Soil Mechanics And Foundation Set 2

The dry density reduces by addition of water after attaining optimum moisture content ✘ The line joining the peak of three moisture content graphs obtained by using three compactive energies, is called line of optimus ✘ Well graded coarse grained soils can be compacted to a very high density as compared to fine grained soils ✘ All the above ✔

The object of classifying soils is to arrange them into groups according to their properties and behaviour ✘ A soil classification system is meant to provide an accepted and systematic method of describing the various types of soils eliminating personal factors ✘ The first category of soil classification is based on grain size of the soil ✘ All the above ✔

constant for any type of soil ✘ different for different types of soils and also different for a soil under different states of consolidation ✘ different for different types of soils but same for a soil under different states of consolidation ✘ independent of type of soil but depends on the stress history of soil ✔

decreases with increase in liquid limit ✘ increases with increase in liquid limit ✘ first increases and then decreases with increase in liquid limit ✘ remains constant at all liquid limits ✔

In a direct shear box test, the plane of shear failure is predetermined ✘ Better control is achieved on the drainage of the soil in a tri-axial compression test ✘ Stress distribution on the failure plane in the case of tri-axial compression test is uniform ✘ Unconfined compression test can be carried out on all types of soils ✔

A uniform soil has more strength and stability than a non-uniform soil. ✘ A uniform soil has less strength and stability than a non-uniform soil. ✘ Uniformity coefficient does not affect strength and stability. ✘ Uniformity coefficient of a poorly graded soil is more than that of a well graded soil. ✔

Bearing capacity of a soil depends upon the amount and direction of load. ✘ Bearing capacity of a soil depends on the type of soil. ✘ Bearing capacity of a soil depends upon shape and size of footing. ✘ Bearing capacity of a soil is indepen-dent of rate of loading. ✔

coefficient of compressibility of an over-consolidated clay is less than that of a normally consolidated clay ✘ coefficient of compressibility of an over-consolidated clay is greater than that of a normally consolidated clay ✘ coefficient of compressibility is cons-tant for any clay ✘ none of the above ✔

Effective cohesion of a soil can never have a negative value. ✘ Effective angle of internal friction for coarse grained soils is rarely below 30° ✘ Effective angle of internal friction for a soil increases as state of compact-ness increases. ✘ Effective angle of internal friction is a complicated function of mineralogy and clay size content. ✔

In a direct shear box test, the plane of shear failure is predetermined ✘ Better control is achieved on the drainage of the soil in a tri-axial compression test ✘ Stress distribution on the failure plane in the case of tri-axial compression test is uniform ✘ Unconfined compression test can be carried out on all types of soils ✔