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
EBK PRINCIPLES OF GEOTECHNICAL ENGINEER
- A consolidated-undrained tri-axial test was conducted on a normally consolidated clay sample and the results are as follows: Chamber confining pressure = 110 kPa, Deviator stress at failure = 95 kPa, Pore Water Pressure = 58kPa. 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 165 kPa.arrow_forwardAnswer any one asap 1.A triaxial test is performed on a normally consolidated clay. The sample is further consolidated by the test of all-around confining pressure prior to the application of the axial load. The axial force is applied very slowly. The equipment pore pressure lines remain open so that drainage of the soil pore water can occur during the test. The sample fails when minor principal stress is 49 kPa and the major principal stress is 91 kPa. Determine the angle of internal friction with no decimal places. 2.A dry sand sample was tested in direct shear and yielded a shear strength of 132 kPa under a normal stress of 215 kPa. Lab results indicate the soil's wet unit weight is 18.1 kN/m3 and the saturated unit weight is 20.2 kN/m3. Determine the shear strength, in kPa, within the native sand deposit at a depth of 2.5 m below the water table. The water table is 3 m below ground surface. Provide your answer with 2 decimal places, do not include the units and assume a unit…arrow_forward9. A consolidated drained test was carried out on a sandy clay under a cell pressure of 250 kPa. A constant back pressure of 120 kPa applied throughout the test. The dimensions of the sample were 76 mm x 38 mm. Addional test data recorded at failure were: Load transducer force = 368 N 3 Measured change in volume = 2.42 x 10 m³ Axial deformation = 2.05 mm Determine the major principal stress, o, at failure. (455 kPa)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_forwardW1arrow_forwardA triaxial test is performed on a normally consolidated clay. The sample is further consolidated by the test of all-around confining pressure prior to application of the axial load. The axial force is then applied very slowly. The equipment pore pressure lines remain open so that drainage of soil pore water can occur during the test. (The described conditions outline the procedure for a consolidated–drained-type test.) The sample fails (shears) when the σ3 pressure is 21 kPa and the s1 value is 61 kPa. From these data, determine the angle of internal friction for the effective stress strength–failure envelope (that is, determine fCD).arrow_forward
- 8, The results of three consolidated-undrained triaxial tests on identical specimens of a particular soil are: Test no. a (kPa) a-a at pcak (kPa) u at peak (kPa) 200 244 55 107 2. 300 314 3. 400 384 159 Determine c and o. What would be the expected pore pressure at failure for a test with 03= 100 kPa? 9, A cylindrical specimen of a saturated soil fails under an axial stress 150 kN/m2 in an unconfined compression test. The failure plane makes an angle of 52° with the horizontal. Calculate the cohesion and angle of internal friction of the soil 10 An undisturbed soil sample, 100 mm in diameter and 200 mm high, was tested in a triaxial machine. The sample failed at an additional axial load of 3 kN with a vertical deformation of 20 mm. The failure plane was inclined at 50° to the horizontal and the cell pressure was 300 kN/m2, Determine, from Mohr's circle, the total stress parameters. A further sample of the soil was tested in a shear box under the same drainage conditions as used for the…arrow_forwardTable 2.A consolidation test data An oedometer test is conducted for a soil sample.The sample is consolidated under vertical stress of 50 kPa. The Time (min) Dial gauge reading (mm) 194 0.01 0.02 193 0.05 190.5 oedometer test finished at 144 min and 0.1 186.5 data are given in Table I. Average thickness of the sample is 20 mm. Predict the coefficient of 0.2 181 0.5 173 1 168 2 164.5 consolidation (c, in mm?/min) using Casagrande log t method and Taylor square root of t method. Please use the empty graphical papers. 5 161.5 10 160 20 158.5 50 156.9 100 155.7 144 155.1arrow_forwardIn a CBR test, the load sustained by a remoulded soil specimen at 5 mm penetration is 120 kg. If the standard load for 5 mm penetration is 2400 kg, then find the CBR value of the soil.arrow_forward
- A cohesionless soil sample is subjected to a triaxial test. The critical state friction angle of the soil is 28 degrees and the normal effective at the failure is 200 kPa. Determine the critical state shear stress. Determine the plunger stress. Determine the cell pressure.arrow_forwardIn Triaxial test, which of the following parameters do not need to be recorded the confining pressure specimen diameter changes ) the generated pore pressure the axial force A Triaxial test was performed on a dry, cohesionless soil. If the sample failed vhen the minor principal stress was half of the major principal stress, the soil's angle of internal friction is: O 22.5 19.5 33.3 O 25 A technician obtained a soil void ratio of 1.5. It is okay because it is possible to measure void ratio values above 1. True False |arrow_forwardA series of consolidated, undrained triaxial tests were carried out on specimens of a saturated clay under no backpressure. The test data at failure are summarized:arrow_forward
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