Test: Mohr's Stress Circle - Civil Engineering (CE) MCQ

The shearing resistance of soil is constituted by
1) The structural resistance to displacement of the soil because of the interlocking of the particles
2) The frictional resistance to translocation between the individual soil particles at their contact points.

The shear strength in cohesion less soils from inter granular friction, while in other soils it results both from internal friction as well as cohesion.

In a loaded soil mass, there exist three typical planes, mutually orthogonal to each other. These planes are called the principal planes.

The failure conditions for a soil may be expressed in terms of limiting stress, called shear strength or as a function of the principal stresses.

Shearing deformation of soil may be in the form of sinking of a footing, or movement of a wedge of soil particles or on masses upon the action of a shear stress.

 Major, intermediate and minor principal stresses are represented by the corresponding symbols σ1, σ2, and σ3.

The circle drawn from two dimensional stress systems is known as Mohr’s circle of stress (Mohr, 1870).

The maximum shear stress τmax is equal to (σ1 – σ3)/2 which occurs on planes with α= 45°.

The normal stresses acting on principal planes are called the principal stresses.

Through a point in a loaded soil mass, innumerable planes passes and stress component on each plane depend upon the direction of the plane.