Geotechnical Engineering Exam 1 with
correct answers
Water content, w - ** VERIFIED ANSWERS **✔✔Ww/Ws (0 to 200%)
Degree of Saturation, S - ** VERIFIED ANSWERS **✔✔Vw/Vv (0 to 100%)
Unit Weight, gamma - ** VERIFIED ANSWERS **✔✔W/V (62.4 pcf or 9.81 kN/m3 for water)
Mass Density, rho - ** VERIFIED ANSWERS **✔✔M/V = gamma/gravity (1000 kg/m3 for water)
Total (wet) Unit Weight - ** VERIFIED ANSWERS **✔✔Wt/Vt = (Ws + Ww)/(Vs + Vv)
= (1+w)*(dry unit weight)
=Gs(1+w)(unit weight of water)/(1+e)
Dry Unit Weight, gamma d - ** VERIFIED ANSWERS **✔✔Ws/V (60 to 125 pcf)
Saturated Unit Weight, gamma sat - ** VERIFIED ANSWERS **✔✔(Ws + Ww)/V , Vair = 0 (90 to
140 pcf)
((Gs + e)/(1+e)) *(Unit Weight of water)
Specific Gravity of Solids, Gs - ** VERIFIED ANSWERS **✔✔Ws/Vs * 1/unit weight of water (2.6 to
2.8)
Void Ratio, e - ** VERIFIED ANSWERS **✔✔Vv/Vs (0.2 to 5.0)
n/(1-n)
= (Gs*(unit weight water) / Unit Weight dry) -1
, Porosity, n - ** VERIFIED ANSWERS **✔✔Vv/V (0.2 to 0.9)
e/(1+e)
Gs*w = - ** VERIFIED ANSWERS **✔✔S*e
Fines - ** VERIFIED ANSWERS **✔✔Smaller than the #4 sieve
Coarse - ** VERIFIED ANSWERS **✔✔Everything retained on the #4 sieve
% finer than d2 = - ** VERIFIED ANSWERS **✔✔100 * (wpan + w4 + w3)/Wt
Best shape of soils for good strength? - ** VERIFIED ANSWERS **✔✔Angular!! Roughest, sharpest,
best shear strength
Terminal Velocity, vs - ** VERIFIED ANSWERS **✔✔Effective depth / elapsed time
Gradation curve - ** VERIFIED ANSWERS **✔✔Grain size (x axis), percent passing or percent finer
(y)
Well-graded soil - ** VERIFIED ANSWERS **✔✔Linear gradation curve, slight s shape, good
amount of every size of soil. Most ideal soil
Uniform/poorly graded soil - ** VERIFIED ANSWERS **✔✔Majority if the soil is in a narrow range
of size. Creates a vertical part of the curve
Gap-graded soil - ** VERIFIED ANSWERS **✔✔Sample is missing a range of soil size, creates a
horizontal part of the curve. Can have lots of fines and lots of gravel, but not a lot of medium size.
Easy for the fines to get swept away
correct answers
Water content, w - ** VERIFIED ANSWERS **✔✔Ww/Ws (0 to 200%)
Degree of Saturation, S - ** VERIFIED ANSWERS **✔✔Vw/Vv (0 to 100%)
Unit Weight, gamma - ** VERIFIED ANSWERS **✔✔W/V (62.4 pcf or 9.81 kN/m3 for water)
Mass Density, rho - ** VERIFIED ANSWERS **✔✔M/V = gamma/gravity (1000 kg/m3 for water)
Total (wet) Unit Weight - ** VERIFIED ANSWERS **✔✔Wt/Vt = (Ws + Ww)/(Vs + Vv)
= (1+w)*(dry unit weight)
=Gs(1+w)(unit weight of water)/(1+e)
Dry Unit Weight, gamma d - ** VERIFIED ANSWERS **✔✔Ws/V (60 to 125 pcf)
Saturated Unit Weight, gamma sat - ** VERIFIED ANSWERS **✔✔(Ws + Ww)/V , Vair = 0 (90 to
140 pcf)
((Gs + e)/(1+e)) *(Unit Weight of water)
Specific Gravity of Solids, Gs - ** VERIFIED ANSWERS **✔✔Ws/Vs * 1/unit weight of water (2.6 to
2.8)
Void Ratio, e - ** VERIFIED ANSWERS **✔✔Vv/Vs (0.2 to 5.0)
n/(1-n)
= (Gs*(unit weight water) / Unit Weight dry) -1
, Porosity, n - ** VERIFIED ANSWERS **✔✔Vv/V (0.2 to 0.9)
e/(1+e)
Gs*w = - ** VERIFIED ANSWERS **✔✔S*e
Fines - ** VERIFIED ANSWERS **✔✔Smaller than the #4 sieve
Coarse - ** VERIFIED ANSWERS **✔✔Everything retained on the #4 sieve
% finer than d2 = - ** VERIFIED ANSWERS **✔✔100 * (wpan + w4 + w3)/Wt
Best shape of soils for good strength? - ** VERIFIED ANSWERS **✔✔Angular!! Roughest, sharpest,
best shear strength
Terminal Velocity, vs - ** VERIFIED ANSWERS **✔✔Effective depth / elapsed time
Gradation curve - ** VERIFIED ANSWERS **✔✔Grain size (x axis), percent passing or percent finer
(y)
Well-graded soil - ** VERIFIED ANSWERS **✔✔Linear gradation curve, slight s shape, good
amount of every size of soil. Most ideal soil
Uniform/poorly graded soil - ** VERIFIED ANSWERS **✔✔Majority if the soil is in a narrow range
of size. Creates a vertical part of the curve
Gap-graded soil - ** VERIFIED ANSWERS **✔✔Sample is missing a range of soil size, creates a
horizontal part of the curve. Can have lots of fines and lots of gravel, but not a lot of medium size.
Easy for the fines to get swept away
