(a)
Find the factor of safety with respect to sliding for case (a).
(a)
Answer to Problem 13.22P
The factor of safety with respect to sliding for case (a) is
Explanation of Solution
Given information:
The bed slope
The angle
The cohesion
The unit weight of the soil
The depth (H) of slope is 15.2 m.
Calculation:
Calculate slope angle
Substitute 2 for
Assume the developed angle of friction
Find the factor of safety
Substitute
Find the Taylor’s stability number (m).
Refer Figure 13.17, “Taylor’s stability number” in the textbook.
Take the value of Taylor’s stability number corresponding friction angle
The Taylor’s stability number (m) is 0.098.
Find the developed cohesion
Substitute
Find the factor of safety with respect to cohesion
Substitute
Similarly find the factor of safety
Summarize the values of the factor of safety
m | ||||
5 | 2.01 | 0.098 | 25.76 | 1.30 |
6 | 1.68 | 0.090 | 23.65 | 1.41 |
8 | 1.25 | 0.078 | 20.50 | 1.63 |
10 | 1 | 0.064 | 16.82 | 1.99 |
Plot the graph of factor of safety
Refer Figure 1.
Find the factor of safety
Draw a line from origin of the graph with an angle of
Therefore, the factor of safety with respect to sliding for case (a) is
(b)
Find the factor of safety with respect to sliding for case (b).
(b)
Answer to Problem 13.22P
The factor of safety with respect to sliding for case (b) is
Explanation of Solution
Given information:
The bed slope
The angle
The cohesion
The unit weight of the soil
The depth (H) of slope is 9.15 m.
Calculation:
Calculate slope angle
Substitute 1 for
Assume the developed angle of friction
Find the factor of safety
Substitute
Find the Taylor’s stability number (m).
Refer Figure 13.17, “Taylor’s stability number” in the textbook.
Take the value of Taylor’s stability number corresponding friction angle
The Taylor’s stability number is 0.133.
Find the developed cohesion
Substitute
Find the factor of safety with respect to cohesion
Substitute
Similarly find the factor of safety
Summarize the values of the factor of safety
m | ||||
5 | 4.16 | 0.133 | 22 | 0.87 |
10 | 2.06 | 0.105 | 17.37 | 1.10 |
15 | 1.36 | 0.080 | 13.23 | 1.45 |
20 | 1 | 0.058 | 9.7 | 2 |
Plot the graph of factor of safety
Refer Figure 2.
Find the factor of safety
Draw a line from origin of the graph with an angle of
Therefore, the factor of safety with respect to sliding for case (b) is
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Chapter 13 Solutions
Fundamentals of Geotechnical Engineering (MindTap Course List)
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