ENGINEERING
TECHNICAL
FIELD
INFORMATION
TECHNICAL
NOTES
DATA
REPORTS
CURRENT
RETRIEVAL
TEXTS
AWARENESS
SYSTEM
Field
Volume
4
f
Numbers
9 and 10
a Massively
Thomas
K.
Thomas W.
S
October 1972
of
and
Billie
Crankcase
G. Hicks
Oils
Stockdale
Preservation
F.
-
Unstable Region
Collins
Classification
George
September
Geology
Engineering
in
Notes
-_
of Tree
Land Corners
Butts
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NOTES
FIELD
REGION
A MASSIVELY UNSTABLE
EARLY DETECTION OF SLIP-SURFACE GEOMETRY
ENGINEERING
By
GEOLOGY
IN
Thomas K. Collins and Billie G. Hicks
Klamath National Forest Region 5--California
The Klamath
National Forest in northern California contains one of
most landslide-prone regions of the world.
High rainfall steep
slopes and weak foundation materials have combined to produce
hundreds of landslides.
The greatest instability is found in the
the
western part of the Forest in a zone 20 miles wide centered along
the Klamath River.
Graphitic slates and serpentinized-ultrabasic
rocks are especially unstable in this zone.
on the Klamath Forest about 70 miles of new roads are
timber harvesting and recreational access.
One of the jobs
of the engineering geologists is to make foundation studies for road
route planning
and design.
The foundation studies provide
location
data for building roads which will have the least impact
in terms of
triggering new landslides or reactivating dormant landslides.
The
following deals with one aspect of these foundation studies Making
a preliminary estimate of slip-surface geometry based
on the field
expression of head scarps and lateral scarps.
Every year
built
for
ROADS AND
INCIPIENT
LANDSLIDES
massively unstable zone on the Klamath National Forest one
common situations encountered during reconnaissance
engineering geology is the discovery of a ground crack across a
The ground crack may be very subtle but it
proposed road route.
can usually be traced up the slope then across the slope and
finally down the slope to where it crosses the proposed road route
A landslide is developing
and the ground
crack marks the
again.
In the
of
the
trace
of
the
and lateral scarps.
If
the landslide is
scarp
the scarps
will be visible and their angles can be
head
more developed
measured.
con-struction
on this field data the effect of the landslide on road
must be determined.
How large and how deep is the
landslide
What
is the shape
of the slip surface
and will the road
cut slope undermine it
with
other
foundation
Along
conditions
some estimates of the landslide geometry must be made to determine
Based
1.
Whether
this
section of
causing unacceptable
at
Engineering
Geologists held
1971
can be built
without
resource damage
Annual Meeting of the Association of
in Portland Ore.
1/Presented
the
road
1
What
2.
to
alteration of design standards
may be required
the landslide with least disturbance
and
cross
Whether
potential maintenance costs or resource damage
justifies expenditures for landslide stabilization.
3.
pro-gram
On the Klamath Forest evaluation of incipient
landslides must
be
made
without
benefit
of
and
seismic
drilling
usually
exploration.
The landslides are usually inaccessible
by hiking and there
except
are so many landslides that the cost of a detailed exploration
for each one is prohibitive.
field evidence was
Therefore
examined to see what clues there might be to the size and shape of
the slip surface.
Scores
of landslides in various stages
of
examined.
We
found
that
the
topographic expression
development were
of ground cracks head
scarps and lateral scarps on some incipient
landslides could
be used to make rough estimates of slip-surface
These
projections were found most applicable to slumps
geometry.
and to bedrock failures
e.g. wedge failures.
slip-surface
addition
reconnaissance
geometric analysis
exploration program
The preliminary estimate of
on existing
roads._
the
geometry guided
placement of drill holes and seismic
foundation
data with least cost and
spreads to obtain maximum
of
the
a better
estimate
exploration costs.
proposed
In
to
location
road
this
pro-vided
in drawing up
was helpful
for landslides
LANDSLIDE
a drilling and
seismic
WIDTH
stability analysis usually pictures a landslide in longitudinal
cross
section from the crown to the foot.
Based on the known slope
distance and the elevation difference of the crown and the foot
various hypothetical slip surfaces
are fitted to the longitudinal
When the only limiting conditions are the slope
cross section.
distance and the elevation difference between crown and foot then
many slip surfaces must be considered in safety factor analysis
and many geometric variations from the actual slip surface must be
Slope
considered.
determine the slip-surface geometry
especially depth more
Landslide
the width of a landslide can be very useful.
accurately
width can lead to more realistic boundary limits than landslide
Three problems are found in using length
length slope distance.
To
alone
1.
As
time
passes
the
head
scarp
often continues
to
fail
the crown migrates upslope.
The potentiality of
many variations in landslide length introduces many
variations in estimating slip-surface geometry especially
On most landslides
width is a more stable boundary
depth.
measurement.
In general length will change more than width.
and
2
2.
length is a greater distance than
the length may be 800 feet and the
width 200 feet.
If only the length and width are known
there is more room for errors in determining the depth
of the slide surface by using length rather than width.
On many landslides
width.
3.
TRANSVERSE
example
For
Length alone will not indicate the correct orientation
Some
of the longitudinal profile of a slip surface.
landslides e.g. wedge failures do not move directly
down the dip of the slope they move at some angle to
the dip of the slope.
By considering the symmetry or
asymmetry of the width boundaries lateral scarps the
orientation of the slip surface can be better located.
PROFILES
A landslide can be viewed along
its width by a transverse cross
section just as its length can be viewed by a longitudinal cross
section.
Some typical transverse profiles of slip surfaces can be
After the landslide debris
examined
on existing slope failures.
has moved downslope out of the source
area the slip surface is
Field
examination
of
numerous
exposed
slip surfaces reveals
exposed.
similar to the profiles in
transverse profiles of slip surfaces
of bedrock failures
1.
The
is
characteristic
V-shaped
figure
profile
controlled by major geological structures
such
as faults and bedding
The U-shaped profile is characteristic of failures in
planes.
as soil and marine
or weakly consolidated materials such
terrace deposits.
uncon-solidated
it is possible to obtain a rough
Using this schematic geometry
of
surface
on many landslides.
For example
depth
approximation
slip
fail.
A
fresh
head
and
lateral
hillside
has
started
to
a
scarp
In plan view fig.
the lateral scarps
are
are visible.
scarps
the
width
of
the
landslide
is
therefore
fairly
roughly parallel
constant.
The width measured from the left to right lateral scarp
4
is
100
feet.
lateral scarp
2
In transverse profile fig.
dip 450 and measure 5 feet
each
the
in
left
slope
and
right
distance.
is likely to reach
the maximum depth that the slip surface
The 450 lateral scarps are projected to maximum
will be considered.
depth in this case 50 feet See transverse profile of slip surface A
in fig. 2.
A wedge failure along
the intersection of two faults
could
such
a
produce
V-shaped profile.
However unless there is
evidence to suggest a wedge failure the slip surface will probably
the slip surface
not have such a steep
Instead
V-shpaed profile.
the lateral scarps
will be more U-shaped.
Based on this assumption
Transverse
be
to
more
transverse
can
projected
probable
profiles.
First
profiles
U-shapes.
B C
The
and
D
in figure
general
shape
2
and
are projections of some typical
maximum depth of profiles
B C
3
and
Figure
1.
--Transverse Profiles
Landslide
4
of
Slip Surfaces
ORIGINAL
GROUND SURFACE
LATERAL
S
CARP
LANDSLIDE
D
0
SURFACE
--
- - --/
41
C
10
20
30
B
\
00
/
40
50
VERTICAL
Figure
2.
CROSS
SECTION
--Transverse Profiles
Landslide
of
Slip Surfaces
D are based on field measurements of exposed
on
slip surfaces found
On landslides having a U-shaped slip surface such
other
landslides.
slumps
as
consolidated materials the maximum depth from the
surface to the slip surface often ranges from 10 to
the landslide width.
in weakly
initial ground
percent of
35
Depending on how much of the lateral scarp is exposed and on the
the estimated
shape of the ground surface
range for maximum depth
can be narrowed down even further.
Also the topographic expression
of other
landslides in the area may provide some clues to the shape
maximum depth of the transverse profile to be projected.
For
example colluvium in a certain area might usually fail on a bedding
the slip surface will
plane which parallels the slope therefore
have a longer flatter central profile than a deep slump would have.
Another aid is the head scarp.
The angle of the head scarp can be
measured and a probable slip surface can be projected from it onto a
and
Then the slip surface on the longitudinal
longitudinal cross section.
cross section can be correlated with the slip surface on the transverse
cross section.
The geometry of the slip surface can be further
delimited by interpretation of the boundary scarp of the landslide.
PLAN VIEW
The boundary
the
left
of
lateral
can
plan views
scarp
Two
shapes
of
a landslide includes
scarp
right
both the head
The plan view
scarps.
sometimes indicate the general shape of
and
slip
are illustrated
in
figure
3
as
of
the
the
scarp
and
boundary
slip
surface.
representative
of
two
surfaces.
In plan view A the boundary scarp
has an inverted
The
V-shape.
distinctive feature is the asymmetry and linearity of the lateral
The trace of one or both lateral scarps on the ground
scarps.
surface does not run directly down the dip of the slope.
A linear
lateral scarp which trends downslope at a large angle to the dip of
the slope is characteristic of many landslides controlled by a major
geological structure e.g. a fault a bedding plane or a prominent
When major geological structures are planar their trace on
joint.
a uniform slope is linear.
When randomly orientated planar
structures
are involved
in landslides
they often produce linear asymmetrical
lateral scarps.
For a given slope the trend of the lateral scarp
will depend on the strike and dip of the planar
structure.
On
controlled by the intersection of two planar surfaces
the
transverse profile of the slip surface from lateral scarp to lateral
will usually have an asymmetrical.V-shape fig.
scarp
item A.
land-slides
1
3
B
In the second
item
plan view fig.
the trace of the head scarp
on the ground surface is a curve and the traces of the lateral
are rough symmetrical lines which trend directly down the
scarps
dip of the slope.
Sometimes
the boundary scarp will include only
6
B
Figure
3.
--Landslide
Plan View
7
Boundary
Scarps
The significance of the
head scarp to the rough symmetrical lateral
the
from a steep to a more gentle dip along
type of landslide the transverse profile of
from the left to the right lateral scarp is
the
curved
COMPARISON
section.
OF THE
TWO
from the
change
scarps
is
the
curved
change
On this
slip surface.
the slip surface taken
U-shaped.
PLAN VIEWS
first plan view the asymmetry and linearity of the boundary
characteristic of landslides controlled by major geological
The landslide
i.e. faults bedding plans and joints.
structures
In the
are
scarp
can
be
viewed
failure
as
in
an
anisotropic
medium.
In
the
second
uncon-solidated
view
boundary scarp
and
in weakly consolidated
are characteristic of landslides
materials e.g. colluvium and marine terrace deposits.
In some
the landslide can be viewed as failure in an
respects
plan
the
curve
and
the
rough
symmetry
of
the
isotropic medium.
THE
CHORD
A landslide whose boundary scarp has a plan view similar to figure 4
often has a slip surface which drops off steeply from the crown and
the lateral scarps
then
flattens
out between
to an angle
approximately
the
The longitudinal
equal to or less than
original ground slope.
profile of the slip surface in figure 5 is a schematic representation
the actual slip
of this relationship.
This profile is diagrammatic
be
On
the
view
in
4 a chord
surface may
more curved.
plan
figure
line is drawn which connects
the extremities of the curve
of the
and which lies within the plane
of the original ground surface.
crown
From the top of the crown a perpendicular line to the chord can be
constructed which lies within the plane
of the original ground surface.
The slope distance along
this perpendicular line is labeled
In
S.
5
D
longitudinal cross section fig.
a perpendicular line labeled
surface is constructed from the chord to
to the original ground
the slip surface.
This perpendicular line will intersect the slip
surface near the area along which the slip surface abruptly changes
from a steep
to
a more gentle
is a
dip.
Perpendicular line
D
If
approximation of the maximum depth to the slip surface.
of the head scarp
and the original ground slope are known
angle
can be solved trigonometrically.
For example
depth
line
rough
the
the
D
50
feet
S
Slope
crown
distance
to
500
Angle
of head
250
Angle
of
from
top
of
chord
scarp
original ground slope
8
rn
D
n
D
N
cý
o
v
a
6
1HS
SCARP
1da31d1
LATERAL
dýdýS
LEFT
1
rn
ý
$
o
HEADSCARP
50
j
/
Gj
PROJECTION
OF CHORD
s
o
SýýpE
\
ýPNp
/
/
VERTICAL
i ýPQ
PROý\MP
Figure
5.
--Longitudinal Profile of
Landslide Slip Surface
CROSS
SECTION
D
S
Tan
of
angle
of head
scarp
-
angle
original ground slope
D
50
Tan
D
23
feet
50
- 25
0
portion of the slip surface from the crown to the abrupt
the
and not as continuously steep
as
dip may be curved
the angle
of the head
head scarp it is usually best to decrease
will
used in the formula by several degrees depth
scarp
Since
the
change
in
D
corre-spondingly
be
reduced.
SUMMARY
measure-ments
gathering all field measurements which limit the topographic
expression of the slip surface and then correlating these
in longitudinal and transverse cross section the geometry of
This geometric
a slip surface can be estimated within certain
ranges.
but it is not
helpful on numerous landslides
analysis has been found
By
The
cases presented are
meant to apply to all landslides.
general
meant as guides.
The
of unstable slopes will often
complex
causes
For example
produce many variations from this schematic geometry.
the plan view of a boundary scarp
in an isotropic medium may be
rather
than symmetrical because of the non-uniform
asymmetrical
distribution of ground water.
work is continuing on these and other aspects
of slip-surface
More
data
some
of
these
initial
modify
geometric
geometry.
may
The
is
to
the
best
3-dimensional
projections.
goal
put together
picture of the slip surface that limited data permits.
Field
CLASSIFICATION OF CRANKCASE
OILS
com-bined
By
Thomas
W.
Stockdale
Region 3--Albuquerque
conditions
under which internal combustion engines
have been
operating have gradually become more severe.
These
conditions
with anti-pollution devices
and higher operating temperature
have made it necessary to develop higher gradecrankcase
lubricating
The
oils.
For many
The user
the
MIL
years there was no one industry-wide rating system for oils.
of a MIL specification found
it very difficult to correlate
specification with an SAE specification
for example.
11
SAE
American Petroleum
Recently the Society of Automative Engineers
Institute
American Society of Testing Material
many
and the military combined forces
to
of the vehicle manufacturers
classification
The
set
of
and
one
specifications
system.
develop one
API
ASTM
desig-nations
following two
and
charts
show
descriptions
the
of
latest
each
in
oil
the
the previous
classes
normal gasoline and commercial
categories
New
API
Old Class
Crankcase Oil Classification
Gasoline Engine Type
New
Class
SA
ML
-
Description of Oil
oil w/o
Mild conditions
additive except possibly
a foam depressant
anti-oxidant
and antiscuff.
MM
Minimum protection
afforded by
some antioxidant
SB
compound-ing
and
antiscuff
capa-bilities.
In use since
1930s.
MS1964
SC
Covers
1964-1967
manu-facturers
warranty low
temperature antisludge and
antirust performance.
MS1968
SD
Covers
1968-1971
manu-facturers
warranty more
protection against low
temperature antisludge
and antirust performance.
May be
None
SE
used
in
place of
SC.
Covers
highest
require-ments
of 1972 model
vehicles high
temperature
antioxidation plus low
temperature antisludge
and
Note
designated in the
station type
lubricants for gasoline
Oils
to
service
12
S
antirust.
series
crankcase
engines.
refer
New
API
Crankcase
Oil
Classification
-
Commercial Engine Type
Old Class
old
MIL-A
MIL-B
Sup.
1
old
old
New
Class
Description of Oil
diesel with
quality fuel and mild
gasoline
engine service.
Used in late 1940s and
1950s.
Normal
protection from
corrosion and deposits.
CA
Light
DG
duty
aspira-tion
MIL-A
MIL-B
Moderate duty diesel
with low quality fuel and
mild gasoline
engine
Introduction in
service.
1949.
Normal aspiration
protection from corrosion
CB
CB
1
Sup.
DM
old
old
and
deposits.
super-S-3
MIL-B
Moderate
CC
101-B
DM
duty
diesel and
lightly
Introduced in.
charged.
1961.
Protection from
gasoline
old
high
temperature deposits
diesel
only
engines
and low
rust
tempera-ture
corrosion
deposits.
DS
duty diesel with
supercharger and in high
MIL-L-45199B
speed high output
S-3
CD
Severe
pro-tection
from corrosion
high temperature deposits
with any fuel range.
Note
C
designated in the
series refer
commercial type crankcase
lubricants for
gasoline and diesel engines.
Oils
to
Dou-bling
SA and
SB
pumps
furnace
older engines
only or general lubrication for
and electric.motors.
SD type oils are much
better than SC especially in rusting and deposit
resistance.
the zinc dithosphate
from 0.09
to 0.18 percent has helped make
the SE type oil.
Other additives
include sulfurized phenates and
oils
are
for
blowers
13
The SE type oil may be used in place
calcium alkyl phenyl sulfides.
The new classification for both normal gasoline
of SD or SC oils.
engine oils and commercial engine oils is open ended new categories
Manufacturers
may be added without changing the old designation.
needs
and petroleum companies
may indicate
may indicate lubrication
suitability by the new classification.
However
overall testing of SE oils is handled by the ASTM.
General Motors
assist
in the testing.
manufacturers
also
auto
many
for low temperature rust and high temperature
for example tests
for oil insolubles
Ford tests
sludge
lubricating qualitie6.
manufacturers
also help in the
Other
formation and varnishing.
The U.S.
testing.
Department of Defense tests for bearing corrosion
The cost to be qualified is approximately
in the SE type oils.
The
$8000.
SE
it
be used when the
type oils should always
Most
and manuals.
in his owners guides
station wagons
require
1/2
SE
manufacturer
all
1972
Chevrolet recommends
oil.
recommends
sedans
and
SE
for
oil
3/4.and 1-ton trucks.
Dodge and Ford recommend
SD quality oils.
However a driver may want to use SE oil after
summarizing his specific driving habits loads trailer pulling
1972
their
grease-like
accessories
oil
switch
and
on
to
the
SE
speeds.
driver notices
a
a
solidified
draining oil low
oil might solve the problem.
dip
type
If
stick
slow
oil
pressure
a
A number of oils are now available that may be used as a single
lubricant source for all types of equipment--from the sedan station
wagon light truck variety to large turbocharged crawler-type diesel
tractors.
These
so-called goofproof-type oils enable a diversified
and
fleet to use only one oil.which saves on time inventory
oils may
It is important to note however that many of these
be rated
SE or CD but not both.
Depending upon the type of
a fleet manager may not want to consider oils that do not meet
con-fusion.
equip-ment
highest quality
the
in
levels
boththe normal gasoline
and
commercial
categories.
in providing a crankcase oil
requirements of Caterpillar and the
low ash content
To meet
the warranty
requirements of Detroit Diesel.
must be less
requirements for Detroit Dieselthe total ash content
than 1 percent.
Most of the diversified type fleet oils rated CD
will meet Caterpillar and Detroit Diesel specifications.
These oils
may be used without restriction in all Forest Service diesel
In
the
that
past
would
some difficulty has
meet both the Series
arisen
3
equip-ment.
In
summary with
and
oils
difficult
has
for
most
the
controls
fleet
definitely taken
regulations becoming more strict
the classification
of crankcase
for the better.
The API SAE ASTM
and
manager
a step
14
have combined
Department of Defense and many automotive companies
in providing a most useful
and practical classification
of crankcase
oils.
In most cases the quality of oil required by the manufacturers
owners guides and manuals is satisfactory.
It may be beneficial to use higher quality
recommended by the manufacturer especially
class
one
of
oil in
vehicles
all
in a
lubricants
if
than
those
it is possible
fleet.
By
LAND
CORNERS
to use
using one class it
is possible to save
on storage space
take
advantage of bulk prices
and eliminate the possibility of a lower grade oil being used in an
engine requiring the highest quality lubricant.
PRESERVATION
By
OF TREE
George F. Butts Registered Land Surveyor
Green Mountain National Forest
How
should we remonument a living tree corner
This question was
asked in the Restoration and Monumentation Committee LSD ACSM in
March of 1971.
Our discussion of a method developed and used on the
Green Mountain National Forest seemed to answer
the question.
A
written procedure of this method may assist other
in
surveyors
answering the same question.
This method uses a 5/8-inch
diameter by 36-inch long copperweld survey
marker with a brass head as a reference marker.
Normally two
markers per corner tree are used however three or four are used
when conditions
dictate.
The markers are driven
flush with the
ground very close to the tree but not so close that the growing
tree will displace the marker.
The
flush markers
are not easily
seen
and possibly misinterperted by lay users of the
property bounds.
The
flush markers resist being displaced
by falling
timber logging
vehicles
or other traffic.
When setting the markers good reference
must
be practiced.
marking
A dimple is cut in the brass head to mark
the
on
exact
the
point
1
marker.
Object No.
The
exact
point
of
the
tree
by
set
up
surveyor
developed
at
over
of
On
reference and
Forest we
our
BO-2
ofa
the
this
to obtain
follows
etc.
corner
1-foot
point
the
tree
an identifying character is stamped
generally stamp BO-1 Bearing
is
generally accepted as the center
instrument cannot
Because an
stump height.
a procedure must be used
required measurements.
15
The
that enables the
procedure we
1.
The
2.
With
copperweld
the
rods
bearing
instrument occupying
to corner tree
distances C-12
and
angle
to BO-1 to
set
are
C-12
BO-1
see
to BO-2
corner
described above.
as
fig.
angle
measured
are
tree
1
and
C-12
and
BO-1 to BO-2
are
preserve the actual side shot on the tree a
tack
is placed for sight
and a nail placed on the side
survey
of the tree for distance
so that observations from BO-1 will
define the exact
corner point as near as may be determined
without cutting
the tree.
Figure 2 shows a typical view of
taken.
a
3.
4.
To
corner
The
tree
as
seen
from
the
instrument.
instrument is moved to BO-2
to BO-1
and
BO-2
D-1.
to
C-12
B9-2
to
tree
corner
to
corner
tree
and
are
are
C-12 to D-1.
angles
turned
and distances
C-12
measured.
trees center from BO-2 need not be
If a
enough to detect major blunders.
closed
run sufficient observations have been
made to detect
large blunders in the remaining lines.
The
error generated by a short backsight is eliminated by
The
determination of
exact
the
accurate
only
traverse
is
sighting on
C-12
from BO-2.
CORNER TREE
STA
-2
11116
/
STA C-12
Figure
1.
--Diagram
16
of traverse.
D-I
A
TACK
NAIL
Figure
2.
--Corner
tree
tack and
In
addition
showing
nail.
being recognized by laymen living trees
other land corner monument possesses--they
to
have
an
dis-appearance
advantage
impossible to move.
no
The
trees
are however
subject
to
are
nearly
rapid
bulldozers or other hazards.
by fire hurricane
If the
tree is destroyed
corner
the exact
corner
can be precisely relocated
with little effort from the copperweld markers.
If only one marker
remains
the
bearing
thus
EDITORS
NOTE
exact
the
corner
can
be
original corner
relocated by running the proper
point
is preserved.
Note that the copperweld monument is used for a
reference mark.
Actual legal land corner monuments
installed under the Forest Service Cadastral
Program must meet or exceed standards
in FSM 7150.
Engineer-ing
17
CORRECTIONS
for
1972--Whos
Field
Who
in
4
Volume
Numbers 7 and 8 July-August
Washington Office Division of Engineering.
Notes
the
1
On page
Richard G. Deleissegues name was inadvertently
Please line out
misspelled and placed in the wrong position.
Data System
Dicks name and leave that position Technical
Place Mr. Deleissegues name in the position marked
vacant.
Recruitment
Development
vacant at the top of page 2 Technical
and
Training.
4
The Photographic Laboratory has moved to Rosslyn Va.
page
to area code 703
Ralph Fortunes phone number has changed
On
557-3150.
On
5
page
extension
third
to
paragraph
Change
70491.
18
William
R.
Kinworthys phone