f u n d s .
s p o n s o re d th e p r o je c t, u s in g H ig h w a y p la n n in g
T h a n k s go to th e p e rs o n n e l of t h e s e a g e n c ie s w ho
a s s i s t e d in th e p r o je c t.
.
. '
The A uthor a ls o w is h e s to th a n k e m p lo y e e s o f th e M o n ta n a S ta te
H ig h w a y D e p a rtm e n t, Armco S te e l C o rp o ra tio n , a n d F & S C o n s tr u c tio n
C o m p an y fo r th e ir fin e c o o p e r a tio n in th e fie ld ; an d L eo n ard G ra y so n , te tih n ic ia n fo r th e M o n ta n a S ta te U n iv e rs ity C iv il E n g in e e rin g D e p a rtm e n t, fo r
h is a s s i s t a n c e w ith th e in s tru m e n ta tio n u n d e r th e d ir e c tio n o f M r. S c h e e r .
TABLE OF CONTENTS'
CHAPTER I ‘
INTRODUCTION™ -------------------------------:------------ -------------
CHAPTER II
BACKGROUND INFORMATION ON THE WOLF CREEK
CULVERT--------------- -------------- — ----------------------------------------
CHAPTER III
CHAPTER IV
CHAPTER V
3
THEORY OF CULVERT LOADING AND THE IMPERFECT
TRENCH-------------------------------------------------------- -----------------
7
SELECTION AND DESIGN OF INSTRUMENTATION— :-------
12
GENERAL----------------------------------------------------------
12
STRAIN GAG ES-------------------------------------------------
13
PRESSURE CELLS— ----------- :----------------------------
19
SETTLEMENT CELLS----------------------------------------
- 26
'
,
I
RECONSTRUCTION OF CULVERT AND INSTALLATION OF
INSTRUMENTATION--------------------
29
CULVERT RECONSTRUCTION— ---------------------
29
STRAIN GAGE INSTALLATION----------------
37
PRESSURE CELL INSTALLATION-----------------------
42
SETTLEMENT CELL INSTALLATION-----------------
51
CHAPTER VI
READING INSTRUMENTS AND TAKING MEASUREMENTS-
CHAPTER VII
REDUCTION OF DATA------------------------------------------------------
57
CHAPTER VIII
RESULTS AND ANALYSIS OF DATA----------------- :----------------
66
CHAPTERTX
D ISC U SSIO N , CONCLUSIONS AND RECOMMENDA­
TIONS-----------------------
53
112
-V -
D ISCU SSIO N — ---------------------------------------------
112
C O NCLUSIO N S— ------------------------------------------
117
RECOMMENDATIONS------------------
I
119
APPENDICES— —— — ---------------- — -
121
APPENDIX A - COMPUTER PROGRAM FOR STRAIN
GAGES------------------------------ — — --------------------------------- — —
122
PARTIAL OUTPUT DATA FROM STRAIN GAGE
COMPUTER PROGRAM— ----------------------'-------------------------
126
APPENDIX B - COMPUTER PROGRAM FOR STRESS
METERS----------------- -------------—
------------ .------ ------------— — -
137
PARTIAL OUTPUT DATA FROM STRESS METER
COMPUTER PROGRAM---------------------LITERATURE CITED l -------- ------------------------------------------------- =------------;------
139
142
LIST OF FIGURES
FIGURE
1
PLAN AND PROFILE AT CULVERT SITE--------------------------------- —
—
4
2
TYPICAL CROSS-SECTION OF REBUILT CULVERT-------------------------
10
3
FOIL STRAIN GAGE------------ — ---------
14
4
POSITION OF SR -4 STRAIN GAGES TO MEASURE C IR C U M , FERENTIAL STRAIN IN THE CORRUGATED PLATES— ---------------------
5
17
BALDWIN-LIMA-HAMILTON TYPE N PORTABLE INDICATOR
WITH COMPENSATING GAGES BEFORE WATERPROOFING--------------
19
6
CARLSON SOIL STRESS METER—
20
7
CARLSON STRESS METER G R O S S -S E C T IO N -— ---------------------
23
8
CHECKING EFFECT OF SHEAR STRESSES ON STRESS M ETERS-—
25
9
SETTLEMENT CELL AND MANOMETER BOARD D ETA ILS----------------
27
10
STREAM DIVERSION DAM AND DIVERSION PIPES------------
30
11
TRENCHING FOR PERFORATED PIPE DRAIN------------------------------------
30
12
PIPE ERECTION------------ ----------- --------------- ------------------- :-------------------
33
13
CONTROL DEVICE WITH STREAM FLOW THROUGH CULVERT------
33
14
WALKWAYS, CROSSWALKS, AND FOLDING TABLES IN
-------------------------------- —
CULVERT----------------------------------------------- — ------------------ —
--------
----------
35
15
COMPACTING MATERIAL UNDER HAUNCH— -----------------
35
16
BACKFILL MATERIAL PLACED IN SIX IN CH LAYERS-------------------------
36
17
PLACEMENT OF BALED STRAW FIVE FEET ABOVE CULVERT— --------
36
18
MOUNTED STRAIN GAGES ON PLATE BEFORE ERECTION
AND COMPENSATING GAGES--------------- -------- — ---------------------------
40
—v i i —
FIGURE
19
THREE STRAIN GAGES ON OUTSIDE OF PLATE AFTER
ER E C T IO N -----------------------------------------------------------------------------
40
20
ANGLE IRON PROTECTION FOR GAGES AGAINST THE F IL L - -
41
21
COMPENSATING GAGES HANGING IN CULVERT BELOW
MEASURING G A G E S --------------------
22
________________
LOCATION OF SR-4 STRAIN GAGES, SETTLEMENT CELLS
AND CONTROL DEVICES — ----------------------------------------
23
41
—
43
M OUNTING FRAMES FOR STRESS METERS INSTALLED ON
CULVERT --------------=-------- ------------------------------------------------------
44
24
M OUNTING FRAME WITH MORTAR BACKING---------------------— ‘
45
25
STRESS METER TEST SET AND SW ITCHBOARD---------------------
45
2 6
STRESS METER INSTALLED WITH SAND PROTECTION -----------
47
27
STRESS METER FROM THE INSIDE OF THE CULVERT — ------
47
28
METERS IN FILL IN M OUNTING FRAMES PERPENDICULAR
TO THE CULVERT CENTER L IN E ------------------- -----------------------
29
48
LOCATION OF CARLSON STRESS METERS AND RUBBER
PRESSURE CELLS
------ — — ------ ------------------------------ _____
49
30
RUBBER PRESSURE CELLS PLACED IN FILL ----------------------- —
50
31
BOURDON GAGES AND VALVES INSIDE CULVERT — ----------
50
32
SETTLEMENT CELL IN THE F I L L -------- :--------------------------------
52
33
MANOMETER BOARD AND VALVES MOUNTED ON CONCRETE
H EADWALL------------------------------------------------------- ----------------- —
52
-V iiiFIGURE
34
DETERMINING EARTH PRESSURE FROM .COMPRESSIVE FORCE
IN W A L L S ---- -—■——
35
3 6
----- --------■—
——
—■——
------------ -—■—
EARTH PRESSURES FROM INELASTIC STRAINS--------- — ---------—
.60
62
DETERMINING TEMPERATURE AND EARTH PRESSURE FROM
STRESS METER READINGS— — ------ — — ------ --------------- ------------------
65
37
ERECTION STRESSES IN THE SIX INSTRUMENTED PLATES— — —
67
38
STRESSES CAUSED BY ERECTION AND EARTH PRESSURE----------—
70
39
STRESSES CAUSED BY EARTH PRESSURE— — — -------- -------------- --
71
40
STRESSES CAUSED BY THE ADDITIONAL 78 FEET OF
41
COMBINED STRESSES ON 3 / 2 5 / 6 6 a n d 3 / 2 7 / 6 7 - -------- ------------
42
EQUIVALENT UNIFORM VERTICAL EARTH PRESSURES ON
CULVERT, DEDUCED FROM SR-4 STRAIN GAGES— — — — — —
43
81
EARTH PRESSURE VS. TIME - STRESS METERS N O . I , 6 , 7 ,
1 1 , 2 3 , AND 24— -------- ------------- ----------- — — --------- —
-------—
44
. EARTH PRESSURE V S. TIME - STRESS METERS N O . 19 AND
45
• EARTH PRESSURE VS. TIME - STRESS METERS N O . 3 , 4 , 1 4 ,
1 5 , 18 AND 20—■——
46
79
—
— -------- -------------------------------- ------■ ---
83
85
EARTH PRESSURE V S. TIME - STRESS METERS N O . 2 , 5 , 1 3 , •
■ 1 6 ,. 17 AND 21—
.— — ---------- ----------------------------------------------- —
86
-ix TIGURE
47
EARTH PRESSURE VS. TIME - STRESS METERS N O . 8 , 1 0 ,
AND 12-------------- — — ------------------ :--------------------------------------------------
48
EARTH PRESSURE VS. TIME - STRESS METERS NO v 2 5 ,. 2 6 ,
2 7 , 2 8 , 29
49
50
87
AND 3 0 ---------------------------------------------------------------- —
EAkTH PRESSURES ACTING ON THE CULVERT WALLS
ON I / 4 / 6 6 ----------------------------------------------------------------------- -------EARTH PRESSURES ON I /
88
91
4 /6 6 DETERMINED FROM THE
STRESS METERS AND .,RUBBER PRESSURE CELLS LOCATED
IN THE FILL------------------— ------------------------------------ --------------------51
95
EARTH PRESSURE V S. TIME - RUBBER PRESSURE CELLS
N O . I , 2, 3, 4 , 5
AND 6------------—
------------------------- -------------
98
52
SETTLEMENT OF THE SETTLEMENT CELLS AND TOP OF
53
CULVERT-------------------------------- ------------------------------------------------- — —
!
SETTLEMENT OF THE CULVERT INVERT— T----------------— — ----------
'105
54
AVERAGE HORIZONTAL AND VERTICAL DIAMETER CHANGE----------
107
55
SETTLEMENT OF THE INTERSTATE ROADWAY PAVEMENT--------------
111
56
PRESSURE ON TOP OF CULVERT DETERMINED FROM
RUBBER PRESSURE .CELLS
103
115
LIST OF TABLES
TABLE
1
STRESSES IN THE CHICAGO SUBWAY TUNNEL WALLS '
:
DETERMINED FROM PRESSURE CELLS AND STRAIN GAGES - ■*---- * 21
2
STRESSES CAUSED BY E R E C T IO N ----------------
68
3
STRESSES CAUSED BY ERECTION AND FIVE FEET OF COVER---------
72
4
STRESSfiSi CAUSED BY FIVE FEET OF COVER —
72
5
STRESSES CAUSED BY ERECTION AND 83 FEET OF COVER--------
73
6
STRESSES CAUSED BY 83 FEET OF C O V ER ---------------------------------
73
7
STRESSES CAUSED BY THE ADDITIONAL 7 8 FEET OF COVER------------
8
SETTLEMENT OF THE SETTLEMENT CELLS IN IN C H ES-:--------------LQQ
9
SETTLEMENT OF THE.CULVERT INVERT --------
. IQ
11
-----------------
77
104.
VERTICAL DIAMETER CHANGE— --------------------------------HORIZONTAL DIAMETER.CHANGE--------------------------- — ■-----------
108
109
ABSTRACT
The f a ilu r e o f a n 18 „5 fo o t d ia m e te r s tr u c tu r a l- p la te c u lv e r t
u n d e r 83 f e e t o f c o v e r le d to its r e c o n s tr u c tio n u s in g th e " im p e rfe c t
tre n c h " ty p e o f c o n s tr u c tio n a s w e ll a s o th e r c h a n g e s „ ' T his p a p e r
re p o rts th e fin d in g s -o f a r e s e a r c h p r o je c t th a t w a s in itia te d to s tu d y
th e b e h a v io r o f th e r e c o n s tr u c te d c u l v e r t „ The s tu d y w a s s p o n s o re d by
th e M o n ta n a S ta te H ig h w a y C o m m issio n a n d th e B ureau o f P u b lic R oads
an d w a s p erfo rm ed by th e D e p a rtm e n t o f C iv il E n g in ee rin g a n d E n g in ee rin g
M e c h a n ic s a t M o n ta n a S ta te U n iv e r s ity ,
The r e c o n s tr u c te d c u lv e r t w a s in s tru m e n te d to s tu d y i t s b e h a v io r.
In s tru m e n ta tio n c o n s is te d of: SR-4 s tr a in g a g e s p la c e d o n th e c u lv e rt
w a lls a t a p p ro x im a te ly m id -h e ig h t; C a r ls o n S o il S tr e s s M e t e r s » p la c e d
on th e o u ts id e w a lls of th e c u lv e r t an d in th e fill; ru b b e r p r e s s u r e c e l l s »
w h ic h w e re c o m m e rc ia l h o t w a te r b o ttle s „ p la c e d in th e fill; an d s e t t l e ­
m en t c e l l s , w h ic h w e re p la c e d in th e f ill oh e a c h s id e o f th e c u lv e r t „
A ls o , m e a s u re m e n ts th a t w e re ta k e n in c lu d e d : le v e ls on th e c u lv e rt
in v e r t, v e r tic a l an d h o riz o n ta l d ia m e te r s , an d le v e ls o f-th e ro a d w a y
p r o f ile .
C o m p u te r p ro g ram s w e re d e v e lo p e d to d e te rm in e s t r e s s e s an d e a rth
p r e s s u r e from d a ta o b ta in e d b y p e rio d ic r e a d in g s o f th e in s tru m e n ts ,
O v e r a ll, th e in s tru m e n ta tio n p erfo rm ed s a t i s f a c t o r i l y . R e s u lts
from s tr a in g a g e s , s t r e s s m e te r s , an d ru b b e r p r e s s u r e c e l l s , c o rre la te d
w e ll a n d d e m o n s tra te d th a t th e v e r tic a l lo a d on th e c u lv e r t w a s much l e s s
th a n th e w e ig h t o f th e o v e rly in g co lu m n o f e a rth - a h ig h ly fa v o ra b le
lo a d c o n d itio n w h ic h th e " im p e rfe c t tr e n c h " m eth o d of c o n s tr u c tio n w as
e x p e c te d to p ro d u c e „
■
The SR-4 s tr a in g a g e s , w h ic h m e a s u re d b e n d in g s tr a in s in a d d itio n
to c irc u m fe re n tia l c o m p re s s io n , sh o w e d th a t s ig n if ic a n t r e s id u a l b e n d in g
s t r e s s e s w e re in d u c e d in th e p la te s d u rin g e r e c tio n . T hey a ls o m o n ito red
b e n d in g s t r e s s c h a n g e s th a t o c c u rre d a t th e s tr a in g a g e s i t e s d u rin g and
a f te r th e b a c k f illin g o p e r a tio n . The v ig o ro u s c o m p a c tio n of th e b a c k f ill
on e a c h s id e o f th e c u lv e r t, d u rin g th e e a r ly .s ta g e s o f b a c k f illin g , p ro ­
d u c e d a b e n d in g s t r e s s p a tte rn in th e s id e w a lls th a t p e r s is te d th ro u g h o u t
th e em b an k m en t c o n s tr u c tio n p e rio d an d th e r e a f te r .
T here w a s no m e a s u ra b le d if f e r e n tia l s e ttle m e n t of th e p a v em e n t
a ttr ib u ta b le to th e " im p e rfe c t tre n c h " ty p e o f c o n s tr u c tio n .
CHAPTER I
INTRODUCTION
T his p a p e r d e s c r ib e s th e b e h a v io r o f a n 1 8 .5 fo o t d ia m e te r
s tr u c tu r a l- p la te c u lv e r t th a t w a s r e c o n s tr u c te d a fte r th e f a ilu r e of th e
o r ig i n a l s tr u c t u r e .
f a ll o f 1 9 6 3 .
C o n s tr u c tio n o f th e o rig in a l i n s ta lla t io n b e g a n in th e
T h e .ro c k f i l l , w h ic h p ro v id e d a p p ro x im a te ly '83 f e e t of c o v e r
on th e c u lv e r t, w a s c o m p le te d in th e s p rin g o f 1 9 6 4 .
It w a s d is c o v e re d
th a t th e s tr u c tu r e h a d f a ile d in th e sum m er of 19 6 4 , w ith in th r e e m onths
a f te r th e f il l w a s c o m p le te d , b u t i t is nett’ k now n e x a c tly w h e n th e
f a ilu r e b e g a n .
S o lu tio n s for re p a irin g th e s tru c tu re w e re re v ie w e d a n d th e fin a l
c o n c lu s io n w a s to rem ove th e f ill a n d re b u ild th e f a ile d p o rtio n of th e
c u lv e r t.
R em oval of th e f ill b e g a n th a t w i n t e r . R e c o n s tru c tio n of th e
c u lv e r t w a s d e la y e d u n til th e fo llo w in g f a l l , 1 9 6 5 , b e c a u s e of h ig h e r
th a n norm al ru n o ff a n d th e r e s u ltin g p ro b lem o f stre a m d iv e r s i o n .
E x te n s iv e t e s t in g by th e c u lv e r t c o n tra c to r w a s d o n e to d e te rm in e
th e c a u s e o f th e f a ilu r e .
The t e s t r e s u l t s in d ic a te d th a t th e fa ilu re m ay
h a v e b e e n c a u s e d by "h y d ro g e n e m b rittle m e n t” o f th e z in c - c o a te d high
s tre n g th b o l t s .
I t w a s th o u g h t by so m e o f th e e n g in e e rs in v o lv e d th a t
th e c u lv e r t lo a d in g m ay h a v e b e e n la rg e r th a n a n tic ip a te d ; th e r e f o r e , th e
r e c o n s tr u c tio n w a s d e s ig n e d for a n in c r e a s e d m arg in o f s a f e t y .
In
a d d itio n to c h a n g in g th e ty p e a n d s iz e of b o l t s , a n " im p e rfe c t tre n c h "
-2-
ty p e o f c o n s tr u c tio n w a s u s e d „ I t w a s d e c id e d that, th e cu lv ert, sh o u ld b e
in s tru m e n te d a n d th a t a s tu d y sh o u ld b e m ad e on th e b e h a v io r o f th e
r e c o n s tr u c te d c u l v e r t «
The d e s ig n a n d in s ta lla t io n - o f in s tr u m e n ta tio n » an d th e s tu d y of
th e b e h a v io r of th e r e c o n s tr u c te d s tr u c tu r e w a s perfo rm ed b y th e D e p a rt­
m en t o f C iv il E n g in e e rin g a n d E n g in e e rin g M e c h a n ic s a t M o n ta n a S ta te
U n iv e r s ity .
The s tu d y w a s u n d e r th e s p o n s o r s h ip of th e M o n ta n a S ta te
H ig h w ay C o m m issio n a n d th e B ureau of P u b lic R o a d s .
CHAPTER:.!!
BACKGROUND INFORMATION ON THE WOLF CREEK CULVERT
The c u lv e r t i n s t a l l a t i o n .i s lo c a te d on L ittle P ric k le y P e a r C re e k
n e a r th e s o u th en d of W o lf C re e k C a n y o n .o n .I n te r s ta te R oute 1 5 , a b o u t 25
m ile s n o rth o f H e le n a , M o n tan a „ The I n te r s ta te p la n - p r o f ile a t th e c u lv e rt
s i t e - i s show n in F ig u re I .
The d e s ig n d e t a i l s o f th e o rig in a l c u lv e r t a re
c o v e re d , in a p a p e r by Kraft a n d .E a g le (8)
The c u lv e r t w a s 548 f e e t lo n g „ C o rru g a te d an d g a lv a n iz e d s tru c tu ra l
s t e e l p l a t e s , 3 /8 in c h t h i c k , w e re u s e d in th e m id d le 328 f e e t a n d th in n e r
p la te s w e re u s e d .n e a r th e e n d s „
D e s ig n lo a d in g , on ,th e s tru c tu re w a s 8 „ 2; k ip s p er s q u a re fo o t from
83 f e e t of f il l h a v in g a n a s s u m e d u n it w e ig h t o f 105 p o u n d s p e r c u b ic f o o t.
The u s e o f 3 /8 in c h p la te a n d 3 / 4 , in c h h i g h .s tre n g th b o lts r e s u lte d in a
d e s ig n sea m s tre n g th o f 2 7 0 ,0 0 0 p o u n d s p e r lin e a r fo o t a n d p ro v id e d a n
a p p a r e n t s a f e ty f a c to r of 3 . 5 .
The h ig h s tre n g th ,b o lts u s e d w ith th e 3 /8
in c h p la te s o f th e o rig in a l c u lv e r t w e re z in c - c o a te d .AS TM. A490. b o lts w h ile
th e -re m a in in g b o lts u s e d w ith th e .th in n e r p l a t e s , w e re z in c - c o a te d ASTM
A325 b o l t s .
B e c a u s e th e o rig in a l s tr u c tu r e w a s n o t in s tr u m e n te d , th e
a c tu a l lo a d on th e s tr u c tu r e c o u ld n o t b e d e te rm in e d .
The f a ilu r e w a s d u e to " b r ittl e - l ik e " fr a c tu re of t h e .b o lts a lo n g
th e lo n g itu d in a l s e a m s o f th e lo w e r h a lf o f th e c u lv e r t.
T h e .fa ilu re
N um bers in p a r e n th e s e s re fe r to r e f e r e n c e s lis te d .u n d e r L ite r a tu r e .C ite d .
-4 -
GR£-]I-„^P_?t h ERN
r --- --5—Cfi I
TUNWEL O-X <r
RAILWAY
~
1J-
G ° CURVE
FOLD
3900
3900
= = SCALE: ."t----- —
~Z
F ig u re
I.
HORIZ.
P lan and P ro file a t C u lv e rt S ite
= ZOOZ
-5 -
e x te n d e d th ro u g h o u t th a t s e c tio n o f th e s tr u c tu r e u s in g 3 /8 in c h p la te and .
h ig h s tre n g th b o l t s . H e re th e p la te s h a d s lip p e d o v er e a c h o th e r , in so m e
c a s e s o v e rla p p in g a p p ro x im a te ly s e v e n f e e t , d e c r e a s in g th e o v e ra ll d ia m e ­
te r to a p p ro x im a te ly 16 f e e t „ Lar'ge ru p tu r e s n e a r e a c h en d o f.th e fa ile d
s e c tio n a llo w e d f il l m a te ria l to flo w in to th e s t r u c t u r e „ T his in flu x of
m a te ria l form ed a dam n e a r th e in le t e n d , p o n d in g w a te r a p p ro x im a te ly
s e v e n f e e t d e e p d u rin g a tim e w h e n th e w a te r d o w n stre a m in th e c u lv e rt
w a s tw o to th r e e f e e t d e e p .
The r e s e a r c h c e n te r o f Armco S te e l C o r p o r a tio n ,■th e c u lv e r t c o n ­
tr a c to r , p e rfo rm ed e x te n s iv e te s t in g to d e te rm in e th e c a u s e o f fa ilu r e and
th e r e s u l t s w e re p r e s e n te d b y M a c a d a m (1 2 ).
E x te n s iv e la b o ra to ry s ta t ic
t e s t in g o f b o lte d s e a m s , in c lu d in g p u re c o m p re s s io n a n d p u re b e n d in g ,
s h o w e d .th a t th e p l a t e , n o t th e A490 b o l t s , f a ile d a t th e s e a m „ . B e c a u se of
th e " b r i t t l e - l i k e " a p p e a r a n c e o f th e f a ile d b o lts from th e c u l v e r t , s e c tio n s
of b o lte d p la te w e re a ls o t e s t e d a t e x tre m e te m p e ra tu re s „ In o n e c a s e th e
te m p e ra tu re w a s lo w e re d to -3 2 0 d e g re e s F a h re n h e it by liq u id a ir an d s t a t i c
an d im p a c t t e s t s w e re p e rfo rm e d , b u t th e re w e re no A490 b o lt f a ilu r e s „
T his t e s t in g program sh o w e d th a t th e b o lts w e re m e c h a n ic a lly s o u n d .
- E x te n s iv e t e s t s in v o lv in g a n e le c tr o c h e m ic a l m e c h a n is m w e re c o n ­
d u c te d b e c a u s e h ig h - s tr e n g th s t e e l s a re s u s c e p tib le to h y d ro g e n e m b rittle ­
m en t an d h y d r o g e n - s tr e s s c r a c k in g .
T h is program sh o w e d t h a t A490 b o lts
c o u ld f a il by h y d ro g e n e m b rittle m e n t w ith in .!5 m in u te s u n d er.n o rm al te n s io n
-6 -
lo a d in g a n d c e r ta in e x tre m e e n v iro n m e n ta l c o n d itio n s . A325 b o lts te s t e d
u n d e r th e sam e c o n d itio n s w e re n o t a f f e c te d b y h y d ro g e n e m b rittle m e n t „
M a c a d a m 's re p o rt s u p p o rte d th e h y p o th e s is th a t h y d ro g e n e m b rittle m e n t
w a s th e c a u s e o f th e b o lt f a ilu r e s in th e c u lv e r t an d p ro m p ted a d e c is io n
th a t la rg e r b o lts of a m ild e r s t e e l w o u ld b e s u b s titu te d for a ll h ig h
s tre n g th b o lts in th e r e c o n s tr u c te d c u lv e rt; s p e c i f i c a l l y , 7 /8 in c h A325 b o lts
w e re u s e d in p la c e of th e 3 /4 in c h A490 b o l t s . S p e c if ic a tio n s fo r th e
r e b u ilt c u lv e r t a ls o s tip u la te d th a t th e b o lt te n s io n in d u c e d b y n u t
tig h te n in g sh o u ld b e n o t l e s s th a n 1 8 ,0 0 0 nor rnore th a n 2 2 , 0 0 0 p s i ,
(pounds p e r s q u a re i n c h ) .
T his c o rre s p o n d e d to a to rq u e o f a p p ro x im a te ly
200 f o o t- p o u n d s .
\
I
I
CHAPTER III
THEORY OF CULVERT LOADING AND THE IMPERFECT TRENCH
" M a r s to n 's T heory o f L oads on U n d erg ro u n d C o n d u its " (13) w a s o n e
o f th e f i r s t p r a c tic a l m e th o d s » u s in g p r in c ip le s o f m e c h a n ic s » to e s tim a te
th e lo a d on a n u n d e rg ro u n d s t r u c t u r e „ T h ere a re s e v e r a l d if f e r e n t w a y s in
w h ic h c o n d u its a re p la c e d in th e g ro u n d , s u c h a s in t u n n e l s , in d i t c h e s ,
or b y p la c in g f ill o v e r th e c o n d u it. The l a tte r tw o m e th o d s h a v e b e e n
d iv id e d in to th re e m ain c l a s s e s by M a r s to n „ T h e s e c l a s s e s a re th e " d itc h
c o n d u it" , th e " n e g a tiv e p ro je c tin g c o n d u it" a n d th e " p o s itiv e p ro je c tin g
c o n d u it" „ The o rig in a l an d r e c o n s tr u c te d W o lf C re e k c u l v e r t s , lik e m o st
h ig h w a y c u l v e r t s , w e re in s t a l l e d a s p o s itiv e p ro je c tin g c o n d u its
A p o s itiv e p ro je c tin g c o n d u it i s o n e t h a t i s p la c e d on th e g round s u r­
f a c e (not in a n a rro w tre n c h ) a n d th e n c o v e re d b y f ill m a te r ia l.
The v e r tic a l
s o il lo a d a c tin g on s u c h a c o n d u it m ay b e s m a lle r th a n , e q u a l to ,
o r la rg e r th a n th e w e ig h t of th e v e r t i c a l - s i d e d co lu m n o f s o il lo c a te d d ir e c t­
ly a b o v e th e c o n d u it, d e p e n d in g p rim a rily u p o n w h e th e r th a t c o lu m n s e t t l e s
m ore th a n , th e sa m e a s , or l e s s th a n th e a d ja c e n t c o lu m n s o f e a r t h .
An e x te n s iv e program o f r e s e a r c h h a s d e v e lo p e d from M a r s to n 's w ork on
u n d e rg ro u n d c o n d u its (1 3 , .14) w h ic h h e b e g a n in 190 8 a t th e Iow a E n g in eerin g
E x p erim en t S ta tio n .
In d e p e n d e n t e x p e rim e n ta l w ork a c c o m p lis h e d in th e
19 2 0 's a t th e U n iv e rs ity of N orth C a r o lin a , b y C a in e t ’a l (4 ); an d b y
th e A m erican R ailw ay E n g in e e rin g A s s o c ia tio n , FapLna, I l l i n o i s , (2)
-8 -
a g r e e s w ith - M a rs to n 's w o rk .
R e c e n tly , w ith th e a d v e n t o f h ig h f i l l s in
I n te r s ta te H ig h w a y d e s ig n a n d b u rie d s tr u c tu r e s fo r b l a s t p r o te c tio n , th e re
h as been
m ore e x p e rim e n ta l r e s e a r c h on th e lo a d in g of u n d e rg ro u n d
c o n d u i t s S o m e of t h e s e w o rk s (5 , 6 , 23) a c c e p t- M a r s to n 1s th e o ry of
lo a d in g . - O th e rs ( I , 3 , 11) a p p ro a c h th e s u b je c t from a d iff e r e n t s p i l s tr u c tu r e in te r a c tio n c o n c e p t; h o w e v e r, th is .r e s e a r c h h a s n o t b e e n c o m p le te d
to th e e x te n t th a t it. is a v a il a b le fo r p r a c tic a l a p p lic a tio n .
The im p e rfe c t tre n c h m eth o d o f c o n s tr u c tio n -p ro p o s e d b y M a r s to n .to
r e lie v e e a rth p r e s s u r e s ;d n '-p o s itiv e p ro je c tin g c o n d u its u n d e r c e r ta in s o il
c o n d itio n s w a s a ls o a d v o c a te d a n d t e s t e d b y S p a n g le r (1 9 , 20) w ho w o rk ed
u n d e r M a rs to n a n d c o n tin u e d .M a r s to n 's .w o rk .
T h e ,im p e rfe c t tre n c h m eth o d
is b a s e d on th e th e o ry th a t if h ig h ly c o m p r e s s ib le m a te ria l is p la c e d a b o v e
a c o n d u it th e c o lu m n -o f s o il a b o v e s e t t l e s m ore th a n th e a d ja c e n t s o il on
each s id e .
T his in d u c e s " a rc h in g " s o th a t th e co lu m n of s o il is p a r tia lly
su p p o rte d b y th e a d ja c e n t s o il a n d th e re fo re -tr a n s m i t s , to th e c o n d u it
b e lo w , a lo a d w h ic h , is s m a lle r th a n -th e w e ig h t of th e c o lu m n ,
M arsto n .-reco m m en d ed a c o m p re s s ib le m a te ria l su c h a s lo o s e f i l l
m a te r ia l, or e v e n , le a v e s or s tr a w , b e u s e d a s f ill d ir e c tly a b o v e -th e s tr u c ­
tu r e <; Tbas m a te ria l c a n .b e p la c e d b y c o m p a c tin g th e dull to a n y d e s ir e d
h e ig h t, tre n c h in g a lo n g th e c e n t e r - l i n e o f th e c u lv e r t a n d th e n .b a c k f illin g
w ith th e lo o s e m a te ria l; o r b y p la c in g .b a le s of s tra w alo n g , th e c e n te r lin e
1
-9 -'
o f th e c u lv e r t a t a n y d e s ir e d h e ig h t a n d c o m p a c tin g th e f ill a d ja c e n t
to an d a b o v e th e s tr a w .
T his la t t e r m e th o d w a s u s e d for th e r e b u ilt W olf
C re e k c u l v e r t „. F igure 2 , a ty p ic a l c r o s s - s e c t i o n of th e r e b u ilt c u l v e r t , •
sh o w s th e lo c a tio n .o f th e b a le d s tr a w „
T h e .im p e rfe c t tre n c h ty p e o f c o n s tr u c tio n w a s n o t r e a d ily a c c e p te d
b y som e e n g in e e rs b e c a u s e o f th e fe a r of u n e q u a l s e ttle m e n t o f th e s u rfa c e
o f th e f i l l .
U n e q u a l s e ttle m e n t a t th e s u r f a c e sh o u ld n o t o c c u r a t th e
W o lf C re e k c u lv e r t b e c a u s e of th e h ig h f i l l .
In h ig h f il ls a p la n e of
e q u a l s e ttle m e n t w ill d e v e lo p w ith in th e f il l a n d th e re w ill b e no d if f e r e n tia l
s e ttle m e n t a t th e s u r f a c b ,
U n fo rtu n a te ly , in m o st p r a c tic a l s i t u a t i o n s ,
th e m inim um f ill h e ig h t n e e d e d to p re v e n t d if f e r e n tia l s u r f a c e s e ttle m e n t
c a n n o t b e a c c u r a te ly p r e d ic te d .
R e c e n tly , on la rg e c u lv e r t in s t a l l a t i o n s in v o lv in g b o th rig id and
f le x ib le p ip e , th e im p e rfe c t tre n c h m eth o d o f c o n s tr u c tio n h a s b e e n u s e d
w ith v a ry in g d e g re e s of s u c c e s s ,
Tim m ers (22) re p o rts th e u s e o f a n
.im p e rfe c t tre n c h .fo r th re e 84 in c h d ia m e te r c o rru g a te d m e ta l c u lv e r ts
■ in s ta lle d u n d e r a 137 fo o t f il l in C u llm a n C o u n ty , A la b a m a .
C o s te s an d
P ro u d le y (6) a l s o re p o rt th e u s e of th e im p e rfe c t tr e n c h ;for a 66 in c h .
d ia m e te r c o rru g a te d m e ta l c u lv e r t u n d e r a 170 fo o t f ill in M cD o w e ll
(
C o u n ty , N orth C a r o lin a .
•
'
The m eth o d of b a c k f illin g a tre n c h w ith lo o s e
e a rth , w a s u s e d for t h e s e tw o i n s t a l l a t i o n s »' T h is m ethod d id n o t prove to
—10 —
Umi+s oP granular
Compacted badePiH
m aterial
n /
Two \Qqers
baled straw
ground lin e
F igure 2 .
T y p ic a l C r o s s - S e c tio n of R eb u ilt C u lv e rt
-li­
k e a s s u c c e s s f u l a s a n tic ip a te d , b u t th e lo a d ih g on th e p ip e s w a s g e n e r a lly
n o t g re a te r th a n th e w e ig h t o f th e co lu m n o f e a rth a b o v e th e p ip e s and m any
lo a d m e a s u re m e n ts w e re lo w e r .
L a rso n (9) R eported on th r e e re in fo rc e d
c o n c r e te c u l v e r t s , u n d e r f i l l s 38 to 65 f e e t in h e ig h t, th a t w e re in s ta lle d
in H um b o ld t C o u n ty , C a lif o r n ia , u s in g b a le d s tra w a s th e .c o m p r e s s ib le
m ed iu m .
s tra w .
T h e s e s tr u c tu r e s perfo rm ed b e tte r th a n th o s e i n s t a l l e d w ith o u t
C o n c lu s io n s .of th e w ork in C a lifo rn ia w e re th a t f ill h e ig h ts a b o u t
th re e tim e s th a t a llo w e d b y norm al m e th o d s c o u ld h a v e b e e n u s e d w ith o u t
o v e rlo a d in g th e p ip e .
CHAPTER IV
SELECTION AND DESIGN OF INSTRUMENTATION
O ne o f th e p rim ary o b je c tiv e s o f th e r e s e a r c h p ro je c t w a s to d e te rm in e
th e e a rth p r e s s u r e a c tin g on th e r e b u ilt W o lf C re e k c u lv e rt. T h is p r e s s u r e w a s
d e te rm in e d b y th e d ir e c t m eth o d of m e a s u rin g th e e a rth p r e s s u r e a c tin g on th e
c u lv e r t an d a ls o b y th e in d ir e c t m eth o d o f d e te rm in in g s tr a in s in th e c u lv e r t an d
c a lc u la tin g th e e a rth p r e s s u r e re q u ire d to p ro d u c e th o s e s tr a in s .
C o m m e rc ial in s tr u m e n ta tio n , a v a ila b le on sh o rt n o tic e , w a s u s e d
b e c a u s e of th e p o s s ib il ity th a t th e c o n tra c to r w o u ld b e g in r e c o n s tr u c tio n
o f th e c u lv e r t a t a n e a r ly d a t e .
O ne o f th e probW m s w a s a rra n g in g th e
w ork in su c h a m an n er th a t w h en c o n s tr u c tio n b e g a n th e in s tru m e n ta tio n
c o u ld b e p la c e d w ith o u t d e la y in g th e c o n tr a c to r .
C a r ls o n s o il s t r e s s m e te r s , w h ic h h a v e p ro v e d to b e r e lia b le and
a c c u r a te in o th e r in s ta lla tio n ^ ,w e r e s e le c te d to m e a s u re e a rth p r e s s u r e .
A few h o t w a te r b o ttle s c o n n e c te d to d ir e c t re a d in g Bourdon p r e s s u r e g a g e s
w e re a ls o u s e d .
SR-4 s tr a in g a g e s w e re u s e d to d e te rm in e a x ia l c irc u m ­
f e r e n tia l s tr a in s a n d b e n d in g s tr a in s in th e s id e w a lls of th e c u lv e r t.
S e ttle m e n t c e l l s , w h ic h w ork on a w a te r le v e l p r in c ip le , w e re u s e d to
m e a s u re s e ttle m e n t of th e f ill a d ja c e n t to th e c u l v e r t . M e a s u re m e n ts of
h o riz o n ta l an d v e r tic a l d ia m e te rs w e re m ad e d ir e c tly w ith g ra d u a te d r o d s ,
a n d c u lv e r t flo o r s e ttle m e n t w a s o b ta in e d from p e rio d ic d ir e c t o b s e r v a tio n s
-1 3 -
w ith a n e n g in e e r 's le v e l „
S tra in G a g e s
SR -4 B aldw in s tr a in g a g e s w e re u s e d to m e a s u re c irc u m fe re n tia l
s tr a in s in th e c u lv e r t.
T h e se g a g e s o p e ra te on th e p rin c ip le th a t th e
e le c tr i c a l r e s i s t a n c e of a w ire v a r ie s w ith th e te n s io n a p p lie d to th e
w i r e . By m e a s u rin g th is c h a n g e in r e s i s t a n c e th e s tr a in c a n b e d e te r m in e d .
T his c h a n g e in r e s i s t a n c e , w h ic h c a n b e q u ite s m a l l , in th e ra n g e of a
th o u s a n d th of a n o h m , c a n be m e a s u re d a c c u r a te ly by a W h e a ts to n e b rid g e
c irc u it.
If th e w ire i s p ro p e rly c e m e n te d to a m a te ria l; th e n s tr a in in
th e m a te ria l c a n b e m e a s u re d by m e a s u rin g th e c h a n g e in r e s i s t a n c e of th e
w ire .
T here a re m any ite m s th a t sh o u ld b e c o n s id e re d w h en u s in g s tra in
g a g e s , s u c h a s th e ty p e s tr a in b e in g m e a s u re d , th e ty p e m a te ria l th a t is
b e in g s tr a in e d a n d th e e n v iro n m e n ta l c o n d itio n s th e g a g e w ill b e s u b je c te d
to .
O ne e x c e lle n t re f e r e n c e for th e p ro p e r u s e s of v a rio u s ty p e s o f s tr a in
g a g e s i s "T he S tra in G a g e Prim er" by P erry an d L is s n e r ,(1 5 ).
The SR-4 s tr a in g a g e s s e le c te d fo r th is p ro je c t w e re e p o x y b a c k e d ,
ty p e F A -1 0 0 -1 2 .
T his ty p e of g a g e is a m e ta llic - f o il s tr a in g a g e w h ich
o ffe rs a n u m b er of a d v a n ta g e s o v er th e o ld e r p a p e r b a c k e d w ire s tra in
gage.
O ne p rim ary a d v a n ta g e , b e c a u s e o f i t s ep o x y b a c k in g , is its
s u p e rio r lo n g -te rm s t a b i lity u n d e r a d v e r s e e n v iro n m e n ta l c o n d itio n s .
This
—14 —
g a g e is a ls o m ade from th in s t r a i n - s e n s i t i v e fo il w hich o ffe rs o th e r a d v a n ­
ta g e s .
The fo il g a g e c a n be m ade so th a t th e w id th of th e fo il a t th e end of
e a c h loop c an be in c re a s e d to re d u c e th e s e n s itiv ity to tr a n s v e r s e s tra in s ,
and th e c r o s s - s e c t i o n of a g a g e Can be sm a ll in re la tio n to its s u rfa c e a re a
so th a t th e c em e n t hold in g th e g a g e is c o n s id e ra b ly s tro n g e r th a n th e fo il.
The in c r e a s e in w id th a t th e end of e ac h loop and th e c r o s s - s e c t i o n of a
g a g e is show n in Figure 3.
The g a g e f a c to r , w hich in d ic a te s th e s e n s itiv ity
of a g a g e , is h ig h e r for th e fo il g a g e th a n th e e q u iv a le n t w ire g a g e .
C a re fu l a tte n tio n m u st b e g iv e n to p ro p e rly a tta c h in g th e s tra in g a g e s
to a s s u r e p roper fu n c tio n in g .
It w as know n th a t th e g a g e s w ould be in
u s e o v er an e x te n d e d p e rio d of tim e and m ore th a n lik e ly w o u ld be su b ­
je c te d to s e v e re m o istu re c o n d itio n s .
A lso , th e g a g e s h ad to b e p la c e d on
th e p la te s in th e fie ld w h ere c o n d itio n s w ere m ore s e v e re th a n in th e
la b o r a to r y . The c e m e n t s e le c te d w as E astm an 910 c e m e n t b e c a u s e it
w ould c u re a t r e la tiv e ly low te m p e ra tu re s and had a very ra p id c u rin g tim e .
f
Foil G rid
Epoxy B acking
SECTION A-A
A
N ot to S c a le
F igure 3 .
Foil S train G ag e
-15-
S tra in g a g e s m u s t b e lo c a te d p ro p e rly i f u s e f u l r e a d in g s a re to be
o b ta in e d .
SR -4 w ire s tr a in g a g e s w e re u s e d on a 66 in c h d ia m e te r c o rru ­
g a te d m e ta l c u lv e r t in N o rth C a ro lin a a n d th e r e s u l t s w e re re p o rte d by
C o s te s a n d P ro u d le y (6) .
S tra in g a g e s w e re lo c a te d c irc u m fe re n tia lly on
th e g e o m e tric n e u tra l a x is of th e c o rru g a tio n s a t th e m id - h e ig h t an d th e
to p a n d b o tto m o f th e c u lv e r t „ R e s u lts from th is i n s ta lla t io n w e re d is a p ­
p o in tin g an d th e fo llo w in g r e a s o n s w e re re p o rte d a s p o s s ib le c a u s e s :
1 „ The s tr a in g a g e s t h a t w e re p la c e d on th e b o tto m c o u ld h a v e b e e n
g r o u n d e d , a lth o u g h th e y w e re w a te rp ro o fe d a n d p ro te c te d „
2 „ L o c a l b u c k lin g m ay h a v e c a u s e d e x c e s s iv e s tr a in a t th e lo c a ­
tio n o f a s tr a in g a g e .
3.
S tra in s o th e r th a n u n ia x ia l c irc u m fe re n tia l s tr a in m ay h a v e b e e n
in tro d u c e d b e c a u s e o f e a rth m o v e m e n ts a n d u n o rth o d o x c o n s tr u c tio n p r a c tic e s .
4.
The s tr a in g a g e s w e re i n s ta lle d a t th e g e o m e tric n e u tr a l a x is of
th e c o rru g a tio n s „ A s lig h t erro r in g a g e lo c a tio n w o u ld c a u s e th e m e a s u re ­
m e n ts to in c lu d e som e b e n d in g s tr a in .
5.
The m e ta l m ay h a v e b e e n s t r e s s e d b e y o n d i t s e l a s t i c lim it w h ere
th e lin e a r s t r e s s - s t r a i n r e la tio n s h ip w o u ld n o lo n g e r b e v a lid .
This n o n ­
lin e a r s t r e s s w o u ld a l s o c a u s e a s h if t o f th e n e u tra l a x i s .
6 . I t w o u ld b e d if f ic u lt to e v a lu a te th e s t a t e of s t r e s s from a
s in g le u n id ir e c tio n a l s tr a in m e a s u re m e n t e v e n w ith a ll s t r e s s e s b e lo w th e
I
-16--
e la s tic -lim it.
SR-4 fo il s tr a in g a g e s w e re u s e d q u ite s u c c e s s f u lly d u rin g te s tin g
o f c o rru g a te d alum inum a llo y c u lv e r ts a s re p o rte d by Koepf (7 ).
M an y of
th e p ro b le m s e n c o u n te re d in th e N orth C a ro lin a r e s e a r c h w e re e lim in a te d b y
b e tte r p la c e m e n t of th e g a g e s on th e alu m in u m c u l v e r t s .
Two g ro u p s of
s ix g a g e s w e re p la c e d a t th e q u a d ra n t p o in ts (to p , b o tto m , a n d e a c h sid e )
for e a c h t e s t s e c t i o n . . E ach gro u p o f s ix g a g e s w a s p la c e d w ith a p a ir on
th e in s id e c r e s t , on th e in s id e v a lle y an d a t th e g e o m e tric n e u tr a l a x is
o f th e c o r r u g a tio n s .
The g a g e s w e re p r o te c te d from m o is tu re b u t ru n n in g
w a te r w a s n o t a problem b e c a u s e th e c u lv e r ts w e re t e s t s tr u c tu r e s and n o t
d ra in a g e s t r u c t u r e s . All o f th e g a g e s w e re p la c e d on th e in s id e o f th e
c u lv e r t.
From th e s t r e s s - s t r a i n r e la tio n s h ip , th e s t r e s s a t th e e x tre m e
fib e rs c o u ld b e d e te rm in e d by a lg e b r a ic p ro p o rtio n , an d th e a v e r a g e
c o m p re s s iv e s t r e s s an d m axim um b e n d in g s t r e s s d e te r m in e d .
The s tr a in g a g e s u s e d on the. W o lf C re e k c u lv e r t w e re p la c e d
s im ila rly to th o s e re p o rte d by Koepf (7) e x c e p t th a t g a g e s w e re a ls o p la c e d
on th e o u ts id e o f th e c u l v e r t .
Six s tr a in g a g e s w e re i n s t a l l e d to m e a s u re
c ir c u m fe re n tia l s tr a in s on e a c h in s tru m e n te d p la te a s sh o w n in F ig u re 4 .
The g a g e s w e re p la c e d in p a i r s , on o p p o s ite sid es- of th e p l a t e , a t th re e
lo c a tio n s ; a t th e n e u tra l a x is o f th e c o rru g a tio n s an d a t th e b e n d s on e a c h
s id e of th e n e u tra l a x i s .
By p la c in g th e g a g e s in t h e s e p o s i t i o n s , th e
-17-
SR- 4
S rh ram G a g e s
Neutral Axis -----)
I n s id e oP
C u lv e r t
C u lv e r t
G age 'IV
T O P VIE.W OF
CULVERT SECTION
+ 10,000
SR-4 Readings
Average Compression
- 10,000
-
20,000
-30,000
F igure 4 .
-30,000
P o s itio n of SR-4 S tra in G a g e s to M e a s u re
C irc u m fe re n tia l S tra in in th e C o rru g a te d P la te s
-1 8 -
b e n d in g m em ent c o u ld be co m p u ted a n d th e 'a v e r a g e c o m p re s s io n d e te rm in e d
a s in d ic a te d in F ig u re 4 .
Six s e p a r a te p la te s w e re in s tru m e n te d u tiliz in g a
to ta l o f 3 6 m e a s u rin g g a g e s .
A d d itio n a l g a g e s w e re c e m e n te d to s m a ll g a lv a n iz e d p la te s an d u s e d
a s c o m p e n s a tin g g a g e s .
The c o m p e n s a tin g g a g e a c te d a s a know n r e s i s t a n c e
w h e n m e a s u rin g th e un k n o w n or c h a n g in g r e s i s t a n c e of th e g a g e a tta c h e d to
th e c u lv e r t p l a t e .
The c h a n g e in r e s i s t a n c e , b e tw e e n an y m e a s u rin g g a g e
a n d th e c o m p e n s a tin g g a g e , is p ro p o rtio n a l to th e lo a d - in d u c e d s tra in in
th e c u lv e r t a t th e lo c a tio n o f th e m e a s u rin g g a g e .
The c o m p e n s a tin g g a g e
a l s o p ro v id e s te m p e ra tu re c o m p e n s a tio n b e c a u s e i t is p la c e d in s id e th e
c u lv e r t n e a r th e m e a s u rin g g a g e s an d u n d e r e s s e n t i a l l y th e sam e e n v iro n ­
m e n ta l c o n d itio n s .
L ead w ire s of 18 g a g e s tra n d e d c o p p e r w ire w ith te flo n in s u la tio n
w e re a tta c h e d to th e s tr a in g a g e s .
.
L ead w ire s 15 f e e t lo n g w e re u s e d in
o rd e r to e lim in a te p o s s ib le s tr a in e rro rs a s s o c ia te d w ith th e u s e of lo n g e r
le a d w i r e s . T his a rra n g e m e n t n e c e s s i t a t e d th e u s e of a p o rta b le s tra in
in d ic a to r th a t c o u ld b e c a r rie d in s id e th e c u lv e r t to th e lo c a tio n of e a c h
in s tru m e n te d p l a t e .
A B a ld w in -L im a -H a m ilto n Type N p o rta b le s tra in i n d ic a ­
to r, w h ic h in d ic a te s th e s tr a in c h a n g e d ir e c tly in u n its of m ic ro -in c h e s
p e r i n c h , w a s u s e d in th e s tu d y .
F ig u re 5" sh o w s th e p o rta b le s tra in
in d ic a to r an d a ls o tw o c o m p e n s a tin g g a g e s , c e m e n te d to s m a ll g a lv a n iz e d
—1 9 —
f la t p la te s w ith le a d w ire s a tta c h e d , b e fo re w a te r - p r o o f in g »
F ig u re 5 . B a ld w in -L im a -H a m ilto n T ype N P o rtab le S tra in In d ic a to r
w ith C o m p e n sa tin g G a g e s B efore W ate rp ro o fin g
P r e s s u r e C e lls
E arth p r e s s u r e s c a n b e m e a s u re d b y m any m eth o d s; so m e of w h ich a re
c o v e re d in " F o u n d a tio n E n g in e e rin g " by L e o n a rd s (10) „ The c o m m e rcial
p r e s s u r e c e l l s e le c te d to m e a s u re e a rth p r e s s u r e on th e W o lf C re e k c u lv e rt
w a s th e C a r ls o n S o il S tr e s s M e te r illu s t r a t e d in F igure 6 „ P rev io u s s tu d ie s
h a v e sh o w n th is s t r e s s m e te r to b e d e p e n d a b le an d a c c u r a te .
I t w a s a ls o
s e le c te d b e c a u s e i t w a s r e a d ily a v a ila b le a llo w in g in s ta l l a t i o n w ith o u t
d is ru p tin g th e c o n tr a c to r s c o n s tr u c tio n s c h e d u le .
The m eter s e le c te d
m e a s u re s p r e s s u r e s up to 150 po u n d s
i n c h , is 7 1/4
p e r s q u a re
in c h e s in d ia m e te r , o n e in c h th ic k , an d h a s a stem on th e b a c k w h ich
-2 0 -
h o u s e s th e w ire r e s i s t a n c e c o ils „
F ig u re 6 . C a r ls o n S oil S tr e s s M e te r
In 1943 T e rz a g h i (21) u s e d p r e s s u r e c e l l s to m e a s u re th e c o n ta c t
p r e s s u r e b e tw e e n th e b ottom of th e in v e r t a n d th e u n d e rly in g s o ils d u rin g
an d a f te r th e c o n s tr u c tio n o f th e C h ic a g o S ubw ay T u n n e ls „ W ith re g a rd to
th e C a r ls o n s t r e s s m e te r , T e rz a g h i re p o rte d :
B e c a u s e o f th e w id e p re v io u s u s e of G o ld b e c k c e l l s , i t w as
c o n s id e r e d d e s ir a b le to m ake a n i n s t a l l a t i o n of t h e s e d e v ic e s in th e
in v e rt s e c tio n a n d to c o m p are th e r e a d in g s by m e an s of th e C a rls o n
c e l l s a n d th e s tr a in g a g e r e a d in g s in th e rib s . . . . . . . . . . . . . . . . . . .
............................................................................................ .A ll th e G o Id b e c k c e ll s
-2 1 -
re m a in e d in o p e ra tio n a n d g a v e f a irly c o n s i s t e n t r e s u l t s . H o w ev e r,
th e in d iv id u a l r e a d in g s w e re so s c a tte r e d th a t th e y g a v e no in d ic a tio n
o f th e tru e d is tr ib u tio n o f th e c o n ta c t p r e s s u r e a s d is c l o s e d by th e
C a r ls o n c e l l s
= 00 = 000
A c o m p a ris o n o f th e r e s u l t s of th e u s e o f th e p r e s s u r e c e l l s and
s tr a in g a g e s u s e d by T e rz a g h i i s sh o w n in T a b le I .
TABLE I . STRESSES IN THE CHICAGO SUBWAY TUNNEL WALLS DETERMINED
FROM PRESSURE CELLS AND STRAIN GAGES
M e th o d
S tr e s s iln '.Ki.p.sI-Per Foot
S tra in g a g e s , a s s u m in g th a t lin e r
p la te s a c t w ith th e r i b s ................... . . ............................. .... . , . = 6 6 . 0
arI s on ^3*e Ils 0 • 0 = 0 0 0 0 •
0= 0 0 = 0 = == 0 0 = 0 00 00 • 6 6 00
Idlo e c k (Se Ils 0 0 0 = • 0 = o#= = 0 0 0 0 =0 0 = = 0 • = 0 =010 6 • 5
C o m puted o v e rb u rd e n , 1 18 Ib /cu = f t ................................................... 7 2 . 6
The C a r ls o n m e te r w a s u s e d q u ite s u c c e s s f u lly on th e G a rris o n Dam
P ro je c t a s re p o rte d b y .S ik so a n d Jo h n so n (1 8 ), w h e re 26 o f 30 c e ll s in s ta lle d
w e re o p e ra tin g a fte r 11 y e a r s o f s e r v ic e = T h e s e c e ll s w e re i n s t a l l e d u n d e r
th e p o w e rh o u se an d th e s tillin g b a s in w ith th e c e ll in c o n c r e te an d th e
f a c e flu s h w ith th e b ottom o f th e fo o tin g a n d b e a rin g a g a in s t th e fo u n d a tio n
s o il =
In a r e c e n t re v ie w o f s t r e s s an d s ta i n m e a s u re m e n ts in s o i l , S elig
(17) found th a t th e C a r ls o n m e te r w a s o n e o f th e m o st s u c c e s s f u l u s e d in
a n y of the re v ie w e d fie ld t e s t s .
O ne d is a d v a n ta g e of th e C a r ls o n c e ll is
-22-
th e la rg e p ro tru s io n on th e b a c k in w h ic h th e r e s i s t a n c e w ires, a re -h o u s e d „
A m o d ifie d c e l l , w h ic h i s m ore c o m p a c t, h a s b e e n d e v e lo p e d a n d .re p o rte d ly
y ie ld s b e tte r r e s u l t s „
The s t r e s s m e te r h a s a p r e s s u r e s e n s i t i v e fa c e w h ic h tra n s m its p r e s ­
s u re b y th e u s e o f m e rc u ry to a fle x ib le d ia p h ra g m „ The d ia p h ra g m is
c o n n e c te d to a m o v a b le b a r on w h ic h tw o c e ra m ic s p o o ls a r e m o u n ted a s
i l l u s t r a t e d in .F ig u re 7 „ A d ja c e n t to th e m o v a b le b a r i s a fix e d b a r on w h ic h
tw o c e ra m ic s p o o ls a r e a l s o m o u n ted „ W ire is. w o und.,under te n s io n b e tw e e n
a fix e d s p o o l a n d a m o v a b le s p o o l p ro d u c in g tw o s e p a r a te w ire r e s i s t a n c e
c o ils .
The c e ra m ic s p o o ls a re m o u n te d i n a p o s itio n :. such t h a t w h en
p r e s s u r e c a u s e s a m o v e m e n t of th e -d ia p h ra g m th e te n s io n i n c r e a s e s on o n e
c o il a n d d e c r e a s e s o n th e o th e r „
T he u s e o f tw o c o ils p ro d u c e s a m o re s e n s itiv e in s tru m e n t an d
d e c r e a s e 's th e e f f e c t o f te m p e r a tu r e „
T e m p e ra tu re d o e s a f f e c t th e re a d in g s
b u t te m p e ra tu re c o r r e c tio n s c a n b e a p p lie d , b y m e a s u rin g th e r e s i s t a n c e
o f th e c o i l s „ T he c h a n g e in r e s i s t a n c e c a u s e d b y p r e s s u r e a n d te m p e ra tu re
i s m e a s u re d by a W h e a ts to n e .b r id g e .
. T he s h a p e o f th e m e te r , p a r tic u la r ly th e p ro tru s io n on th e b a c k ,
c r e a te d d if f ic u ltie s in m o u n tin g i t on th e c o rru g a te d m e ta l c u lv e r t wall=,
T he C a r ls o n m e te r i s n o rm a lly m o u n te d in a rig id w a ll o r fo o tin g w ith i t s
■
s e n s i t i v e f a c e flu s h w ith th e w a ll s u rfa c e a n d a g a in s t th e s o i l . -.In
CARLSON STRESS METER
Movable Bar
F a c e P la te
F ig u re 7 .
Internal Plate
C a rls o n S tr e s s M e te r C r o s s - S e c tio n
-2 4 -
th is c a s e a m o u n tin g fram e w a s m ad e to p ro v id e a rig id b a c k in g for th e
c e l l an d to p re v e n t b e n d in g m om ent a c r o s s th e c u lv e r t c o r r u g a tio n s .
F ig u re 24 on p a g e 45 sh o w s a m ou n tin g fram e in p la c e on th e C ulvert
w a ll.
The b a c k in g , for th e m o u n tin g fram e w a s m ade from a 3 /1 6 in ch
th ic k s t e e l p l a t e , 18 in c h e s s q u a r e , w ith a I 3 /4 in c h d ia m e te r h o le
in th e c e n te r for th e s te m .
A o n e in c h th ic k p ie c e .o f e x te r io r plyw ood
w ith a 7 1 /2 in c h d ia m e te r h o le w a s a tta c h e d to th e s te e l p la te to k e e p
th e s e n s itiv e f a c e flu s h w ith, th e m o u n tin g fram e s u r f a c e . A s e c tio n of
I 3 /4 in c h p i p e , lo n g en o u g h to p ro te c t th e stem of th e c e l l , w a s a tta c h e d
to th e b a c k o f th e m ounting" fram e w ith e p o x y c e m e n t.
Two h o le s w e re
d r ille d 12 in c h e s a p a r t, to f it th e .c u lv e r t c o r r u g a tio n s , th ro u g h w h ich
.th e fram e w a s b o lte d to th e c u lv e r t.
The s t r e s s m e te rs a n d th e ir c a lib r a tio n ;d a ta w e re c h e c k e d in th e
la b o ra to ry by r e p e a te d ly lo a d in g th e m e te rs to a s tr e s s of 100 p o u n d s
p e r s q u a r e in c h in -a 'sm all te s t i n g m a c h in e .
The in d ic a to r u s e d to b a la n c e
■th e W h e a ts to n e b rid g e c ir c u it w a s a s ta n d a rd s t f e s s m e te r t e s t i n g s e t
s u p p lie d b y th e m a n u fa c tu re r of th e s t r e s s m e te r s .
It w a s know n th a t th e re w ou ld b e s h e a r i n g .s t r e s s e s of su b sta n tia lm a g n itu d e a c tin g on th e f a c e s of m a n y , if n o t a l l , !of th e s t r e s s m e te rs
on th e s id e s of th e c u lv e r t.
T his w a s a n tic ip a te d from th e s t a r t ,■ and
e x p e rim e n ts w e re c o n d u c te d in th e C iv il E n g in ee rin g L a b o ra to rie s n t
-2 5 -
M o n tan a S ta te U n iv e rs ity , s e v e ra l m onths p rio r to c u lv e rt e re c tio n , to a s c e r ta in
th e e ffe c ts of s h e a rin g s t r e s s e s on th e o p e ra tio n of th e m e te rs . M e te rs w ere
lo a d e d , fa c e d o w n , in a c o m p re ss o n te s tin g m a c h in e a s show n in F ig u re 8, and
th e n ja c k e d h o riz o n ta lly u n til s lip p a g e o c c u rre d b e tw e e n th e fa c e of th e m eter
an d th e bed of th e te s tin g m a c h in e .
The b e a rin g b e tw ee n th e w ood b lo ck
an d th e s id e of th e m eter s im u la te d th e b e a rin g b e tw e e n th e s id e of th e
m e te r and th e plyw ood m ounting fram e w hen s h e a r s t r e s s e s on th e fa c e of
a m eter push it hard a g a in s t th e s id e of th e m ounting h o le in th e plyw ood
p a rt of th e m ounting fra m e .
From th e la b o ra to ry te s t s it w as c o n c lu d e d th a t
s h e a rin g s t r e s s e s on th e fa c e of a m eter w e re n o t lik e ly to c a u s e an error
of m ore th a n 5 p e rc e n t in th e m eter o u tp u t, w h ic h w as c o n s id e re d a c c e p ta b le
Pipe t-br Loading
MeFer wiFh a Mole
Por Fhe Cable -
Cable
Bed oP T esting Machine
F igure 8 .
C h ec k in g th e E ffect of S h ear S tr e s s e s on S tre s s M e te rs
-2 6 -
E arth p r e s s u r e c a n a l s o b e m e a s u re d b y th e u s e o f a ru b b e r b la d d e r ,
s u c h a s a com m on h o t w a te r b o t t l e , f ille d w ith a r e la tiv e ly in c o m p re s s ib le
f lu id , w h ic h is c o n n e c te d to a B o u rd o n -tu b e p r e s s u r e g a g e . T h is c e ll w a s
u s e d to d e te rm in e e a rth p r e s s u r e s a c tin g o n alu m in u m c u lv e r ts .an d w a s
r e p o r te d .b y K oepf (7) w ho w a s p le a s e d w ith th e ir p e rfo rm a n c e a n d s ta te d
th a t p r e d ic te d p r e s s u r e s c o m p a re d w e ll w ith m e a s u re d p r e s s u r e s .
Six ru b b e r b la d d e r p re s s u re c e l l s o f th e h o t w a te r b o ttle ty p e ,
u tiliz in g a m ix tu re o f w a te r a n d a n tif r e e z e , w e re u s e d to m e a s u re p r e s s u r e
u n d e r th e b a le d s tra w a t th e W o lf C re e k c u lv e r t s i t e .
H o le s w e re d rille d
in .th e b o ttle s to p p e r s a n d c o p p e r f ittin g s a tta c h e d w ith e p o x y c e m e n t.
F le x ib le c o p p e r tu b in g ra n .iro m e a c h b o ttle to a s ta tio n in s id e th e c u lv e rt
w h e re th e tu b in g te rm in a te d in .a b le e d e r v a lv e , a s h u t- o f f v a lv e , an d a
100 p s i (p o u n d s p e r s q u a r e .in c h ) c a p a c ity B ourdon g a g e ..
S e ttle m e n t C e lls
S e ttle m e n t of th e s o il a d j a c e n t to. th e W o lf C re e k c u lv e r t w a s
d e te rm in e d b y th e u s e .o f liq u id le v e l s e ttle m e n t c e l l s .
a s e ttle m e n t c e l l a n d
m a n o m e ter d e t a i l s .
F ig u re 9 sh o w s
The s e ttle m e n t c e l l s w e re
c o n n e c te d to a m a n o m eter b o a rd w ith tu b in g w h ic h c o n ta in e d a f l u i d .
Any c h a n g e in e le v a tio n o f th e c e l l w a s in d ic a te d .b y th e .f lu id le v e l in
th e m a n o m e ter s t a n d p i p e .. The u s e of th is ty p e o f s e ttle m e n t c e l l w a s
re p o rte d by S c h lic k (16) d u rin g w ork oh n e g a tiv e p ro je c tio n c o n d u its .
SETTLEMENT C]
P ip e C ap
Zu
Air v e n + e d i o in sid e
Culvert ('4 ' 0 . D. Flexible
c o p p e r t u b in g )
Di a. t h r e a d e d p ip e
H arrow d is c .
(A p p ro x . I' d ia.)
D i s c w e l d e d -to p ip e
O v e r P lo w lin e
slig h + ly a b o v e lin e
■ho m a n o m e t e r b o a r d -
t— - D r ille d v e n t h o le s
s lig h t ly a b o v e
o v e r P low lin e
P ip e c a p
to
Dia. b l a c k Iron p ip e
m a n o m e te r board
Air v e n t
MANOMETER
SETTLE.WENT C EIL
F igure 9 .
OverPlow line vented to
inside cu lv ert ( 3/ e O.D.
p e r Porated Plexible
cop p er- tu b in g )
BOARD
MANOMETER BOARD
(F o r e ig h t s e ttle m e n t cells)
S e ttle m e n t C e ll an d M an o m eter Board D e ta ils
I
-2 8 The u s e o f a s im ila r c e ll w a s re p o rte d b y C o s te s e t a l (6) b u t a c o m p lic a te d
m e rc u ry m a n o m e ter d e v ic e w a s u s e d b e c a u s e th e re a d in g s w e re .tak en in
th e c u lv e r t a t a p o in t lo w e r th a n th e s e ttle m e n t c e l l s in th e f i l l .
The s e ttle m e n t c e l l s w e re f a b r ic a te d a t th e U n iv e rs ity in s tru m e n t
s h o p , from h a rro w d i s c s a n d tw o - in c h , th re a d e d p ip e .
o f p ip e w a s w e ld e d in s id e th e h a rro w d i s c .
A s h o rt s e c tio n
T his s e c tio n of p ip e w a s
th re a d e d on e a c h en d a n d c a p p e d . At th e lo w e r end tw o c o n n e c tio n s ,
o n e for a 3 /8 in c h , f le x ib le , .c o p p e r lin e an d o n e fo r a 1 /2 in c h o u ts id e
d ia m e te r , b la c k , iro n p ip e , w e re c o n n e c te d to s ta n d p ip e s in s id e th e 2
in c h p ip e .
The f le x ib le , c o p p e r lin e w a s c o n n e c te d to th e s ta n d p ip e th a t
w a s s lig h tly h ig h e r th a n th e o th e r an d w a s u s e d a s an o v e rflo w lin e .
The
1 / 2 . i,nch p ip e w a s c o n n e c te d to th e lo w e r s ta n d p ip e an d w a s u s e d a s th e ,,
lin e to th e m a n o m e ter b o a r d .
The c o n n e c tio n a t th e to p w as- v e n te d to th e
in s id e o f th e c u lv e r t to in s u r e a tm o s p h e ric p r e s s u r e in th e s e ttle m e n t c e l l .
The o v e rflo w lin e w a s a ls o v e n te d to th e .in s id e o f th e c u lv e r t an d w a s p e r ­
fo ra te d to in s u r e d ra in a g e , o f th e o v e rflo w .
D rill h o le s w e re p la c e d in th e
2 in c h p ip e s e c tio n s lig h tly a b o v e th e le v e l o f th e o v e rflo w ,s ta n d p ip e in
c a s e th e o v e rflo w lin e c o u ld n o t d ra in . The m a n o m eter b o a rd c o n s is te d o f a
la rg e s h e e t o f p a in te d e x te r io r p lyw o o d to W hich 8 s e c tio n s o f c le a r p la s t ic
V
tu b in g w e re c o n n e c te d to in d ic a te th e liq u id le v e l in e a c h o f th e 8 s e t t l e ­
m en t c e l l s .
CHAPTER V ",
RECONSTRUCTION OF CULVERT AND INSTALLATION OF INSTRUMENTATION
The in s tru m e n ta tio n w a s in s ta lle d w h ile th e c u lv e r t an d fill w e re u n d e r
c o n s tr u c tio n so th e tw o to p ic s a re v e ry c lo s e ly r e l a t e d . H o w e v e r, th e m ain
p o in ts o f th e c u lv e r t r e c o n s tr u c tio n o p e ra tio n w ill b e re p o rte d f ir s t in ord er
to p ro v id e a g e n e r a l p e r s p e c tiv e o f th e e n tire p ro je c t b e fo re c o n c e n tra tin g
o n th e in s t a l l a t i o n d e ta i ls o f each , s e t o f in s tr u m e n ta tio n .
C u lv e rt R e c o n s tru c tio n
F o llo w in g th e re m o v a l o f th e .ro c k f ill from th e d a m ag e d c u lv e r t in th e
w in te r a n d s p rin g o f 1965, d is a s s e m b ly o f th e f a ile d p o rtio n w a s b e g u n apd
s te p s w e re ta k e n .to d iv e rt th e s tre a m . U n p re c e d e n te d h ig h w a te r th w a rte d
a l l s tre a m d iv e r s io n a tte m p ts u n til S e p te m b e r w h en a s u c c e s s f u l d iv e rs io n w a s
f in a lly e ffe c te d th ro u g h th e u s e o f tw o d iv e r s io n p ip e s ,54 in c h e s an d 72 In c h e s
in d ia m e te r . F ig u re 10 sh o w s th e d iv e rs io n dam a n d th e in le ts o f th e two d iv e r ­
s io n p i p e s , w ith th e u n d a m ag e d in le t end o f th e la rg e c u lv e r t v is ib le in th e ! '
b a c k g r o u n d . Both,of th e u n d a m d g ed end s e c t i o n s , h a v in g a c o m b in e d le n g th o f
o v e r 200 f e e t , w e re le f t I n ta c t.
O n ly th e f a ile d c e n tr a l s e c tio n w a s r e b u ilt.
The in ta c t en d s e c tio n s a re v is ib le in Figure 11 w h ic h a ls o sh o w s th e
tr e n c h e s in w h ic h p e rfo ra te d d ra in p ip e s w e re p la c e d to d e w a te r th e
fo u n d a tio n in th e r e c o n s tr u c tio n z o n e . The p e rfo ra te d p ip e s w e re c o n tin ­
u a lly p u m p ed , d u rin g c u lv e r t e r e c tio n , b e c a u s e th e re w a s n o w a y to
—3 0 -
F ig u re 1 1 . T ren c h in g for P e rfo ra te d P ip e D ra in
(Looking D o w n stream )
-31-
d ra in them b y g r a v ity .
The c u lv e r t b e d d in g w a s h ig h q u a lity g ra n u la r
b a c k f ill m a te ria l a n d i t w a s p re p a re d a c c o rd in g to s p e c if ic a tio n s w h ich
c a lle d for th e b e d to -b e cut. to f it th e c u lv e r t c u rv a tu re „ The c o n tra c to r
m ad e a s t e e l te m p la te to m a tc h th e c u lv e r t c u rv a tu re an d a tta c h e d i t to
a p a tro l b la d e to c u t th e .b e d d in g „ Four in c h e s of lo o s e m a te ria l w a s
th e n h a n d p la c e d to f i t th is c u rv e d b e d d in g „ The b e d d in g w a s c o m p le te d
in th e m id d le of O c to b e r, 19 65,
D is a s s e m b le d p la te s w e re s to c k p ile d in a n a c c e s s a b l e a re a do w n ­
s tre a m from th e c u lv e r t, . S p e c ia l p ro v is io n s a llo w e d th e r e - u s e . o f
u n d a m a g e d p la te s in w h ic h th e .b o lt h o le s w e re a c c u r a te ly a n d c o n c e n ­
t r i c a lly re a m e d , w ith o u t d a m a g e to th e p l a t e s ,. to a h o le s i z e n o t la rg e r
th a n o n e .in c h in d ia m e te r , I t w a s a ls o re q u ire d th a t a ll re a m e d h o le s b e
p a in te d w ith a z in c o x id e p rim er fo r a th ic k n e s s of tw o to th r e e m ils .
All p la te s d e te rm in e d a s u n s a tis f a c to r y b y th e S ta te I n s p e c to r w e re re p la c e d
.by n ew p la te s r o lle d to th e sam e r a d iu s a s th e o rig in a l p l a t e s ,
The b o tto m p la te s w ere, i n s ta lle d f i r s t , b e tw e e n th e i n t a c t end
s e c tio n s .
T hen th e c u lv e r t c o n tra c to r e r e c te d p la te s .fro m e a c h end
to w a rd th e m id d le a s sh o w n in..F igure 12a
E re c tio n o f th e c u lv e r t w a s
e s s e n t i a l l y c o m p le te ;b y th e .b e g in n in g o f N o v em b er an d c o n tro l d e v ic e s .
w ere, in s ta lle d , to c h e c k m ovem en t or r o ta tio n o f th e c u lv e r t d u rin g ,b a c k ­
f illin g o p e ra tio n s „ E ach c o n tro l d e v ic e c o n s is te d of a 3 /4 in c h ro d ,
-32-
3 1 /2 f e e t in l e n g t h , w e ld e d to a b a s e p la te w h ic h w a s b o lte d to th e
c u lv e r t f lo o r . . A plum b bob w a s s u s p e n d e d from th e ro o f d ir e c tly a b o v e
th e .ro d .
■
The ro d w a s p ro te c te d from g r a v e l , b o u ld e r s » an d o th e r d e b r i s ,
b y a s e c tio n of c o r r u g a te d , m e ta l p ip e .
T h is s e c tio n o f p ip e w a s 15
in c h e s in d ia m e te r an d th r e e f e e t in le n g th an d w a s w e ld e d to th e .b a s e
p la te .
The c o n tro l d e v ic e s a ls o s e rv e d a s s i t e s fo r v e r tic a l d ia m e te r
m e a s u re m e n ts a n d flo o r s e ttle m e n t m e a s u r e m e n ts . O ne of th e c o n tro l
d e v ic e s is. v is ib le in .F ig u re 13 w h ic h a l s o sh o w s p a rt o f a w a lk w a y
th a t w a s c o n s tr u c te d in s id e th e c u lv e r t.
W h ile th e c u lv e r t w a s b e in g e r e c te d , a n d w ith th e c o n tra c to r s
c o o p e r a tio n , a w a lk w a y w a s c o n s tr u c te d on th e
south s id e of th e c u lv e r t
from th e in le t to th e d o w n stre a m end o f th e 3 /8 in c h p l a t e .
A w a lk w ay
w a s a ls o c o n s tr u c te d on th e n o rth s i d e , a lo n g th a t s e c tio n of c u lv e rt
c o m p o se d of 3 /8 in c h p l a t e , an d c r o s s w a lk s w e re p la c e d a t e a c h s ta tio n
w h e re v e r tic a l a n d h o riz o n ta l d im e n s io n s a n d e le v a tio n s w e re to b e ta k e n
T a b le s lth a t w o u ld fo ld up a g a in s t th e c u lv e r t w e re p la c e d a t e a c h ,a r e a
w h e re in s tru m e n t r e a d in g s w e re to b e t a k e n .
T h e 'w a lk w a y s , c r o s s w a lk s
a n d fo ld in g t a b le s c a n .b e s e e n in F ig u re 1 4 .
-. B a c k fill'w o rk s ta r te d th e s e c o n d w e e k o f N o v e m b er, 1 9 6 5 . . The. b a c k
f ill a d ja c e n t to th e c u lv e r t w a s a c ru s h e d g ra n u la r m a te ria l of b a s e c o u r s e q u a lity a n d w a s p la c e d an d c o m p a c te d in la y e r s a p p ro x im a te ly 6
-33 -
F ig u re 1 3. C o n tro l D e v ic e w ith S tream Flow Through
C u lv e rt
-34-
in c h e s , th ic k .
The c o m p a c tio n a n d g ra d a tio n , s p e c if ic a tio n s w e re a s
fo llo w s:
All b a c k f ill m a te ria l s h a l l b e c o m p a c te d to a m inim um of
95% of m axim um d e n s ity a s d e term in e d , b y AASHO T -9 9 , M eth o d D,
a n d .AASHO T -1 4 7 . . O ptim um m o is tu r e .c o n te n t s h a ll b e m a in ta in e d
w ith in p lu s or m in u s. 15% a s d e te rm in e d b y AASHO T -99,- M ethod^D .
G ra d a tio n o f m a te ria l s h a ll b e a s fo llo w s:
S ie v e
P a s s in g
I 1 /2 , i n c h .........................
100%
• 3 /4 in c h . ........................
6 7 - 82%
3 / 8 . ig c h
................................. 3 7 - 55%
# 1 0 ..................................................... 1 3 - 27%
# 4 0 . . . . . . ■ ..................
7 - 18%
# 2 0 0 ..................
4 - 12%
C a re w a s .ta k e n to o b ta in p ro p e r c o m p a c tio n a t th e h a u n c h e s a s i l l u s ­
tr a te d in F ig u re 1 5 .
T h e :b a c k fill-m a te ria l w a s .b r o u g h t'u p - e q u a lly on e a c h
side,.Tcf th e c u lv e r t an d w a s c o m p a c te d .b y s m a ll, p n e u m a tic - tir e d ro lle r s a s
in d ic a te d in -F ig u re 1 6 .
T his m a te ria l w a s p la c e d to a d e p th of fiv e f e e t
a b o v e th e c u lv e r t an d 12 f e e t on e a c h s id e a s .in d i c a te d in F ig u re 2 .
In l a t e N ovem ber a n d e a r ly D e ce m b e r th e s tra w w a s p la c e d o n .th e
b a c k f ill m a te ria l to form th e - im p e r f e c t tr e n c h .
The s tra w w a s p la c e d in
tw o la y e r s w ith in th e ;lim its in d ic a te d , in F ig u re 2 an d a s sh o w n in F igure
-1 7 .
T h e .b in d e r tw in e w a s c u t a fte r e a c h .la y e r o f s tra w w a s p la c e d .
L oose
r o c k .f ill w a s th e n p la c e d on th e s tra w an d n o t c o m p a c te d n o r w a s an y e q u ip
m e n t a llo w e d .to c r o s s .t h i s s e c tio n .u n til th e lo o s e m a te ria l r e a c h e d a .h e ig h t
of e ig h t f e e t a b o v e th e s tr a w .
The re m a in in g f i l l , c o n s is tin g of m a te ria l
th a f w a s d u m p e d .b y v a r io u s .h a u lin g e q u ip m e n t, w a s th e n p u s h e d in to p la c e
-3 5 -
F ig u re 1 4 . W a lk w a y s , C ro s s w a lk s a n d F o ld in g T a b le s in
C u lv e rt
F ig u re 1 5 . C o m p a c tin g M a te r ia l u n d e r H a u n ch
-3 6-
Figuce 1 6 . B a c k fill M a te ria l P la c e d in Six In c h L a y e rs
(Looking U p stre am )
F ig u re 1 7 . P la c e m e n t o f B aled S traw
F iv e F e e t a b o v e C ulvert.
-37-
a n d c o n tin u a lly w o rk ed by a D -9 C a te r p illa r „
The re m a in d e r of th e ro c k f ill w a s c o m p le te d e a rly in Ja n u a ry of
1966 an d a g ra v e l s u rfa c e w a s p la c e d a s a te m p o ra ry m e a s u re to o p en th e
h ig h w a y to tr a f f ic .
The f in a l s u rfa c in g o f a s p h a ltic c o n c r e te , w a s p la c e d
in A u g u st o f 1 9 6 6 .
F le x in g o f th e p la te s r e s u ltin g from p la c e m e n t of th e f il l re lie v e d
th e te n s io n in m any of th e b o lts to th e e x te n t th a t th e n u ts c o u ld b e
tu rn e d w ith th e f i n g e r s . In th e sum m er of 1966 a w ork c re w s y m te m a tic a lly
tig h te n e d th e a c c e s s i b l e lo o s e n u ts .
S tra in G a g e I n s ta lla tio n
In A u g u st o f 1 9 6 5 , w h ile stre a m d iv e rs io n a tte m p ts w e re s t i l l u n d e r
w a y , th e c u lv e r t c o n tra c to r p la c e d s ix of th e n ew 3 /8 in c h th ic k c o rru g a te d
s tr u c tu r a l p la te s in a n e a s ily a c c e s s i b l e o u td o o r w ork a r e a .
It w a s in
t h i s a re a t h a t th e SR-4 s tr a in g a g e s w e re a p p lie d , w a te rp ro o fe d ', and
c h e c k e d b e fo re th e p la te s w e re i n s t a l l e d in th e c u lv e r t.
C a re w a s ta k en , to p re p a re th e s u r f a c e o f th e p la te w here th e g a g e s
w e re to b e c e m e n te d to a s s u r e a good b o n d .
B e c a u se of th e ro u g h e x te rio r
of th e g a lv a n iz in g a t s o m e .l o c a tio n s , th e a r e a w a s. file d a n d th e n fin is h e d
w ith .fin e e m ery p a p e r .
In a ll c a s e s . t h e fin e em ery p a p e r w a s u s e d to
a s s u r e a c l e a n , lig h tly ro u g h e n e d s u rfa c e to p ro v id e good a d h e s io n .
th is p r e p a r a tio n , th e s u rfa c e w a s th o ro u g h ly c le a n e d w ith a c e to n e .
A fter
The
-3 8 -
g a g e s w e re th e n a tta c h e d a c c o rd in g to th e d ire c tio n s in c lu d e d in th e BLH
E a stm a n 910 c e m e n t k i t .
G a g e s w e re p la c e d on th e s id e o f th e p la te s w h ic h w o u ld b e on th e
in s id e o f th e c u lv e r t, an d t h e s e g a g e s w e re from th e sam e s h ip m e n t or lo t
h a v in g a g a g e f a c to r o f 2 .1 3 .
A few o f th e g a g e s w e re ru in e d d u rin g
a p p lic a tio n or f a ile d to m e e t th e fu n c tio n a l o p e ra tio n t e s t an d h a d to b e
r e p la c e d .
M o re g a g e s w e re re q u ire d an d th e jo b w a s f in is h e d w ith g a g e s
from a s e c o n d .lo t w h ic h h a d a g a g e f a c to r o f 2 .0 8 .
M o st o f th e g a g e s
th a t w e re p la c e d on th e s id e of th e p l a t e w h ic h w o u ld b e on th e o u ts id e
o f th e c u lv e r t, w e re from th e s e c o n d l o t .
O ne of th e d is a d v a n ta g e s of
th is a rra n g e m e n t w a s th a t tw o c o m p e n s a tin g g a g e s , o n e w ith a g a g e
fa c to r of 2 .1 3 an d o n e w ith a g a g e f a c to r o f 2 .0 8 , h a d to b e u s e d w ith
fiv e o f th e s ix in s tru m e n te d p l a t e s .
L ead w ire s w e re a tta c h e d u s in g a r o s in - c o r e s o ld e r a n d a sm all
e le c tr i c s o ld e rin g ir o n .
C a re w a s ta k e n to e lim in a te a n y e x te r n a l s tr a in s
b y p ro v id in g s la c k an d ta p in g th e le a d s d o w n .
The g a g es a n d le a d s w e re
th o ro u g h ly c le a n e d a g a in w ith a c e to n e , p rim a rily to re m o v e s o ld e r flu x in g
m a te ria l w h ic h m ig h t h a v e g ro u n d e d or s h o r t- c ir c u ite d , th e g a g e s . The
f u n c tio n a l b e h a v io r of th e g a g e s w a s th e n c h e c k e d a c c o rd in g to th e m an u ­
fa c tu re rs . re c o m m e n d a tio n s a f te r w h ic h th e g a g e s w e re w a te r -p ro o fe d a n d
p ro te c te d by tw o la y e r s o f e p o x y c e m e n t a n d a .la y e r.o f- s ilic o n e ru b b e r
.
-39-
s e a la n t,
E ach la y e r w a s a llo w e d to d ry b e fo re a n o th e r w a s a p p lie d .
F ig u re 18 sh o w s a p la te w ith th e s tr a in g a g e s a tta c h e d an d w a te rp ro o fe d .
Sm all h o le s w e re d r ille d th ro u g h th e p la te so th a t th e le a d w ire s
from th o s e g a g e s th a t-w o u ld b e on th e o u ts id e of th e c u lv e r t c o u ld b e
th re a d e d to th e in s id e of th e c u lv e r t.
The le a d s w e re p r o te c te d .b y s i l i ­
c o n e ru b b e r s e a l a n t a s sh o w n in F ig u re 1 8 ,
T h e se w ire s w e re .th e n ta p e d
dow n on th e in s id e so th a t th e y w o u ld b e o u t of th e w ay d u rin g ,e re c tio n .
The c o n tra c to r p la c e d th e p la te s c o n ta in in g s tr a in g a g e s in p re ­
s e le c te d lo c a t i o n s , . O ne of t h e s e p la te s i s illu s tr a te d in F ig u re 19.
The g a g e s w e re p o s itio n e d o n .th e p la te s so th a t th e y w o u ld b e lo c a te d
s lig h tly a b o v e th e m id - h e ig h t o f th e c u lv e r t.
A fter th e p la te s w e re in
p la c e , p re fa b ric a te d a n g le ir o n s , c a p p e d a t e a c h end w ith s m a ll m e ta l
p la te s w h ic h f it th e c o rru g a tio n c u r v a tu r e , w e re p la c e d o v e r th o s e g a g e s
.th a t w o u ld b e a g a in s t th e f ill m a te ria l to p ro te c t th e m .
Epoxy c em e n t
w a s u s e d to a tta c h th e a n g le iro n s to th e p la te a s sh o w n in F ig u re 2 0 .
. In e a c h c a s e th e b o tto m end of th e c a p p e d a n g le iro n w a s b u tte d a g a in s t a
se a m or a b o lt.
For th e g a g e s show n in F ig u re 1 9 , h o le s w e re d rille d
s e v e r a l in c h e s b e lo w th e g a g e s for th e a n g le iro n su p p o rt b o l t s .
C o m p e n sa tin g g a g e s w ith th e sa m e g a g e fa c to r a s th e m e a s u rin g g a g e s
w e re p la c e d in th e c u lv e r t n e a r th e m e a s u rin g g a g e s a s in d ic a te d in F ig u re
21,
T h e s e c o m p e n s a tin g g a g e s w e re s u s p e n d e d by w ire h a n g e rs from
-40-
F ig u re 1 8 o M o u n ted S tra in G a g e s on P la te b e fo re
E re c tio n a n d C o m p e n sa tin g G ag e
F ig u re 1 9 . T hree S tra in G a g e s o n O u ts id e o f P la te a f te r E rec tio n
(L o c a te d N e ar Top o f P la te in C e n te r o f P ic tu re )
-41-
-42-
e r e c tio n b o l t s , so th a t e x te r n a l fo rc e s c o u ld n o t a f f e c t th e m .
S p ad e ty p e
en d c o n n e c tio n s w e re s o ld e r e d to th e le a d w ire s of a ll g a g e s a n d th e w ire s
w e re la b e l e d , b u n d le d a n d p la c e d so th a t th e y w o u ld b e a c c e s s i b l e for
ta k in g r e a d i n g s .
The p la te s c o n ta in in g g a g e s w e re id e n tif ie d a s p la te s r'A" , "B ", "C ",
" D " , "E" , a n d "F" . The s tr a in g a g e s lo c a te d on th e in s id e o f th e c u lv e r t,
u s in g p la te "A" a s a n e x a m p le , w e re n u m b e re d " A l" , "A 2 ", a n d "AS" w h ile
th o s e on th e o u ts id e w e re " A l l " , "A 2 2 ", a n d "AS3" a s sh o w n in F igure 4 .
F ig u re 22 sh o w s th e lo c a tio n s of th e p la te s on w h ic h s tr a in g a g e s w ere
a tta c h e d .
The rin g s w e re n u m b ered from I th ro u g h 70 from d o w n stre a m to
u p s tre a m e n d , a s th e y w e re in th e o rig in a l c u lv e r t, for id e n tif ic a tio n p u r­
p o s e s . Ring num ber 39 i s u n d e r th e c e n te r lin e o f th e I n te r s ta te ro a d w a y .
P r e s s u r e C e ll I n s ta lla tio n
I n s ta lla tio n o f th e s t r e s s m e te rs w a s s ta r te d a s so o n a s th e n e c e s s a r y
p la te s w e re e r e c te d b y th e c u lv e r t c o n tr a c to r .
The h o le s fo r b o lts w e re
d r ille d a n d th e h o le s for th e c e l l s te m s w e re c u t w ith a n a c e ty le n e to r c h .
All h o le s w e re p a in te d w ith th e sam e z in c o x id e p a in t th e c o n tr a c to r u s e d
for p a in tin g th e re a m e d b o lt h o le s on r e - u s e d p l a t e s .
E ig h te e n m o u n tin g fra m e s w e re b o lte d to th e c u lv e r t.
In e v e ry c a s e
th e b o tto m e d g e o f th e fram e w a s b u tte d a g a i n s t a b o lte d s e a m , a s in d ic a te d
• Settlem ent Cells
■■ Plate on SouHi Side
a P late on Worth Side
Straw
Plate L
/// X ///////////////////////,
Ring Wo. 55
Control Devices
Symmetric about t
F ig u re 2 2 .
Plate1F
P la te 1A'
v / / / / / / / / / / / / / / / ///A ^ /////V /////y / / / / / 7 ^
CROSS-SECTION
S cale: I" ” 40'
L o c a tio n o f SR -4 S tr a i n G a g e s , S e t t l e m e n t C e l l s a n d C o n tr o l D e v i c e s
-44-
in F ig u re 2 3 . To p ro v id e a r e la tiv e ly rig id b a c k in g , th e v o id a re a b e tw e e n th e
fram e an d th e c o rru g a te d s u rfa c e w a s fille d w ith p la s t e r of P a ris or a s a n d c e m e n t m o rtar a s sh o w n in F ig u re 24 . M o u n tin g fram es w e re n o t u s e d for th o s e
m e te rs p la c e d on th e to p c e n te r lin e of th e s t r u c t u r e . T h e se m e te rs w e re p la c e d
in a b e d d in g of s a n d -c e m e n t m o rta r.
L ead c a b le s w e re a tta c h e d to th e m e te rs b e fo re p la c in g them in th e fram es
to a s s u r e good c o n n e c tio n s . A fter th e m e te rs w e re p la c e d in th e fram es, th e
c a b le s w e re s tru n g to a s w itc h b o a rd in s id e th e c u lv e r t so th a t a ll re a d in g s c o u ld
b e ta k e n a t o n e lo c a tio n . T h r e e - p o le , d o u b le -th ro w , k n ife s w itc h e s , w ith la rg e
c o n ta c t s u r f a c e s , w e re u s e d to ra p id ly s w itc h from o n e m e te r to a n o th e r.
The
le n g th s of a ll c a b le s w e re m e a s u re d so th a t th is a d d itio n a l r e s i s t a n c e c o u ld b e
c o n s id e r e d . O ne of th e fo ld in g ta b le s w a s lo c a te d a t th is s w itc h b o a rd to f a c i l i ­
ta t e th e ta k in g of re a d in g s . The sw itc h b o a rd , fo ld in g ta b le a n d t e s t s e ts for
th e s t r e s s m e te rs an d SR-4 s tr a in g a g e s a re sh o w n in F ig u re 2 5 .
F ig u re 2 3 . M o u n tin g F ram es for S tr e s s M e te rs I n s ta lle d on
C u lv e rt (N o tic e a ll F ram es B utt a g a i n s t B olts a t a ll S eam s)
-45-
F ig u re 2 4 . M o u n tin g Fram e w ith M o rta r B acking
F ig u re 25 „ S tr e s s M e te r T e s t S et a n d S w itc h b o a rd
—4 6 -
Sand w a s p la c e d a g a in s t th e f a c e o f th e s t r e s s m e te rs to k e e p th e
c o a r s e r m a te ria l from d a m ag in g th em or a p p ly in g u n e v e n p r e s s u r e a s th e
f ill w a s p l a c e d o In s p ite of th is p r e c a u tio n , c o n s tr u c tio n e q u ip m e n t
d a m a g e d so m e m e te rs ; n o te th e tir e m a rk s on s t r e s s m e te r N o „ 17 sh o w n in
F ig u re 2 6 .
S tr e s s m e te r N o .. 17 is a ls o sh o w n ,fro m th e in s id e of th e c u l - ■
v e rt in -F ig u re 27 a n d sh o w s c le a r ly th e p ro tru s io n a t th e b a c k of th e
m e te r.
S ilic o n e ru b b e r s e a la n t w a s p la c e d b e tw e e n th e e d g e of th e s t r e s s
m e te r an d th e m o u n tin g fram e to k e e p fin e s a n d or b a c k f ill m a te ria l from
b in d in g th e e d g e of th e m e te r.
F iv e s t r e s s m e te rs w e re p la c e d in th e f ill p e rp e n d ic u la r to th e
c u lv e r t c e n te r l i n e , a s sh o w n in F ig u re 2 8 , a b o v e rin g 4 3 , w h e n th e b a c k ­
f ill m a te ria l w a s o n e fo o t a b o v e th e c u lv e r t.
The sam e ty p e o f m ounting
fram e d e s c r ib e d e a r lie r w a s u s e d to p ro te c t th o s e m e te rs in th e f i l l .
The lo c a tio n of th e 30 s t r e s s m e te rs a n d th e ir id e n tif ic a tio n nu m b ers ■
i s in d ic a te d in F ig u re 2 9 .
From th is i t c a n .b e s e e n th a t th e fram e in .th e
lo w e r r ig h t c o rn e r of F ig u re 23 i s for m e te r N o . 8 an d th e fram e in th e
u p p e r le f t c o rn e r is for m e te r N o ., 1 8 .
S ix ru b b e r p r e s s u r e c e l l s w e re p la c e d p e rp e n d ic u la r to th e c u lv e rt
c e n te r l i n e , a b o v e rin g 3 8 , a fte r th e s e l e c t b a c k f ill m a te ria l, w a s p la c e d
to i t s fu ll h e ig h t, fiv e f e e t a b o v e th e to p o f th e c u l v e r t . In o rd e r to
p la c e th e c e l l s a -trench w a s c u t a c r o s s ,t h e b a c k f ill dow n to th e c u lv e r t.
•
—4 7“
F ig u re 2 6 . S tr e s s M e te r I n s ta lle d w ith Sand P ro te c tio n
(N ote T ire M ark)
f ig u r e 2 7 . S tr e s s M e te r from th e I n s id e o f th e C u lv e rt
(N ote Stem o f S tr e s s M e te r P ro tru d in g in to
C u lv e rt)
-4 8 -
H o l e s w e r e c u t in t h e c u l v e r t w ith a n a c e t y l e n e to r c h fo r t h e c o p p e r t u b i n g
c o n n e c t i n g t h e r u b b e r b o t t l e s to t h e B ourdon g a g e s .
F igure 2 8 . M e te rs in F ill in M o u n tin g F ram es P e rp e n d ic u la r to th e
C u lv e rt C e n te r L ine
S h e lv e s w e re c u t in th e c o m p a c te d b a c k f ill a d ja c e n t to th e tre n c h so
th a t th e ru b b e r w a te r b o ttle s w o u ld b e a p p ro x im a te ly s ix in c h e s b e lo w th e
s tra w l a y e r . The ru b b e r b la d d e r s w e re p la c e d on a s a n d b e d d in g on th e u n ­
d is tu rb e d b a c k f ill a n d p ro te c te d by c o m p a c te d sa n d a s i llu s tr a te d in F ig u re
30 . The p r e s s u r e c e l l s w e re c o n n e c te d to B ourdon g a g e s p la c e d in s id e th e c u l ­
v e rt an d th e c o p p e r tu b in g w a s p ro te c te d by s e c tio n s o f p l a s t i c w a te r h o s e . A
v a lv e w a s p la c e d in th e lin e adj a c e n t to th e B ourdon g a g e a s sh o w n in F igure 3 1 .
F lu id w a s fo rc e d from th e o v e rfille d b o ttle s to th e v a lv e in o rd e r to b le e d th e a ir
o u t o f th e s y s t e m .
The lo c a tio n of th e ru b b e r p r e s s u r e c e ll s , w ith re la tio n to
th e s t r e s s m e t e r s , is in d ic a te d in F ig u re 2 9 .
• S-Hress Me-Hers on CutverH
° SHness VAeHers in FiW
° Rubber Cetts in FiW
Roaduuay
O
Stress Meters on UorHh Side
Rubber Celts in Fitl
CROSS-SECTION
S c a le : I" = 40'
I'
F igure 2 9 .
L o c a tio n of C a rls o n S tr e s s M e te rs an d Rubber P re s s u re C e lls
-50-
F ig u re 3 1 . B ourdon G a g e s a n d V a lv e s In s id e C u lv e rt
-51-
S e ttle m e n t C e ll I n s ta lla tio n
T re n c h e s w e re c u t for th e p la c e m e n t of th e s e ttle m e n t c e l l s a t th e
sa m e tim e th a t th e tre n c h w a s c u t for th e ru b b e r p r e s s u r e c e l l s , w h en th e
b a c k f ill s u r f a c e w a s fiv e f e e t a b o v e th e c u lv e r t.
C r o s s - t r e n c h e s w ere
c u t p e rp e n d ic u la r to th e c u lv e r t c e n te r l i n e „ 134 f e e t, 166 f e e t an d 206
f e e t d o w n stre a m from th e c u lv e r t i n l e t .
A tre n c h w a s a ls o c u t a lo n g th e
s o u th s id e o f th e c u lv e r t to th e in le t fo r th e 1 /2 in c h , b l a c k , iro n p ip e
b e tw e e n th e c e l l s a n d th e m a n o m eter b o a rd .
O ne c e ll w a s p la c e d on th e n o rth s id e o f e a c h p e rp e n d ic u la r tre n c h
a n d tw o on th e s o u th s i d e .
F ig u re 3 2 .
A s e ttle m e n t c e l l , in p la c e , is sh o w n in
The lo c a tio n o f th e c e ll s i s sh o w n in F ig u re 2 2 .
The c e lls
w e re p la c e d so th a t th o s e on th e s o u th s id e w e re a b o u t a fo o t a b o v e th e
to p . of th e c u lv e r t.
The c e l l s .p l a c e d on th e n o rth s id e o f th e c u lv e r t w e re
a b o u t a fo o t h ig h e r th a n th o s e on th e s o u th s i d e .
This w a s to in s u re a
g ra d ie n t from th e c e l l to th e low p o in t lo c a te d b e lo w th e m an o m eter
b o a rd .
The a ir a n d o v e rflo w lin e s w e re v e n te d to th e in s id e of th e c u lv e rt
th ro u g h h o le s c u t w ith a n a c e ty le n e to r c h .
V a lv e s w e re p la c e d a t th e
lo w p o in t of th e m a in p ip e lin e to f a c i l i t a t e f illin g and d ra in in g th e
s y s te m .
The m a n o m e ter b o a rd w a s a tta c h e d to th e c o n c r e te in le t h e a d w a ll
The c o m p le te s y s te m a t th e h e a d w a ll is illu s tr a te d in F ig u re 3 3 .
1
-5 2 -
F ig u re 3 2 . S e ttle m e n t C e ll in
th e f ill
F ig u re 3 3 . M a n o m e te r Board an d V a lv e s M o u n ted o n C o n c re te
H e a d w a ll
CHAPTER VI
READING INSTRUMENTS AND TAKING MEASUREMENTS ■
S tra in g a g e .r e a d in g s w e re ta k e n a s s o o n a s th e g a g e s w e re a tta c h e d
to th e p la te s a n d w h ile th e p la te s w e re s t i l l ly in g in d iv id u a lly on th e
g ro u n d in th e s to c k p ile a r e a .
T h e se i n i t i a l r e a d in g s e s t a b l i s h e d a b a s is
fo r a e ro s tr a in so th a t a n y a d d itio n a l s tr a in c o u ld b e d e te rm in e d .
A fter th e c u lv e r t w a s e r e c te d an d b e fo re a n y b a c k f ill w a s p la c e d ,
re a d in g s w e re ta k e n in o rd e r to d e te rm in e th e s tr a in s c a u s e d b y e r e c tio n . ■
R e a d in g s w e re th e n ta k e n a t c lo s e tim e in te r v a ls u n til th e fu ll f ill h e ig h t
w as reach ed .
The in te r v a ls b e tw e e n re a d in g s , w e re in c r e a s e d a f te r th e f ill
w a s c o m p le te d .
S p e c ia l re a d in g s w e re a ls o ta k e n p e r io d ic a lly to c h e c k
for in d ic a to r d rift w hich" p ro v e d to b e n e g l i g i b l e .
S tr e s s m e te r r e a d in g s w e re ta k e n fo r a l l m e te rs a t th e c e n tr a l
s w itc h b o a rd .
P re lim in a ry re a d in g s w e re ta k e n to d e te rm in e th e e ffe c t of
th e v a rio u s le n g th s of c a b le c o n n e c tin g th e m e te rs to th e s w itc h e s and
c o r r e c tio n s w e re m ad e for th fe a d d e d r e s i s t a n c e .
S tr e s s m e te r re a d in g s -
w e re a ls o ta k e n b e fo re a n d a f te r th e 's w itc h e s w e re c o n n e c te d b u t th e re
w a s no in d ic a tio n th a t th e s w itc h e s a ff e c te d th e r e a d i n g s .
The re a d in g s
c o n s is te d o f r e a d in g s fo r d e te rm in in g te m p e ra tu re c o rre c tio n s a n d re a d in g s
for d e te rm in in g th e p r e s s u r e o n e a c h m e te r.
S tr e s s m e te r re a d in g s w ere .
ta k e n a t th e sa m e tim e th a t th e s tr a in g a g e r e a d in g s w e re ta k e n .
A fter th e ru b b e r p re s s u re b la d d e r s w e re c o n n e c te d to th e B ourdon
g a g e s a n d t h e .a ir y r p m p v e d , t h e g a g e p o i n t e r s w e r e a d j u s t e d to reacl z e r o .
-5 4 -
T h is g a v e a n in i t i a l z e ro ’re a d in g fo r m e a s u rin g e a rth p r e s s u r e .c o rre c te d
for th e p r e s s u r e c a u s e d b y th e d iff e r e n c e in e le v a tio n 'b e tw e e n .th e .B o u rd o n
g a g e a n d th e ru b b e r c e l l . R e a d in g s of th e B ourdon g a g e s w e re ta k e n a t th e
sa m e tim e a s th o s e of th e s tr a in g a g e s .a n d th e s t r e s s m e te rs „
E ach s e ttle m e n t c e ll w a s m ad e o p e ra tio n a l b y f illin g th e s y ste m
u n d e r p r e s s u r e w ith a g a rd e n s p ra y pum p w h ic h i s v is ib le in F ig u re 3 3 .
. I n i t i a l l y , a h a l f - a n d - h a l f m ix tu re o f w a te r a n d a n ti- f r e e z e .w a s u s e d to
p re v e n t, f r e e z i n g .
The pump w a s c o n n e c te d to th e v a lv e .a t th e .lo w p o in t
■in th e s y s te m a n d .flu id w a s .fo rc e d , in to t h e . l i n e , w ith. th e .to p of th e
s ta n d p ip e p lu g g e d to p re v e n t o v e rflo w , u n til th e .lin e s w e re c o m p le te ly
•f i l l e d .
At th is tim e th e v a lv e w a s c l o s e d , th e pump d is c o n n e c te d .a n d th e
p lu g a t th e to p of th e s ta n d p ip e re m o v e d . A fter th e .f lu id s e t t l e d in th e
s ta n d p ip e , t o :th e -.le v e l of th e c e l l ,, a p l a s t i c s c a le w a s f a s te n e d to th e .
b o a rd w ith th e z e ro m ark a t th e f l u i d .l e v e l .
S e ttle m e n t a t a n y s u b s e q u e n t
tim e w as. th e n re a d d ir e c tly a s .t h e s c a le .re a d in g of th e .liq u id s u r f a c e .
A s m a ll am o u n t o f liq u id w a s a d d e d ,, to e lim in a te p o s s ib le le a k a g e
o r e v a p o ra tio n e rro rs , to e a c h s ta n d p ip e a n d a llo w e d to s ta b iliz e .b e f o r e
re a d in g th e s e ttle m e n t. . A fter t h e .f i r s t fe w w e e k s ,th e r e a d in g s .b e ca m e
.h ig h ly e r r a t i c .
P a rt o f th is tro u b le w a s a p p a r e n tly d u e to -th e v e n t lin e s
b e in g in te r m itte n tly p lu g g e d w ith f r o s t.
A lso ,, te m p e ra tu re d iff e r e n c e s
an d d iff e r e n c e s , in .a n ti- f r e e z e .c o n c e n tr a ti o n a ffe c te d th e d e n s ity of th e
-5 5 -
flu id in th e m a n o m e te r: a s co m p ared to th a t in th e lin e s in th e f il l,
enough to g iv e in c o rre c t r e a d in g s .
s e v e r a l m o n th s .
The re a d in g s w ere h ig h ly e rra tic for
F in a lly , p ro p er fu n c tio n in g w as re s to re d by d ra in in g th e
s y ste m an d k e e p in g i t em pty b e tw e e n s e ttle m e n t o b s e rv a tio n s . R ead in g s
w e re th e n ta k e n by fillin g th e s y ste m w ith w a te r a s p re v io u s ly e x p la in e d ,
le ttin g th e s y ste m s ta b i liz e a n d , a fte r re c o rd in g th e new s e ttle m e n t
l e v e l , d ra in in g th e s y s te m . R e p ro d u c ib ility w a s g e n e ra lly b e tte r th an
p lu s or m inus '0 . 1 0 in c h e s by th is m e th o d , th e sam e a s in e a rly la b o ra to ry
e x p e rim e n ts w ith th e c e l l s .
M e a s u re m e n ts of th e h o riz o n ta l an d v e r tic a l c u lv e rt d ia m e te r w ere
ta k e n w ith a te le s c o p in g rod at. 13 s ta tio n s in s id e th e c u lv e rt a t th e
c o n tro l d e v ic e s , a s so o n as. th e c u lv e rt w a s e re c te d and b e fo re an y b a c k ­
f ill w a s p la c e d .
P e rio d ic re -m e a s u re m e n ts a t th e sam e s ta tio n s during
p la c e m e n t of th e b a c k f ill p ro v id ed a v a lu a b le re c o rd of culvert, d e f le c ­
tio n s th a t y ie ld e d in fo rm atio n a b o u t th e b e h a v io r of th e re c o n s tr u c te d
c u lv e r t.
The c o n tro l d e v ic e s on th e c u lv e r t flo o r w ere u s e d a s m e asu rin g
s ta tio n s for d e te rm in in g v e r tic a l d ia m e te r c h a n g e s an d flo o r s e ttle m e n t.
Plumb b o b s w e re hung from th e ro o f of th e c u lv e rt d ir e c tly ab o v e
th e ro d s in th e c o n tro l d e v ic e s to d e te rm in e a n y ro ta tio n of th e c u lv e r t.
No m e a s u ra b le ro ta tio n of th e c u lv e rt w a s d e te c te d d u rin g p la c e m e n t of
th e f ill or th e r e a f te r .
O b s e rv a tio n s fo r ro ta tio n w ere d is c o n tin u e d in
-5 6 -
F e b ru a ry o f 1966 w h e n ic e a n d h ig h w a te r b e n t th e ro d s „ The ro d s w ere
s tr a ig h te n e d a f te r h ig h w ater re c e d e d a n d w e re a g a in u s e d fo r v e r tic a l
d ia m e te r a n d flo o r s e ttle m e n t m e a s u re m e n ts „
F lo o r s e ttle m e n t w a s o b ta in e d from p e rio d ic o b s e r v a tio n s of th e
e le v a tio n a t th e ! to p o f e a c h c o n tro l d e v ic e - r o d , u s in g a n e n g in e e r 's
le v e l n e a r th e c u lv e r t i n l e t .
T h e se o b s e r v a tio n s were- n e c e s s a r i l y m ade
d u rin g p e rio d s o f lo w w a te r .
L e v e ls w e re ta k e n p e r io d ic a lly to d e te rm in e -if th e re w a s e x c e s s iv e
s e ttle m e n t of th e ro a d w a y s u rfa c e a b o v e th e c u lv e r t.
T h e s e ,le v e ls w ere
s ta r te d in S e p te m b e r o f 1 9 6 6 , a s so o n a s th e a s p h a ltic c o n c r e te su rfa c in g
w a s c o m p le te d .
CHAPTER VII
REDUCTION OF DATA
D a ta ta k e n in th e f ie ld h a d to b e re d u c e d to g iv e in fo rm a tio n th a t
w o u ld b e 4o f v a lu e in d e te rm in in g th e b e h a v io r o f th e s tr u c tu r e .
The s tr a in
g a g e r e a d i n g s , in m ic r o - in c h e s p e r in c h , w e re re d u c e d to g iv e th e s t r e s s e s
a c tin g on th e p la te an d th e e q u iv a le n t un ifo rm e a rth p r e s s u r e th a t w ould
c a u s e th o s e s t r e s s e s .
B ending m o m en ts in th e p la te s W ere a ls o c a lc u la te d
from th e o b s e rv e d s t r e s s e s .
S tr e s s m e te r re a d in g s w e re in u n its o f r e s i s ­
ta n c e , o h m s , an d h a d to b e c o n v e rte d to g iv e te m p e ra tu re s an d e a rth
p r e s s u r e s . R e a d in g s p ro d u c e d b y th e ru b b e r p r e s s u r e c e ll s a n d s e t t l e ­
m e n t c e l l s w e re re a d d ir e c tly in p s i an d d id n o t h a v e to b e r e d u c e d . .
P h y s ic a l m e a s u re m e n ts s u c h a s h o riz o n ta l a n d v e r tic a l d ia m e te r s an d in v e rt
e le v a tio n s w e re u s e d d i r e c t l y , e x c e p t w h e n th e y w e re s u b tr a c te d from a
b a s e m e a s u re m e n t to sh o w a c h a n g e .
S tra in G a g e s
S tra in g a g e re a d in g s for z e ro r e fe re n c e p u rp o s e s w e re ta k e n w h ile
th e p la te s w e re in th e; s to c k p ile a re a p rio r to e re c tio n of th e c u lv e r t.
The s tr a in re a d in g s ta k e n im m e d ia te ly a f te r e re c tio n o f th e c u lv e r t w ere
s u b tr a c te d from th e z ero r e f e r e n c e r e a d in g s to d e te rm in e th e e re c tio n
s tr a in s a n d s t r e s s e s .
The d iff e r e n c e b e tw e e n th e re fe re n c e re a d in g
a n d a n y re a d in g ta k e n w h ile t h e .f ill w a s b e in g c o n s tr u c te d ,
a f te r c o n s tr u c tio n w a s
c o m p le te d , g a v e th e
s tr a in
or
in th e
—58 —
c u lv e r t c a u s e d by e r e c tio n a n d e a rth p r e s s u r e . • A lso , th e d iff e r e n c e
b e tw e e n th e re a d in g ta k e n im m e d ia te ly a f te r c u lv e r t e r e c tio n a n d an y
la te r re a d in g g a v e th e s tr a in in th e c u lv e r t a ttr ib u ta b le to e a rth p re s s u re
o n ly .
The l a t t e r r e la tio n s h ip i s v a lid o n ly w h e n a ll s t r e s s e s a re b e lo w
th e p ro p o rtio n a l lim it.
!
;
The s tr a in g a g e s , i n s t a l l e d a s sh o w n in F ig u re 4 , p ro v id e d m e a s u re ­
m e n ts o f c ir c u m fe re n tia l s tr a in a t th e e x tre m e fib e rs a s w e ll a s th e c irc u m fe r­
e n tia l s tr a in a t th e g e o m e tric n e u tr a l a x is o f th e s i d e w a l l . W h en th e s tr a in s
w e re w ith in th e e l a s t i c ra n g e o f th e s t e e l , th e s t r e s s w a s d e te rm in e d a s th e
p ro d u c t Of th e s tr a in a n d th e m o d u lu s o f e l a s t i c i t y (30 x IO^ p s i ) .
The s t r e s s p a tte rn r e s u ltin g from th e c o m b in e d b e n d in g a n d c o m p re s ­
s io n w a s u s e d to c a lc u la te b o th th e b e n d in g m om ent an d c o m p re s s iv e
fo rce .
The ty p ic a l s t r e s s d ia g ra m o f F ig u re 4 !will b e u s e d to il l u s t r a t e
th e s e c a lc u la tio n s .
A ssu m in g a. lin e a r r e la tio n s h ip in th e e l a s t i c r a n g e ,
th e ,m e th o d o f l e a s t s q u a r e s w a s u s e d to d e te rm in e th e s t r e s s lin e b e tw e e n
e x tre m e fib e rs of th e p l a t e .
The c o m b in e d s t r e s s a t a n y d i s t a n c e , x , from
th e n e u tr a l a x is m ay b e e x p r e s s e d a s :
S = P + Mx
c
----------A
I
W h ere:
.
Sc = c o m b in e d s t r e s s , p s i
P
,
,
= to ta l c o m p re s s iv e f o r c e , p o u n d s p e r
in c h o f c u lv e r t le n g th
-5 9 -
A - c r o s s - s e c t i o n a l a re a of th e c u lv e r t w a ll, in
p e r in c h of le n g th
= 0 ,4 6 7 In^ p e r in c h .fo r th e 3 /8 in c h p la te
o f th e W o lf C re e k c u lv e rt
9
M = b e n d in g m o m en t, in c h -p o u n d s p e r in c h of le n g th
I = m om ent of in e r tia of th e w a ll c r o s s - s e c t i o n ,
in p e r in c h o f le n g th
= 0 „ 234. in ^ p e r in c h o f th e W o lf C re e k c u lv e rt
P = d ir e c t c o m p re s s iv e s t r e s s , S , , p s i
A
d
M x= b e n d in g s t r e s s , S ^ , p s i
At th e e x tre m e fib e rs :
x = c = 1 ,1 8 8 in c h e s ' for th e W o lf C re e k C u lv ert
At th e n e u tra l a x i s , w h e re x .i s e q u a l to z e r o , th e d ir e c t c o m p re s s iv e
s t r e s s i s about. 9000 p s i in F ig u re 4 ,. In th is exam p ie .th e to ta l c o m p re s ­
s iv e fo rc e is th e n :
P = Sd °A = 9000 (0 ,4 6 7 ) = 4200 I b / i n
T h e .b e n d in g s t r e s s i s d e te rm in e d b y a lg e b r a ic a lly s u b tra c tin g th e
c o m p re s s iv e s t r e s s from th e co m b in ed s t r e s s a t a n y p o in t,
At th e e x trem e
f ib e r s , th e b e n d in g s t r e s s h a s a .n u m e ric a l v a lu e o f a b o u t 1 4 ,0 0 0 p s i in
th e e x a m p le of F ig u re 4 ,
In th e Same e x a m p le , th e b e n d in g m o m en t, in - l b
p er in c h o f c u lv e r t l e n g t h , i s th e n :
M = Sb I_ = 1 4 ,0 0 0 (0 ,2 3 4 ) = 2760 i n - l b / i n
C .
1 ,1 8 8
F ig u re 34 sh o w s a fr e e b o d y d iag ram o f th e to p half- of? a s e c tio n of
—6 0 —
th e c u lv e r t an d sh o w s how th e c o m p re s s iv e fo rc e a c tin g in th e c u lv e rt
w a ll m ay b e r e la te d to th e a v e r a g e e q u iv a le n t v e rtic a l e a rth p r e s s u r e .
The to ta l v e r tic a l lo a d on th e c u lv e r t c a n b e e x p r e s s e d a s
V - (w)(D)(L)
W h ere:
V = to ta l v e r tic a l l o a d , p o u n d s , on a s e c tio n L
in c h e s lo n g
w = a v e ra g e e q u iv a le n t v e r tic a l e a rth p r e s s u r e , p s i
D=. c u lv e r t h o riz o n ta l d ia m e te r , i n c h e s , ta k e n a s
216 in c h e s for th e d e f le c te d W o lf C re e k c u lv e rt
L - le n g th of s e c tio n , c o n v e n ie n tly ta k e n a s o n e in c h .
—w , in p o u n d s p e r s q u a re in ch
M
SI
D ia m e te r = 2 1 6 in c h e s
V-
'P tF ig u re 3 4 .
D e te rm in in g E arth P re s s u re from C o m p re s s iv e F o rce in W a lls
It is e v id e n t, from th e fre e b o d y d ia g ra m , th a t th e to ta l v e rtic a l
lo a d , V, i s a ls o e q u a l to 2P; th e re fo re :
-61-
V = 2P = wDL or w = 2P
'
-D L
i
T hese- e q u a tio n s w e re u s e d to c o m p u te th e a v e ra g e e a rth p r e s s u r e ,
w , c o rre s p o n d in g to th e v e r tic a l c o m p re s s iv e fo r c e , P.
In so m e .c a s e s th e e l a s t i c lim it w a s e x c e e d e d , an d in th e s e c a s e s a
n u m e ric a l su m m a tio n p r o c e s s w a s u s e d to c a lc u la te th e c o m p re s s iv e fo rc e
a n d b e n d in g m o m e n t. For th is c o n d itio n th e s lo p e of th e s t r e s s lin e w a s
■
c a lc u la te d by th e sam e m eth o d a s b e fo re e x c e p t th a t .the s t r e s s in c r e a s e
w a s te rm in a te d a t th e y ie ld s t r e s s o f 3 0 ,0 0 0 ' p s i .
The c o m p re s s io n fo rc e
an d b e n d in g m om ent w a s fo u n d a s i llu s tr a te d in F ig u re 3 5 .
The com ­
p r e s s io n f o r c e , P , w a s d e te rm in e d b y ta k in g th e a lg e b r a ic a l su m m atio n
o f th e a re a o f th e s e g m e n ts of th e p la te tim e s th e a v e r a g e s t r e s s a c tin g
on th e se g m e n t:
.
'
P = g 5 ) (A1)
W h ere:
S = s t r e s s , p s i , a c tin g on A1
A"= a re a of s e g m e n t, i n 2
The a re a w a s c a lc u la te d for 10 s e g m e n ts , o f e q u a l w id th , on e a c h
s id e of th e n e u tra l a x is or a to ta l of 20 s e g m e n ts a s sh o w n in F ig u re 3 5 .
The b in d in g m o m en t, M , w a s d e te rm in e d b y ta k in g th e su m m a tio n of th e
p ro d u c ts c a lc u la te d a b o v e tim e s th e d is ta n c e b e tw e e n th e a r e a an d th e
g e o m e tric n e u tra l a x is :
M =gSc ) (A") (x)
—62 —
Seqm enla (T) thru @
Force on Segm enE (§)
= S t r e s s o l (5) tim e s AreaoP(§)
P = T o t a l F o r c e = "E S t r e s s • A rea
E a r t h P r e s s u r e ,uu «
a s in Fig.34
MomenV Prom SegmenV (5) Force
- Force on (§) tim es X
Total Moment = ^ Force *X
SECBON OF V& INCH PLATE
In E la s lic Range Only :
S t r e s s = E* Strain
E= SOiMOt PSI
-IO1OOO PSl
Yi e U Stress=
-20,000 PSI
-30,000 PSl
STRESS DIAGRAM
F ig u r e 3 5 .
E arth P r e s s u r e from I n e l a s t i c S tr a i n
3 0 ,0 0 0 PSl
-63-
W h ere:
x = d is ta n c e b e tw e e n a re a and n e u tra l a x i s , in c h e s
W ith th e c o m p re s s io n fo rc e d e te rm in e d , th e a v e ra g e e a rth p re s s u re
w a s c o m p u te d a s in d ic a te d by F ig u re 3 4 .
The y ie ld s t r e s s o f 3 0 ,0 0 0 p s i
w a s e s ta b lis h e d from tw o t e n s i l e t e s t s an d m ay n o t b e r e p r e s e n ta tiv e of
th e to ta l s t r u c t u r e . A d iff e r e n t y ie ld s t r e s s , or e v e n ig n o rin g th e
y ie ld , w o u ld n o t c h a n g e '.the c a lc u la te d a v e r a g e e a rth p r e s s u r e to an y
g re a t e x te n t.
B e c a u se o f th e la rg e num ber of r e a d in g s ta k e n , a c o m p u te r program
w a s d e v e lo p e d to perform th e c o m p u ta tio n s .
The program a ls o p rin te d
o u t id e n tif ic a tio n in fo rm a tio n su c h a s th e p la te and g a g e n u m b e rs , the
d a te , th e h e ig h t of c o v e r an d th e s t r e s s a t e a c h g a g e .
C o m p u ta tio n s
in c lu d e d ; th e s lo p e of th e b e s t lin e to f it th e s t r e s s c o o r d in a te s , th e
s t r e s s a t th e e x tre m e f i b e r s , w h e th e r or n o t th e c a lc u la te d s t r e s s a t th e
e x tre m e
fib e r s e x c e e d e d th e y ie ld s t r e s s , th e uniform a v e r a g e e arth p re s
s u re th a t w o u ld c a u s e th a t p a r tic u la r s t r e s s c o n d itio n ,, a n d th e b en d in g
m om ent in th e w a ll a t th e s tr a in g a g e lo c a t io n .
The c o m p u te r program is
g iv e n in A ppendix A.
S tr e s s M e te rs
The s t r e s s m e te r re a d in g s h a d to b e re d u c e d to o b ta in th e m eter
te m p e ra tu re an d th e p r e s s u r e a c tin g on th e m e te r a t th e tim e of e a c h
- -64-
re a d in g „ The c a lib r a tio n in fo rm a tio n r e c e iv e d from th e m a n u fa c tu re r and
c h e c k e d a t th e U n iv e rs ity w a s u s e d , w ith s lig h t m o d if ic a tio n s , to c o n v e rt
th e m e te r r e a d in g s .in to te m p e ra tu re s an d e a rth p r e s s u r e s „ F ig u re 36 i l l u s ­
t r a t e s how e a rth p r e s s u r e w a s d e te rm in e d from, th e re a d in g s o f s t r e s s m e te r
N o .. I .
The tw o c h a r ts w e re c o n s tr u c te d ' from th e b a s ic c a lib r a tio n d a ta
for m e te r N o.. I , a n d th e ir u s e i s i llu s tr a te d b y th e fo llo w in g n u m e ric a l
e x am p le: • A ssum e th a t th e te m p e ra tu re read in g - Rf. is 7 4 .4 o h m s a t th e sam e
tim e th a t th e ra w r e s i s t a n c e re a d in g RRp i s 1 0 4 .1 8 o h m s.
E n terin g th e ■
g ra p h w ith th e te m p e ra tu re re a d in g of 7 4 ,4 0 ohm s i t is fo u n d th a t th e
te m p e ra tu re i s a p p ro x im a te ly 60 d e g re e s F a h re n h e it an d th e c o rre c tio n of
th e r e s i s t a n c e re a d in g i s p lu s 0 .0 2 o h m s .
A pplying th e c o r r e c tio n to th e
r e s i s t a n c e re a d in g an d e n te rin g th e g ra p h o n th e le f t w ith 1 0 4 .2 0 ohm s
th e e a rth p r e s s u r e is fo u n d to b e - 2 5 .5 p s i .
T h is m eth o d w a s u se d , to
r e d u c e th e s t r e s s m e te r r e a d in g s to e a r th p r e s s u r e s a n d a s e p a r a te g rap h
h a d to b e p re p a re d for e a c h m e te r.
The te d io u s g ra p h ic a l re d u c tio n of th e s t r e s s m e te r re a d in g s w a s
a b a n d o n e d .a f te r a c o m p u te r program w a s d e v e lo p e d to perform th e sam e
ta s k a n a ly tic a lly .
T his program p rin te d o u t th e d a te th e re a d in g w a s
ta k e n , th e .h e ig h t of c o v e r on th a t d a te , th e m e te r
id e n tif ic a tio n n u m b er,
th e te m p e ra tu re a t th e tim e o f r e a d in g , a n d th e e a rth p r e s s u r e .
puter. program i s g iv e n in A ppendix B .
The c o m - ■
S ta n d a r d C o n d itio n s ,
S t r e s s M ete-r Wo. I :
RRp, C o r r e c te d
104.7
104.61
104.2
Rt = 74.4 Ohms RRp= 104.18 Olnms
v> 77
Enher Rx and Find RR Correchion
J
C orrect'on = + 0 .0 2 and Temp= GOa F
O
C o r r e c t e d RRp = 104.18 + 0.02 = 104.20 Ohms 1 - ^ a
Enher Corrected RRp and Find P ressu re c 74
Z 6 .5 P5I
E a rth P r e s s u r e
-o 73
T
x
/
S 7233 Zero
Ck
Corrector}/
-6 5 -
R e s is ta n c e R e a d in g s ~ O hm s
Resistance ReadinQ at Zero Pressure and 42°F. , RR6 104.61 Ohms
Resistance Reading Correction = 0.606P51 /0.01 Ohm
Reading at Zero Temperature , R0 = G7.07 Ohms
Temperature ah Zero Correction = 4 2 .0 ° F
Temperahure Factor = 7 . 89 ° / Ohm For Qj
Example :
Tl
/
3
y|
104.0
69
I
oT
68
67
Z
0
6
CM
Xj-
10 20 30 40 50 GO 70 80 90
Temperature D egrees Fahr.
-0.04 _ -0.02
0
+0.02
+005
Resishance Reading Correction
103.2
80
ZO 25.5 30
Earhh P ressu re on S t r e s s Meter Wo. I ~ Fbunds per Square Inch
F ig u re 3 6 .
D e te r m in in g T e m p e r a tu r e a n d Earth P r e s s u r e From S t r e s s M e t e r R e a d in g s
CHAPTER VIII
RESULTS AND ANALYSIS OF DATA
D a ta w a s c o m p ile d from th e v a r io u s 's e ts o f in s tru m e n ta tio n d u rin g e a c h
p h a s e of c o n s tr u c tio n a n d a n a ly z e d to d e te rm in e th e b e h a v io r o f th e c u l v e r t .
S tra in G a g e s
S tra in g a g e m e a s u re m e n ts w e re ta k e n b e fo re an d im m e d ia te ly a fte r
th e c u lv e r t w a s e r e c te d in o rd e r to d e te rm in e th e c ir c u m fe re n tia l e re c tio n
s t r e s s e s a t th e s tr a in g a g e s i t e s .
The e x tre m e fib e r e r e c tio n s t r e s s e s
ra n g e d from 3 ,8 0 0 p s i in p la te C to 2 1 ,9 0 0 p s i in p la te A.
P la te s B, D ,
a n d E m ig h t b e c o n s id e r e d t y p i c a l , w ith e r e c tio n s t r e s s e s b e tw e e n 9 ,0 0 0
a n d 1 0 ,0 0 0 p s i in th e e x tre m e f i b e r s .
P la te A w a s o n e o f th e l a s t p la te s
to b e in s t a l l e d a n d h a d to be fo rc e d v ig o ro u s ly in to p la c e w h ic h m ay a c ­
c o u n t for i t s h ig h s t r e s s o f 2 1 ,9 0 0 p s i .
w h e n the e r e c tio n
All o f th e g a g e s w e re o p e ra tio n a l
s t r e s s e s 'w e r e d e te rm in e d e x c e p t fo r g a g e D22 w h ich
w a s d e s tr o y e d by a b u lld o z e r d u rin g b a c k f illin g o p e ra tio n s an d g a g e C 22
w h ic h g a v e e r r a tic r e a d in g s a n d m ay h a v e b e e n d a m ag e d a l s o .
The e r e c tio n s t r e s s e s a re sh o w n g r a p h ic a lly in F ig u re 37 „ The e x ­
c e l l e n t lin e a r ity of th e s t r e s s d ia g ra m s , from th e e x tre m e o u ts id e fib e rs
'
t o th e e x tre m e in s id e fib e rs o f e a c h p l a t e , sh o w s th a t th e g a g e s p e r­
form ed in a h ig h ly c o n s i s t e n t f a s h io n .
T h is c o n s is te n c y i s an in d ic a tio n
o f r e lia b le r e s u l t s . A ls o , th e v ery low s t r e s s e s m idw ay b e tw e e n th e
—6 7 -
G a g e s 22.
2
+ 2 0 ,0 0 0 P5I
4-10,000 PSI
O PSl
-10,000 PSI
-20,000 PSl
Plate D
Plate A
+10,000 PSI
O PSI
-10,000 PSI
P l a t e £>
P late E
+ 10,000 PSl
-1 0 ,0 0 0 PSI
P late F
P late C
22
3
2
F ig u r e 3 7 .
G aqes
22
2
E r e c tio n S t r e s s in t h e S ix I n s t r u m e n t e d P l a t e s
-
68
-
e x tre m e fib e rs sh o w th a t th e e r e c tio n s t r e s s e s w e re la rg e ly th e r e s u lt of
b e n d in g ,of th e p la te s d u rin g e re c tio n , w h ic h i s n o t s u r p r is in g .
Some b e n d ­
in g i s o fte n re q u ire d to i n s e r t th e b o l t s , a n d a d d itio n a l b e n d in g ta k e s
p la c e w h e n th e n u ts a re tig h te n e d „ The s m a ll am ount o f a x ia l e re c tio n
s t r e s s , P /A , th a t is a p p a r e n t in F ig u re 3 7 , i s n o t s u rp ris in g e ith e r .
It
d o u ld e a s i l y r e s u l t from th e p u s h in g of p u llin g re q u ire d to m ake, some,-
I
p la te s f i t .
T a b le ,2 s u m m a riz e s th e e re c tio n s t r e s s e s , w h ic h w e re s e g r e g a te d
in to a x ia l a n d b e n d in g c o m p o n e n ts a s p r e v io u s ly d e s c r ib e d , a n d a ls o
s h o w s th e b e n d in g m o m en ts re q u ire d to p ro d u c e th e o b s e rv e d e r e c tio n
s tre s s p a tte rn s .
TABLE 2 . STRESSES CAUSED BY ERECTION
A
B
C
D1
E
F
2 1 ,9 0 0
9 ,6 0 0
3 ,8 0 0
9 ,6 0 0
9 ,2 0 0
7 ,8 0 0
M C /I S tre s s
psi
psi
- 800
- 1,.O'0Q
- 400
_ - ■ 4
- 400' '
- 1,100 '
21,100
8 ,6 0 0
3 ,4 0 0
9 ,6 0 0
8 ,8 0 0
6 ,7 0 0
*■" C o m p re s s io n T e n s io n '
+
** O u tsid e - fib e rs ( a d ja c e n t to b a c k f ill) in c o m p re s s io n O u ts id e fib e rs (a d ja c e n t to b a c k fill) in. te n s io n +
B en d in g M om ent
to c a u s e M C /I* *
In -lb /in
- 4 ,2 0 0
O
psi
■P/A S tr e s s *
o .
C o m b in ed S tr e s s
I
I—1
P la te
.
+ 700
- 1 ,9 0 0
- 1 ,7 0 0
+ 1 ,3 0 0
-6 9 -
S tra in g a g e m e a s u re m e n ts w e re ta k e n a t in te r v a ls a s th e b a c k f ill w a s
p la c e d to a. le v e l 5 f e e t a b o v e th e c u lv e r t a n d a s th e ro c k f ill w a s p la c e d
to a d e p th o f 83 f e e t a b o v e th e c u lv e r t.
S tr e s s e s c a u s e d b y th e s e o p e r a -
)
tio n s a re sh o w n in F ig u re .38 a n d 3 9 , a n d p e rtin e n t r e s u l t s a re su m m a riz ed
1 '
.
.
in T a b le s 3 , 4, 5 , an d 6 . W h ile th e b a c k f ill w a s b e in g p la c e d a n d com ­
p a c te d on e a c h s id e of th e c u lv e r t, la rg e c h a n g e s in .b en d in g s t r e s s
o c c u rre d b u t th e re w a s .l i t t l e in c r e a s e in v e r tic a l a i i a l c o m p re s s io n s t r e s s
a s w o u ld -b e e x p e c te d . . The c o m b in e d s t r e s s a t th e e x tre m e fib e rs of
p la te A re a c h e d th e y ie ld s t r e s s o f a p p ro x im a te ly 3 0 ,0 0 0 p s i b e fo re ,th e
d e p th o f c o v e r re a c h e d 5 f e e t .
The p la c e m e n t an d c o m p a c tio n of th e b a c k f ill o n .th e s id e s of th e
c u lv e r t c a u s e d a 'r e d u c tio n o f a p p ro x im a te ly 2 in c h e s in th e .h o riz o n ta l
d ia m e te r an d a c o rre s p o n d in g in c r e a s e in .th e v e r tic a l d ia m e te r , an d
p ro d u c e d a c o m p re s s iv e b e n d in g s t r e s s in th e o u ts id e ,f ib e r s an d te n s i le
b e n d in g s t r e s s in th e in s id e fib e rs o f th e s id e w a lls , a t th e s tr a in g a g e
s ite s .
(All g a g e s num ber "22" w e re on th e e x tre m e o u ts id e fib e rs and
a l l g a g e s n u m b ered "3" w e re on th e e x tre m e in s id e fib e rs d i-th e s id e w a lls )
—7 0 —
22
2
Gages 22
2
+ 30,000 P5I ---- - 20,000 P5I
-10,000 P5I
-20,000 PSl
Plate A
-30,000 PSl
Plate D
+ 10,000 PSI
-20,000 PSI
P late
P la t e £>
E.
+10,000 PSI
0 PSI
-10,000 PSI
P la te C
A
□
F ig u r e 3 8 .
0—
5 F e e t oP Cover
8 3 F e e t oF C over
PI at e F
1 2 -2 -GB
1 -4 -6 6
S t r e s s e s C a u s e d b y E r e c tio n a n d Earth P r e s s u r e
-7111
I
I£ H
33
3
G ages
22
2
14 Il
33
3
33
3
+ 10,000 PSI
0 PSI
-10,000 PSI
-20,000 PSI
Plate
Plate &
D
-MO1OOO PSI
0 PSI
-10,000 PSI
P la te E
Plate B
+ 10,000 PSl
O PSI
-10,000 PSI
-20,000 PSl
P lafe
Plate C
22
2
I 4 Il
33
A
3
G a g es
22
5 F e e i- oP C o v e r
n 8 3 F ee+ oP C over
F ig u re 3 9 .
2
14 Il
1 2 -2 -6 5
I-4 -< 5 6
S t r e s s e s C a u s e d b y E arth P r e s s u r e
F
-7 2 TABLE 3 .
P la te
A
STRESSES CAUSED BY ERECTION AND FIVE FEET OF COVER - 12/2/65 '
C o m b in ed S tr e s s
psi
P/A S tr e s s *
psi
3 0 ,0 0 0 * * *
M C /I S tr e s s
psi
B ending M om ent
to C a u s e M C /!* *
In -lb /in
- 2 ,5 0 0
27,5.00
-5,800
B
■1 7 ,0 0 0
-2,200
14,800
-2,900
C
5,500
-2,000
3 ,5 0 0
-.700
D
1 8 ,3 0 0
-1,500
16,800
- 3 ,3 0 0
E
1 8 ,4 0 0
-2,200
CD
r-= f
O
O
(N I
-3,200
F
3 ,6 0 0
-1,800
1, 800
-4 0 0
TABLE 4 .
P la te
STESSES .CAUSED BY FIVE FEET OF COVER - 1 2 /2 /6 5
C om bined
S tr e s s
psi
P/A
S tr e s s *
psi ■
M C /I
S tr e s s
psi
E arth P re s su re
to C a u s e P/A
psi
B ending M om ent
to C a u s e M C/1**'
i n - l b / in
A
8,100
- 1 ,7 0 0
6 ,4 0 0
7
- 1 ,7 0 0
B
7 ,4 0 0
-1,200
6,200
6
- 1,200
C
" 8 ,5 0 0
- 1 ,6 0 0
6,900
7
- 1 ,4 0 0
D
8 ,7 0 0
-1 ,5 0 0 '
7,200
7
- 1 ,4 0 0
E
9 ,2 0 0
- 1 ,8 0 0
7 ,4 0 0
8
- 1 ,5 0 0
F
9 ,1 0 0
-7 0 0
8 ,4 0 0
3
-1,700
* ** S ee F o o tn o te s on p a g e 68
*** Y ield s t r e s s
TABLE 5 .
STRESSES CAUSED BY ERECTION AND 83 FEET OF COVER 1/ 4 /6 6
M C / I S tr e s s
psi
B ending M om ent
to C a u s e M C /I* *
in -lb /in
C o m bined S tr e s s
psi
A
30,000***
-9,800
****
****
B
26,800
-7,000
19,800
-3,900
C
11,300
-7,300 •
4,000
-800
D
30,000***
-7,200
22,800
-4,700
E
28,000
- 11,000
17,000
-3,300
F
1 2 ,9 0 0
-7,600
5, 300
-1,000
.
P/A S tr e s s
psi
*
P la te '
TABLE 6 .
STRESSES CAUSED BY 83 FEET OF COVER - 1 / 4 /6 6
P la te
C o m b in ed
S tr e s s
psi
P/A
M C /I
S tre s s * S tr e s s
psi
psi
E arth P re s s u re
to C a u s e P/A
psi
B ending M om ent
to C a u s e M C /l* *
in -lb /in *
****
39
****
17,100
-6,000
11,100
26
-2,200
C
14,300
-6,900
7, 400
' ‘ 30
D
2 1 ,5 0 0
-7,200
14, 3,00
31
-2,800
E
18,800
-10,500
8,300
45
-1,600
F
18,400
-6,500
11,900 ■•
28
-2,400
B
■'
* S ee F o o tn o te s on p a g e 68 an d 7 2 .
**** N ot d e te rm in e d b e c a u s e of e x te n t o f y ie ld in g
C n
O
O
-9,000
I
H -*
* * **
A
-7 4 -
For p la te s .A , B, D , a n d E, t h e s e b e n d in g s t r e s s e s w e re d ir e c tly a d d itiv e
to e r e c tio n s t r e s s e s a n d th e re fo re p ro d u c e d r e l a t i v e l y la rg e c o m p re s s iv e
s t r e s s e s in th e o u ts id e f i b e r s .
For p la te s C an d F, h o w e v e r, th e s e
s t r e s s e s w e re o f o p p o s ite s ig n to th e e r e c tio n s t r e s s e s an d th e re fo re h ad
a c a n c e llin g e f f e c t w h ic h e x p la in s .th e f la t s lo p e s an d low s t r e s s e s o f th e
s t r e s s d ia g ra m s .fo r p la te s C an d F in F ig u re. 3 8 .
The ro c k f ill w a s p la c e d in a o n e an d o n e - h a lf m onth p e rio d b e tw e e n
th e m id d le o f N ov em b er of 1965 an d th e f i r s t of Ja n u a ry , 1 9 6 6 .
The s t r e s s e s
on J a n u a ry 4 , 1 9 6 6 , j u s t a few d a y s a f te r c o m p le tio n of th e f i l l , a re
sh o w n in F ig u re s 38 an d 39 a n d T a b le s 5 an d 6 .
D uring c o n s tr u c tio n of th e
ro c k f i l l , th e c o m b in e d s t r e s s in p la te D r e a c h e d th e y ie ld p o in t in th e
e x tre m e o u ts id e f ib e r s .
T his i s e v id e n t in F ig u re 38 w h ic h a l s o sh o w s
th a t i n e l a s t i c a c tio n o c c u rre d in p la te s A an d D o n ly , of th e in s tru m e n te d
p l a t e s , an d w a s lim ite d to r a th e r s m a ll z o n e s in e a c h of th o s e tw o p l a t e s .
The s m a ll e x te n t to w h ic h i n e l a s t i c a c tio n w a s p r e s e n t w a s n o t c o n s id e re d
s u ffic ie n t, to s e r io u s ly in v a lid a te th e s u p e r p o s itio n te c h n iq u e th a t w a s
u s e d to o b tain , th e s t r e s s e s c a u s e d b y ;th e e m b an k m en t lo a d o n ly , in F ig u re
.39 an d T a b le s 4 a n d 6 .
By th is te c h n iq u e , e r e c tio n s t r e s s e s w e re s u b ­
tr a c te d from to ta l s t r e s s e s to g e t th e s t r e s s e s a ttr ib u ta b le to th e em b an k ­
m en t lo a d .
TO p u t i t so m e w h a t d if f e r e n tly ,' t h e s e s t r e s s e s a re th o s e th a t
-7 5 -
w o u ld h a v e b e e n c o m p u te d if th e SR-4 g a g e s h a d b e e n c e m e n te d to th e
w a lls a f te r th e c u lv e r t w a s e r e c t e d » or if r e a d in g s h a d n o t b e e n ta k e n
u n til a f te r th e c u lv e r t w a s e r e c t e d „
The c o n s i s t e n t s lo p e p a tte rn of th e s t r e s s d ia g ra m s in F ig u re s 38
a n d 39 sh o w th a t th e r e w a s l i t t l e b a s i c c h a n g e in th e b e n d in g s t r e s s
p a tte r n s a t th e s tr a in g a g e s i t e s a s th e h e ig h t of c o v e r w a s in c r e a s e d
from 5 f e e t to 83 f e e t .
In e v e ry c a s e th e b e n d in g s t r e s s .'rem ain ed
c o m p re s s io n in th e o u ts id e f i b e r s . -U n d o u b te d ly th e s id e w a lls w o u ld
e v e n tu a lly h a v e b u lg e d o u tw a rd s u f f ic ie n tly to r e v e r s e th e e a r ly b e n d ­
in g p a tte r n if th e a d ja c e n t b a c k f ill h a d b e e n p o o rly -c o m p a c te d „ As i t
tu rn e d o u t, th e s id e w a lls n e v e r re g a in e d th e o rig in a l p o s itio n th a t
th e y h a d b e fo re th e p la c e m e n t a n d c o m p a c tio n .o f th e b a c k f ill m a te r ia l.
. F ig u re 40 i n d ic a te s th e s t r e s s e s c a u s e d b y th e a d d itio n a l 78 f e e t
o f c o v e r o v e r th e 5 f e e t in d ic a te d in F ig u re 3 9 . . The a lm o s t le v e l lin e s
fo r p la te s A, C , a n d E d e m o n stra te : th a t th e a d d itio n a l e a rth lo a d
c a u s e d c o m p re s s iv e s t r e s s e s p rim a rily . .In p la te s B D , a n d F th e
b e n d in g s t r e s s e s w e re s ig n if ic a n t.
T a b le .7 c o n ta in s th e ta b u la tio n
o f t h e s e s t r e s s e s a lo n g w ith th e a d d itio n a l e a rth p r e s s u r e s a n d b en d in g
m o m en ts c a u s e d by th is a d d itio n a l cover.
—7 6—
Zl
Z
33
3
Gaqes
ZZ
2
33
3
33
3
--------- +10,000 P 5 I --------0 P5I
-10,000 P5I
'2 0 ,0 0 0 P5I
P late
A
+ 10,000 P5I
O P5I
-1 0 ,0 0 0 P5I
P la t e
B
P la t e £
+10,000 P3l
-10,000 P51
Plate F
Plare C
22
2
Hill
F ig u re 4 0 .
33
3
G ages
ZZ
Z
1*11
S t r e s s e s C a u s e d b y t h e A d d itio n a l 78 F e e t o f C o v e r
—7 7 —
TABLE .7 0 STRESSES CAUSED BY THE ADDITIONAL '78 FEET OF COVER 1/ 4 /6 6
P la te
C o m bined
S tr e s s
psi
P/A
S tr e s s
psi
M C /I ■
S tre s s
psi
A
****
- 8 ,7 0 0
****
38
****
B
9)800
- 4 ,7 0 0
5 ,1 0 0
20
-1,000
C
5 ,8 0 0
- 5 ,3 0 0
500'
23
-IBO
1 2 ,8 0 0
- 5 ,7 0 0
7 ,1 0 0
25
-1,400
E
9,600
- 8 ,8 0 0
1,000
38
- 20'Q
F
9,300
- 5 ,8 0 0
3 ,5 0 0
25
-7 0 0
D■
E arth P re s s u re
to C a u s e P/A
psi
B ending M om ent
to C a u s e MQT**'
in I b /in
** S ee fo o tn o te s on p a g e s .6'8 , 7 2 'a n d .73
The r e s u l t s p r e s e n te d a re o n ly s a m p le s o f th e la rg e q u a n tity d e te rm in e d
from th e SR-4 s tr a in g a g e in s t a l l a t i o n s ..
The o u tp u t from th e s tr a in g a g e
c o m p u te r p ro g ram s p ro v id e d s t r e s s , e a rth p r e s s u r e , an d b e n d in g m om ent
d a ta for e a c h of th e a p p ro x im a te ly 46 d a te s on w h ich a s e t of s tr a in g a g e
■readings w e re ta k e n .
S a m p le s of th e c o m p u te r o u tp u t a re g i v e n i n Appendix-A
an d th e c o m p le te o u tp u t, a lo n g w ith a ll o rig in a l d a ta , is on f il e in th e
D e p a rtm e n t o f C iv il E n g in e e rin g an d E n g in e e rin g M e c h a n ic s a t M o n tan a
S ta te U n iv e r s ity .
The d a ta of Jan u a ry 4 , 1 9 6 6 ,. w a s s e le c te d for p r e s e n ta ­
tio n b e c a u s e th e lo a d s on th e c u lv e r t w e re n e a r th e ir p e a k v a lu e s an d m o st
of th e SR-4 g a g e s w e re s t i l l fu n c tio n in g p ro p e rly a t th a t tim e . ■
. - 78-
The r e s u l t s from som e o f the- s tr a in g a g e s , a fte r Ja n u a ry o f 1966,
b e g a n to d e v ia te s ig n if ic a n tly from th e lin e a r p a tte rn e s ta b lis h e d e a r l i e r .
At f i r s t i t w a s th e o riz e d th a t th is m ig h t b e d u e to lo c a l i z e d b e n d in g ,
lo n g itu d in a l s t r e s s e s , or g e n e ra l s tr a in g a g e d e te r io r a tio n .
It e v e n tu a lly
b e c a m e a p p a r e n t h o w e v e r , th a t t h e .f i r s t lo t o f g a g e s , w ith a g a g e fa c to ro f 2 .1 3 , w e re c o n tin u in g to b e h a v e in a h ig h ly c o n s is te n t a n d lin e a r
f a s h io n w h ile th e g a g e s from th e s e c o n d l o t , w ith a g a g e fa c to r of 2 . 0 8 /
s te a d ily b e c a m e m ore e r r a tic an d i n c o n s i s t e n t .
The s u p e rio r b e h a v io r
o f th e f i r s t lo t of g a g e s w a s re c o g n iz e d b e c a u s e p la te s A a n d B c o n tin u e d
to e x h ib it h ig h ly c o n s i s t e n t s tr a in p a tte r n s , m uch b e tte r th a n th e o th e r
fo u r p l a t e s .
P la te s A a n d B w e re u n iq u e in th a t a ll of th e g a g e s on
P la te A, a n d a ll b u t o n e o f th e g a g e s on P la te B , c am e from th e f ir s t lo t
of g a g e s p ro c u re d for th e p r o je c t.
E ach o f th e o th e r four p la te s h a d
th r e e g a g e s from th e f i r s t lo t on th e in s id e w a ll (g a g e s 1 , 2 , a n d 3) an d
th r e e g a g e s from th e s e c o n d lo t on th e o u ts id e w a ll (g a g e s 1 1 , 2 2 , and
3 3 ).' E x a m in a tio n of th e s tr a in d a ta r e v e a le d t h a t , in g e n e r a l, th e g a g e s
from th e f i r s t lo t w d re g iv in g .c o n s is te n t re a d in g s w h ile th o s e from th e
s e c o n d lo t w e re fa r m ore v a r ia b le .
S ix m o n th s a fte r i n s t a l l a t i o n m o st of
th e s e c o n d lo t of g a g e s w e re c o m p le te ly u n r e lia b le .
M o s t of th e f ir s t
lo t a re s t i l l g iv in g c o n s i s t e n t s tr a in r e a d in g s a fte r m ore th a n 18 m onths
o f o p e r a tio n .
T his m ay b e s e e n from F ig u re 41 w h ic h s h o w s s t r e s s p a tte rn s
-7 9 -
22
2
33
3 G ages 22
2
---------1+30,000 P51 — -—
33
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+ 10,000 P51
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A &3 F e e f oF Cover
□ 8 3 F e e t oF Cover
F ig u r e 4 1 .
3-29-67
C o m b in e d S t r e s s e s o n 3 / 2 5 / 6 6 a n d 3 / 2 9 / 6 7
3
-8 0 d e d u c e d from th e f i r s t lo t of g a g e s on w id e ly s e p a r a te d d a te s „
T here h a s b e e n no s a ti s f a c to r y e x p la n a tio n fo r th e c o n s is te n tly ,
s u p e rio r b e h a v io r o f th e firs t, lo t o f g a g e s „ I t .is tru e th a t th e s e c o n d lo t
o f g a g e s a re a l l on th e o u ts id e w a lls in c o n ta c t w ith th e f il l (but p ro ­
te c t e d by a n g le iro n h o u s e s ) w h ic h m ay b e r e la te d to th e ir p o o r perfo rm ­
a n c e . .I t i s c o n s id e r e d h ig h ly s ig n if ic a n t, h o w e v e r, th a t g a g e s from th e
f i r s t l o t , in s im ila r e x te r n a l p o s itio n s on p la te s A an d B , d id n o t d e te r ­
io r a te s im ila r ly .
A fter th e c o m p u te r program w a s. d e v e lo p e d to re d u c e th e s tr a in g a g e
d a t a , a c o m p le te a n a ly s is w a s m ad e u s in g o n ly th e s tr a in d a ta from f ir s t
lo t g a g e s , 1 , 2 , a n d 3 , on e a c h p l a t e .
The r e s u l t s fo r th e e a r lie r d a te s
w e re e s s e n t i a l l y th e sa m e a s w h en a ll o f th e g a g e s w e re u s e d .
For th e
d a te s fo llo w in g c o m p le tio n of th e e m b an k m en t i t w a s a p p a r e n t th a t th e
v
s e c o n d lo t o f g a g e s sh o u ld b e e x c lu d e d from th e a n a l y s i s . ■A d e c is io n w a s
m ad e to u t i l i z e th e re a d in g s o b ta in e d from th e l , r 2 , an d 3 n u m b ered g a g e s
a s th e prim ary s tr a in g a g e re a d in g s fb r c a lc u la tin g e a rth p r e s s u r e and
b e n d in g m o m e n ts .
The e q u iv a le n t v e r tic a l e a rth p r e s s u r e s on th e c u l v e r t , c a lc u la te d
from th e s tr a in g a g e r e a d in g s , a re sh o w n g ra p h ic a lly in F ig u re 42 w h ich
i n d i c a t e s , in g e n e r a l , th a t th e e a rth p r e s s u r e re a c h e d a -m axim um in
Jan u a ry or e a r ly F e b ru a ry , 1 9 6 6 .
The p r e s s u r e s d e c r e a s e d d u rin g th e
IOO
90
80
70
GO
50
i
co
i—
*
I
40
30
20
K)
O
1966 196-7
F ig u r e 4 2 .
E q u i v a l e n t U niform V e r tic a l Earth P r e s s u r e s on
C u l v e r t , D e d u c e d From SR-4 S tr a in G a g e s
-8 2
w in te r an d s p rin g a n d e v e n tu a lly s ta b i liz e d a t a v a lu e n e a r 30 p s i „ There
is a n in d ic a tio n of a s lig h t up w ard tre n d in p r e s s u r e s ta r tin g in S ep tem b er
of 1 9 6 6 .
The m axim um e a rth p r e s s u r e s ra n g e d from 28 to 47 p s i w h ich is
m uch l e s s th a n th e e s tim a te d n o m in a l o v e rb u rd e n p r e s s u r e of 72 p s i , or
10 ksf. (k ip s p e r s q u a re f o o t) , w h ic h o n e m ig h t e x p e c t from 83 f e e t of c o v e r
w e ig h in g a p p ro x im a te ly 125 p c f .
P la te F sh o u ld b e c o n s id e r e d s e p a r a te ly from th e o th e r 5 in s tr u ­
m e n te d p l a t e s .
F ig u re 42 sh o w s th a t p la te F in d ic a te s a s u b s ta n tia lly
s m a lle r e a rth p r e s s u r e th a n th e re m a in in g 5 p la te s an d th is is e n tire ly
c o n s is te n t w ith e x p e c ta tio n s b e c a u s e p la te F i s u n d e r th e s lo p in g s id e of
th e em b an k m en t a t a p la c e w h e re th e v e r tic a l d e p th of c o v e r is o n ly 45
f e e t (as s c a le d from F ig u re 22) a s co m p ared to th e 83 f e e t d e p th o v er th e
c e n tr a l p a rt of th e c u lv e r t w h e re p la te s A, B , an d E a re lo c a t e d .
P la te s C
an d D m ay b e g ro u p e d w ith A, B, an d E b e c a u s e th e y a re u n d e r a lm o s t th e
fu ll d e p th o f c o v e r n e a r th e in te r s e c tio n of th e top- of.' th e em b an k m en t
a n d th e s id e s lo p e .
S tr e s s M e te rs
The e a rth p r e s s u r e s on th e c u lv e r t w a lls a s d e te rm in e d d ir e c tly from
t
th e C a r ls o n s o il s t r e s s m e te rs a s th e f ill w a s c o n s tr u c te d , a n d th e r e a f te r ,
a re skow n. g r a p h ic a lly a s e a rth p r e s s u r e v e r s u s tim e in F ig u re s 43 th ro u g h
48.
The s t r e s s m e te rs a re g ro u p e d b y th e ir r e la tiv e lo c a tio n s a s m e a su re d
im f e e t )
/7 ^
EARTH PRESSURE, p , IU PSl
( f il l UEiGUT
^ 5 5 7 ^ 7 . t^ W / ^'///aV ///^ W^57!
APR. WAY JUNE JULY
F ig u re 4 3 .
m IJune ijily
E arth P r e s s u r e v s . Tim e - S t r e s s M e t e r s N o . I , 6 , 7 , 1 1 , 2 3 a n d 24
HEiGUT
( f il l
EARTH PRESSURE, p , \Vl PSl
[JuneIjuly
F ig u re 4 4 .
my
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Earth P r e s s u r e v s . Time - S t r e s s M e t e r s N o . 19 a n d 22
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I;
196,5 1966
F ig u re 4 5 .
1966 1967
Earth P r e s s u r e v s . Time - S t r e s s M e t e r s N o . 3 , 4 , 14, 15, 18 a n d 2 0 .
1967
-8 5 -
50
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ZZ
60
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0
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—
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70
60
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HEIGHT in
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60
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GO
E&RTH PRESSURE, p, IN PSl
50
40
30
20
IO
may Ijune Ijuly IAUd IseptI Oct.
F ig u r e 4 6 .
E arth P r e s s u r e v s . Time - S t r e s s M e t e r s n o . 2 , 5 , 1 3 , 1 6 , 17
and 21.
O
IOO
90
80
TO
60
50
■
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I
40
30
20
IO
O
Figure 47.
Earth P r e s s u r e v s . Time - S t r e s s M e t e r s n o . 8 , 10, a n d 12
(FILL WEIGHT IN FEET)
VERTICAL EARTH PRESSURE IN PSl
MAR. APR. MAY JllHL
Figure 48.
Earth P r e s s u r e v s . Time - S t r e s s M e t e r s n o . 2 5 , 2 6 , 2 7 , 2 8 , 2 9 a n d 30
-89-
in d e g re e s from th e to p c e n te r lin e o f th e c u lv e r t.
For e x a m p le , m e te rs I ,
6 , . 7 , 1 1, 2 3 ,. an d 24 in F ig u re 43 a re lo c a te d on th e to p c e n te r lin e w h ile
m e te rs 2 , 5 , 1 3, 1 6 , 1 7 , an d 21 in F ig u re 46 a re lo c a te d on th e, c u lv e rt
s id e s 66 1 /2 or 71 1 /2 d e g re e s from th e .to p c e n te r l i n e .
The f il l h e ig h t
sh o w n in t h e s e fig u re s i s th e - h e ig h t of f ill a b o v e th e c u lv e r t, or th e
d e p th o f c o v e r .
The m a jo rity of th e m e te rs in d ic a te d a m axim um p r e s s u r e w h e n th e
fu ll f ill h e ig h t w a s re a c h e d or s h o rtly t h e r e a f t e r . As a g e n e r a l tr e n d ,
t h e s e p r e s s u r e s a ls o d e c r e a s e d , a s th e e a rth p r e s s u r e s d e te rm in e d from
th e s tr a in g a g e s d id , u n til th e f a ll of 1 9 6 6 .
A few of th e m e te rs d id sh o w
a n in c r e a s e th ro u g h o u t th e p e rio d c o v e re d by th is r e p o r t. I t m ay b e s e e n in
/
F ig u re 43 th a t a ll of th e m e te rs lo c a te d a t th e to p o f th e c u lv e r t sh o w ed
a s m a ll in c r e a s e e x c e p t for m e te r 24 w h ic h d ro p p e d to z e ro an d s ta r te d to
in d ic a te te n s io n in A u gust of 19 6 6 . I t w a s c o n c lu d e d th a t m e te r 24 w a s
\
d e f e c tiv e , or h a d b e e n d a m a g e d b y c o n s tr u c tio n e q u ip m e n t, a n d sh o u ld b e
ig n o re d w h e n s tu d y in g F ig u re 4 3 .
F ig u re 43 sh o u ld a ls o b e s tu d ie d in
c o n ju n c tio n w ith .F ig u re 29 w h ic h sh o w s th e ,m p p ro x im a te d e p th of c o v er
a b o v e e a c h m e te r. . For i n s t a n c e , m e te r N o . I i s u n d e r th e em b an k m en t
s lo p e an d h a s a v e r tic a l d e p th o f c o v e r of a p p ro x im a te ly 45 fe e t; w h ile
m e te r 6 h a s a p p ro x im a te ly 63 f e e t o f v e r tic a l c o v e r .
The e f f e c t of th e
v a ry in g d e p th of c o v e r i s n o t p a r tic u la r ly a p p a re n t in F ig u re 43 w h ich
-90-
sh o w s re m a rk a b ly c l o s e a g re e m e n t am ong m e te rs 1 , 6 , - 1 1 ,. a n d .2 3 ,
The so m e w h a t h ig h e r p r e s s u r e r e g is te r e d by m e te r 7 i s p ro b a b ly in d ic a ­
tiv e of th e r a th e r la r g e lo c a l p r e s s u r e v a ria tio n th a t c o u ld b e e x p e c te d
from p o in t to p o in t on th e to p o f a la rg e c u lv e r t. C o n s id e rin g th e sm all
s i z e o f th e p r e s s u r e m e a s u rin g a re a of a s t r e s s m e te r, th e tig h t g ro u p in g
o f m e te rs I , 6 , 11 an d 23 i s r a th e r m ore s u rp ris in g th a n th e m o d e ra te
d e v ia tio n of m e te r 7.
' The a g re e m e n t b e tw e e n F ig u re s 42 an d 4 3 , o b ta in e d w ith to ta lly
in d e p e n d e n t s e t s of d is t i n c t l y d iff e r e n t in s tr u m e n ta tio n , is g r a tif y in g .
It s h o u ld b e k e p t in m in d , h o w e v e r, th a t F ig u re 42 g iv e s a n a v e r a g e
v e r tic a l p r e s s u r e o v e r th e w id th of th e c u lv e r t w h ile F ig u re 43 g iv e s
o n ly th e v e r tic a l p r e s s u r e a t th e to p c e n te r lin e of th e c u lv e r t.
F ig u re s 4 4 , 4 5 , 4 6 , a n d 47 g iv e th e e a rth p r e s s u r e on th e s id e s of
th e c u lv e r t a s m e a s u re d w ith th e s t r e s s . m e t e r s .
The g e n e r a l tre n d i s th e
sam e a s th a t of F ig u re 4 2 , a d e c r e a s e in p r e s s u r e th ro u g h th e s p rin g an d
sum m er of 1 9 6 6 ,. fo llo w e d by a le v e lin g ^ o ff or a s lig h t i n c r e a s e in
p r e s s u r e s ta r tin g in th e au tu m n o f 1 9 6 6 .
W h en th e p r e s s u r e s w e re l a r g e s t , s h o rtly a f te r c o n s tr u c tio n o f th e
e m b a n k m e n t, th e p r e s s u r e s on th e. s id e s of th e c u lv e r t, in so m e p la c e s a t
l e a s t , w e re c o n s id e r a b ly la rg e r th a n th e, p r e s s u r e s on to p .
T h is is
e v id e n t in F ig u re 49 w h ic h sh o w s th e s t r e s s p a tte rn fu rn is h e d by th e
-91-
Maximum
Pressure
3 5 P5I P r e s s u r e
- P r e s s u r e in Pounds
Per S q u a r e Inch — ■
-
Minimum P r e ssu r e -
✓ 19.0
72.2
A 19.6
G age Mumbers
and Location
L o o k in g D o w n s t r e a m
P r e s s u r e S cale'. I* = GO P2>1
F ig u re 4 9 .
Earth P r e s s u r e s A cting on th e C u lv e rt W a lls on 1 /4 /6 6
-92s t r e s s m e t e r s o n t h e c u l v e r t w a l l s ' u n d e r t h e c e n t r a l p a r t of t h e e m b a n k m e n t
o n J a n u a r y 4 , 1966 „
From F ig u re s 43 th ro u g h 48 i t is a p p a r e n t th a t s e v e r a l o f th e m e te r s ,
n o ta b ly 3 , 4 , 18 an d 2 9 , w e re o p e ra tin g d e f e c tiv e ly in th e sa m e fa s h io n a s
m e te r 2 4 .
M e te rs on th e s id e s o f th e c u lv e r t w e re e s p e c ia ll y s u s c e p tib le
to s id e s w ip in g by c o n s tr u c tio n e q u ip m e n t in th e e a rly s ta g e s of b a c k f illin g .
A c tu a lly , a d a m ag e d m e te r th a t i s le a k in g w o u ld b e e x p e c te d to sh o w a
s te a d ily d e c r e a s in g p r e s s u r e lik e m o st of th e m e te rs of F ig u re s 45 and 4 6 .
Such a m e te r m ig h t a ls o be e x p e c te d to r e g is te r a n a b n o rm a lly low p re s s u re
r ig h t from th e s t a r t .
M e te r 1 7 , for e x a m p le , is know n to h a v e b e e n s c r a p e d
b y a tru c k tire (s e e F ig u re 26); an d th e low p r e s s u r e s re p o rte d b y th a t m e te r,
a n d sh o w n in F ig u re 4 6 , c o u ld b e e r r o n e o u s . I t is s u s p e c te d th a t m an y , if
n o t a l l , of th e m e te rs r e g is te r in g v ery low p r e s s u r e s a re d a m a g e d .
It is c o n ­
c lu d e d , h o w e v e r,, th a t m e te rs su c h a s 8 , 1 0 , an d 12 (s e e F ig u re 47) a re n o t
le a k in g b e c a u s e th e y sh o w a p r e s s u r e in c r e a s e s ta r tin g in th e autum n of
1966.
L a te ra l p r e s s u r e a g a in s t th e stem of a s t r e s s m e te r c o u ld c a u s e h ig h ly
e rro n e o u s r e a d i n g s . In a few c a s e s th e re p ro b a b ly is c o n ta c t p re s s u re b e ­
tw e e n th e ste m of a m e te r an d th e e d g e of th e h o le in th e w a ll th ro u g h w h ic h
th e ste m p ro tru d e s in to th e c u lv e r t.
m e te r p ro tru d e s in to th e c u lv e r t.
F ig u re 27 ,shows how th e stem of e a c h
The h o l e s , w h ic h a re so m e w h a t irre g u la r
-93-
b e c a u s e t h e y w e re c u t w ith a c u ttin g t o r c h , sh o u ld h a v e b e e n m ad e so m e w h a t
la rg e r to e n tir e ly e lim in a te th e d a n g e r of a c c id e n ta l c o n t a c t b e tw e e n th e
ste m an d th e s id e of th e h o le .
A nother p o s s ib le s o u rc e o f la te r a l fo rc e on
a s t r e s s m e te r stem is from te n s io n in th e e le c tr i c c a b le c o n n e c te d to th e
s te m . .All of th e .c a b le s w e re s tru n g w ith a la rg e am o u n t o f s la c k and
c h e c k e d p e r io d ic a lly to s e e th a t th e y w e re n o t a p p ly in g s ig n if ic a n t fo rc e s
on th e s te m s of th e s t r e s s m e te rs „
O v e r a ll, th e p e rfo rm a n c e of th e s t r e s s m e te rs is c o n s id e r e d s a t i s ­
fa c to ry . A c o n s e r v a tiv e in te r p r e te r of th e r e s u l t s m ig h t ig n o re a ll r e a d ­
in g s o f l e s s th a n a b o u t 20 p s i „ F ig u re 49 e f f e c tiv e ly su m m a riz e d th e
p r e s s u r e d is tr ib u tio n on th e c u l v e r t , a s in d ic a te d b y th e s t r e s s m eter r e a d ­
in g s of Ja n u a ry 4 , 1966 „ The d iff e r e n c e b e tw e e n th e m axim um an d minimum
r e a d in g s c o u ld b e in te r p r e te d a s random v a r ia tio n in p r e s s u r e from p o in t to
p o in t, or a s e x p e rim e n ta l e r r o r , or a s a c o m b in a tio n o f b o t h . In an y c a s e ,
F ig u re 49 i n d ic a te s th a t th e a v e ra g e p r e s s u r e o v e r th e ro o f a re a of th e -c u l-i
v e rt w a s p ro b a b ly c lo s e to 35 p s i on Ja n u a ry 4 , 1 9 6 6 , b u t so m e w h a t m ore
th a n 35 p si. o n th e s i d e s . A r e - e x a m in a tio n o f F ig u re 42 sh o w s th a t th e
SR-4 g a g e s a ls o in d ic a te d a n a v e ra g e v e r tic a l p r e s s u r e c l o s e to 35 p s i
on th a t d a t e „ (The a c tu a l n u m e ric a l a v e r a g e of th e p r e s s u r e s in d ic a te d
b y E la te s A, B, C , .D a n d E on th a t d a te i s 34 p s i ) .
P rim a rily a s a r e s u l t o f th e d e m o n s tra te d good a g re e m e n t b e tw e e n
-94-
th e tw o m ajo r s e t s o f in s tr u m e n ta tio n , i t i s c o n c lu d e d th a t b o th s e t s g a v e
r e a s o n a b ly r e lia b le .o r a c c u r a te r e s u l t s .
F ig u re 48 g iv e s th e p r e s s u r e s from th e s ix s t r e s s m e te rs th a t w e re
b u rie d in th e f ill to m e a s u re v e r tic a l e a rth p r e s s u r e in th e e a rth at/ a n ;..
e le v a tio n o n e fo o t a b o v e th e to p o f th e c u lv e r t.
C o n s tr u c tio n e q u ip m e n t
c o u ld h a v e o v e r s tr e s s e d som e o f th e s e m e te rs b e fo re th e d e p th o f f ill a b o v e
th em c o u ld p ro te c t, them from h ig h lo c a l w h e e l l o a d s . An a tte m p t w a s m ade
to k e e p a ll v e h ic le s o ff th e im m e d ia te a re a u n til th e m e te rs w e re .c o v e re d to.
'
;•
!
a d e p th o f o n e fo o t b u t i t a p p e a rs th a t m e te rs 2 6 , 2 7 , an d 29 w e re d a m a g e d ;
an d p erh ap ti m e te rs 28 an d 30 a s w e l l .
a re p lo tte d on F ig u re 50
The r e a d in g s , on J a n u a ry 4 , 1 9 6 6 ,
T aken c o lle c tiv e ly t h e s e m e te rs in d ic a te a n
a v e r a g e v e r tic a l p r e s s u r e a b o v e th e c u lv e r t w h ic h is in th e v ic in ity _ ,o f 30
p s i , w h ic h c o n s ti tu te s good g e n e r a l a g re e m e n t w ith the* m e te rs on th e
c u lv e r t w a lls a n d th e SR -4 s tr a in g a g e s , a n d s u g g e s ts th a t th e d am ag ed
m e te rs w e re s t i l l g iv in g f a ir ly a c c u r a te r e a d in g s a t th a t e a r ly d a t e .
I
The r e la tiv e ly v e ry h ig h e a rth p r e s s u r e s o n m e te rs 25 a n d 3 0 , w e ll
a b o v e th e e s tim a te d n o m in a l o v e rb u rd e n o f 72 p s i , c o n s ti tu te s s tro n g i n ­
d e p e n d e n t e v id e n c e th a t th e " im p e rfe c t tre n c h " c o n s tr u c tio n d e ta i l w a s
w o rk in g in th e m a n n er v is u a liz e d b y th o s e w h o c o n c e iv e d i t a n d a c tiv e ly
p ro m u lg a te d i t a s a p r a c tic a l w ay to r e lie v e th e v e r tic a l p r e s s u r e on c u l­
v e rts .
If th e " im p e rfe c t tre n c h " r e lie v e s th e p r e s s u r e on th e c u lv e r t ,it
-95-
P r e s s u r e s m Pounds
p er Square Inch •-----
i
I i ii.oM
i i
i
I
Rubber
GeUs
f C * | «
M e fe r N um bers
a n d L o c a tio n s '
L o o k in g D o w n s t r e a m
S c a le : I
G F t.
GO PSl
F ig u re 5 0 .
Earth P r e s s u r e s on 1 /4 /6 6 D eterm in ed from th e S tr e s s M e te rs
an d R ubber P re s s u re C e lls L o c a ted in th e F ill
-96-
m u s t, n e c e s s a r i l y , ,in c r e a s e th e p r e s s u r e on th e e a rth a d ja c e n t to th e c u l­
v e rt b e c a u s e th e w e ig h t o f th e o v e rb u rd e n m u s t b e su p p o rte d so m e w h e re .
R ubber P r e s s u r e C e lls
S till a n o th e r s e t of in d e p e n d e n t p r e s s u r e - m e a s u r in g in s tru m e n ta ­
tio n w a s th e s e t o f s ix ,ru b b e r d ia p h ra g m p r e s s u r e c e ll s th a t w e re in s ta lle d
s ix in c h e s b e lo w th e s tr a w , a b o v e rin g 38 of th e r e b u ilt c u lv e r t.
As e x ­
p e c te d , th e s e c e ll s r e g is te r e d s u b s ta n tia lly lo w e r p r e s s u r e s th a n th e
o th e r in s tru m e n ta tio n b e c a u s e th e y w e re p la c e d s ix in c h e s u n d e r th e s tra w .
T he k n o w le d g e th a t th e y m ig h t h a v e b u rst, u n d e r h e a v y e a rth lo a d s or c o n ­
s tr u c t i o n e q u ip m e n t lo a d s w a s th e p rim ary m o tiv a tio n fo r p la c in g them in
th e h ig h ly c u s h io n e d lo c a tio n th a t w a s c h o s e n for th e m .
C e ll Nk .,2, w h ic h w a s c o n n e c te d to th e c e n te r B ourdon g a g e show n
in F ig u re 3 1 , d e v e lo p e d a v is ib le le a k a t th e s i t e of th e b le e d e r v a lv e
b e lo w th e B ourdon g a g e a n d th e p r e s s u r e o n th is c e ll in e v ita b ly d ro p p ed
o ff s te a d ily a s flu id le a k e d o u t an d c o n tin u e s to do s o .
The o th e r fiv e c e l l s
a p p e a re d to fu n c tio n f la w le s s ly e x c e p t fo r a v e ry m inor le a k th a t d e v e lo p e d
b e tw e e n th e s h u to ff v a lv e an d th e B ourdon g a g e of c e ll N o . 6 .
For th is
p a r tic u la r c e l l , th e sh u to ff* v a lv e h a s b e e n a n d i s k e p t c lo s e d b e tw e e n p r e s s u re r e a d in g s , a m d 'is o p e n e d for no lo n g e r th a n h a lf a m in u te a t a tim e to
ta k e a r e a d in g on th e B ourdon g a g e .
No m ore th a n a s m a ll f r a c tio n of a
-97-
c u b ic c e n tim e te r of liq u id h a s e s c a p e d from c e l l N o . 6 a n d i t h a s seem inglyfu n c tio n e d a c c u r a te ly from th e b e g in n in g .
. F ig u re 51 p ro v id e s a g ra p h ic a l re c o rd o f th e p r e s s u r e s r e g is te r e d by
th e ru b b e r p r e s s u r e c e l l s .
The p r e s s u r e v a r ia tio n s sh o u ld n o t b e in te r p r e te d
a s random s c a t t e r b e c a u s e a ll o f th e p r e s s u r e v a r ia tio n s , from c e ll to c e l l ,
is d e m o n s tra b ly a fu n c tio n of c e ll l o c a t i o n .
T his b e c o m e s a p p a r e n t w h en -
th e p r e s s u r e s fo r a n y g iv e n d a y a re p lo tte d on a c r o s s - s e c t i o n a t th e
lo c a tio n of e a c h c e l l .
F ig u re 50 sh o w s t h e s e p r e s s u r e s , a s of Jan u a ry 4 ,
1 9 6 6 , in a d d itio n to p r e s s u r e s from th e b u r i e d . s t r e s s . m e t e r s .
For th e s a k e
o f e f f ic ie n c y , b o th p r e s s u r e d ia g ra m s a re sh o w n p lo tte d o n th e sa m e c r o s s s e c tio n . d ia g ra m b u t th e r e a d e r sh o u ld b e a r in m ind th a t th e ru b b e r p r e s s u r e
c e l l s a re a p p ro x im a te ly 30 f e e t d o w n stre a m from th e b u rie d s t r e s s m e te rs a s
w e ll a s a p p ro x im a te ly 3 1 /2 f e e t a b o v e th e m . .
In F ig u re 5 0 , th e p lo tte d p r e s s u r e s fo r th e ru b b e r c e l l s d e fin e a sm ooth
a n d n e arly , s y m m e tric a l p r e s s u r e d ia g ra m .
T he m axim um p r e s s u r e i s a t c e l l
N o . .3 , r ig h t a t th e c e n te r , w ith a sm o o th tr a n s itio n to a m inim um p r e s s u r e
o n e a c h s i d e , a t c e l l s I a n d 6 w h ic h a re lo c a te d u n d e r th e o u te rm o s t b a le s
o f s tra w a t th e lo c a tio n s o f a n tic ip a te d m inim um p r e s s u r e . A cco rd in g to th e
ru b b e r p r e s s u r e c e ll r e a d in g s , th e a v e r a g e v e r tic a l p r e s s u r e a t th e b a s e of
the. s tra w w a s a p p ro x im a te ly 17 p s i on Jan u a ry 4 , 19-66.
The lo o s e ro c k f ill a b o v e th e s tra w a r c h e s b e tw e e n th e " w a lls " of f ill
feet)
in
h e ig h t
VERTICAL EARTH PRESSURE IN PSl
( f il l
555%!
IhS ioec
. jam.
1965 1966
Figure 51.
Earth P r e s s u r e s v s . Time - Rub ber P r e s s u r e c e l l s n o . I , 2, 3, 4 , 5 a n d 6
—99 —
o n e a c h s id e o f th e s tra w (refer b a c k to F ig u re 2) a n d th e w e ig h t of th e a r c h ­
in g f il l i s s u p p o rte d la r g e ly by th is a rc h in g a c ti o n , e x c e p t fo r th e lo w e rm o st
p o rtio n of th e lo o s e f il l n e a r m id s p a n w h ic h is to o c l o s e to th e s tra w to b e
s u p p o rte d by th e a rc h a b o v e i t an d th e re fo re b e a r s d ir e c tly a g a in s t th e s tra w
in th e m id s p a n re g io n an d c a u s e s th e p r e s s u r e on th e s tra w to b e g re a te r a t
m id s p a n th a n e ls e w h e r e .
S e ttle m e n t C e lls
R e p r e s e n ta tiv e o b s e rv e d s e ttle m e n ts of th e e ig h t s e ttle m e n t c e ll s l o ­
c a te d in th e f il l on e a c h s id e o f th e c u lv e r t, a n d s lig h tly a b o v e th e e le v a tio n
o f th e to p o f - th e - c u lv e r t, a re g iv e n in T a b le '8 , The d e s ig n a te d c e n tr a l s e g ­
m e n t of th e ta b le e n c o m p a s s e s th e p e rio d d u rin g w h ic h a p p a r e n t f r o s t p ro b lem s
an d v a ry in g d e n s i t i e s o f th e liq u id in th e o p p o s in g le g s of th e m anom eter
s y s te m s p ro d u c e d so m e o b v io u s ly in c o n s i s t e n t a n d in a c c u r a te s e ttle m e n t
re a d in g s , In. s p ite o f s e v e r a l g la rin g i n a c c u r a c i e s , th e c e n tr a l p a rt of th e
ta b le s t i l l in d ic a te s a n a v e r a g e tre n d w h ic h is c o n s is te n t w ith th e e a r lie r an d
th e la te r s e t t l e m e n t s ,
The b ottom p a rt o f th e t a b l e , w h ic h s h o w s a la rg e num ­
b e r of s e ttle m e n t r e a d in g s ta k e n d u rin g a tim e p e rio d w h en s e ttle m e n t w a s
o c c u rrin g v e ry s lo w ly , a n d a f te r th e s o u rc e of th e e a r lie r e r r a tic re a d in g s w a s
id e n tif ie d a n d e lim in a te d , p ro v id e s a g o o d in d ic a tio n of th e r e p ro d u c ib ility
or in h e re n t p o te n tia l a c c u r a c y of th e s im p le U tu b e m a n o m eter s y s te m o f th e
-100-
TABLE 8 .
SETTLEMENT OF THE SETTLEMENT CELLS IN INCHES
.D ate
C e ll.N u m b e r an d L o c a tio p (N o rth , South)
I
S c.
2
N
4
S
3
S
5
N
7
S
6
S
8
N
O
Cn
00
cn
O
O
CO
OO
Cn
CO
O
O O
O O
CO
3.05
CO
OO
O
I
i
O
CO
4N
OO
O
O
4.15
4.20
CO
— - - - - - - - R e a d in g s w ith in th is s e c tio n a re u n re lia b le „
* T he T in e s w e re p lu g g e d .
O
O
Np
___ *
NP
CO
IN. O
Ns O
(NI
2.40
2.45
3.90
3.95
3.95
O
O
3.75
LO
(NI
oo
Q
2.70
2.50
2.45
3.00
2.90
3.65
I
2.25
O
CO
LO
CO
LO
CS!
O
4.80
4.95
5 . OS
CO
Np
O
4.85
(NI
LO
LO
I
II
I
I
O
NP
3.80
2.80
3.30
3.20
Np
CO
LO
O
LO
(NI
r^.
O
I
I ^
l/
B
O
LO
O
NP
LO
LO
CO
O
O
NP
CO
Np
LO
NP
CO
4.65
4.70
3.20
S
CO
2.20
I
O
O
O
O
00
cn
I-1
O
O
Hj
O
O
3.75
CO
O
O
!
CO
2.10
4.45
4.40
4.45
1.50
1.90
1.70
1.80
O
CO
CO
2.35
,
I
!
'
i
I
'
3.60
2.00
2.05
1.95
1.90
s .
LO
LO
N f1
»
NP
6 /1 4 /6 6
6 /2 3 /6 6
8 / 9 /6 6
$ / 2 /6 6
1 2 /1 3 /6 6
3 /2 9 /6 7
2.00
1.40
1.10
1.60
1.55
2.95
LO
O
i—I
2.15
1.70
1.65
2.40
2.20
2.95
Cs!
4.70
5.20 .
0.60
O
O
$>N
CO
CO
NP
1.55
O
O
J—
J
1.15
O
CO
0.80
LO
CO
(NI
2.70
3.45
3.5-5
O
O
O
O
O
O
NP
O
LO
O
O
O
0.70
1.30
2.10
O
O
O
1.35
2.10
2.20
1.40
1 . 50
2.80
O
CO
O
3.20
2.80
2.70
2.90
3.90
O
CO
1 2 /2 2 /6 5
1 2 /3 0 /6 5
I /1 3 /6 6
2 / 3 /6 6
3 /1 0 /6 6
5 /3 1 /6 6
O
O
O
O
2,10
2,10
(NI
1 2 / 3 /6 5
1 2 / 7 /6 5
1 2 / 8 /6 5
1 2 /1 3 /6 5
12/15/65
O
in c h e s
3.15
-101-
s e ttle m e n t c e l l s .
S e ttle m e n t c e l l s num ber -2, 5 , and 8 w e re lo c a te d on th e n o rth s id e of
th e c u lv e r t a n d c e l l s 1 , 3 ,
A1 6 ,
a n d 7 w e re on th e so u th s i d e .
The r e a d ­
in g s w e re i n i t i a l l y ta k e n by a d d in g f lu id , a s p re v io u s ly m e n tio n e d , and th e n
. le ttin g th e s y s te m s t a b i l i z e , b u t w a s la te r c h a n g e d to d ra in in g th e sy ste m
a n d r e f illin g i t w ith th e pump e a c h tim e .a s e ttle m e n t re a d in g w a s d e s i r e d .
T h is m eth o d w a s b e g u n in June o f 1 9 6 6 .
Som e o f th e r e a d in g s w e re
o b v io u s ly v e ry .m u c h in e r r o r , n o ta b ly .a ll of th e r e a d in g s ta k e n on M ay 3 1 ,
1966.
I t w a s e a r ly in June o f 1966 b e fo re i t w a s d is c o v e re d th a t th e ra th e r
c a r e l e s s l y p ro p o rtio n e d h a l f - a n d - h a l f m ix tu re o f w a te r an d P re s to n e th a t
w a s p e r io d ic a lly p o u red in to th e s ta n d p ip e s on th e m a n o m eter b o a rd w a s
c a u s in g a d iff e r e n c e in th e s p e c if ic g r a v itie s of th e liq u id in o p p o s in g le g s ■
o f th e m a n o m e te rs .
The r e s e a r c h e r s w e re p rim in g th e s ta n d p ip e s w ith a to o -
ric h m ix tu re of P re s to n e a n d w a te r w h ic h w a s p r o g r e s s iv e ly d e p r e s s in g th e
e q u ilib riu m le v e l in th e s ta n d p ip e s b e c a u s e P re s to n e is s ig n if ic a n tly m ore
<
d e n s e th a n w a t e r . -All o f th e s e ttle m e n t re a d in g s ta k e n on a n d a fte r June 1 4 ,
1 9 6 6 , in d ic a te th a t th e p re c e d in g re a d in g s sh o w e d f ic titi o u s ly la rg e s e t t l e ­
m e n ts .
The a v e r a g e s e ttle m e n t o f th e s e ttle m e n t c e l l s is illu s tr a te d in F igure
52 a n d p lo tte d a s s e ttle m e n t v e rs u s tim e . . S e ttle m e n t c e l l s N d . 5 an d 8 on
th e n o rth s id e an d s e ttle m e n t c e ll s N o . 3 , 4 , 6 , an d 7 , on th e s o u th s id e a re
u s e d for th is p u r p o s e . The c e l l s w e re i n s t a l l e d w h en th e re w a s fiv e f e e t of
-102-
c o v e r a n d th e re w a s no in d ic a tio n of s e ttle m e n t u n til a fte r f ill w a s p la c e d
.on th e s tr a w .
The re f e r e n c e lin e sh o w n re f e r s to th e to p o f th e c u lv e r t, in
th e v ic in ity of th e s e ttle m e n t c e l l s , im m e d ia te ly a fte r th e ir i n s ta lla t io n „
In F ig u re 5 2 , th e s e ttle m e n t of th e s e ttle m e n t c e l l s sh o u ld b e com ­
p a re d o n ly to t h a t p o rtio n of th e s e ttle m e n t of th e to p o f th e c u lv e r t w h ich
o c c u rre d a f te r D e ce m b e r 6 , 1966„
For e x a m p le , th e u ltim a te s u b s e q u e n t
s e ttle m e n t of th e to p of th e c u lv e r t, a f te r D e ce m b e r 6 , a s m e a s u re d from
p o in t B in F ig u re 5 2 , i s o n ly a p p ro x im a te ly 2 „ 0 in c h e s „ D uring th e sam e
tim e 'i n t e r v a l , th e s e ttle m e n t o f th e n o rth s id e s e ttle m e n t c e l l s a v e ra g e d
3 .0 in c h e s (as m e a s u re d from p o in t A) w h ile th e s e ttle m e n t o f th e so u th
s id e s e ttle m e n t c e l l s a v e ra g e d 3 .9 i n c h e s .
T h e se fig u re s sh o w th a t th e
s o il on e a c h s id e of th e c u lv e r t s e tt le d m ore th a n th e to p o f th e c u lv e rt or
th e s o il d ir e c tly a b o v e th e c u lv e r t.
In d o in g s o , th e s o il on e a c h s id e
w o u ld , n e c e s s a r i l y , s u b je c t th e in te rv e n in g s o il (d ire c tly a b o v e th e
c u lv e rt) to d o w nw ard f r ic tio n a l d ra g f o r c e s .
A d d itio n a l M e a s u re m e n ts
5
The s e ttle m e n t o f th e c u lv e r t in v e r t w a s d e te rm in e d p e r io d ic a lly w ith
a n e n g in e e r 's le v e l an d p a r tia l r e s u lts a re g iv e n in T a b le 9 .
T his ta b le
sh o w s th e e le v a tio n of th e iro n p in s in th e c o n tro l d e v ic e s im m e d ia te ly
a f te r e r e c tio n , an d th e s e ttle m e n t of t h e s e p in s in f e e t a t v a rio u s d a te s
th e r e a f te r .
■
ght in F ee t
Fill Height" in F e e t
SETTLEMEUT VS. TIME
(^ReP^rence Lvne PorT>p oP Culvert 12/
-1 0 3 -
^ T o p oP Culve
Cells Mortln Side
F igure 5 2 .
S e ttle m e n t of th e S e ttle m e n t C e lls an d Top of C u lv e rt
S e t t le m e n t in Inches
S e -H -Ie m e n t in In ch e s
r-R e F a re n c e Line P o r S e t t l e m e n t Gell1B
-104-
TABLE 9 .
S ta tio n .
I
2
3
4
5
6
7
8
9
10
11
12'
13
SETTLEMENT OF THE CULVERT INVERT
E le v a tio n
a fte r
12/29/65
E re c tio n
fe e t
0 .0 6
3829.09
0 .0 5
28.99
0.12
28.83
0.11
23.61
28.62
0 .1 0
2 8 .5 1
0 .0 9
0 .0 7
2 8 .5 6
2 8 .3 1 ' 0 .0 5
0.11
28.00
2 8 .0 0
0.09
2 7 .7 4
0 .0 6
27.62
0.06
0.00
.27.56
1/13/66
fe e t
0 .0 6
0 .0 5
0.11
0 .1 3
0 .0 8
0 .0 9
0 .0 7
0 .0 5
0 .0 7
0 .0 8
0 .0 3
0 .0 4
0.00
6/9/66
fe e t
------0 .0 6
0.12
0.10
0 .0 9
0 .0 8
0 .0 6 '
0 .0 5
0 .0 6
0.08
0 .0 3
0.02
0.01
6/15/66 6/23/66 7/28/66
fe e t
fe e t
fe e t
—
-----—
0 .0 7
0 .0 6
0 .0 7
o .io
■ 0 . 1 1 - 0 .1 5
0.10
0.11
0 .1 3
0 .0 9
0.10
0 .0 9
0 .0 7
0 .0 9
■0.08
0 .0 8
0 .0 7
0 .0 5
0 .0 4
0 .0 5
0 .0 6
0 .0 7
0 .0 6
0 .0 4
0 .0 8
0 .0 8
0 .0 8
0 .0 5
0.02
0 .0 5
0.02
0 .0 5
0 .0 3
—
0.00
0.01
The c o n tro l d e v ic e a t s ta tio n num ber o n e w a s d am ag ed d u rin g th e
w in te r m onths a n d w a s n o t u s e d a fte r Jan u a ry of 1966.
Som e of th e d iffe r­
e n c e in re a d in g s c a n b e a ttr ib u te d to e rro rs in re a d in g th e le v e l rod
b e c a u s e of th e poor lig h tin g in s id e th e c u lv e r t an d o th e r d if f ic u ltie s in
ta k in g le v e ls w ith th e le v e l o u ts id e th e c u lv e r t an d s e t up in th e c r e e k .
An e x a m p le of th is is s ta tio n , n in e w h e re th e a p p a re n t s e ttle m e n t in
D e c e m b e r, 1965 , w a s 0 .1 1 f e e t a n d th e l a s t in d ic a tio n in J u ly , 1966,
w a s 0 .0 4 f e e t .
The in te rm e d ia te r e a d in g s s u g g e s t th a t b o th th e 0 .1 1 an d
th e 0 .0 4 re a d in g s a re in e r r o r .
F ig u re 53 s h o w s th e a v e ra g e to ta l s e ttle m e n t of th e c u lv e r t flo o r
CULVERT
INVERT SETTLEMENT IN INCHES
JULY 1 9 6 6
-SOI-
Se-Htemerrt In Inches
RePerence Lme Nov. \9<SS
C o n tr o l
Figure 53.
Device
N lum ber
S e t t l e m e n t of t h e C u l v e r t I n v e r t
—1 0 6 —
a s o f J u ly , 1 9 6 6 .
T his s e ttle m e n t is in in c h e s an d is o b ta in e d from an
a v e r a g e of th e th re e s e t s o f re a d in g s ta k e n in J u ly . The a v e r a g e o f th e
flo o r s e ttle m e n ts a t s ta t io n s 6 , 7 , 8 a n d 9 w a s a d d e d to th e v e r tic a l
d ia m e te r c h a n g e to d e te rm in e th e s e ttle m e n t o f th e to p o f th e c u lv e r t.
■The c h a n g e in th e a v e r a g e v e r tic a l a n d h o riz o n ta l d ia m e te r o f th e
c u lv e r t in in c h e s is i l l u s t r a t e d in F ig u re 5 4 , u s in g s ta tio n s 6 th ro u g h 9
w h ic h w e re u n d e r th e h ig h e s t p o rtio n o f th e f i l l .
The to p p o rtio n o f th is
fig u re sh o w s th e r e la tio n s h ip b e tw e e n th e to p o f th e c u lv e r t an d th e fill
h e ig h t a s th e d ia m e te rs c h a n g e d .
th e c u l v e r t .
The f il l h e ig h t sh o w n i s in f e e t ab o v e
The b a c k f illin g b e g a n a t a n e le v a tio n a p p ro x im a te ly 19 f e e t
b e lo w th e to p o f th e c u lv e r t.
The b o tto m c u rv e s sh o w th e c h a n g e in
d i a m e t e r s . T h e fig u re sh o w s th a t th e v e r tic a l d ia m e te r in c r e a s e d by
a p p ro x im a te ly 1 .4 in c h e s a s th e b a c k f illin g p ro g r e s s e d u n til th e c u lv e r t
w a s c o v e re d a n d th e n d e c r e a s e d u n til i t w a s a p p ro x im a te ly 0 . 8 in c h e s
l e s s th a n th e d ia m e te r j u s t a f te r e r e c tio n .
The h o riz o n ta l d ia m e te r f ir s t
d e c r e a s e d b y a p p ro x im a te ly 1 .9 in c h e s a n d th e n b e g a n to i n c r e a s e a fte r
th e c u lv e r t w a s c o v e r e d .
The h o r iz o n ta l d ia m e te r re m a in s a p p ro x im a te ly
0 .5 in c h e s l e s s th a n i t w a s a t th e tim e of e r e c t i o n . The a c tu a l d ia m e te r
c h a n g e s a t v a rio u s d a te s are. lis t e d in T a b le s 10 an d 11.
CULVERT
IN RELA,'
(ON TQ FILL UE G U T ^
AVERAGE DIAMET
VERTICAL AVERAGE DIAMETER CWANGE
<1 -
2.
Figure 54.
Average H orizontal and Vertical D iam eter C hange
-ZOT-
^//WA\WA\\VA\WA^ \VA\W/A vW /A \\V A W A ?
108-
TABLE 1 0.
S ta tio n
1 1 /1 6 /6 5 '
in c h e s .
VERTICAL DIAMETER CHANGE
1 1 /2 3 /6 5
in c h e s
1 1 /2 9 /6 5
in c h e s
1 2 /1 7 /6 5
in c h e s
1 /1 8 /6 6
in c h e s
8/9/66
in c h e s
I
0.00
0.88
1 .1 3
0 .3 6
0 .2 5
2
0.00
1 .5 0
1 .1 3
0 .5 0
- 0 .1 5
- 0 .3 5
3
0.00
1 .5 0
1 .2 5
1.00
0 .4 0
0 .5 0
4'
0.00
1 .6 3
1 .2 5
0.88
0.10
0 .2 5
1 .2 5
0.88
0 .5 0
- 0 .5 5
- 0 .6 0
0 .6 3
- 0 .6 5
I
7
0.00
1 .5 0
0.88
0.63
- 0 .9 0
- 0 .9 5
8
0.00
1 .6 3
0 .5 0
0.00
I
.9
0.00
1 .1 3
0 .5 0
—------
- 0 .6 0 .
- 1 .1 5 ‘
10
0.00
1.88
1.00
• 0 .5 0
-0.40
I
11
0.00
1 .3 3
0 .7 5
12
0.00
1 .5 0
13
0.00
1 .5 0
CDO
1.00
O
1 .2 5
O
O
0.00
LO
LO
6
O
5
O
—
- 1 .1 5
O
LO
O
I
LO
LO
O
0.12
- 0 .6 0
1.00
0 .2 5
- 0 .5 0
- 0 .5 0
0.88
0.00
- 1.00
- 0 .7 5
'
—10 9 —
TABLE 1 1 .
1 1 /2 2 /6 5
in c h e s
11/29/65
in c h e s
12/17/65
in c h e s ■
1/8/66
in c h e s
8/9/66
in c h e s
0.00
7
0.00
s'.
0.00
- 1 .6 3
- 0 .6 0 .
- 0 .5 5
- 0 .6 0
- 2 .5 0
- 1 .6 3
-0.96
- 0 .5 8
- 0 .7 7
- 1 .2 5
- 0 .7 2
- 0 .5 3
- 0 .7 2
- 0 .3 6
-0 . 2 0
- 0.22
- 0 .1 8
- 0.22
0.10
.
- 0 .8 0
CD
■
cn
- 0 .8 4
I
- 1 .5 0
I
- 1.20
I
O
, 6
cn
- 2.00
CO
0.00
- 1.00
OO
5
O
- 1 .6 3
- 1 .9 2
' I
0.00
- 1 .6 3
I.
4
0 .6 2
CO
'
0 .5 2
I
- 2.00
0 .2 4
CO
CO
CO­
CO
0.00
—
CO
CO
I
3
O
0.00
0.10
CO
CO
2
- 1 .5 0
I-1
- 2 .7 5
.
I- H
0.00
I
I
.
S ta tio n
1 1 /1 6 /6 5
in c h e s
HORIZONTAL DIAMETER CHANGE
•
- 0 .7 2
-
- 0 .3 6
- 0 .0 3
12
0.00
- 1 .2 5
13
0.00
-2 .2 5
- 1 .7 5
O
I
I
• O
O
- 1 .3 8
O
- 1 .6 3
IN .
O
0.00
(N I
11
- 0 .8 2
O
CO
CO
I
- 0 .1 8
CO
CO
CO
- 1 .1 3
I
O
- 1 .6 3
O
CO
CO
- 1.00
■
i—4
- 2.00
10'
o.oo
o.do
9
I
- 1 .2 5
0 .0 5 .
E le v a tio n s w e re m e a s u re d a lo n g th e c e n te r - lin e of th e p a v e d ro a d ­
w ay to d e te rm in e if th e re w a s m ore s e ttle m e n t o v er th e c u lv e r t th a n e l s e ­
w h e re .
The i n itia l le v e ls w e re ta k e n in S e p tem b er of 1966 a f te r th e
s u rfa c in g w a s c o m p le te d .
As s ta te d p r e v io u s ly , th e f ill w a s c o m p le te d
in J a n u a ry , 1 9 6 6 , an d th e s u rfa c in g w a s b e g u n in A u g u st, 1 9 6 6 , and
d u rin g th is tim e th e ro a d w a y .w as o p e n to t r a f f i c .
S in c e th e le v e l s w ere
I
1 '
_
,
-iio-
n o t ta k e n u n til th e s u rfa c in g w a s c o m p le te d , a - la rg e p o rtio n of th e
em b an k m en t s e ttle m e n t u n d o u b te d ly h a d ta k e n p la c e by th e n .
F ig u re 55 in d ic a te s - th e s e ttle m e n t of th e ro a d w a y b e tw e e n S e p te m b e r,
1 9 6 6 , a n d M arch ', 1967 „ T his fig u re s h o w s th a t th e s e ttle m e n t o f th e
p a v e m e n t o v e r th e c u lv e r t w a s ..n o t m ore th a n th e s e ttle m e n t o f th e p a v e ­
m en t on e a c h s id e o f th e c u l v e r t .
I n f a c t , i t i n d ic a te s th a t th e r e w a s
m ore s e ttle m e n t o f th e p a v e m e n t 100 f e e t s o u th of th e c u lv e r t th a n
d ir e c tly a b o v e th e C u lv e rti.
The la r g e s t s e ttle m e n t w a s 0 .1 2 f e e t a t
a p p ro x im a te ly s ta t io n 129 p lu s 5 5 .
J
ElevaPion P o in ts -
R e P e r e n c e Line
9/2l/i£<£>
S e t t l e m e n t 3 /2 9 /6 7
-
111
-
C u lvert
13 0 1 Cl .7
\n te r s t- a te
Figure 55.
S t a t io n s
S ettlem en t of the I n te r s ta te Roadway Pavement
CHAPTER IX
D ISC U SSIO N , CONCLUSIONS AND RECOMMENDATIONS
.D is c u s s i o n
.
■
T he b e h a v io r, of th e r e c o n s tr u c te d c u lv e r t-w a s c h a r a c te r iz e d quj-te
a d e q u a te ly b y th e in s tr u m e n ta tio n .r e s u lts a n d m e a s u re m e n ts w h ic h w e re
b e g u n a t th e .tim e o f e r e c tio n in O c to b e r ,. 1 9 6 5 .
The c u lv e r t w a s e r e c te d
in a n e l l i p i t i c a l s h a p e , a p p ro x im a te ly 19 f e e t 4 in c h e s b y 1 7. f e e t 1.0 in c h e s
■AS;th e .b a c k f il l m a te ria l w a s c o m p a c te d on e a c h , s id e o f th e c u l v e r t ,
th e v e r tic a l d ia m e te r in c r e a s e d by I -.4 in c h e s a n d th e. h o riz o n ta l d ia m e te r
d e c r e a s e d .b y 1 .9 i n c h e s . . D uring p la c e m e n t o f th e b a c k f ill a n d e m b an k ­
m e n t, th e c u lv e r t flo o r s e t t l e d a m axim um a m o u n t o f a b o u t 1 .4 in c h e s
n e a r th e u p s tre a m e n d of th e r e b u ilt S e c tio n , b u t g e n e r a lly le s s , th q n I
in c h o v e r th e c e n te r p o r tio n .
T h e .th e o ry , e x p r e s s e d .b y som e e n g in e e r s , t h a t th e .c u lv e r t m ig h t
b ^ v e a .te n d e n c y to d e f le c t u p w a rd in to th e c o m p re s s ib le s tr a w i s -le n t
so m e ,su p p o rt by th e r e la tiv e ly la rg e S id e p r e s s u r e s , a s sh o w n in F ig u re
4 9 . ■F u rth er s u p p o rt fo r th is th e o ry i s th e f a c t t h a t th e s id e w a l l s ; Jhat
w e re c o m p re s s e d in w a r d , n e v e r re tu rn e d to th e ir o rig in a l p o s i t i o n .
A ls o .th e b e n d in g m o m en ts a t th e s tra iri g a g e s i t e s re m a in e d c o n s is te n t in
s e n s e w ith a n in w a rd m ovem ent o f th e s id e a n d u p w ard m o v em en t of th e
r o o f , a n d p la te s B a n d D a c tu a lly d e m o n s tra te d a. s ig n if ic a n t in c r e a s e in
th is b e n d in g te n d e n c y a s th e c o v e r in c r e a s e d from 5 f e e t to 83 f e e t . •
-113-
T his is a p p a r e n t from th e s te e p s lo p e s of th e s t r e s s d ia g ra m s for p la te s
B an d D in F ig u re 40 „ The v e r tic a l d ia m e te r a ls o sh o w e d a d e c r e a s e
w h ic h m e a n s th a t th e re m u s t h a v e b e e n a s lig h t o u tw ard m o v em en t of th e
w a lls so m ew h e re b e tw e e n th e m id - h e ig h t an d th e to p o f th e c u lv e r t.
The m ajo r s t r e s s in th e c u lv e r t w a lls a t th e s tr a in g a g e s i t e s
d u rin g e r e c tio n w a s b e n d in g s t r e s s of s ig n if ic a n t m a g n itu d e , w h ic h
in c r e a s e d a s th e 'c u lv e r t w a s b a c k f ille d on e a c h s id e .
As th e f ill h e ig h t
w a s i n c r e a s e d , th e s t r e s s in th e c u lv e r t w a ll in c r e a s e d , p rim a rily in
d ir e c t c o m p re s s io n .
The m axim um co m b in ed s t r e s s re a c h e d th e y ie ld
s t r e s s on tw o o f th e s ix p la te s in s tru m e n te d w ith s tr a in g a g e s .
A m e a s u re of th e e a rth p r e s s u r e a c tin g on th e c u lv e r t w a s o b ta in e d
from th e s tr a in g a g e s an d s t r e s s m e te rs „ The a v e r a g e e a rth p r e s s u r e , a t
th e fu ll f i l l h e ig h t o f 83 f e e t , w a s a b o u t 35 p s i or 5 k s f .
The s t r e s s
m e te rs a ls o in d ic a te d a la rg e r a v e ra g e p r e s s u r e on th e s id e s o f th e
c u lv e r t of a t l e a s t 50 p s i or 7 k s f .
T his la rg e r s id e p r e s s u r e m ig h t be
e x p e c te d if th e " im p e rfe c t tre n c h " i s w o rk in g p ro p e rly b e c a u s e th e co lu m n s
o f e a rth a d ja c e n t to th e c u lv e r t sh o u ld b e c a rry in g a p o rtio n o f th e lo ad
from th e co lu m n o f e a r th .o v e r th e c u lv e r t.
T his in c r e a s e d lo a d on th e
a d ja c e n t c o lu m n s w o u ld in tu rn in c r e a s e th e la te r a l p r e s s u r e a c tin g on
th e c u lv e r t.
The la rg e v e r tic a l p r e s s u r e on th e c o lu m n s of s o il a t th e s id e s
-114-
o f th e .c u lv e r t w a s v e rifie d by m e te rs 25 a n d 30 a s in d ic a te d in F ig u re '
50.
The h ig h p r e s s u r e s on m e te rs 25 an d 3 0 , th e m uch lo w e r p re s s u re s :
on m e te rs 2 6 , 2 7 , 28 a n d 2 9 , an d th e s y m m e tric a l s h a p e o f th e e n tire
p r e s s u r e d ia g ra m in d ic a te s th a t th e " im p e rfe c t tre n c h " w a s p erfo rm in g
e s s e n t i a l l y a s e x p e c te d .
R ubber p r e s s u r e c e ll s lo c a te d in th e f ill s ix in c h e s b e lo w th e
s tra w in d ic a te d a n a v e r a g e p r e s s u r e o f 17 p s i or a b o u t 3 k s f on Jan u ary 4 ,
1966. . The p r e s s u r e s o b ta in e d from th e ru b b e r p r e s s u r e c e l l s m ay b e
c o m p a re d to th e o th e r p r e s s u r e s a s illu s t r a t e d in F ig u re 5 6 .
To o b ta in
th e a v e r a g e v e r tic a l p r e s s u r e a c tin g on th e s o il a t th e to p o f th e c u lv e rt
4 1 /2 f e e t b e lo w th e ru b b e r c e l l s , a fr e e b o d y d iag ram a n d th e e q u a tio n s
of e q u ilib riu m m ay b e u s e d .
A la te r a l p r e s s u r e of 50 p s i i s a s s u m e d to
a c t u p o n th e r e c ta n g u la r b lo c k o f s o il ly in g b e tw e e n
th e to p of th e c u lv e r t.
a s s u m p tio n .
th e ru b b e r c e ll s and
F ig u re 49 I n d i c a t e s th a t th is is a r e a s o n a b le
The s e ttle m e n t c e ll r e s u l t s in d ic a te th a t th e s o il a d ja c e n t
to th e c u lv e r t h a s s e t t l e d v e r tic a lly m ore th a n th e s o il b lo c k d ir e c tly
a b o v e th e c u lv e r t.
In d o in g th is th e a d ja c e n t s o il e x e r ts a s h e a rin g do w n ­
w ard f r ic tio n a l s t r e s s on th e s id e s o f th e b lo c k p ic tu re d in F ig u re 56.
The m a g n itu d e o f th is v e r tic a l s t r e s s m ay b e r e a s o n a b ly e s tim a te d a s a t
l e a s t 25 p s i , or h a lf th e la te r a l p r e s s u r e .
The c a lc u la tio n s sh o w n in F ig u re 56 i l l u s t r a t e th a t th e 17 p s i p re s s u re
-115-
IT PSI
Average
P ressu re
14.0
2 5 PSI
8.6
s 25 PSI
50 PSI
5 0 PSl
25 PSl ^
25 PSI
3 3 .4 P5I A v e r a g e Pressure
Assume a Developed Internal Friction CoeFPiclent oF 0.5
Shearing Stress - 50PSI*0.5-25PSI
UmPorm Pressure due to Shearing Forces
25 PSI- 45 Ft. • 12 In./Ft.•2 Sidles
=
^nol
16 Ft • 12 In./Ft.
L
Uniform Pressure due to Weight, W, oP Soil below Rubber Cells
125 PCF • 4.5 Ft.
= 3.9 PSl
144 Sg. In./Sq. Ft.
Total UniPorm Load =■ 17-H2.5+-3.9 = 3 3 .4 PSl a t Top oP Culvert
F igure 5 6.
P re s s u re on Top of C u lv e rt D eterm in ed from R ubber P re s s u re
C e lls .
-116“
on to p o f th e b lo c k s h o u ld b e in c r e a s e d b y a b o u t 12 „5 p s i to a c c o u n t for
th e e f f e c t o f th e f r ic tio n a l d ra g s t r e s s e s , a n d a n a d d itio n a l 3 „ 9 p s i to
a c c o u n t fo r th e w e ig h t, W , o f th e s o il in th e b l o c k „ T his g iv e s a n
e s tim a te d m e an v e r tic a l p r e s s u r e o f a b o u t 33 „4 p s i a t th e to p o f th e
c u lv e rto
The w e ig h t o f th e a d d itio n a l s o il, b e lo w th e to p o f th e c u lv e r t,
a n d a d d itio n a l d ra g fo r c e s a c tin g on th a t s o i l , c o u ld e a s i l y m ak e th e
to ta l e q u iv a le n t uniform v e r tic a l e a rth p r e s s u r e on th e c u lv e r t e q u a l
to 35 p s i , o r m o re .
The v a rio u s s e t s o f in s tru m e n ta tio n w e re d e lib e r a te ly c h o s e n to
p ro v id e a c h e c k on e a c h o th e r .
i s p e rfo rm in g a s in te n d e d .
From a l l in d ic a tio n s th e in s tru m e n ta tio n
I t is re c o g n iz e d th a t th e d is c o n t in u itie s
t h a t p r e s s u r e c e l l s c r e a te in a f ill o r o n a c u lv e r t c o u ld c a u s e an y
m e a s u re d p r e s s u r e to d e v ia te from th e " tru e " p r e s s u r e th a t w o u ld h a v e
e x is t e d a t th e sa m e s p o t if th e p r e s s u r e c e l l a n d i t s a p p u r te n a n c e s h a d
n o t b e e n t h e r e . H o w e v e r, w h e n s e v e r a l s e t s of in s tru m e n ta tio n p ro v id e
in d e p e n d e n t e v id e n c e t h a t th e v e r tic a l p r e s s u r e on a c u lv e r t is; in th e
v ic in ity of 35 p s i , o n e i s te m p te d to c o n c lu d e th a t th is i s p ro b a b ly
n o t fa r from th e tru e p r e s s u r e .
C o n s e r v a tiv e ly in te rp re tin g th e e v id e n c e p r e s e n te d a s in d ic a tin g
a m e an v e r tic a l p r e s s u r e o f 40 or e v e n 45 p s i , a n d c o n c e d in g t h a t th e
- .117—
m e a s u re m e n ts c o u ld b e a s m uch a s 25 p e rc e n t in e r r o r , o n e w o u ld s t i l l
c o n c lu d e th a t th e lo a d on th e c u lv e r t is s ig n if ic a n tly l e s s th a n th e
n o m in a l o v e rb u rd e n p r e s s u r e of a p p ro x im a te ly 72 p s i .
\
The s tr a in g a g e s a n d s t r e s s m e te rs in d ic a te d a d e c r e a s e in p r e s s u r e ,
s ta r tin g s h o rtly a f te r th e fu ll f il l h e ig h t w a s r e a c h e d , u n til th e f a ll of
1966 w h e n a n in c r e a s in g p r e s s u r e tre n d w a s n o tic e d .
The d e c r e a s e in
p r e s s u r e c o u ld h a v e b e e n .c a u s e d b y v e ry s m a ll e a rly y ie ld in g m o v em en ts
of th e c u lv e r t w h ic h w o u ld r e lie v e th e e a rth p r e s s u r e s . . The s lig h t
s u b s e q u e n t in c r e a s e c o u ld b e c a u s e d b y g e n e ra l c o n tin u e d s e ttle m e n t
of th e em b an k m en t e s p e c ia ll y in th e im p e rfe c t tre n c h r e g io n . .The r e c e n t
in d ic a tio n o f a s lig h t p r e s s u r e in c r e a s e is n o t of s u f f ic ie n t m a g n itu d e
t o 'c r e a te c o n c e rn th a t th e p r e s s u r e r e l i e f o f th e im p e rfe c t tre n c h is
b e g in n in g to f a i l .
|
i
C o n c lu s io n s
F in d in g s of th is s tu d y led" to th e fo llo w in g c o n c lu s io n s :
1.
E re c tio n o f th e s tr u c tu r a l p l a t e , a n d p la c e m e n t a n d c o m p a c tio n
of th e b a c k f ill a t th e s id e s of th e c u lv e r t, p ro d u c e d s ig n if ic a n t b e n d in g
s t r e s s e s in th e c u lv e r t p la te s a t th e s tr a in g a g e s i t e s .
2.
As th e f ill .w a s b ro u g h t .up on e a c h s id e of th e c u lv e r t, th e
s id e s d e f le c te d in w a rd a n d th e to p d e f le c te d u p w a rd .
T h is a c tio n
-118-
r e v e r s e d a s th e re m a in d e r o f th e f ill w a s p la c e d ; h o w e v e r , th e h o riz o n ta l
d ia m e te r n e v e r r e g a in e d i t s o rig in a l v a lu e a n d th e v e r tic a l d ia m e te r d e ­
c r e a s e d to a v a lu e s lig h tly l e s s th a n th e o r ig in a l.
3.
In g e n e r a l , th e lo a d on th e c u lv e r t re a c h e d i t s m axim um v a lu e
w ith in a m onth or tw o fo llo w in g c o m p le tio n o f th e e m b a n k m e n t, an d th e n
d e c r e a s e d s ig n if ic a n tly for a p e rio d o f a p p ro x im a te ly s ix m o n th s a fte r
w h ic h i t a p p e a re d to i n c r e a s e s lig h tly .
The in c r e a s e i s to o s m a l l , a n d
o f to o s h o rt d u r a tio n , to b e c o n s id e r e d a s ig n if ic a n t tre tid a t th is tim e
(M a y , 1 9 6 7 ).
4.
The d e m o n s tra te d good a g re e m e n t o r c o r r e la tio n atnong th e
fin d in g s from a l l o f th e m a jo r s e t s o f in s tru m e n ta tio n ; in c lu d in g s tr a in
g a g e s , s o il s t r e s s m e te rs o n th e c u lv e r t, s o il s t r e s s m e te rs in th e f i l l ,
ru b b e r d ia p h ra g m p r e s s u r e c e l l s , a n d s e ttle m e n t c e ll s ; p ro v e s b e y o n d a
r e a s o n a b le d d u b t th a t th e " im p e rfe c t tre n c h " fu n c tio n e d in e s s e n t i a l l y
th e e x p e c te d m a n n er a n d c a u s e d th e . lo a d on th e c u lv e r t to b e s u b s t a n t i a l i t ­
ie s s th a n th e w e ig h t o f th e o v e rly in g f i l l . .
5.
D u rin g th e e ig h t-m o n th p e rio d fo llo w ih g c o m p le tio n o f th e
ro a d w a y p a v e m e n t a b o v e th e c u lv e r t, th e r e h a s b e e n n o m e a s u ra b le
d if f e r e n tia l s e ttle m e n t o f t h e p a v e m e n t a ttr ib u ta b le to th e "im p e rfe tit
tre n c h " .
-1 1 9 -
R e c o m m e n d a tio n s
The i n s tr u m e n ta tio n of t h i s c u lv e r t w a s s u c c e s s f u l b u t th e re are
so m e ite m s t h a t s h o u ld b e c o n s i d e r e d for c h a n g e s or a d d i t i o n s in any
s im ila r fu tu re p r o j e c t . It a p p e a r s th a t s t r a i n g a g e s p l a c e d o n th e o u t­
s i d e of a c u l v e r t of t h i s t y p e , n e x t to th e f il l m a t e r i a l , a r e s u s c e p t i b l e
to d a m a g e or r a p id d e t e r i o r a t i o n a n d a r e n e ith e r n e c e s s a r y n o r p a r tic u la r ly
d e sira b le .
The s a m e g a g e s c o u ld b e m ore e a s i l y a n d p r o f ita b ly p la c e d
i n s i d e th e c u l v e r t .
The s t r e s s e s in th e c u lv e r t w a l l s , d e te r m in e d by th e s t r a i n g a g e s ,
i n d i c a t e d la r g e b e n d in g m o m en ts d u rin g c u l v e r t e r e c tio n a n d b a c k f illin g
o p e ra tio n s.
T h e s e b e n d in g s t r e s s e s a r e o fte n ig n o re d in c u l v e r t d e s i g n .
F u tu re r e s e a r c h s h o u ld b e c o n d u c te d to le a r n more a b o u t t h e m a g n itu d e of
a n d d i s t r i b u t i o n of t h e s e s t r e s s e s u n d e r d if f e r e n t lo a d in g c o n d i t i o n s .
A fe w of th e s t r e s s m e te rs i n d i c a t e d la r g e d ro p s in p r e s s u r e a fte r
t h e fu ll f il l h e ig h t w a s r e a c h e d a n d i t i s n o t know n if t h i s w a s c a u s e d
b y lo c a l a r c h in g a b o v e th e m e te rs or b y f a u l t y m e t e r s .
On fu tu re
i n s t a l l a t i o n s i t i s re c o m m e n d e d t h a t ru b b e r d ia p h ra g m p r e s s u r e c e l l s be
p l a c e d n e a r th e s t r e s s m e te rs a s c h e c k g a g e s , o n e for a n u m b e r of s t r e s s
m e te rs i f d e s i r e d .
S e ttle m e n t c e l l s c o u ld h a v e b e e n p l a c e d in th e fill a b o v e the.
s tr a w in o rd e r to d e te r m in e t h e s e t t l e m e n t of a h o r iz o n ta l p la n e a b o v e
-1 2 0 th e s tr a w l a y e r a n d on e a c h s i d e of i t .
A p la te on top of th e s tr a w ,
w e ld e d to a rod th a t p ro tr u d e s dow n in to a h o le in th e c u l v e r t ro o f , is
a n o th e r m e th o d w h ic h c o u ld b e u s e d to a d v a n t a g e o u s l y m e a s u r e s tra w
c o m p r e s s i o n . It i s re c o m m e n d e d t h a t b o th of t h e s e m e th o d s b e g iv e n
s e r io u s c o n s i d e r a t i o n for a n y s im ila r fu tu re p r o j e c t .
R e s e a r c h s h o u ld b e c o n d u c te d to d e te r m in e th e p ro p er h e ig h t a b o v e
a c u l v e r t a t w h ic h th e s tr a w s h o u ld be p l a c e d . If th e s tr a w i s p la c e d
to o h ig h , i t s p r e s s u r e r e l i e f e f f e c t w ill b e n u llif ie d b y t h e f r ic ti o n a l
d ra g fo r c e s on t h e s i d e s of th e s o i l b lo c k b e lo w th e s t r a w .
If s tra w
i s p l a c e d d i r e c t l y on to p o f t h e c u l v e r t , th e c u l v e r t m ig h t c o l l a p s e
from t h e s i d e s a s a r e s u l t o f i n s u f f i c i e n t v e r t i c a l s u p p o r t .
S in c e m o s t of th e i n s tr u m e n ts on th e r e b u i l t W o lf C r e e k c u lv e r t
a r e fu n c tio n in g s u c c e s s f u l l y , a s of M a y , 1 9 6 7 , i t is re c o m m e n d e d th a t
r e a d i n g s b e t a k e n p e r i o d i c a l l y for a s lo n g a tim e a s p o s s i b l e .
121
APPENDICES
APPENDIX. A
STRAIN GAGE COMPUTER PROGRAM
. AND PARTIAL OUTPUT .'DATA
- 12 3 -
FORTRAN c o m p u t e r p r o g r a m f o r d e t e r m i n i n g t h e ^ t r e s s . b e n d i n g
MOMENT AND EARTH PRESSURE FROM THE STRAIN GAGES
C
C STRESS CALCULATIONS, BENDING MOMENTS AND EARTH PRES­
SURES FOR WOLF CREEK CULVERT
DIMENSION I D (6) , YINTAL(S) ,X (6) , Y(S) ,ANAME(S)
DIMENSION BARX(20), ■A R E A ( 2 0 ) YSTR(20) ,XBAR(20)
1 FORMAT (3X, 12)
3 FORMAT (E14 „ 8) •
5 FORMAT (3X,I2 , SX^ E 1 4 .8 , SX ,E 1 4 . 8)
READ 3 , BLAST
READ 2 0 , (BARX(J), AREA(J), J = I , 20)
20 FORMAT (2 F 1 0 .6 )
4 READ 2, ANAME
KOUNT=O
2 FORMAT (8A4)
PRINT 9 ANAME
9 FORMAT (lH l,8 X ,p A 4 )
READ I , N
READ 4 0 , C O RP, CORM
4 O- FORMAT ( F 8 .3 ,F 1 1 .3 )
PRINT 4 5 , CORP
45 FORMAT ( 1 H 0 ,1 2 X ,3 3 H APPARENT EARTH PRESSURE (PSI) = F 1 5 .3 )
PRINT 4 6 , CORM
46 FORMAT .(13X, 3.7H ERECTION STRESS MOMENT (IN -LB /IN ) = F l 1 . 3.)
READ 5 , (ID(I) ,YINTAL(I) ,X(I) ,1=1 ,N)
6 READ 7 , IDATEl ,IDATE2 ,IDATE3 ,TEM P, COVER, (Y(I), I = I , N)
7 FORMAT (312 , 3X, 13,13!, SHFO6S)
C
C KOUNT SEQUENCE TO GET THREE SETS OF DATA TO A PAGE
KOUNT=KO UNT+1
IF(KDATE1)4, 9 9 , 8 8
88 IF(KOUNT~3)8, 8 , 8 9
89 KOUNT=I
PRINT 8 7 , ANAME
87 FORMAT (1H 1,8X ,8A 4)
. 8
DO 11 I=I-, N
C
C CALCULATE STRAIN AND DETERMINE STRESS
Y(I)=Y(I)-YINTAL(I)
LL Y(I)=Y(I)*ELAST
17 FORMAT (1 H O , 1 2X, 8H DATE = 1 2 , 1 H / , I 2 , 1 H / , I 2 , 15H TEMPERATURE
I = 1 3 , 9H I COVER.= 13)
- 124 -
19
FORMAT (20X ,3H G 1 2 ,6H X = F 7 .4 ,6 H Y = P U . 2)
PRINT 1 7 , ID A T E l, IDATE2 „IDATE3 , TEMP,COVER
PRINT T9, (ID ([),X ([), Y(I), I - 1 ,N )
C
C DETERMINE THE SLOPE OF THE STRESS LINE BY THE METHOD OF
LEAST SQUARES
SUMSQ=O. 0
SUMX = 0 . 0
SUMY=O. 0
SUMXY=O. 0
DO 140 1=1, N
SUMSQ=SUMSQ + X(I)**2
SUMX=SUMXfX(I)
SUMY=SUMYfY(I)
140 SUMXY=SUMXYfXCl)*Y(I)
XN=N
, SM =((SUM Y*8UM X)-(XN*SUM Y))/((SUM X**2)-(XN*SUM SQ))
SB=((SUMX*SUMXY)-(SUMY*SUMSQ))((SUMX**2)-'(XN*SUMSQ))
PRINT 1 4 5 , SM , SB
145 FORMAT ( lH O ,1 2 X ,llH SLOPE M = E 1 4 . 8 , 1 5 H INTERCEPT B =
I E 1 4 .8 )
X X = I.1875
YPOS = SM*XXfSB
PRINT 15 0 , YPOS
'
150 FORMAT (lH O ,1 9 X ,2 4 H STRESS AT SR4 GAGE 3 = ISX f F l l . 2)
IF(ABSF(YPOS)-3 0 0 0 0 .) 2 0 0 , 2 0 0 , 2 1 0
200 XX = - 1 . 1 8 7 5
YNEG=SM **XXf SB
PRINT TSSjYNEG.
155 FORMAT (20X ,25H STRESS AT SR4 GAGE 22 = 14K Y F11.2)
IF (ABSF(YNEG)-SOOOO. > 2 0 5 ,2 0 5 ,2 1 0
205 XX=O.0
YY=SM *XXf SB
PRINT 1 6 0 ,YY
160 FORMAT (2 0 X ,3 9 H STRESS AT CENTER SR4 GAGES I a n d 11 = F l I . 2)
C
C DETERMINE BENDING MOMENT AND EARTH PRESSURE
P=0.00433*Y Y -C O R P
' ■
' YAVE=YNEG-YY
YMOM=(YAVE)* 0 . 197-CO RM
PRINT 2 0 6 , P
206 FORMAT, (lH O ,1 2 X ,2 4 H EARTH PRESSURE (PSI) = F 8 .3 )
PRINT 2 0 7 ,YMOM
207
■
210
2 11
C
FORMAT (13X ,19H MOMENT IN -L B /IN = F 1 3 .3 )
GOTO 6
PRINT 2 Tl
FORMAT (! H O , 12X, 2 6H STRESS GREATER THAN YIELD)
DETERMINE BENDING MOMENT AND EARTH PRESSURE WHEN THE
STRESS IS GREATER' THAN THE YIELD STRESS
YY=O.0
XMOMT=-CORM
FORCE=O .0
.
21 DO 30 J = I . 20
YSTR(J)=BARX(J)*SM+SB
IF(YSTR(J)+30000 .) 3 3 ,2 9 ,3 1
3 1 IF (Y S T R (J )-3 0 0 0 0 .)2 9 ,2 9 ,3 2
33 Y STR (I)=-30000.
GO TO 29
33 YSTR(I)^OLLOO.
29 XMOMT=XMOMT-BARX(I)*YSTR(I)*AREA(I)/3.
30 F ORCE=FORC E+YS TR(I) *AREA (J) . .
PRESS=FORCE/324.)-CORP
PRINT 3 4 , PRESS
34 FORMAT (lH O ,1 2 X ,2 4 H EARTH PRESSURE (PSI) = F 8 .3 )
PRINT 3 5 , XMOMT
35 FORMAT (13X, 19H MOMENT IN -L B /IN = F l 3 . 3 )
GO TO 6
99 CALL .EXIT
END
-1 2 6 -
■PARTIAL OUTPUT DATA FROM STRAIN GAGE COMPUTER PROGRAM
PLATE. A
!I
X
i-H
f—I
D A T E = Il/ 9 / 6 5
■ TEMPERATURE.= 40
COVER = -1 8
Y = -21330.00
G 22 X = - 1 . 1 8 7 5
Y = -1 4 7 9 0 .0 0
G .2 X = - .8 1 2 5
Y = - 1 8 9 0 .0 0
G I X = 0.0000
0.0000
Y = - 1860.00
G
Y = 1 3 9 2 0 .0 0
G 33 X =
.8125
Y = 21090.00
G 3 X = 1 .1 8 7 5
SLOPE M = „ 1 7 7 9 9 3 9 7E+05
INTERCEPT B = - . 8 1 0 0 0 0 0 0 + 0 3
■ STRESS AT SR4 GAGE 3 =
•
2 0 3 2 6 .7 8
■STRESS AT SR4 GAGE 22 =
.
-2 1 9 4 6 .7 8
STRESS AT CENTER SR4 GAGES I AND 1 1 = 8 1 0 .0 0
EARTH PRESSURE (PSI) = - . 3 . 5 0 7 (C o rre c te d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
=
4
1
6
3
.
9
4
6
(C
o rre c te d to 0. 0 for re m a in in g
MOMENT TN -LB/IN
c o m p u ta tio n s )
COVER =
TEMPERATURE = 41
DATE= 1 2 / 2 / 6 5
■
Y = -3 2 0 7 0 .0 0
G 22.X = --1 .1 8 7 5
Y = - 2 2 1 7 0 .0 0
G 2 X = - - .8 1 2 5
Y = - 3 2 4 0 :0 0
G I X = 0 .0 0 0 0
Y = -3 1 8 0 .0 0
0
.
0
0
0
0
G 11 X =
Y = 1 7 8 2 0 .0 0
.8 1 2 5
G 33 X =
Y = 2 7 9 9 0 .0 0
G 3 X = 1 .1 8 7 5
INTERCEPT B = ■-. 24750000E+04
SLOPE M = . 25071849E+05
2 7 2 9 7 .8 2
STRESS AT SR4 GAGE 3 =
—
3
2 2 4 7 .8 2
STRESS AT SR4 GAGE 22
STRESS GREATER THAN YIELD
7 .1 0 3
EARTH PRESSURE (PSI) = M O M E N T 'IN -L B /IN
= -1 6 4 7 .7 1 2
DATE= I / 4 / 6 6
G 22 X
G 2X
G IX
G IL X
G 33 X
G 3 X
=
=
=
=
=
=
TEMPERATURE.= 2
Y = -4 1 1 6 0 .0 0
--1 .1 8 7 5 ,
Y = - 3 1 2 6 0 .0 0
-- .8 1 2 5
Y = -1 2 5 1 0 .0 0
0 .0 0 0 0
Y = - 1 2 1 8 0 .0 0
0 ,0 0 0 0
Y=
9 6 0 0 .0 0
.8 1 2 5
Y = 2 0 4 9 0 .0 0
1 .1 8 7 5
COVER =
'
-1 2 7 -
SLOPE.M = o25698566E+05
INTERCEPT B
STRESS AT SR4 GAGE 3 =
STRESS AT SR4.GAGE 22 =
STRESS GREATER.THAN YIELD
EARTH PRESSURE.(PSI) = 3 9 .9 5 9
MOMENT IN -L B /IN ' = - 1 2 7 6 .3 2 3
11170 000E+05
19347.0.4■
- 4 1 6 8 7 .0 4
-1 2 8 -
PLATE B
DATE= 1 1 / 9 / 6 5
TEMPERATURE = 40
COVER = -1 8
G 2 X = -.8 1 2 5
Y = -7 1 4 0 .0 0
G l X = 0 .0 0 0 0
Y = - 5 4 0 ,0 0
G S X = 1 .1 8 7 5
Y = 7 5 3 0 .0 0
SLOPE M = . 72954443E+04
INTERCEPT B = - . 96193052E+03
STRESS AT SR4 GAGE 3 =
7 7 0 1 .4 0
STRESS AT SR4 GAGE 22 =
-9 6 2 5 .2 7
STRESS AT CENTER SR4 GAGES I AND 11 = - 9 6 1 .9 3
EARTH PRESSURE (PSI) =— 4 . 1 6 5 (C o rre c te d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
MOMENT IN -L B /IN
= - 1 7 0 6 . 6 7 8 (C o rre c te d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
TEMPERATURE = 41
COVER
DATE = 1 2 / 2 /6 5
Y = -1 2 5 7 0 .0 0
G 2 X = -.8 1 2 5
Y = - 1 8 3 0 .0 0
G l X = 0. 0000
Y
= 1 2 3 3 0 .0 0
G 3 X = 1 .1 8 7 5
INTERCEPT B = -.22414285E-UM
SLOPE M = , 1 2 4 1 1429E+05
1 2 4 9 7 .1 4
STRESS AT S R -4 GAGE 3 ='
-1 6 9 7 9 .9 9
STRESS AT S R -4 GAGE 22=
STRESS AT CENTER SR-4 GAGES I AND 11 = - 2 2 4 1 .4 2
EARTH PRESSURE (PSI) = 5 .5 4 0
MOMENT IN -L B /IN
= „ -1 1 9 6 .8 2 0
COVER =
TEMPERATURE = 2
DATE = I / 4 / 6 6
Y = -2 1 3 0 0 .0 0
G 2 X = -.8 1 2 5
Y = - 5 6 4 0 .0 0
G l X = 0.0000
Y = 1 2 2 7 0 .0 0
G 3 X = 1 ,1 9 7 5
INTERCEPT B = - . 6 9 7 25 OSSjE-HM
SLOPE M = . 1 666077E+05
STRESS AT SR4 GAGE 3^=
1 2 8 1 1 .3 3
STRESS AT SR4 GAGE 22 =
-2 6 7 5 6 .3 5
STRESS AT jCENTER SR4 GAGES I AND 11 = - 6 9 7 2 .5 0
EARTH PRESSURE (PSI) = 2 6 .0 2 5
MOMENT IN -L B /IN
= -2 1 9 0 .7 3 8
83
-1 2 9 -
PLATE C
DATE = 1 1 / 8 /6 5
TEMPERATURE = 40
G 2.X = - . 8 1 2 5
Y = 1 8 6 0 .0 0
Y = - 3 3 0 .0 0
G l X = 0.0000
G 3 X = 1 .1 8 7 5
Y = -3 8 7 0 .0 0
SLOPE M = - „ 28735136E+04
INTERCEPT B =
COVER = -1 8
4 2 0 8 1 079E+03
STRESS AT SR4 GAGE 3 =
-3 8 3 3 .1 0
STRESS AT SR4 GAGE 22 =
2 9 9 1 .4 8
STRESS AT CENTER SR4 GAGES I AND 11 - - 4 2 0 .8 1
EARTH PRESSURE (PSI) = M O M E N T 'IN -L B /IN
=
1 .8 2 2 (C o rre c te d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
672 „223 (C o rre c te d to 0 „ 0 for re m a in in g
' c o m p u ta tio n s )
DATE = 1 2 / 2 /6 5
TEMPEkATURE = 41
G 2 X = -.8 1 2 5
Y = -4 3 5 0 .0 0
G l X = 0 .0 0 0 0 '
Y = -2 0 7 0 .0 0
G 3 X = I p1875
Y = 1 4 7 0 .0 0
SLOPE M = „ 29152124E+04
COVER =
INTERCEPT B = -„ 20144014E+04
STRESS AT SR4 GAGE 3 =
' 1 4 4 7 .4 1
■ STRESS AT SR4 GAGE 22 =
-5 4 7 6 .2 1
STRESS AT CENTER SR4 GAGES I AND 11 = - 2014 „40
EARTH PRESSURE (PSI) = 6 .9 0 0
MOMENT IN -L B /IN
= -1 3 5 4 .2 0 0
TEMPERATURE = 2
DATE = I / 4 /6 6 .
Y = -9 8 7 0 .0 0
G 2 X = -.8 1 2 5
G l X = 0.0000
Y = -7 5 0 0 .0 0
Y = -3 1 8 0 .0 0
G 3 X = 1 ,1 8 7 5
SLOPE M = . 33664866E+04
COVER
INTERCEPT B = - „ 72708105E+04
5
-1 3 0 -
STRESS AT SR4. GAGE 3 =
- 3 2 7 3 .1 0
STRESS AT.SR4 GAGE-22 =
-1 1 2 6 8 .5 1
STRESS AT CENTER SR4 GAGES I AND 11 = - 7 2 7 0 .8 1
EARTH PRESSURE (PSI) = 2 9 .6 6 0
MOMENT IN -L B /IN
= -1 4 5 9 .770
-1 3 1 -
PLATE. D
TEMPERATURE = '40
DATE.= 1 1 / 8 /6 5
Y = -6 6 9 0 .0 0
G 2 X = -.8 1 2 5
1 5 0 .0 0
G l X = 0.0000
Y=
Y = 9 5 7 0 .0 0
G 3 X ?= 1 .1 8 7 5
SLOPE M = „ 8 1 1 5 5 2 1 6E+04
COVER = - 1 8
INTERCEPT B = -.4 4 4 0 2 1 6 4 E + 0 1
STRESS AT SR4 GAGE 3 =
• 9 6 3 2 .7 4
STRESS AT SR4 GAGE 2 2 =
- 9 6 4 1 .6 2
STRESS AT CENTER SR4 GAGES I AND 11 = 4 .4 4
EARTH PRESSURE (PSI) = MOMENT IN -L B /IN
.0 1 9 (C o rre c te d to 0 . 0 for re m a in in g
com putations.)
= - 1 8 9 8 . 5 2 5 (C o rre c te d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
TEMPERATURE = 41
DATE = 1 2 / 2 /6 5 .
Y = -1 3 0 2 0 .0 0
G 2 X = -v 8 1 2 5
Y = - 1 4 7 0 .0 0
G l X = 0.6000
Y = 1 5 2 1 0 .0 0
G 3 X = 1 ,1 8 7 5
SLOPE M = . 14109962E+05
COVER =
■ INTERCEPT B = -.„ 15237453E+04
STRESS AT SR4 GAGE 3 =
.
.1 5 2 3 1 .8 3
STRESS AT SR4 GAGE 22 =
-1 8 2 7 9 .3 2
STRESS AT CENTER SR4 GAGES I AND 11 = -- 1 5 2 3 .7 4
EARTH PRESSURE (PSI) = 6 .5 7 8
M O M E N T 'IN -L B /IN
= -1 4 0 2 .3 2 4
TEMPERATURE = 2
DATE = I / 4 /6 6
■ Y = -2 3 0 4 0 .0 0
G 2 -X = - . 8 1 2 5
Y = - 8 1 6 0 .0 0
G l X = 0.0000
Y = 1 7 0 1 0 .0 0
G 3 X = 1 .1 8 7 5
SLOPE M = . 20110888E+05
COVER
' INTERCEPT B = - . 72.438608E+04
5
STRESS AT SR4 GAGE 3
STRESS AT SR4 GAGE;2 2
STRESS GREATER THAN YIELD
EARTH PRESSURE (PSI) = - 3 1 .3 5 7
MOMENT IN - L B /I N
= '- 2 7 7 3 . 8 7 5
1 6 6 3 7 .8 1
-3 1 1 2 5 ,5 3
-1 3 3 -
PLATE E
.DATE = 1 1 / 9 /6 5
TEMPERATURE.= 40
Y = - 6 8 7 0 .0 0
G 2 X = -.8 1 2 5
Y=
G I X = 0.000Q
.3 3 0 .0 0
Y=
8 0 1 0 .0 0
G 3 X = 1 .1 8 7 5
/ SLOPE M = o73686490E+04
COVER = - 1 8
INTERCEPT B = - .43108002E +03
. STRESS'AT SR4 GAGE 3 =
8 3 1 9 .1 8
STRESS AT SR4 GAGE 22 =
-9 1 8 1 .3 5
STRESS AT.CENTER SR4 GAGES I AND 11 = - 4 3 1 .0 8
EARTH PRESSURE (PSl) = MOMENT IN -L B /IN
1 .8 6 6 (C o rre c te d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
= - 1 7 2 3 . 8 0 3 (C o rre c te d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
TEMPERATURE = 41 ,
DATE = 1 2 / 2 /6 5
Y = -1 3 8 6 0 .0 0
G 2 X = -.8 1 2 5
Y = - 1 2 0 0 .0 0
G l X = 0.0000
Y = 1 3 7 1 0 .0 0
G 3 X = 1 .1 8 7 5
SLOPE M = .1 3 6 9 4 8 2 6 E + 0 5
COVER =
INTERCEPT B = - . 2 1 618532E+04
STRESS AT SR4 GAGE 3 =
1 4 1 0 0 .7 5
STRESS AT SR4 GAGE 22 =
. -1 8 4 2 4 .4 5
STRESS AT CENTER SR4 GAGES I AND 11 = - 2 1 6 1 .8 5
EARTH PRESSURE (PSI) = - ■ 7 .4 9 4
MOMENT Iltf-LB/IN
= -1 4 7 9 .9 3 0
.
TEMPERATURE
DATE = I / 4 / 6 6
Y -2 3 7 6 0 .0 0
G .2 X = - .80125
Y - 8 9 7 0 .0 0
G l X = 0.0000
5 3 1 0 .0 0
Y
G 3 X = 1 .1 8 7 5
SLOPE ME = : 143508882+05
COVER = 8 3
INTERCEPT B = - . 10933861E+05
5
—13 4 —
STRESS AT SR4 GAGE 3 =
6107.81
STRESS AT SR4 GAGE 22 =
-27975.54
STRESS AT CENTER SR4 GAGES I AND 11 = - 1 0 9 3 3 . 8 6
EARTH PRESSURE (PSI) = - 4 5 . 4 7 7
MOMENT IN -L B /IN
=-1633.407
-1 3 5 PLATE F
DATE
1 1 / 9 /6 5
G 2X
G I X
G 3 X
TEMPERATURE = 40'
-.8 1 2 5
Y = - -ssartLoo
0 .0 0 0 0
Y = - - 9 9 0 .0 0
1 .1 8 7 5
Y = -7 8 3 0 .0 0
SLOPE M = -;5 5 9 3 2 0 4 9 E + 0 4
COVER*? - 1 8
INTERCEPT B = - . 11308494E+04
STRESS AT SR4 GAGE 3 =
-7 7 7 2 ,7 8
STRESS AT SR4 GAGE 22 =
5 5 1 1 .0 8
STRESS AT CENTER SR4 GAGES I AND 11 = - 1 1 3 0 . 8 4
EARTH PRESSURE (PSI) = MOMENT IN -L B /IN
4 .8 9 6 . ( C o r r e c t e d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
= 1 3 0 8 .4 6 1 (C o rr e c te d to 0 . 0 for re m a in in g
c o m p u ta tio n s )
TEMPERATURE = 41
DATE = 1 2 / 2 /6 5
Y = -3 5 1 0 .0 0
G 2 X = -.8 1 2 5
Y = -1 1 4 0 .0 0
G l X = 0.0000
Y = - 3 6 0 .0 0
G 3 X = 1 .1 8 7 5
SLOPE M = . 15076448E+04
.
COVER =
5
INTERCEPT B = - . 18584554E+04
STRESS AT SR4 GAGE 3 =
6 8 .1 2
STRESS AT SR4 GAGE 22 =
-3 6 4 8 .7 8
STRESS AT CENTER SR4 GAGES I AND 11== - 1 8 5 8 . 4 5
EARTH PRESSURE (PSI) = 3 .1 5 1
MOMENT IN -L B /IN
= -1 6 6 1 .1 5 5
DATE
I / 4 /6 6
G 2X
G I X
G 3X
TEMPERATURE = 2
Y = -1 2 7 8 0 .0 0
-.8 1 2 5
Y = - 4 9 8 0 .0 0
0.0000
Y
= - 3 3 6 0 .0 0
1 .1 8 7 5
SLOPE M = . 44645562E+04
COVER =
INTERCEPT B = - . 7 5 9 8 0 693E+04
STRESS AT SR4 GAGE 3 =
- 2 2 9 6 .4 0
STRESS AT SR4,GAGE 22 =
-1 2 8 9 9 .7 2
STRESS AT CENTER SR4 GAGES I AND 1 1 = ' - 7 5 9 8 .0 6
83.
EARTH PRESSURE-(PSI) =
2 8 .0 0 3
MOMENT IN -L B /IN
= -2 3 5 2 .8 8 8
-137-
APPENDIX B
STRESS ■METER -COMPUTER.PROGRAM .
AND PARTIAL OUTPUT DATA
*
- 138 -
■FORTRAN COMPUTER PROGRAM FOR DETERMINING THE TEMPERATURE AND
EARTH PRESSURE FROM THE STRESS METERS
C
C
C
C
C TEMPERATURE AND EARTH PRESSURE CALCULATION FROM STRESS
METER FOR WOLF CREEK CULVERT
DIMENSION XTEMP(SO) ,RO(SO) ,XT(30) ,RTO(SO), TEMP(SO),
I CORR(SO) ,RR(SO) ,RRO(SO) ,XP(SO) ,ID (S O ), PRESS(SO)
READ 5 , N
5 FORMAT (15)
READ 1 0 , (ID (I),R O (I),X T (I),R T O (I),RRO(I) ,X P (I),1 = 1 ,N)
10 FORMAT ( 1 2 , 5 F 7 .2)
15 READ 20 , ID A T E l, IDATE2, !DATES , COVER, (RR(I) ,XTEMP(I) ,1=1, N)
20 FORMAT ( 3 1 2 ,1 3 ,5 ( F 7 . 2 , F 6 . 2 ) /
I (9X, F 7 .2 , F 6 . 2 , F 7 .2 , F6 .2 , F 7 .2 , F 6 . 2 , F 7 .2 , F 6 .2 ,E7.2 , F6 .2))
IF(IDATEl)2 5 , 9 9 , 2 5
25 DO 30 1 = 1 ,N
C DETERMINE TEMPERATURE
TEMP(I)=(XTEM P(I)-RO(I) *XT (I)
C '!DETERMINE TEMPERATURE CORRECTION
C ORR(I)= (XTEMP (I) -RTO (I)) *XT (I) / 1 0 00 .
RR(I)=RR(I)-CORR(I)
C DETERMINE THE EARTH PRESSURE
30 PRESS (I)=(RR(I)-RROd)) *XP(I)
PRINT 4 0 , ID A T E l, IDATE2, !DATES , COVER
40 FORMAT (1 H 1 , 3 ( / ! H O ) , 1 6X, SHDATE=I2 , I H / , 12 , I H / , 1 2 , 10X, 14H
1 COVER (FT) = 13)
PRINT 4 5 , (ID (I), TEMP (I), PRESS (I), I = I , N)
45 FORMAT (1H O , 17X, ISH CARLSON GAGE, 2X, 12H TEMPERATURE, 2X,
1 15H EARTH PR ESSU R E/lH , 2 2X, S H N O . , I OX, 6H D E G . F , I OX, 5H (PSI)
2 / / ( 1 H , I 2 4 , F16 „0 , F 1 6 . 2))
GO TO 15
99 CALL EXIT
END '
-139-
PARTIAL OUTPUT ,'DATA FROM THE STRESS METER COMPUTER PROGRAM
DATE = 1 / 4 / 6 6
CARLSON GAGE
NO „
1
2
3
4
5
6
7
8
10
11
12
13
14
■ 15
• 16
17
18
' 19
20
21
22
23
24
25
. 26
27
28
29
30
COVER (FT) = 83
TEMPERATURE
DEG „F
16.
H
o
13 o
12 o
I O o
14 o
14.
IQ/
9o
15 o
.9 .
I O o
10.
10,0
17.
10.
12.
14.
11.
9o
14.
16.
15.
36.
33.
30.
22.
32/
35.
.
'
EARTH PRESSURE
(PSI)
22.12
14.88
25.07
-15.03
29.41
23.08
33.64
35.98
95.60
1 8 .0 5
70.51
72.15
48.81
43.09
48.36
19.51
■1 9 .0 1
46.45
22.93
19.76
47.87
23.23
26.20
.88.27
31.49
10.99
47.07
5.86
80.70
'
'
-140-
COVER (FT) = 83
DATE = 1 1 / 1 / 6 6
CARLSON GAGE
NO o
TEMPERATURE
D E G 0F
EARTH PRESSURE
(PSD
1
2
3
4
5
6
7
8
10 ,
11
12
13 .
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
.30
38.
36.
37.
36.
36.
35.
37.
36.
36..
38.
36.
36.
37.
3,7.
38.
37.
40.
40.
38.
37.
40.
4 1.
40.
49.
51.
52. .
4 8.
52.
50.
23.42
16.37
i .4 0
-77.61
7.45
23.78
40.45
23;56
58.78
25.69
38:62
84.88
25.10
12.00
15.48
5.85
-11.35
7.96
4.56
6.83
23.18
33.92
.74
103.60
.56
2.01
10.12
- 1.65
26.83
'
'
-1 4 1 -
DATE.= 3 / 2 9 / 6 7
CARLSON GAGE
NO.
1
2
3
4
5
6
7
8
. 10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
2^
29
30
COVER.. (FT) = 83
TEMPERATURE
DEG. F
■3 8 .
37.
38.
' 36.
' 36.
36.
36.
36.
36.
37.
36.
36.
36.
36.
37.
37.
37.
38.
37.
36.
38.
38.
38.
39.
35.
37.
38.
36.
37.
.
EARTH PRESSURE
(PSI)
.3 1 .3 5
18.78
1 .0 7
-7 4 .6 5
.4 .9 4
2 6 .1 9
4 5 .8 4
2 8 .4 4
6 2 .4 9
.3 1 .1 4
5 2 .7 3
9 8 .3 5
3 3 .1 0
. 1 5 .5 8
1 5 .4 4
10.11
5 .7 0
.1 3 .4 7
9 .2 2
9 .7 1
.3 0 .0 0
2 9 .1 4
2.10
1 0 4 .1 8
.8 5
2,92
■1 6 .4 4
-3 .7 2
2 1 .6 5
■
■142-
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libraries
B e h a v io r o f t h e
reconstructed 'Xolf
C reek c u l v e r t .