Find the factor of safety
Answer to Problem 15.12P
The factor of safety
Explanation of Solution
Given information:
The slope with an inclination
The unit weight
The angle of friction
The cohesion
The height (H) of the retaining wall is 45 ft.
Calculation:
Trial 1:
Consider the factor of safety as 2.
Determine the cohesion
Substitute
Determine the angle
Substitute
Determine height of the slope that will have a factor of safety of 2.0 against sliding using the formula.
Substitute
The height of the retaining wall is not equal to the calculated height of the wall.
Hence, the assumption is incorrect.
Trial 2:
Consider the factor of safety as 2.5.
Determine the cohesion
Substitute
Determine the angle
Substitute
Determine height of the slope that will have a factor of safety of 2.0 against sliding using the formula.
Substitute
The height of the retaining wall is not equal to the calculated height of the wall.
Hence, the assumption is incorrect.
Trial 3:
Consider the factor of safety as 2.25.
Determine the cohesion
Substitute
Determine the angle
Substitute
Determine height of the slope that will have a factor of safety of 2.25 against sliding using the formula.
Substitute
The height of the retaining wall is equal to the calculated height of the wall.
Thus, the factor of safety with respect to sliding is
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Chapter 15 Solutions
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