Download - Undisturbed Slope Analysis for Section 4
-
8/2/2019 Undisturbed Slope Analysis for Section 4
1/27
-
8/2/2019 Undisturbed Slope Analysis for Section 4
2/27
Undisturbed Slope Analysis for Section D-D ( Before Cut and Fill )
Slope analysis 1
The Contour View shows the possible slip surface and the safety factor of 1.576 indicates it
is safe from slipping
Slice information
Slice 1 - Morgenstern-Price Method
2.1372
0.86163
2.0915
0.84606
0.039251
-
8/2/2019 Undisturbed Slope Analysis for Section 4
3/27
Critical slice - Morgenstern-Price Method
Factor of Safety 1.5764
Phi Angle 33
C (Strength) 0 kPa
C (Force) 0 kN
Pore Water Pressure 0 kPa
Pore Water Force 0 kN
Pore Air Pressure 0 kPa
Pore Air Force 0 kN
Phi B Angle 0
Slice Width 0.62806 m
Mid-Height 0.21268 m
Base Length 0.8783 m
Base Angle -44.35
Anisotropic Strength Mod. 1
Applied Lambda 0.5344
Weight (incl. Vert. Seismic) 2.1372 kN
Base Normal Force 2.0915 kN
Base Normal Stress 2.3813 kPa
Base Shear Res. Force -1.3582 kN
Base Shear Res. Stress -1.5464 kPa
Base Shear Mob. Force -0.86163 kN
Base Shear Mob. Stress -0.98102 kPa
Left Side Normal Force 0 kNLeft Side Shear Force 0 kN
Right Side Normal Force 0.84606 kN
Right Side Shear Force 0.039251 kN
Horizontal Seismic Force 0 kN
Point Load 0 kN
Reinforcement Load Used 0 kN
Reinf. Shear Load Used 0 kN
Surface Pressure Load 0 kN
Polygon Closure 0.032058 kN
Top Left Coordinate 63.114m, 34.377m
Top Right Coordinate 63.742m, 34.189m
Bottom Left Coordinate 63.114m, 34.377m
Bottom Right Coordinate 63.742m, 33.763m
-
8/2/2019 Undisturbed Slope Analysis for Section 4
4/27
Cohesive vs Distance
Co
hes
ive
(k
Pa
)
Distance (m)
-1
0
1
0 5 10 15 20 25
Frictional vs Distance
Fr
ic
tiona
l(
kPa
)
Distance (m)
0
5
10
15
20
25
0 5 10 15 20 25
Shear Strengthl vs
Distance
Shear
Streng
th
(kPa
)
Distance (m)
0
5
10
15
20
25
0 5 10 15 20 25
Shear Mobilized vs
Distance
Shear
Mo
bilize
d
(kPa
)
Distance (m)
0
2
4
6
8
10
12
14
0 5 10 15 20 25
-
8/2/2019 Undisturbed Slope Analysis for Section 4
5/27
Slope analysis 2
The Contour View shows the possible slip surface and the safety factor of1.541 indicates it is
safe from slipping
Slice Information
-
8/2/2019 Undisturbed Slope Analysis for Section 4
6/27
Critical slice - Morgenstern-Price Method
Factor of Safety 1.5406
Phi Angle 33
C (Strength) 0 kPa
C (Force) 0 kN
Pore Water Pressure 0 kPa
Pore Water Force 0 kN
Pore Air Pressure 0 kPa
Pore Air Force 0 kN
Phi B Angle 0
Slice Width 0.4771 mMid-Height 0.21863 m
Base Length 0.79642 m
Base Angle -53.199
Anisotropic Strength Mod. 1
Applied Lambda 0.5558
Weight (incl. Vert. Seismic) 1.6689 kN
Base Normal Force 1.7174 kN
Base Normal Stress 2.1564 kPa
Base Shear Res. Force -1.1153 kN
Base Shear Res. Stress -1.4004 kPa
Base Shear Mob. Force -0.72395 kN
Base Shear Mob. Stress -0.90901 kPa
Left Side Normal Force 0 kN
Left Side Shear Force 0 kN
Right Side Normal Force 0.94301 kN
Right Side Shear Force 0.060403 kN
Horizontal Seismic Force 0 kN
Point Load 0 kN
Reinforcement Load Used 0 kN
Reinf. Shear Load Used 0 kN
Surface Pressure Load 0 kN
Polygon Closure 0.008587 kN
Top Left Coordinate 192.24m, 10.802m
Top Right Coordinate 192.72m, 10.601m
Bottom Left Coordinate 192.24m, 10.802m
Bottom Right Coordinate 192.72m, 10.164m
-
8/2/2019 Undisturbed Slope Analysis for Section 4
7/27
Cohesive vs Distance
Co
hes
ive
(kPa
)
Distance (m)
-1
0
1
0 5 10 15
Frictional vs Distance
Fr
ic
tiona
l
(kPa
)
Distance (m)
0
5
10
15
20
25
0 5 10 15
Shear strength vsDistance
Shear
Streng
th
(kPa
)
Distance (m)
0
5
10
15
20
25
0 5 10 15
Shear mobilized vsDistance
Shear
Mo
bilize
d
(kPa
)
Distance (m)
0
5
10
15
0 5 10 15
-
8/2/2019 Undisturbed Slope Analysis for Section 4
8/27
Slope Analysis for Section D-D ( After Cut, Fill and Loading )
The loadings of 5 storeys apartment, double storeys terrace house, car park and roads was
then key in. 6 critical locations has been chosen to carried out the slope analysis, where only
2 locations past the required factor of safety.
Location 1
The Contour View shows the possible slip surface and the safety factor of1.580 indicates it is
safe from slipping
-
8/2/2019 Undisturbed Slope Analysis for Section 4
9/27
Critical slice information
Factor of Safety 1.58
Phi Angle 37
C (Strength) 0 kPa
C (Force) 0 kN
Pore Water Pressure 0 kPa
Pore Water Force 0 kN
Pore Air Pressure 0 kPa
Pore Air Force 0 kN
Phi B Angle 0
Slice Width 0.17112 m
Mid-Height 0.14424 m
Base Length 0.43044 mBase Angle -66.575
Anisotropic Strength Mod. 1
Applied Lambda 0.6237
Weight (incl. Vert. Seismic) 0.46899 kN
Base Normal Force 0.53166 kN
Base Normal Stress 1.2351 kPa
Base Shear Res. Force -0.40063 kN
Base Shear Res. Stress -0.93075 kPa
Base Shear Mob. Force -0.25356 kN
Base Shear Mob. Stress -0.58907 kPa
Left Side Normal Force 0 kN
Left Side Shear Force 0 kN
Right Side Normal Force 0.3864 kN
Right Side Shear Force 0.024961 kN
Horizontal Seismic Force 0 kN
Point Load 0 kN
Reinforcement Load Used 0 kN
Reinf. Shear Load Used 0 kN
Surface Pressure Load 0 kN
Polygon Closure 0.0026583 kN
Top Left Coordinate 0.22192m, 49.662m
Top Right Coordinate 0.39304m, 49.555m
Bottom Left Coordinate 0.22192m, 49.662m
Bottom Right Coordinate 0.39304m, 49.267m
-
8/2/2019 Undisturbed Slope Analysis for Section 4
10/27
Cohesive vs Distance
Co
hes
ive
(kPa
)
Distance (m)
-1
0
1
0 1 2 3 4 5 6 7
Frictional vs Distance
Fr
ic
tiona
l
(kPa
)
Distance (m)
0
2
4
6
8
10
12
14
0 1 2 3 4 5 6 7
Shear strengthl vs
Distance
Shear
Streng
th
(kPa
)
Distance (m)
0
2
4
6
8
10
12
14
0 1 2 3 4 5 6 7
Shear Mobilizedl vs
Distance
Shear
Mo
bilize
d
(kPa
)
Distance (m)
0
1
2
3
4
5
6
7
8
0 1 2 3 4 5 6 7
-
8/2/2019 Undisturbed Slope Analysis for Section 4
11/27
Location 2
The Contour View shows the possible slip surface and the safety factor of1.241 indicates it is
not safe and will slip.
Slice information
-
8/2/2019 Undisturbed Slope Analysis for Section 4
12/27
Critical slice - Morgenstern-Price Method
Factor of Safety 1.241
Phi Angle 37
C (Strength) 0 kPa
C (Force) 0 kN
Pore Water Pressure 0 kPa
Pore Water Force 0 kN
Pore Air Pressure 0 kPa
Pore Air Force 0 kN
Phi B Angle 0
Slice Width 0.16887 m
Mid-Height 0.16416 m
Base Length 0.3692 m
Base Angle -62.78 Anisotropic Strength Mod. 1
Applied Lambda 0.7916
Weight (incl. Vert. Seismic) 0.52671 kN
Base Normal Force 0.50554 kN
Base Normal Stress 1.3693 kPa
Base Shear Res. Force -0.38095 kN
Base Shear Res. Stress -1.0318 kPa
Base Shear Mob. Force -0.30697 kN
Base Shear Mob. Stress -0.83145 kPa
Left Side Normal Force 0 kN
Left Side Shear Force 0 kN
Right Side Normal Force 0.30971 kN
Right Side Shear Force 0.022495 kN
Horizontal Seismic Force 0 kN
Point Load 0 kN
Reinforcement Load Used 0 kN
Reinf. Shear Load Used 0 kN
Surface Pressure Load 0 kN
Polygon Closure 0.0052671 kN
Top Left Coordinate 12.325m, 43m
Top Right Coordinate 12.493m, 43m
Bottom Left Coordinate 12.325m, 43m
Bottom Right Coordinate 12.493m, 42.672m
-
8/2/2019 Undisturbed Slope Analysis for Section 4
13/27
Cohesive vs Distance
Co
hes
ive
(k
Pa
)
Distance (m)
-1
0
1
0 1 2 3 4 5 6 7 8
Frictional vs Distance
Fr
ic
tiona
l(
kPa
)
Distance (m)
0
2
4
6
8
10
12
14
16
0 1 2 3 4 5 6 7 8
Shear Strenglth vsDistance
Shear
Streng
th
(kPa
)
Distance (m)
0
2
4
6
8
10
12
14
16
0 1 2 3 4 5 6 7 8
Shear Mobilized vsDistance
Shear
Mo
bilize
d
(kPa
)
Distance (m)
0
2
4
6
8
10
12
14
0 1 2 3 4 5 6 7 8
-
8/2/2019 Undisturbed Slope Analysis for Section 4
14/27
Location 3
The Contour View shows the possible slip surface and the safety factor of1.653 indicates it is
safe from slipping
Slice information
-
8/2/2019 Undisturbed Slope Analysis for Section 4
15/27
Critical Slice - Morgenstern-Price Method
Factor of Safety 1.6533
Phi Angle 37
C (Strength) 0 kPa
C (Force) 0 kN
Pore Water Pressure 0 kPa
Pore Water Force 0 kN
Pore Air Pressure 0 kPa
Pore Air Force 0 kN
Phi B Angle 0
Slice Width 0.3904 m
Mid-Height 0.20764 m
Base Length 0.76527 m
Base Angle -59.326 Anisotropic Strength Mod. 1
Applied Lambda 0.6101
Weight (incl. Vert. Seismic) 1.5402 kN
Base Normal Force 1.6322 kN
Base Normal Stress 2.1329 kPa
Base Shear Res. Force -1.2299 kN
Base Shear Res. Stress -1.6072 kPa
Base Shear Mob. Force -0.7439 kN
Base Shear Mob. Stress -0.97208 kPa
Left Side Normal Force 0 kN
Left Side Shear Force 0 kN
Right Side Normal Force 1.0275 kN
Right Side Shear Force 0.067717 kN
Horizontal Seismic Force 0 kN
Point Load 0 kN
Reinforcement Load Used 0 kN
Reinf. Shear Load Used 0 kN
Surface Pressure Load 0 kN
Polygon Closure 0.008161 kN
Top Left Coordinate 1.7672m, 48.7m
Top Right Coordinate 2.1576m, 48.458m
Bottom Left Coordinate 1.7672m, 48.7m
Bottom Right Coordinate 2.1576m, 48.042m
-
8/2/2019 Undisturbed Slope Analysis for Section 4
16/27
Cohesive vs Distance
Co
hes
ive
(k
Pa
)
Distance (m)
-1
0
1
0 2 4 6 8 10 12 14
Frictional vs Distance
Fr
ic
tiona
l(
kPa
)
Distance (m)
0
10
20
30
0 2 4 6 8 10 12 14
Shear strength vsDistance
Shear
Streng
th
(kPa
)
Distance (m)
0
10
20
30
0 2 4 6 8 10 12 14
Shear Mobilized vsDistance
Shear
Mo
bilize
d
(kPa
)
Distance (m)
0
2
4
6
8
10
12
14
16
18
0 2 4 6 8 10 12 14
-
8/2/2019 Undisturbed Slope Analysis for Section 4
17/27
Location 4
The Contour View shows the possible slip surface and the safety factor of0.333 indicates it is
not safe and will slip.
Slice information
-
8/2/2019 Undisturbed Slope Analysis for Section 4
18/27
Critical slice - Morgenstern-Price Method
Factor of Safety 0.33339
Phi Angle 45
C (Strength) 0 kPa
C (Force) 0 kN
Pore Water Pressure 0 kPa
Pore Water Force 0 kN
Pore Air Pressure 0 kPa
Pore Air Force 0 kN
Phi B Angle 0
Slice Width 0.0089 m
Mid-Height 0.019248 m
Base Length 0.039496 m
Base Angle -76.977 Anisotropic Strength Mod. 1
Applied Lambda 1.725
Weight (incl. Vert. Seismic) 0.0034236 kN
Base Normal Force 0.028926 kN
Base Normal Stress 0.73238 kPa
Base Shear Res. Force -0.028926 kN
Base Shear Res. Stress -0.73238 kPa
Base Shear Mob. Force -0.086764 kN
Base Shear Mob. Stress -2.1968 kPa
Left Side Normal Force 0 kN
Left Side Shear Force 0 kN
Right Side Normal Force 0.0078465 kN
Right Side Shear Force 0.0014994 kN
Horizontal Seismic Force 0 kN
Point Load 0 kN
Reinforcement Load Used 0 kN
Reinf. Shear Load Used 0 kN
Surface Pressure Load 0.08897 kN
Polygon Closure 0.0013345 kN
Top Left Coordinate 105.88m, 11m
Top Right Coordinate 105.89m, 11m
Bottom Left Coordinate 105.88m, 11m
Bottom Right Coordinate 105.89m, 10.961m
-
8/2/2019 Undisturbed Slope Analysis for Section 4
19/27
Cohesive vs Distance
Co
hes
ive
(k
Pa
)
Distance (m)
-1
0
1
0 0.1 0.20.3 0.4 0.5 0.6 0.70.8 0.9
Frictional vs Distance
Fr
ic
tiona
l(
kPa
)
Distance (m)
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
Shear strength vs
Distance
Shear
Streng
th
(kPa
)
Distance (m)
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
Shear moblilized vs
Distance
Shear
Mo
bilize
d
(kPa
)
Distance (m)
0
1
2
3
4
5
6
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
-
8/2/2019 Undisturbed Slope Analysis for Section 4
20/27
Location 5
The Contour View shows the possible slip surface and the safety factor of0.250 indicates it is
not safe and will slip.
Slice information
Slice 1 - Morgenstern-Price Method
0.0002267
0.00021591
6e-005
5.9071e-005
8.3089e-006
-
8/2/2019 Undisturbed Slope Analysis for Section 4
21/27
Critical slice - Morgenstern-Price Method
Factor of Safety 0.24953
Phi Angle 37
C (Strength) 0 kPa
C (Force) 0 kN
Pore Water Pressure 0 kPa
Pore Water Force 0 kN
Pore Air Pressure 0 kPa
Pore Air Force 0 kN
Phi B Angle 0
Slice Width 0.0011 m
Mid-Height 0.011054 m
Base Length 0.022135 m
Base Angle -87.152 Anisotropic Strength Mod. 1
Applied Lambda 10.12
Weight (incl. Vert. Seismic) 0.0002267 kN
Base Normal Force 7.1496e-005 kN
Base Normal Stress 0.00323 kPa
Base Shear Res. Force -5.3876e-005 kN
Base Shear Res. Stress -0.002434 kPa
Base Shear Mob. Force -0.00021591 kN
Base Shear Mob. Stress -0.0097543 kPa
Left Side Normal Force 0 kN
Left Side Shear Force 0 kN
Right Side Normal Force 5.9071e-005 kN
Right Side Shear Force 8.3089e-006 kN
Horizontal Seismic Force 0 kN
Point Load 0 kN
Reinforcement Load Used 0 kN
Reinf. Shear Load Used 0 kN
Surface Pressure Load 0 kN
Polygon Closure 1.1335e-006 kN
Top Left Coordinate 163.89m, 9.5m
Top Right Coordinate 163.89m, 9.5m
Bottom Left Coordinate 163.89m, 9.5m
Bottom Right Coordinate 163.89m, 9.4779m
-
8/2/2019 Undisturbed Slope Analysis for Section 4
22/27
Cohesive vs Distance
Co
hes
ive
(k
Pa
)
Distance (m)
-1
0
1
0 0.5 1 1.5
Frictional vs Distance
Fr
ic
tiona
l(
kPa
)
Distance (m)
0
1
2
3
0 0.5 1 1.5
Shear strengthl vs
Distance
Shear
Streng
th
(kPa
)
Distance (m)
0
1
2
3
0 0.5 1 1.5
Shear mobilized vs
Distance
Shear
Mo
bilize
d
(kPa
)
Distance (m)
0
2
4
6
8
10
0 0.5 1 1.5
-
8/2/2019 Undisturbed Slope Analysis for Section 4
23/27
Location 6
The Contour View shows the possible slip surface and the safety factor of0.644 indicates it is
not safe and will slip.
Slice information
-
8/2/2019 Undisturbed Slope Analysis for Section 4
24/27
Critical slice - Morgenstern-Price Method
Factor of Safety 0.64379
Phi Angle 29
C (Strength) 5 kPa
C (Force) 1.519 kN
Pore Water Pressure 0 kPa
Pore Water Force 0 kN
Pore Air Pressure 0 kPa
Pore Air Force 0 kN
Phi B Angle 0
Slice Width 0.0719 m
Mid-Height 0.14756 m
Base Length 0.3038 m
Base Angle -76.31 Anisotropic Strength Mod. 1
Applied Lambda 0.0005
Weight (incl. Vert. Seismic) 0.20154 kN
Base Normal Force 1.2757 kN
Base Normal Stress 4.1991 kPa
Base Shear Res. Force -0.81188 kN
Base Shear Res. Stress -2.6724 kPa
Base Shear Mob. Force -1.2611 kN
Base Shear Mob. Stress -4.1511 kPa
Left Side Normal Force 0 kN
Left Side Shear Force 0 kN
Right Side Normal Force 1.5218 kN
Right Side Shear Force 7.2132e-005 kN
Horizontal Seismic Force 0 kN
Point Load 0 kN
Reinforcement Load Used 0 kN
Reinf. Shear Load Used 0 kN
Surface Pressure Load 0.71777 kN
Polygon Closure 0.007609 kN
Top Left Coordinate 215.7m, 6.5015m
Top Right Coordinate 215.77m, 6.5014m
Bottom Left Coordinate 215.7m, 6.5015m
Bottom Right Coordinate 215.77m, 6.2063m
-
8/2/2019 Undisturbed Slope Analysis for Section 4
25/27
Cohesive vs Distance
Co
hes
ive
(k
Pa
)
Distance (m)
4.5
5
5.5
0 1 2 3 4 5
Cohesive vs Distance
Fr
ic
tiona
l(
kPa
)
Distance (m)
-5
0
5
10
15
20
0 1 2 3 4 5
Shear strength vs
Distance
Shear
Streng
th
(kPa
)
Distance (m)
0
5
10
15
20
25
0 1 2 3 4 5
Shear Mobilized vs
Distance
Shear
Mo
bilize
d
(kPa
)
Distance (m)
0
10
20
30
40
0 1 2 3 4 5
-
8/2/2019 Undisturbed Slope Analysis for Section 4
26/27
Comments on slope analyses section D-D :
Location 1, 2, 3 :
Local soil failure occurs when the shear strength is mobilized in a limited zone of the subsoil.
General slope failure occurs when kinematic conditions are such that the soil mass can
experiencelarge displacements. Slopes are generally characterized by non-uniform stress field.Additional stresses induced by changes in boundary conditions can emphasize local
differences in the stress level. As a consequence, every failure process is, at first, local, with
formation of plastic zones, then general.
Our analyses on these 3 locations justified what is explained. Location 1 and 2 are the local
analyses and we get the value factor of safety of 1.58 and 1.241, which are safe and unsafe
respectively. However, location 3 is the global analyse and the factor of safety is 1.653 which
is safe from slipping. This mean that location 2 will have a possibility of local failure first and
cause the general failure at location 3 although location 3 is show safe during analyse.
i) Apply man made surface drainange and control water infiltration.As rain water infiltrates a slope, it definitely increase the moisture content, causing a
lowring of the soil suction in unsaturested zone and making the pore pressures less
negative, hence lowering the shear strengths of the soil. In addition, sufficient
rainfall and infiltration uphill of a slope can raise the water table in the slope.
Furthermore, the wetting of the soil mass makes it heavier and causing destabilizing
forces to increase. Thus, we can cover the slope surface by some thin gabion with
siemen or install geotextile to act as man made surface drainage in order to prevent
the infiltration of rainfall water. Besides that, it can be added man made concretegullies to properly drain down the surface water. These surface structure must be
free of cracs and be well maintained.
ii) Soil nailing
Soil nailing is a technique in which soil slopes, excavations or retaining walls are
reinforced by the insertion of relatively slender elements - normally steel reinforcing
bars. The bars are usually installed into a pre-drilled hole and then grouted into
place or drilled and grouted simultaneously. They are usually installed untensioned
at a slight downward inclination. A rigid or flexible facing (often sprayed concrete) or
isolated soil nail heads may be used at the surface.
Location 4 :
Since the reduce level was already attained from the planning location map, the cut was
planned in a way to suit the best angle in order to allow the structure to maintain the
architectural requirements. At location 4 and 5 , the slope is cut straight at 90 degree and isside by side with the structure of buildings.
http://en.wikipedia.org/wiki/Earthworks_%28engineering%29http://en.wikipedia.org/wiki/Grouthttp://en.wikipedia.org/wiki/Grouthttp://en.wikipedia.org/wiki/Earthworks_%28engineering%29 -
8/2/2019 Undisturbed Slope Analysis for Section 4
27/27
Hence, the slope will be straight forward supported by the structure of builidngs with
ground anchored inserted.
Location 6 :
In location 6, we will assigned a retaining wall next to the road. A retaining wall is astructure designed and constructed to resist the lateral pressure of soil when there is a
desired change in ground elevation that exceeds the angle of repose of the soil. The active
pressure increases on the retaining wall proportionally from zero at the upper grade level to
a maximum value at the lowest depth of the wall. After installation of retaining wall, our
slope factor of safety is apparently increase from 0.644 to 2.027