Introduction to Geotechnical Engineering 2nd. Edition by Braja M. Das, Nagaratnam Sivakugan | 9781305257320 | 1305257324

Geotechnical

Introduction to Geotechnical Engineering

116 SOLVED PROBLEMS

Question: 14.5

Repeat Example 14.4 and use Coulomb’s active pressure for calculation and δ′ = 2φ′/3. ...

Verified Answer:

Refer to Figure 14.14 for the pressure calculation...

Question: 14.6

Determine the safety factors for the cantilever retaining wall shown in figure 14.16 with respect to sliding and overturning, using Coulomb’s active earth pressures. Assume δ′ is 24° and the unit weight of concrete is 24 kN/m³. How would you improve the stability of this wall? ...

Verified Answer:

From Table 11.4 for α = 10°, φ′ = 36° and δ′ = 24°...

Question: 14.4

A concrete gravity retaininvg wall is shown in Figure 14.13. Determine: a. The factor of safety against overturning b. The factor of safety against sliding c. The pressure on the soil at the toe and heel (Note: Unit weight of concrete = γc = 150 lb/ft³.) ...

Verified Answer:

H^\prime =15+25=17.5

K_a=...

Question: 14.3

In Example 14.2, if there is a possibility that the soil in front of the wall will be removed sometime later, neglect the passive resistance and compute the factors of safety. ...

Verified Answer:

The passive resistance

P_p

was not ...

Question: 14.2

Figure 14.11 shows a gravity retaining wall for a granular (c′ = 0) backfill. The same soil is present at the bottom of the wall and on the left. The unit weight and the friction angle of the backfill are 18.5 kN/m³ and 35°, respectively. The unit weight of the concrete is 24.0 kN/m³. Determine ...

Verified Answer:

The retaining wall and the soil regions of interes...

Question: 14.1

The cross section of a cantilever retaining wall is shown in Figure 14.10. Calculate the factors of safety with respect to overturning, sliding, and bearing capacity. Use 150 lb/ft³ for the unit weight of concrete. ...

Verified Answer:

Refer to Figure 14.10. Note that

H^\prime =...

Question: 12.6

A square foundation is shown in Figure 12.9. Assume that the load eccentricity e = 0.5 ft. Determine the ultimate load, Qult. ...

Verified Answer:

With c′ = 0, Eq. 12.20 becomes

q_u^\prime =...

Question: 12.5

A 2 m × 3 m spread foundation placed at a depth of 2 m carries a vertical load of 3000 kN and moment of 300 kN⋅m, as shown in Figure 12.8, Determine the factor of safety. ...

Verified Answer:

From Eq. (12.17), eccentricity

e =\frac{M}{...

Question: 12.4

A continuous foundation is shown in Figure 12.7. If the load eccentricity is 0.5 ft, determine the ultimate load, Qult, per unit length of the foundation. ...

Verified Answer:

With c′ = 0, Eq. (12.20) gives

q_u^\prime =...

Question: 12.1

Consider a shallow foundation with the following: ● Foundation: B = 3 ft L = 5 ft Df = 3 ft ● Soil: γ = 110 lb/ft³ φ′ = 25° c′ = 400 lb/ft² Determine the gross allowable load the foundation can carry. Use FS = 4. ...

Verified Answer:

From Eq. (12.7), noting that

F_{ci} = F_{qi...