Question 1

Which of the following statements describes why soil testing is conducted following compaction during construction?

Accepted Answer

A)  Verify that the proper moisture content required by the specifications was achieved during compaction
B)  Verify that the soil density required by specifications was achieved
C)  Develop a moisture density curve to identify optimum moisture
D)  All of the above D

Question 2

What are the three categories of lateral earth pressure on a vertical plane (wall)?

Accepted Answer

A)  Minor, major, excessive
B)  At rest, active, passive
C)  Static, variable, dynamic
D)  None of the above B

Question 3

Stresses within a given soil may result from an external load or the volumetric weight of the material. In addition to these properties, which statement regarding stresses below also applies to soils?

Accepted Answer

A)  Soils can only transfer compressive normal stresses and no tensile stresses
B)  Shear stresses can only be transmitted if they are relatively small when compared to normal stresses
C)  Part of the stresses is transferred by water in the pores
D)  All of the above D

Question 4

What is the lateral force against an 8-foot high retaining wall in an active pressure condition, given the lateral pressure at the bottom of the wall is 0.32 kips per square foot (ksf)?

Accepted Answer

A)  1.2 kips per foot of wall
B)  120 pounds per foot of wall
C)  1200 kips per foot of wall
D)  Not enough information provided

Question 5

What is the lateral pressure (in kips per square foot (ksf)) at the bottom of an 8-foot tall, 18-inch thick poured concrete retaining wall in an active pressure condition, given the backfill placed behind the wall is sandy gravel with a dry unit weight of 122 pounds per cubic foot (pcf), and an internal friction of 28 degrees? Assume the wall does not retain water and the Rankin active earth pressure coefficient Ka = 0.33.

Accepted Answer

A)  0.32 ksf
B)  3.2 ksf
C)  322 ksf
D)  Not enough information provided

Question 6

What is the change in total stress resulting from a vacuum triaxial test that reduced the pore pressure of a dry sand sample by 4 kPa?

Accepted Answer

A)  - 4 kPa
B)  No change
C)  + 4 kPA
D)  Not enough information provided

Question 7

Which of the following soil tests is performed to determine the magnitude and rate of volume decrease that a laterally confined soil sample undergoes when subjected to varying vertical pressures?

Accepted Answer

A)  Convection
B)  Compaction
C)  Consolidation
D)  All of the above

Question 8

What is the superimposed total lateral force resulting from groundwater pressure on a 8-foot high wall if the groundwater level behind the wall is located 4 feet below the backfill surface?

Accepted Answer

A)  249 pounds
B)  499.2 pounds
C)  998 pounds
D)  Not enough information provided to determine

Question 9

What is the voids ratio of a compaction test sample where the mean values resulting from compaction of a large diameter sewer trench are as follows?
Moisture content, w, = 14.5%
Specific gravity, Gs , = 2.65
? = 18 kN/m3

Accepted Answer

A)  0.65
B)  0.8
C)  1.65
D)  1.8

Exam 14: Soil Mechanics

Which of the following statements describes why soil testing is conducted following compaction during construction?

What are the three categories of lateral earth pressure on a vertical plane (wall) ?

Stresses within a given soil may result from an external load or the volumetric weight of the material. In addition to these properties, which statement regarding stresses below also applies to soils?

What is the lateral force against an 8-foot high retaining wall in an active pressure condition, given the lateral pressure at the bottom of the wall is 0.32 kips per square foot (ksf) ?

What is the change in total stress resulting from a vacuum triaxial test that reduced the pore pressure of a dry sand sample by 4 kPa?

Which of the following soil tests is performed to determine the magnitude and rate of volume decrease that a laterally confined soil sample undergoes when subjected to varying vertical pressures?

What is the superimposed total lateral force resulting from groundwater pressure on a 8-foot high wall if the groundwater level behind the wall is located 4 feet below the backfill surface?

What is the voids ratio of a compaction test sample where the mean values resulting from compaction of a large diameter sewer trench are as follows? Moisture content, w, = 14.5% Specific gravity, G_s , = 2.65 ? = 18 kN/m³

Exam 14: Soil Mechanics

Which of the following statements describes why soil testing is conducted following compaction during construction?

What are the three categories of lateral earth pressure on a vertical plane (wall) ?

Stresses within a given soil may result from an external load or the volumetric weight of the material. In addition to these properties, which statement regarding stresses below also applies to soils?

What is the lateral force against an 8-foot high retaining wall in an active pressure condition, given the lateral pressure at the bottom of the wall is 0.32 kips per square foot (ksf) ?

What is the change in total stress resulting from a vacuum triaxial test that reduced the pore pressure of a dry sand sample by 4 kPa?

Which of the following soil tests is performed to determine the magnitude and rate of volume decrease that a laterally confined soil sample undergoes when subjected to varying vertical pressures?

What is the superimposed total lateral force resulting from groundwater pressure on a 8-foot high wall if the groundwater level behind the wall is located 4 feet below the backfill surface?

What is the voids ratio of a compaction test sample where the mean values resulting from compaction of a large diameter sewer trench are as follows? Moisture content, w, = 14.5% Specific gravity, Gs , = 2.65 ? = 18 kN/m3

What is the voids ratio of a compaction test sample where the mean values resulting from compaction of a large diameter sewer trench are as follows? Moisture content, w, = 14.5% Specific gravity, G_s , = 2.65 ? = 18 kN/m³