All Chapters Included
SOLUTIONS MANUAL
, Craig’s Soil Mechanics Seventh Edition Solutions Manual
Table Of Contents
1 Basic characteristics of soils 1
2 Seepage 6
3 Effective stress 14
4 Shear strength 22
5 Stresses and displacements 28
6 Lateral earth pressure 34
7 Consolidation theory 50
8 Bearing capacity 60
9 Stability of slopes 74
,2 Basic characteristics of soils
Chapter 1
Basic characteristics of soils
1.1
Soil E consists of 98% coarse material (31% gravel size; 67% sand size)
and 2% fines. It is classified as SW: well-graded gravelly SAND or, in
greater detail, well-graded slightly silty very gravelly SAND.
Soil F consists of 63% coarse material (2% gravel size; 61% sand size)
and 37% non-plastic fines (i.e. between 35 and 65% fines); therefore, the
soil is classified as MS: sandy SILT.
Soil G consists of 73% fine material (i.e. between 65 and 100% fines)
—
and 27% sand size. The liquid limit is 32 and the plasticityindex is 8 (i.e.
32 24), plotting marginally below the A-line in the ML zone on the
plasticity chart. Thus the classification is ML: SILT (M-SOIL) of low
plasticity. (The plasticity chart is given in Figure 1.7.)
Figure Q1.1
, Basic characteristics of soils 3
Soil H consists of 99% fine material (58% claysize; 47% silt size). The
liquid limit is 78 and the plasticity index is 47 (i.e. 78 31), plotting above
—
the A-line in the CV zone on the plasticity chart. Thus the classification is
CV: CLAY of very high plasticity.
1.2
From Equation 1.17
1.00
1 + e = G (1 + w ρw 2.70 × 1.095 × = 1.55
s ) =
ρ 1.91
;e =
0.55
Using Equation
1.13
wGs 0.095 × 2.70
Sr = = = 0.466 (46.6%)
e 0.55
Using Equation 1.19
Gs + e 3.25 3
ρsat = ρw = × 1.00 = 2.10 Mg/m
1 +e 1.55
From Equation 1.14
e 0.55
w= = = 0.204 (20.4%)
Gs 2.70
1.3
Equations similar to 1.17–1.20 apply in the case of unit weights; thus,
Gs 2.72 3
цd = цw = × 9.8 = 15.7 kN/m
1+e 1.70
Gs + e 3.42 3
цsat = цw = × 9.8 = 19.7 kN/m
1+e 1.70
Using Equation 1.21
Gs — 1 1.72
ц' = ц = × 9.8 = 9.9 kN/m
3
1 + e w 1.70
Using Equation 1.18a with Sr = 0.75
Gs + Sre 3.245 3
ц= ц = × 9.8 = 18.7 kN/m
1 + e w 1.70
SOLUTIONS MANUAL
, Craig’s Soil Mechanics Seventh Edition Solutions Manual
Table Of Contents
1 Basic characteristics of soils 1
2 Seepage 6
3 Effective stress 14
4 Shear strength 22
5 Stresses and displacements 28
6 Lateral earth pressure 34
7 Consolidation theory 50
8 Bearing capacity 60
9 Stability of slopes 74
,2 Basic characteristics of soils
Chapter 1
Basic characteristics of soils
1.1
Soil E consists of 98% coarse material (31% gravel size; 67% sand size)
and 2% fines. It is classified as SW: well-graded gravelly SAND or, in
greater detail, well-graded slightly silty very gravelly SAND.
Soil F consists of 63% coarse material (2% gravel size; 61% sand size)
and 37% non-plastic fines (i.e. between 35 and 65% fines); therefore, the
soil is classified as MS: sandy SILT.
Soil G consists of 73% fine material (i.e. between 65 and 100% fines)
—
and 27% sand size. The liquid limit is 32 and the plasticityindex is 8 (i.e.
32 24), plotting marginally below the A-line in the ML zone on the
plasticity chart. Thus the classification is ML: SILT (M-SOIL) of low
plasticity. (The plasticity chart is given in Figure 1.7.)
Figure Q1.1
, Basic characteristics of soils 3
Soil H consists of 99% fine material (58% claysize; 47% silt size). The
liquid limit is 78 and the plasticity index is 47 (i.e. 78 31), plotting above
—
the A-line in the CV zone on the plasticity chart. Thus the classification is
CV: CLAY of very high plasticity.
1.2
From Equation 1.17
1.00
1 + e = G (1 + w ρw 2.70 × 1.095 × = 1.55
s ) =
ρ 1.91
;e =
0.55
Using Equation
1.13
wGs 0.095 × 2.70
Sr = = = 0.466 (46.6%)
e 0.55
Using Equation 1.19
Gs + e 3.25 3
ρsat = ρw = × 1.00 = 2.10 Mg/m
1 +e 1.55
From Equation 1.14
e 0.55
w= = = 0.204 (20.4%)
Gs 2.70
1.3
Equations similar to 1.17–1.20 apply in the case of unit weights; thus,
Gs 2.72 3
цd = цw = × 9.8 = 15.7 kN/m
1+e 1.70
Gs + e 3.42 3
цsat = цw = × 9.8 = 19.7 kN/m
1+e 1.70
Using Equation 1.21
Gs — 1 1.72
ц' = ц = × 9.8 = 9.9 kN/m
3
1 + e w 1.70
Using Equation 1.18a with Sr = 0.75
Gs + Sre 3.245 3
ц= ц = × 9.8 = 18.7 kN/m
1 + e w 1.70
