Question 1

Before preparing to mobilize drill rigs to a proposed construction site, which of the following resources should be reviewed and analyzed?&#10;A)Aerial photographs and/or satellite imagery&#10;B)Existing subsurface exploration reports, soil surveys and well logs&#10;C)Utility maps (electrical, gas, water, sewer)&#10;D)All of the above

Accepted Answer

Before preparing to mobile drill rigs to a proposed construction site, all of the resources listed should be reviewed and analyzed. Aerial photographs and satellite imagery can provide information on existing structures, potential staging areas, local water and land features, and access points. Existing subsurface exploration reports, soil surveys and well logs contain valuable information on local soils, hydrogeological conditions, and other environmental issues. Utility maps provide critical information on buried infrastructure, possible overhead obstructions, easement limits, and property delineations. By reviewing all available information prior to conducting field reconnaissance, you will have a better idea of what to expect and to look for during the initial site visit.

Question 2

Eskers are soil deposits formed by precipitation of water-suspended materials flowing in ice tunnels. What is the engineering significance of eskers?&#10;A)Spread footings are recommended to support foundation loads&#10;B)Small diameter sample spoons are recommended&#10;C)Potential source of sand and gravel materials&#10;D)A. and C.

Accepted Answer

The engineering significant of eskers is that spread footings are recommended to support foundation loads placed on this landform type and that eskers are a potential source of sand and gravel material used in construction. Because eskers contain gravel, piles are not recommended to support foundation loads. Large diameter spoons are recommended so that a representative sample can be obtained (large particle size may not be captured by small spoons).

Question 3

While conducting a subsurface exploration program, which of the following characteristics of coarse-grained soils is not determined?&#10;A)Presence of organic materials&#10;B)In-situ density&#10;C)Stiffness&#10;D)Gradation

Accepted Answer

While conducting a subsurface exploration program, stiffness of coarse-grained soils is not determined. Stiffness is determined for each stratum of fine-grained soils, in addition other following characteristics such as:
• Natural moisture contents
• Atterberg limits
• Presence of organic material
• Swelling
• Unconfined compressive strength
• Shear strength
• Compressibility

Question 4

Which of the following is not a common in-situ test conducted to evaluate the engineering properties of a soil sample?&#10;A)Standard Penetration&#10;B)Membrane Filtration&#10;C)Cone Penetration&#10;D)Vane Shear

Accepted Answer

Membrane filtration is not a common in-situ test conducted to evaluate a soil's engineering properties of a soil sample. Membrane filtration analysis is a method used to test water samples to test for the presence of bacteria indicator organisms. The standard penetration and cone penetration tests are the most commonly used tests to evaluate soil samples. The procedures for conducting these tests are described in American Association of State Highway and Transportation Officials (AASHTO) and ASTM International (formerly known as the American Society for Testing and Materials) standards.

Question 5

When classifying a soil using the Unified Soil Classification System, what can be assumed for a given soil sample based on the following sieve analysis results? Sieve: Percent Finer
# 4: 100
# 10: 100
# 20: 98
# 40: 94
# 60: 80
# 100: 75
# 200 60
0.01 mm: 62
0.002 mm: 63

A)Soil is fine-grained
B)Soil is medium-grained
C)Soil is coarse-grained
D)Not enough information provided

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Accepted Answer

Based on the provided sieve analysis results, the given soil sample is assumed to be fine-grained when classifying a soil using the Unified Soil Classification System. Since 50% or more of the sample passes through the #200 sieve, the soil is considered to be fine-grained. If less than 50% of the sample passed through the #200 sieve, the soil would have been considered to be coarse-grained.

Question 6

When classifying a soil using the Unified Soil Classification System, what can be assumed for a given soil sample based on the following sieve analysis results? Sieve: Percent Finer
# 4: 100
# 10: 100
# 20: 98
# 40: 94
# 60: 80
# 100: 75
# 200 60
0.01 mm: 62
0.002 mm: 63

A)Soil is fine-grained
B)Soil is medium-grained
C)Soil is coarse-grained
D)Not enough information provided

Accepted Answer

Based on the provided sieve analysis results, the percent sand in this soil is assumed to be 93% when classifying a soil using the Unified Soil Classification System. The percentage of sand in a soil sample is the amount of soil captured by the #200 to #4 sieves. (In this example, the percentage of sand is 100% - 7% = 93%.) Gravel is captured in the #4 to 3" sieves. (In this example, the percentage of gravel is 0%.)

Question 7

What are the four levels of rock sample care defined in the ASTM D5079-02 standard practices for preserving and transporting rock core samples?&#10;A)Routine, special, soil-like, critical&#10;B)Routine, special, intensive, critical&#10;C)Normal, special, intensive, emergency&#10;D)None of the above

Accepted Answer

The four levels of rock sample protection as defined in ASTM D5079-02 standard practices for preserving and transporting rock core samples are routine, special, soil-like, and critical care. The standard practices for routine and soil-like care are consistent with other geotechnical explorations (defined in ASTM D4220-95(2007)). Special care may be appropriate if rock core's moisture state may be affected by exposure to the elements, and/or if fluids must be maintained in the sample. Critical care practices are appropriate when samples need to be protected against shock, vibration, and/or variations in temperature.

Question 8

Which of the following definitions best describes a soil profile?&#10;A)Inclination of the surface of the soil from the horizontal&#10;B)A layer parallel to the surface of the soil&#10;C)A plane at right angles to the surface of the soil&#10;D)None of the above

Accepted Answer

A soil profile is a plane at right angles to the surface of the soil. A soil profile is exposed by cutting vertically through the soil. A soil profile description, as provided on a typical boring log, includes soil properties that were determined by testing and analyzing each stratum of the soil column. The width of a soil profile can vary between a few inches to several yards or greater, depending on local geomorphological and hydrogeological variability.

Question 9

Which of the following types of soil erosion is largely due to the consequences of human activity?&#10;A)Accelerated&#10;B)Landslip&#10;C)Tunnel&#10;D)All of the above

Accepted Answer

Accelerated erosion is largely due to the consequences of human activity. Common causes for accelerated erosion include livestock grazing, agricultural tilling, deforesting, and uncontrolled stormwater discharge. Landslip erosion is associated with the mass movement of soil caused by geologic processes. Tunnel erosion is caused by water flowing in subsurface layers.

Question 10

Which of the following hammers is not commonly used for conducting Standard Penetration Tests (SPTs)?&#10;A)Split-spoon&#10;B)Automatic&#10;C)Donut&#10;D)Safety

Accepted Answer

A split-spoon is not a hammer used for conducting SPTs. A split spoon is a sampling tube, approximately 20 - 36-inches long, that is placed inside a drill rod to collect soil samples. Automatic, donut, and safety hammers are used to drive the drill rods into the soil.

Deck 18: Subsurface