ERRONEOUS QUESTIONS AND ANSWERS IN HYDRAULICS
AND GEOTECHNICAL ENGINEERING
a. 0.8 m/day
b. 20,000 m^3/day
c. 3750 days
A confined aquifer is recharged by a continuous supply of water
from a certain source. The average thickness of the aquifer was
determined to be 25 m and the average width is 4 km. The
hydraulic conductivity (coefficient of permeability) of the aquifer
was obtained at 50 m day and its porosity is 0.25. The piezometric
heads on two wells 1 km apart are 65 m and 60 m from a common
reference datum. For the given data obtained...
a. Evaluate the seepage velocity in meters per day
*Error (K=40 m/day)
50 m per day
b. the rate of flow through the aquifer in cu. m. per day
*Error (K=40 m/day)
50 m per day
c. Evaluate the time travel, in days, from the head of the aquifer to
point 4 km downstream.
*Error (K=40 m/day)
*Error (L=3 km)
50 m per day
a. 286.3 kPa
b. 299 kPa
, c. 234 kPa
A square footing 2 m on a side is founded 1.2 m below the ground
surface for which the bulk unit weight of soil is 20 kN/m3, the
cohesion strength is 10 kPa and the angle of internal friction is 15
degrees. Under the condition of general shear failure, evaluate the
soil bearing capacity in kPa. Use Terzaghi's bearing capacity
factors.
Nc=12.86
Nq=4.45
Ny=1.52
*(Bulk unit weight is used since no Sat unit weight given)
a. If the ground water table is at the bottom of the footing.
b. If the ground water table is more than 2 m below the bottom of
the footing.
c. If the ground water table rises to the ground surface.
a. 26.88
b. 243
c. 0
A sample of soil 50 mm in diameter was tested in direct shear. A
normal force P was first applied to the sample and a direct shear
force V was applied. The following combinations of P and V
caused the specimen to exhibit failure.
a. Estimate the nearest value of angle of internal friction of the
soil, in degrees.
AND GEOTECHNICAL ENGINEERING
a. 0.8 m/day
b. 20,000 m^3/day
c. 3750 days
A confined aquifer is recharged by a continuous supply of water
from a certain source. The average thickness of the aquifer was
determined to be 25 m and the average width is 4 km. The
hydraulic conductivity (coefficient of permeability) of the aquifer
was obtained at 50 m day and its porosity is 0.25. The piezometric
heads on two wells 1 km apart are 65 m and 60 m from a common
reference datum. For the given data obtained...
a. Evaluate the seepage velocity in meters per day
*Error (K=40 m/day)
50 m per day
b. the rate of flow through the aquifer in cu. m. per day
*Error (K=40 m/day)
50 m per day
c. Evaluate the time travel, in days, from the head of the aquifer to
point 4 km downstream.
*Error (K=40 m/day)
*Error (L=3 km)
50 m per day
a. 286.3 kPa
b. 299 kPa
, c. 234 kPa
A square footing 2 m on a side is founded 1.2 m below the ground
surface for which the bulk unit weight of soil is 20 kN/m3, the
cohesion strength is 10 kPa and the angle of internal friction is 15
degrees. Under the condition of general shear failure, evaluate the
soil bearing capacity in kPa. Use Terzaghi's bearing capacity
factors.
Nc=12.86
Nq=4.45
Ny=1.52
*(Bulk unit weight is used since no Sat unit weight given)
a. If the ground water table is at the bottom of the footing.
b. If the ground water table is more than 2 m below the bottom of
the footing.
c. If the ground water table rises to the ground surface.
a. 26.88
b. 243
c. 0
A sample of soil 50 mm in diameter was tested in direct shear. A
normal force P was first applied to the sample and a direct shear
force V was applied. The following combinations of P and V
caused the specimen to exhibit failure.
a. Estimate the nearest value of angle of internal friction of the
soil, in degrees.
