(a)
Find the maximum shear stress developed within the soil.
(a)
Answer to Problem 13.27CTP
The maximum shear stress developed within the soil is
Explanation of Solution
Given information:
The depth (H) of slope is 5 m.
The angle
The unit weight of the soil
The cohesion
The angle
Calculation:
The maximum shear stress developed at soil rock interface (5 m depth).
Find the maximum shear stress
Substitute
Thus, the maximum shear stress developed within the soil is
(b)
Find the maximum shear strength available within the soil.
(b)
Answer to Problem 13.27CTP
The maximum shear strength available within the soil is
Explanation of Solution
Given information:
The depth (H) of slope is 5 m.
The angle
The unit weight of the soil
The cohesion
The angle
Calculation:
Find the maximum shear strength
Substitute
Thus, the maximum shear strength available within the soil is
(c)
Find the factor of safety of the slope.
(c)
Answer to Problem 13.27CTP
The factor of safety of the slope is
Explanation of Solution
Given information:
The depth (H) of slope is 5 m.
The angle
The unit weight of the soil
The cohesion
The angle
Calculation:
Find the factor of safety
Substitute
Therefore, the factor of safety of the slope is
(d)
Find the maximum possible depth for the soil before it becomes unstable.
(d)
Answer to Problem 13.27CTP
The maximum possible depth for the soil before it becomes unstable is
Explanation of Solution
Given information:
The depth (H) of slope is 5 m.
The angle
The unit weight of the soil
The cohesion
The angle
Calculation:
The slope becomes unstable then the factor of safety
Find the maximum possible depth
Substitute
Thus, the maximum possible depth for the soil before it becomes unstable is
(e)
Find the factor of safety with respect to cohesion when the friction is fully mobilized.
(e)
Answer to Problem 13.27CTP
The factor of safety with respect to cohesion when the friction is fully mobilized is
Explanation of Solution
Given information:
The depth (H) of slope is 5 m.
The angle
The unit weight of the soil
The cohesion
The angle
Calculation:
The developed angle of friction is equal to the angle of friction when the friction is fully mobilized. Therefore,
Find the developed cohesion in the soil using the equation:
Substitute
Substitute
Find the factor of safety
Substitute
Thus, the factor of safety with respect to cohesion when the friction is fully mobilized is
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Chapter 13 Solutions
Fundamentals of Geotechnical Engineering (MindTap Course List)
- What is the shearing strength of soil in kPa along a horizontal plane at a depth of 4 m in a deposit of sand having the following properties: Angle of internal friction, ∅ = 35°; Dry unit weight, yd = 17 kN/m3 ; Specific gravity, Gs = 2.7; Assume the ground water table is at a depth of 2.5 m from the ground surface a.11 b.95 c.23 d.41arrow_forwardSand is placed on a rock slope, as shown in Figure Q2. (a) Show that sand will be stable (i.e., no sliding sliding) ifarrow_forwardA soil having the average properties, bulk unit weight = 19 kN/m³; angle of internal friction = 25° and cohesion = 15 kPa, is being formed on a rock slope existing at an inclination of 35° with the horizontal. The critical height (in m) of the soil formation up to which it would be stable without any failure is (round off to one decimal place). [Assume the soil is being formed parallel to the rock bedding plane and there is no ground water effect.]arrow_forwardAn infinite slope of clay soil has a slope of 29 degrees. The soil has a specific gravity of 2.7 and a void ratio of 0.47. The soil has a depth of 5m over ledge rock measured vertically. Effective friction angle and soil cohesion are 14 degrees and 25kPa respectively. Assuming the ground water table is in the ground surface, determine the limiting depth of this soil, measured vertically over ledge rock. A 1.25m B 5.95m 3.67m D 6.88marrow_forwardQ4: For the soil element shown, compute the stresses acting on the plane inclined by 40° with the horizontal plane then draw Mohr circle and place the stresses with respect to O.P. 20kPa 35kPa 100kPa 300 40°arrow_forward4. For the stressed soil element shown. use the pole method and determine: 1) the major and minor principal stresses, 2) the normal and shear stresses on the plane oriented 0 to the horizontal. O is 12⁰. Gy = 50 kN/m² Tyx = 50 kN/m² 0 Txy = 50 kN/m² Ox= 150 kN/m²arrow_forwardThe major principal stress (kPa) on the soil element is (anti-clockwise shear +ve) 100 kPa 50 kPa -50 kPa 50 kPa 130.9 O 55.9 O 19.1 Oarrow_forwardFor a railway track 7 m high embankment is required. The clay to be used for the embankment was found to have c = 20 kN/m2and unit weight = 19 kN/m3 Compute the critical maximum side slope angle for the embankment if a hard rocky stratum was found 3.5 m below the ground level. Assume ϕ for the clay equal to zero. The following values are given from Taylor's chart for depth factor D = 1.5 :arrow_forwardThe soil of an 21 degree infinite slope is subjected to full depth seepage. The soil properties are as follows: Saturated weight is 19 kN/m^3. Friction angle is 19 degrees Cohesion is 20 kN/m^2. Unit weight of water is 10 kN/m^3 Limiting depth of slope is (m) 2.96 m 4.95 m O 5.47 m 8.20 marrow_forwardA soil profile is shown in Figure ?-?. Compute the shear strength on the horizontal and vertical planes at points ? and ?.arrow_forwardA soil along a horizontal plane at a depth of 4 m in a deposit of sand having the following properties: Angle of internal friction, ∅ = 35° ; Dry unit weight, yd = 17 kN/m3 ; Specific gravity, Gs =2.7. Assume the ground water table is at a depth of 2.5 m from the ground surface. Find the change in shear strength in kPa when the water table rises to the ground surface.arrow_forwardA cut slope was excavated in a saturated clay. The slope made an angle of 39.55 degree with the horizontal. Slope failure occurred when the cut reached a depth of 6 m. Previous soil explorations showed that a rock layer was located at a depth of 10 m below the ground surface. Assuming an undrained condition and γsat = 18 kN/m3, Analyze the following. a. undrained cohesion of the clay.b. nature of the critical circle?c. With reference to the toe of the slope, at what distance did the surface of sliding intersect the bottom of the excavation?arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
- Fundamentals of Geotechnical Engineering (MindTap...Civil EngineeringISBN:9781305635180Author:Braja M. Das, Nagaratnam SivakuganPublisher:Cengage Learning