OF
GEQMETRICAL
?HOTDGRAMMETRIC DETERMINATION
PARAMETERS OF SUSPENJ:D CABLE
BRIDGE~
ktor GREGOR, Paval BARTOS, AS50ciate Professors,
Slovak Technical
U~lyers!ty,
rSPRS
Bratislavi,
:ze:h~slovakla
Commission V.
Abstr-act
The basic condition
poi nt o·f
e~
cr reconstruction of strGctures is determination of their real spatial form. From the
cf accuracy required es we21 as the economy cf measurement, the analytlcal photogrammetry is
the most convenient
method
for
determination
Coordinates of detai: points cf the
of
geometrie
parameters
of
5u5pended
cab e
bridges.
idge stru:ture are transformed into the object coordinate system anti
yield information about the symmetry cr assymetry of the structure with regard to the longitudinal sxis of
the bridse.
One of the main aims of the paper i5 the application
2.
n
2.
n a 1 yt i c Cl 1
p hot Cl ;; ;'
a mmet r i
i:
S cf
t war e ORI ENT f 0 r
determination cf structure parameters.
Key words : Cable br-ieigE, Reconstruc:ti
L
. r2';--geting,tiJ etric CCl.mera. Object cooniina.te '"titel!;. ORIENT.
this
INTRüDUCTI ON
article.
the
turned
it
convenient method was the
The original
deforms
or distorts
stru:ture
winds
shape
the
n time
corrOSlon,
milaT t. as
load.
~
BS
a
result
intermittent
estanr,
the t4inter port
metr
graduall
of
accuracy 15
the
cross
terrestrial
weIl
65
phctogram-
€lw-point of the required
and that from the
the
economy
of
rneasuring
war
the ease of
s'.lspended cable
anti
structure
Br
When measuring the
NelahozevBs
spat al
shape
of
the
suspenaed cabis bridges by means of the
islavat
mmetri
method we used the
of the
intersection
that eed deo
enables
the
bridges
the
relatively unambiguous
points
to
The
~
reiSDn
solution is
dentifl the detail points.
cable
case
of the analyt
be
determined
yen
sodification
'r
photogrammetrv,
faVDUf
the PQssibility
the
anal
9
?hotogra-
In
cableccH-tpling
dentificaticn of
even when
making
menocular measurements on single pictures.
2. MEASUREMENT METHODOLCSY
All the given photogrammetry 8Pplications have
more cr less the f
cwing operations in comman:
- surveying measurement -a quadrangle is the basis
of the miCfonet created by the end points of the
photogrammetric base linss,
- contral point targetlng - utilization of artifiFig.l The ball target
ci"d as \<lel as t:stural tar'get!,
- phatography
One of the basic conditions fer the construction
as weIl as the
reccnstruction
of
building
structures is the determinatlon of their actual
u~iver5al
wide-angle metri
camera
determination of the spatial position 0f
detail
UMK 10A Zeiss Jena,
points of the structure by means of spatial
intersect on in the IDeal coordinate system cf
spatial shape. Out of the measuring methods that
counted with regard to the applications siven in
one base line,
259
analytical spatial intersection and at the same ti-
- transformation of detail points coordinates into
the
structure
coordinate
system,
whereby the
me they are the standpoints for determining contral
X - axis is identieal with its longitudinallxis
points that are used to adjust coordinates of
(Bregor, 1991),
structures detail points determined
by
the
means
of
the photogrammetric method.
The basic
geometrie
parameters
of
the
eheeked
eahle bridges are given in Table 1.
2.2 TARGETING
Main parameters of bridges
Ta target the control points
Table 1
surveying
ßuspended
cable bridge
Bridge Distance of Max.elble Pylone
length anchoring
sag
height
utilized
m
direction of
the
camera
axis.
At
116.2
7.0
12.25
places we used points of the structure.
Nelahozeves
160.03
233.6
14.0
22.B5
be unambiguously identified, as
Winter port
165.95
225.9
15.4
25.05
Together with
2.1 SURYEYINB MEASUREMENT
gle was created by four elmera
terminal
points
of
standpoints.
that
photogrammetric
base
lines flanking on botM sides of
quadrangle was
measured
the
angles
bv
quadran-
lengths using the EOT 2000
Zeiss
meter. By using the forced
centering
bridge.
as
Jena
the accuracy of point determination
weIl
we
wide-angle universal camera
al
projection
ane
UMK
10A
proved to be the optimum eamera type,
ean
targets.
optimum
pair
of
bridges
the
Zeiss
Jena
whereby
it
was in all cases possible ta take photographs with
secured
a
a
aceuracy is a functien of
mean
horizontal
camera
axis.The
the
photogrammetry
photograph
scale,
and therefore we try to ehoose the photogrammetric
base lines as near to the
spatial position of
the
for
During the measurements af the given
The
eoordinate error mxy = 0.004 m.
Tne surveying mieronet points
the
2.3 PHOTOBRAPHY
distance-
with
points
that
natural
the orientation point
number gives 5 contral
photographs.
from
inaccessible
76.23
means
perpen-
dicularlY to the direction of the eamera axis, and
partly ball targets (Fig.i) independent
The surveying micronet in the sMape of a
partly
circular
target) with the possibility to turn them
blocks
Piestany
we
targets on a tripod (Frei berg
define
partly
centers
for
measured
structure
as
the
possible. However,
the
quired aeeuracy. in the given case less than 30mm.
the decisive faetar i5 the re-
Fig.2 The numbering system of the structures detail points.
260
82
6'.1'17:':-'-6'#'
......... ........
.
........
.
~\
. ........
'"
\
\
BJ7
8
l3J;VJ
10
8Jll
- --~7 - - - - ------ ---- VS1'- - - eS7
8
es~vs
10
es"
\.
b
. _ . _ . _ . _ . _ . _ . _ . _ . - . _1 . _ . - . _ . _ . _ . _ . _ . - . _ .
roOm
~
bc~================~!---------------------!
Fig.3 The coordinate
atem of the cable br dge
2~
Under
the
condition
that
lha whole bridge
COMPUTATIONS
phcto9raph cnord nates
Wl
be taken on one photograph, the distances
were measured
base lines fcr the wide-angle
stereocomparatnr.
The
structures
points
Jena ranged f
the
required
60 to 150
accuracy,
achieve the optimum rat
ffi,
~ameri
sno
0
UMK 10A Zeiss
what partl
enables
ta
t.oor
bJy - ".
y
detai
mein
detai 1
es
85
18 :3 Zeiss
cf a
numbering
5
system
the
ven in fig. 2 • The
were
pol
Jena
cal
two phases:
!
nts
- determination of spatial coordinates
taken
ng
axes
were
sensiti
crientatec
nts targeted Gn
g1as5
plates
6 DIN.
;n8
CG
ty of
towards
the
in the leeal
Topo
coordinat~
system of the phctogram-
metric base 11n9, utilizing
camera.
equations
'ar
the
spatial intersection.
orientaticr,
Me
- tt.3.nsfof'
ion
rom the
Deal coordinate
intc the structures system with the
the longitudinal bridge axis (Fig,3)
261
system
X-axis
es
In the
Winter
~ase
of the 5uspended table bridge
port
we
utilized
the
in
TMe form of polynomii:!l
the
software
ORIENT
(1)
software ealculation is
modified for ttH: ORIENT
fDI~owin9!
(ORIENT. 1991 bsside the given traditional routine.
The main contribution cf the
the
given
ease
i
aetual eable course
the
c
GRIENT
software
of
determination
compared
to its
(2)
1n
the
4f1
theoretical
2:
(fictitious! shape defined by a quadrat c parabola
according to
g. 4 . The graphlcal compariscn
f
5
4f
b
2
As for the suspended cable bridges there are. from
ths-
z
"{pes üf
x
of
ew poi
tao
;.-::..:t:;
their
spat al
tw~
l
carrying cables that are in
A
PDsition,
the
XZ
plane,
a;
shClwn in tig, 5,
- lateral cable; that in the case
port bridge lay
average by 31.75
Fig.4 The quadrat
in
a
plane
of
the
inclined
Winter
on
c,
paranoIa of the
heoretical share of cable.
166000m
165S64m
P1! :.~.~.090rn
I
+0,079~.1 : P2
+ O.~~.~•••• ••
··· ...+0.215
......
H
".
....
+.~•••'.~.~.....
•.....~~••~43
\i
+ 0.09~•.• ••
~\
r.\
11
"
"
.........
11
-0.343
\.
·1
11
fI
- - - Theoretical cable
........... Measured cable
\
U
Fig.5 Theoretical and measured cable.
When havins a uniforml
dl
buted load the cab s
will take a position. that may be expressed bt the
polYffionial (Agocs,i980):
where
1 -
f
is tne
se of the cable
the horizon al cab e
ength
262
the
CONCLUSION
F:EFEHENCES
Th9 results of measuring the actual shape
suspended table bridges
structures
photogrammetr
tha.t
confirm
of
the
method
s
Agocs, Z
Some
:~80.
Theoretical
Problems of Cable Structures.
this
convenient for similar applications. The
F.acu.l )'
utiliza-
Civil En9i
pe,ges,(i
Structural
Habilitation
wor ,
ing STU. Brat slavs,
slovaki.
tion of the phatogrammetr c ORIENT software i5
the given Cise a contribut on
the
0
cf the structures detailed points
camputation
coordinates
weIl as to the computation and comparison
real and fictit DUS shapes
of
the
the
Building Structures.
cbzor. 37, Nr. lB. Pp. 21m-214. (in slovakl,
are valuable
actual
time basic data for the
B.S
recanstructioG
Gecdeticky
a
Selected
and
kartograficky
compa r son
of the structure for the designer and at tMe
bridges
the Reccnstruction of
of
a
about the
for
carrying
lateral cables. The results of such
informat~on5
Measurements
PhotD9rammetric
t991~
Gregor,V, ,Bartos,F'.,
a5
cf
stete
OHr
199 • Tne
same
menc
F'ad:age,
versal Photcgrammetr c AdjustReference
University of Vienna,
tab e
weIl.
263
i"lanual.
Technical