SLOPE/W Analysis | Assignment

Question two
Solution
Depth factor, Df = 12
6 =2=nd
The slope angle, ß = ta n−1
( 1
2.5 )=21.801 °
Where by 21.801˚ is less than 53 ˚
Ø = 0
Stability number = 6.1 from the Taylor’s chart (Scott, 2013)
So Ns = r × H × F
Cu
F is given by F = Ns × Cu
r × H
Where r= 19kN/m3
Cu= 45kPa
H= 6m
Therefore F= Ns × Cu
r × H = 6.1 × 45
19 ×6 =2.408
The type of critical slip circle is midpoint circle, nd=2
Question three
The data from Geo studio software, Bishop’s stability
Solution
SLOPE/W Analysis
Report generated using GeoStudio 2018 R2. Copyright © 1991-2018 GEOSLOPE International Ltd.
File Information
File Version: 9.01
Revision Number: 13
Date: 04/04/2020
Time: 17:41:17
Tool Version: 9.1.1.16749
File Name: DOUGLAS.gsz

Directory: C:\Users\HP\Desktop\
Last Solved Date: 04/04/2020
Last Solved Time: 17:41:23
Project Settings
Unit System: International System of Units (SI)
Analysis Settings
SLOPE/W Analysis
Kind: SLOPE/W
Method: Bishop
Settings
PWP Conditions from: Piezometric Line
Apply Phreatic Correction: No
Use Staged Rapid Drawdown: No
Limit State Design Approach: BS8006: 1995 Section 7
Unit Weight of Water: 9.807 kN/m³
Slip Surface
Direction of movement: Left to Right
Use Passive Mode: No
Slip Surface Option: Entry and Exit
Critical slip surfaces saved: 1
Optimize Critical Slip Surface Location: Yes
Optimizations Settings
Maximum Iterations: 2,000
Convergence Tolerance: 1e-07
Starting Points: 8
Ending Points: 16
Complete Passes per Insertion: 1
Driving Side Maximum Convex Angle: 5 °
Resisting Side Maximum Convex Angle: 1 °
Tension Crack Option: (none)
Distribution
ODF Calculation Option: Constant
Advanced
Geometry Settings
Minimum Slip Surface Depth: 0.1 m
Number of Slices: 30
Overdesign Factor Convergence Settings
Maximum Number of Iterations: 100
Tolerable difference in ODF: 0.001

Materials
SILTSTONE ( VERY STRONG)
Model: Bedrock (Impenetrable)
Pore Water Pressure
Piezometric Line: 1
SILTY CLAY, STIFF (FBS)
Model: Mohr-Coulomb
Unit Weight: 17.8 kN/m³
Cohesion': 70 kPa
Phi': 32 °
Phi-B: 0 °
Pore Water Pressure
Piezometric Line: 1
SILTY CLAY, FIRM (CIS)
Model: Mohr-Coulomb
Unit Weight: 16 kN/m³
Cohesion': 40 kPa
Phi': 0 °
Phi-B: 0 °
Pore Water Pressure
Piezometric Line: 1
GRAVELLY SAND (FILL)
Model: Mohr-Coulomb
Unit Weight: 18.6 kN/m³
Cohesion': 0 kPa
Phi': 35 °
Phi-B: 0 °
Pore Water Pressure
Piezometric Line: 1
Slip Surface Entry and Exit
Left Type: Range
Left-Zone Left Coordinate: (15, 25) m
Left-Zone Right Coordinate: (30, 25) m
Left-Zone Increment: 8
Right Type: Range
Right-Zone Left Coordinate: (53, 35) m
Right-Zone Right Coordinate: (67, 35) m
Right-Zone Increment: 8
Radius Increments: 4

Slip Surface Limits
Left Coordinate: (15, 25) m
Right Coordinate: (100, 35) m
Piezometric Lines
Piezometric Line 1
Coordinates
X Y
Coordinate
1 15 m 25 m
Coordinate
2 15 m 33 m
Coordinate
3 100 m 33 m
Seismic Coefficients
Horz Seismic Coef.: 0.1
Vert Seismic Coef.: 0.03
Design Factor Set: BS8006: 1995 Section 7
Permanent Point Loads & Surcharge Loads: Favorable = 1, Unfavorable = 1.2
Variable Point Loads & Surcharge Loads: Favorable = 1, Unfavorable = 1.3
Soil Unit Weight: Favorable = 1, Unfavorable = 1.5
Effective Cohesion: 1.6
Effective Coefficient of Friction: 1
Undrained Strength: 1
Shear Strength (Other Models): 1
Pullout Resistance: 1.3
Shear Force: 1.5
Tensile Strength: 1.5
Compressive Strength: 1.5
Seismic Coefficients: 1
Earth Resistance: 1.25
Points X Y

Point 1 15 m 10 m
Point 2 15 m 20 m
Point 3 100 m 20 m
Point 4 100 m 10 m
Point 5 15 m 24 m
Point 6 100 m 24 m
Point 7 30 m 25 m
Point 8 40 m 30 m
Point 9 100 m 30 m
Point
10 50 m 35 m
Point
11 100 m 35 m
Point
12 15 m 25 m
Regions
Output
Material Points Area
Region
1
SILTSTONE ( VERY
STRONG) 1,2,3,4 850 m²
Region
2 SILTY CLAY, STIFF (FBS) 2,5,6,3 340 m²
Region
3 SILTY CLAY, FIRM (CIS) 5,12,7,8,9,
6 410 m²
Region
4 GRAVELLY SAND (FILL) 8,10,11,9 275 m²