Soil Mechanics and Foundation Sheet 29

Which one of the following pairs of parameters and expressions is not correctly matched?

A rectangular footing L x B is to be place at a depth D below ground level such that D/B < 2.5. The factor $N_c$ to be used in deciding on the allowable bearing capacity for the footing as given by Skempton is calculated using the equation (where $N_{C_R}=N_C$ for rectangular footing, $N_{C_S}=N_C$ at surface)

Consider the following statements:

1.   Coulomb's earth pressure theory does not taken the roughness of wall into consideration.

2.   In case of non-cohesive soils, the coefficients of active earth pressure and earth pressure at rest are equal.

3.   Any movement of retaining wall away from the fill corresponds the active earth pressure condition.

Of these statements

Consider the following statements:

Ranking's theory and Coulomb's theory give same values of coefficients of active and passive earth pressure when

1.   the retaining wall has a vertical back.

2.   the backfill is cohesionless.

3.   angle of slope of backfill is equal to the angle of internal friction.

4.   angle of slope of backfill is $0°$

5.   angle of wall friction $\mathrm{\delta } \mathrm{is} 0°$

6.   an

A triaxial test was conducted on a granular soil. At failure ${\sigma }_1\text{'}/{\sigma }_3\text{'}=4$. The effective minor principal stress at failure was 100 kPa. The values of approximate $\varphi$ and the principal stress difference at failure are, respectively

Consider the following statements:

Phreatic line in an earth dam is

1.   elliptic in shape.

2.   an equipotential line.

3.   the topmost flow line with zero water pressure.

4.   approximately a parabola.

Of these statements

Consider the following statements:

1.   'Relative compaction' is not the same as 'relative density'.

2.   Vibrofloatation is not effective in the case of highly cohesive soils.

3.   'Zero air void line' and '100% saturation line' are not identical.

Of these statements

Consider the following statements:

1.   Constant head permeameter is best suited for determination of coefficient of permeability of highly impermeable

      soils.

2.   Coefficient of permeability of a soil mass decreases with increase in viscosity of the pore fluid.

3.   Coefficient of permeability of a soil mass increases with increase in temperature of the pore fluid.

Of these statements

The dry density of a soil is 1.5 g/cc. If the saturation water content were 50%, then its saturated density and submerged density would, respectively, be

Lacustrine soils are soils