土力学英文题(1).docx

Soil Mechanics在此处键入公式。

1.The mass of a moist soil sample having a volume of 0.0057m3 is 10.5kg. The moisture content(w) and the specific gravity of soil soilds(Gs) were determined to be 13% and 2.68 ,respectively. Determine
a. Moist density,ρ(kg/ m3)
b. Dry density,ρd(kg/ m3)
c. Void ratio, e
d. Porosity, n
e. Degree of saturation , s(%)

2 . In its natural state ,a moist soil has a volume of 0.33 ft3 ,and weighs 39.93 Ib. The over-dried weight of the soil is 34.54 Ib .If Gs= 2.67, calculate
a. Moisture content (%)
b. Moist unit weight (Ib / ft3)

3.Following are the results of a sieve analysis.

U.S sieve no Mass of soil retained on each sieve (g)
4(4.75mm) 0
10(2.00) 18.5
20(0.850) 53.2
40(0.425) 90.5
60(0.250) 81.8
100(0.150) 92.2
200(0.075) 58.5
Pan 26.5
a. Determine the percent finer than each sieve size and plot a grain-size distribution curve
b. Determine D10, D30 and D60,from the grain-size distribution curve
c. Calculate the uniformity coefficient CU
d. Calculate the coefficient of gradation Cz

4. Following are the results from the liguid and plastic limit tests for a soil when the in situ moisture content is 30% . Liquid limit = 35.7%,Plastic limit =17.3%
a. what is the plasticity index of the soil ?
b. Determine the liquidity index of the soil ?

5.A soil element is shown in Figure 1. The magnitudes of stresses are,, , and . Determine
a. Magnitudes of the principal stresses
b. Normal and shear stresses on plane AB.
A
B
σx
τ
τ
τ
τ
σy
σx
σy
θ

Figure 1 Soil element with stresses acting on it

6.The plan of a uniformly loaded rectangular area is shown in Figure 2.
Determine the vertical stress increase below point A at a depth of .

3m
1m
2m
A
q=150kN/m2

Figure 2

7.. A soil profile is shown in Figure 1. Note the zone of capillary rise in the sand layer overlying clay. In this zone, the average degree of saturation and the moist unit weight are 60% and 17.6 kN/m3, respectively. Calculate and plot the variation of total stress, pore water pressure u, and effective stress with depth.
Dry sand, g=16.5 kN/m3
a
3.0m
1.0m
Zone of capillary rise
Sand, g=17.6 kN/m3
Clay, gsat=18.9 kN/m3
3.0m
Impermeable layer
b
c
d

Figure 1 Soil profile with capillary rise

8. For the retaining wall shown in Figure 2, determine the force per unit width of the wall for Rankine’s active state. Also find the location of the resultant.

gsat=18 kN/m3
f’=35°
C’= 0.0
g=16 kN/m3
f’=30°
C’= 0.0
3.0m
3.0m
Ground water table

Figure 2 Retaining wall
Rankine’s active earth pressure is given as:

9. For a normally consolidated clay, the results of drained triaxial test are as follows:
Chamber confining pressure= 16lb/in.2
Deviator stress at failure= 25
a. Find the angle of friction, φ’.
b. Determine the angle θ that the failure plane makes with the major principal plane.
φ’
θ
Normal stress
Shear stress
2θ
σ1
σ3
Effective stress failure envelope

Figure 1 Mohr’s circle and failure envelope for a normally consolidated clay