Concept explainers
(a)
Calculate the saturated unit weight of soil.
(a)
Answer to Problem 3.12P
The saturated unit weight of soil is
Explanation of Solution
Given information:
The diameter of the sample
The length of the sampler
The length of the sampler for performing shear strength
The moist weight
The oven-dried weight
The specific gravity of the soil solids
Calculation:
Consider the unit weight of water
Calculate the volume of the sampler
Substitute
Calculate the moist unit weight of the soil
Substitute
Calculate the moisture content
Substitute
Calculate the dry unit weight of the soil
Substitute
Calculate the void ratio
Substitute
Calculate the saturated unit weight of the soil
Substitute
Hence, the saturated unit weight of soil is
(b)
Calculate the moisture content at
(b)
Answer to Problem 3.12P
The moisture content at
Explanation of Solution
Given information:
The diameter of the sample
The length of the sampler
The length of the sampler for performing shear strength
The moist weight
The oven-dried weight
The specific gravity of the soil solids
Calculation:
Refer to part (a).
The void ratio of the soil is
Calculate the moisture content at
Substitute
Hence, the moisture content at
(c)
Calculate the amount of water needed to achieve full saturation.
(c)
Answer to Problem 3.12P
The amount of water needed to achieve full saturation is
Explanation of Solution
Given information:
The diameter of the sampler
The length of the sampler
The length of the sampler for performing shear strength
The moist weight
The oven-dried weight
The specific gravity of the soil solids
Calculation:
Refer to part (a).
The saturated unit weight of soil
The moist unit weight of soil
Calculate the volume of the sampler for performing shear strength
Substitute
Calculate the additional water needed to achieve
Substitute
Hence, the amount of water needed to achieve full saturation is
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Chapter 3 Solutions
Principles of Geotechnical Engineering (MindTap Course List)
- A triaxial test was performed on a dry, cohesionless soil under a confining pressure (?3) of 144 kN/m2. If the sample failed when the deviator stress (∆?) reached 395.8 kN/m2, determine the soil’s angle of internal friction ∅ and the angle of the failure plane θ. Show step by step hand calculation. Show all work.arrow_forwardDuring a subsurface exploration, an undisturbed soil sample was collected in the field using a split-spoon sampler.collected in the field using a split-spoon sampler for laboratory evaluation.sampler) for laboratory evaluation. The sample has a diameter of 1.375in. diameter, 18 in. length, and a wet weight of 1.85 lb. If the oven-dried weight was1.5 lb and Gs = 2.74; calculate the following:(a) Wet unit weight.b) Moisture content.c) Dry unit weight.d) Void ratio.e) Degree of saturation. Translated with www.DeepL.com/Translator (free version)arrow_forwardDetermine the shear strength parameters for a given soil using the direct shear test sample No1. Calculate the Shear Load in Newtons and Shear Stress in KPa in the box below.arrow_forward
- Question 15 A consolidated-undrained tri-axial test was conducted on a normally consolidated clay sample and the results are as follows: Chamber confining pressure = 109 kPa, Deviator stress at failure = 98 kPa, Pore Water Pressure = 53 kPa. These results were used to determine the drained friction angle of the soil. Compute the deviator stress (kPa) at failure when the drained test was conducted with the chamber confining pressure changed to 151 kPa. Round off to two decimal places.arrow_forwardA clay sample was consolidated in a triaxial cell under a backpressure of 50 kPa and cell pressure of 150 kPa. The drainage valve was then closed and the cell pressure was increased to 200 kPa when the pore pressure increased to 98 kPa. What is Skempton’s B-parameter? The above sample was then subjected to a vertical deviator stress, which was increased from zero under undrained conditions. The sample failed when the pore water pressure was 160 kPa and the deviator stress was 70 kPa. What is Skempton’s A-parameter at failure? Assuming the clay is normally consolidated, find the friction angle in terms of effective stresses.arrow_forwardA drained triaxial test on a normally consolidated clay showed that the failure plane makes an angle of 58° with the horizontal. If the sample was tested with a chamber confining pressure of 103.5 kN/m^2, what was the major principal stress at failure?arrow_forward
- The following results were obtained at failure in a series of drained triaxial tests on fully saturated clay specimens originally 38 mm diameter by 76 mm long. All-round pressure (kN/m2) Axial compression (mm) Axial load (N) Pore-water pressure (kN/m2) 200 400 600 7.22 8.36 9.41 480 895 1300 25 75 100 (a) Determine the values of the shear strength parameters c and . (b) Determine the values of the shear strength parameters c and . (c) A different specimen of the same soil is tested in undrained triaxial compression at a cell pressure of 240 kN/m2 and fails when the deviator stress is 160 kN/m2. Calculate the pore water pressure in the specimen at failure.arrow_forwardPlease solve A only. Subject: Geotechnical engi A sample coarse grained soil is 50mm. In diameter and 150mm long was tested in a constant-head apparatus. The soil sample was prepared at a void ratio of 1.5. The total head was kept constant at 300mm and the amount of water is collected in 4 sec. was 50cm^3. The test temperature was 22°Ca.) Compute the temperature correction factor.b.) Compute the corrected coefficient of permeability in cm/sec. c.) Compute the interstitial velocity.arrow_forward2. A soil sample has a unit weight of 16 kN/m^3 and a saturation of 40%. When the saturation is increased to 90%, its unit weight raises to 120 kN/m^3. Calculate the void ratio and the specific gravity of the soil.arrow_forward
- Boreholes reveal that a thin layer of alluvial silt exists at a depth of 50 ft below the surface of the ground. The soil above this level has an average dry unit weight of 96 lb/ft3 and an average water content of 30%. The water table is approximately at the surface. Tests on undisturbed samples give the following data: cu = 1008 lb/ft2, undrained friction angle = 13°, cd = 861 lb/ft2, drained friction angle = 23°. Estimate the shearing resistance in psf of the silt on a horizontal plane when the shear stress builds up rapidly. with fbd a.2185 b.2449 c.861 d.3120arrow_forwardBoreholes reveal that a thin layer of alluvial silt exists at a depth of 50 ft below the surface of the ground. The soil above this level has an average dry unit weight of 96 lb/ft3 and an average water content of 30%. The water table is approximately at the surface. Tests on undisturbed samples give the following data: cu = 1008 lb/ft2, undrained friction angle = 13°, cd = 861 lb/ft2, drained friction angle = 23°. Estimate the shearing resistance in psf of the silt on a horizontal plane when the shear stress builds up SLOWLY a. 2185 b. 3120 c. 861 d. 2449arrow_forwardIn a consolidated drained tri-axial text on a normally consolidated clay soil, a deviator of 152 kPa was required to fail the sample when the confining pressure was 70 kPa. A. What was the angle of shearing resistance? B. Suppose that after consolidation under the 70 kPa confining pressure, the sample is placed in an unconfined compression apparatus and tested. Determine the resulting shear strength.arrow_forward
- Principles of Geotechnical Engineering (MindTap C...Civil EngineeringISBN:9781305970939Author:Braja M. Das, Khaled SobhanPublisher:Cengage Learning