Consider a 2-D object consisting of two triangle compartments, as shown in Figure P9.4. Suppose a solution containing a 511 KeV gamma ray emitting radionuclide with concentration f = 0.5….
What is a geotechnical engineering report?
1. What is a geotechnical engineering report?
2. What is a geotechnical boring log? What information does it commonly include?
3. For each of the following multiple-choice questions, select all of the correct answers.
(1) Which of the following aspects are included in subsurface explo- ration?
A. Determination of the subsurface conditions, such as soil strata
(depth, thickness, and types of soil).
B. Recovery of soil and rock samples, so that further laboratory
testing can be performed.
C. Completion of field tests to obtain the in-situ properties of
the soil or rock.
D. Determination of the depth of the groundwater table.
E. Identification of the existence of any problematic soils, such
as soft soils.
(2) Before a drilling is conducted, the following site information
should be known:
A. Approximate groundwater elevation, particularly confined
B. Location of underground utility lines.
C. Location of overhead utility lines.
D. Stratification of the subsoil.
E. Water content of the subsoil.
(3) Augers are used to:
A. Drill boreholes.
B. Sample soils.
C. Perform field tests.
D. Store soil samples.
E. Measure the groundwater table.
(4) The purposes of using bentonite slurry in drilling are to:
A. Pick up the soil cuttings from the bottom of the borehole and
carry them to the top.
B. Keep the hole from collapsing.
C. Maintain the drilling equipment.
D. Retrieve soil samples below the groundwater table.
E. Loosen and cut the soil at the bottom of the borehole during
mud rotary drilling.
(5) Mud rotary drilling can be used in the following types of soil:
A. Coarse sand and cobbles, in which the slurry can drain freely.
B. Fine sand.
E. Collapsible soils below the groundwater table.
(6) Which of the following sampler can retrieve relatively undisturbed
A. Standard penetration test sampler.
B. Modified California sampler.
C. Shelby tube sampler (thin-walled sampler).
D. Piston sampler.
E. Pitcher barrel sampler.
(7) In a US practice, an SPT is performed and the blow counts in
the first, second, and third 6-inch penetrations are 8, 9, and 10,
respectively. What is the SPT blow count (N value)?
(8) The piston sampler is used to prevent:
A. The soil from entering the sampler before the sampling starts.
B. The soil sample from falling out of the tube when the sampler
is pulled out.
C. The borehole from collapsing.
D. Excessive disturbance of the soil sample.
E. Drilling fluid from entering the sampler.
(9) The Pitcher sampler is mostly suitable for sampling:
A. Alternating hard and soft layers or soils of variable hardness.
B. Soft rocks.
C. Loose sand below the groundwater table.
D. Collapsible clayey soil.
(10) Compared with the SPT, the CPT has the following advantages:
A. It can delineate the entire subsoil profile.
B. It is fast, economical, and productive.
C. It can eliminate operator errors and can provide reliable and
D. It is particularly suitable for soft soils.
E. It can obtain representative soil samples for further laboratory
(11) Compared with the SPT, the CPT has the following disadvantages:
A. It cannot obtain soil samples for further laboratory testing and
B. It cannot penetrate dense, granular soils, such as cobbles.
C. It usually has high capital investment.
D. It requires a skilled operator to run.
E. Data results may contain electronic noise and require calibra-
(12) A flat-plate dilatometer in the context of geotechnical engineer-
A. Employs a flat steel plate and measures the friction resistance
when the plate is pushed into the subsoil.
B. Employs a flat steel plate with a sharp cutting edge, pushes
the plate into the subsoil, and measures the strain induced by
inflating the plate.
C. Employs the SPT sampler and measures the in situ soil pres-
sure when the sampler is driven into subsoil.
D. Measures the rotational resistance when the flat plate
dilatometer is pushed into the soil and rotated.
E. Is particularly designed to be embedded in cracks of
bedrocks and measures the shrinking and expansion of rock
mass due to temperature change.
(13) An inclinometer in the context of geotechnical subsoil exploration
A. Measures the deformation normal to the axis of a pipe by
passing a probe along the pipe.
B. Measures the angle of a slope and embankment using ground
penetration radar (GPS) technology.
C. Can determine characteristics of landslides, slope move-
ments, and deflections in retaining walls.
D. Often involves drilling a borehole and inserting the inclinome-
ter probe into the borehole.
E. Is a nondestructive technique, therefore, a borehole is never
(14) A vane shear test
A. Can measure the in situ soil’s undrained shear strength.
B. Employs a vane shear sampler and can retrieve undisturbed
C. Pushes the vane shear device into subsoil and measures
the friction resistance when the plate is pushed into the
D. Pushes the vane shear device into the subsoil and measures
the strain induced by inflating the device.
E. Cannot be used below the groundwater table due to possible
collapsing of the borehole.
(15) In the ground penetration radar (GPR) technique, the resolution
of the GPR is affected by:
A. Frequency of antenna.
B. Depth in the subsoil.
C. Subsurface material type.
D. Shape of the cable on the ground surface.
E. Number of electrodes used.
(16) Ground penetration radar:
A. Sends electromagnetic wave of high frequency into the
ground and detects the wave that is bounced back from
objects in the soil.
B. Uses dropping of weight, an explosive charge, or a hammer
onto a plate to generate the seismic energy from the ground
C. Sends electrical direct current into the subsoil and measures
the electrical resistivity of the encountered materials.
D. Includes the time-domain and frequency-domain methods.
E. Has limited capabilities in highly conductive materials such as
clayey soils and salt-contaminated soils.
(17) Which of the following geophysical techniques are affected by the
electrical conductivity of subsurface materials?
A. Ground penetration radar.
B. Electromagnetics in frequency domain and in time domain.
C. Electrical resistivity imaging.
E. Seismic refraction and seismic reflection.