Soil Machanics and Foundation Engineering

1

The intensity of vertical pressure at a depth Z directly below the point load Q on its axis of loading is :

A. `(0.4775 Q)/(Z)`
B. `(0.4775 Q)/(Z^2)`
C. `(0.4775 Q)/(Z^3)`
D. `(0.4775 Q)/(sqrt(Z))`

2

The area of cross-section A at failure or during any stage of Triaxial Compression Test and its initial length (L) and volume (V), are related by the equation

A. `A = (V + Delta V)/(L - DeltaL)`
B. `A = (V - Delta V)/(V + DeltaL)`
C. `A = (V - Delta V)/(L - DeltaL)`
D. `A = (V + Delta V)/(L + DeltaL)`

3
If the bulk density of the soil is `rho` and water content `omega` then dry density of the soil, is
A. `1 + omega/rho`
B. `(1 + rho)/(omega)`
C. `(rho)/(1 + omega)`
D. `(omega)/(1 + rho)`

4

According to Rankine's fromula, the minimum depth of foundation

A. `h = P/W ((1 - sin phi)/(1 + sin phi))^2`
B. `h = W/P ((1 - sin phi)/(1 + sin phi))^2`
C. `h = P/W ((1 - sin phi)/(1 + tan phi))^2`
D. `h = P/W ((1 - tan phi)/(1 + tan phi))^2`

5

If `beta` is the surcharge angle of a backfill with an angle of internal friction `phi`, the coefficient of active earth pressure given by Rankine's theory, is :

A. `K_a = sin beta (sin beta - sqrt(sin^2beta - sin ^2 phi))/(sin beta + sqrt(sin^2beta - sin ^2 phi))`
B. `K_a = cos beta (cos beta - sqrt(cos^2beta - cos ^2 phi))/(cos beta + sqrt(cos^2beta - cos^2 phi))`
C. `K_a = tan beta (tan beta - sqrt(tan^2beta - tan ^2 phi))/(tanbeta + sqrt(tan^2beta - tan^2 phi))`
D. none of these.