Chapter 17, Problem 17.1P

(a)

To determine

Whether the statement “Poisson’s ratio of any saturated clay is 0.5” is true or false.

Answer to Problem 17.1P

The given statement is $\underset{\_}{\text{True}}$.

Explanation of Solution

• • Poisson’s ratio is the measure of lateral expansion or contraction compared to longitudinal contraction or expansion.
• • The expansion and contraction of saturated clay is very low. Hence, there is no variation of Poisson’s ratio in the saturated clay.

Therefore, the given statement is $\underset{\_}{\text{True}}$.

(b)

To determine

Whether the statement “A flexible foundation carrying a uniform pressure will settle uniformly” is true or false.

Answer to Problem 17.1P

The given statement is $\underset{\_}{\text{False}}$.

Explanation of Solution

• • A flexible foundation produces a sagging profile of settlement when it is loaded with uniform pressure.
• • In the sagging profile, the settlement at mid-point is higher than the corner. Hence, the differential settlement occurs in the flexible foundation.

Therefore, the given statement is $\underset{\_}{\text{False}}$.

(c)

To determine

Whether the statement “A rigid foundation settling uniformly will not apply uniform pressure to the soil” is true or false.

Answer to Problem 17.1P

The given statement is $\underset{\_}{\text{True}}$.

Explanation of Solution

• • The pressure is redistributed at the area of contact between the foundation and soil for a rigid foundation with uniform settling.
• • Hence, the pressure is not applied uniformly to the soil.

Therefore, the given statement is $\underset{\_}{\text{True}}$.

(d)

To determine

Whether the statement “The soil stiffness beneath a continuous foundation on sands is more than that of a square foundation of the same width” is true or false.

Answer to Problem 17.1P

The given statement is $\underset{\_}{\text{True}}$.

Explanation of Solution

• • The contact area between the soil and the continuous foundation is more than the square foundation.
• • Hence, the stiffness is more in continuous foundation compared to square foundation of the same width.

Therefore, the given statement is $\underset{\_}{\text{True}}$.

(d)

To determine

Whether the statement, “Strain beneath a footing on sands is the maximum at the footing level” is true or false.

Answer to Problem 17.1P

The given statement is $\underset{\_}{\text{False}}$.

Explanation of Solution

• • Generally, the strain varies from zero at the bottom of footing and maximum at 0.5B depth and then becomes zero at the 2B depth. Here, B is the breadth of footing.
• • Also, according to Schmertmann’s method of strain variation, the strain will be zero at the footing level.

Therefore, the given statement is $\underset{\_}{\text{False}}$