Figure 1 shows the Mohr’s circle in which point B indicates the vertical stress and point E represents the active pressure. The circle is tangent to the failure envelope. For this case the relation between Pa and is given by: ———-(1) ———-(2) Where, In the above equation (2) where z = 0 The negative sign indicates that the pressure is negative and tensile, As a result there would be gap between backfill and wall. The tensile Read more […]

## Effect of Sloping Surcharge in Passive Case

The Mohr Circle for the passive case of a retaining wall carrying a sloping backfill is shown in Fig.1. Consider an element subjected to a stress in the in the vertical direction and in the direction parallel to the backfill. As these stresses in one plane are parallel to the direction of another plane, these stresses are conjugate stresses and the planes are the conjugate planes. The equivalent vertical stress-acting acting parallel to Read more […]

## Effect of Sloping Surcharge in Active Case

A wall carrying a sloping backfill is shown in Fig.1. Consider an element subjected to a stress in the vertical direction and in the direction parallel to the backfill. As these stresses in one plane are parallel to the direction of another plane, these stresses are conjugate stresses and the planes are the conjugate planes. The equivalent vertical stress acting parallel to the surface of backfill is given by: ———- (1) The Mohr Read more […]

## Active Earth Pressure for Partially submerged Sand with Surcharge

In Figure 1 active earth pressure for partially submerged sand and surcharge is shown. The height of the wall is Z and the position of the water table is at a depth of Z1 and the surcharge acting at the top of horizontal surface of the wall is q. The height of the wall below water table is Z2. The unit weight of the sand above water table is and that below water table is . CASE 1 Consider a depth z, such that z is less than Z1. Then the Read more […]

## Mohr Circle | Mohr Circle For Passive Earth Pressure

Figure 1 below shows the state of stresses on the base and the side of the prism CA at depth Z in a Mohr circle. The vertical stress is the principal stress. OP and OQ are the two Mohr envelopes satisfying the Coulomb’s equation of shear strength.Initially the stresses and are the major and minor principal stress. The points A and B in the diagram respectively denote these stresses at rest condition. The Circle 1 indicates the in-situ condition, Read more […]

## Mohr Circle | Mohr Circle For Active Earth Pressure

Figure 1 below shows the state of stresses on the base and the side of the prism CA at depth z in a Mohr circle. The vertical stress is the principal stress. OP and OQ are the two Mohr envelopes satisfying the Coulomb’s equation of shear strength. Initially the stresses and are the major and minor principal stresses. The points A and B in the Mohr circle diagram respectively denote these stresses at rest condition. Assume the vertical Read more […]

## Rankine’s Earth Pressure Theory | Classic Earth Pressure Theory

W. J. Rankine in 1857 published his theory of lateral earth pressure from a different approach. Rankine’s earth pressure theories provide the magnitude, direction and point of application of active and passive earth pressures acting on a retaining wall. These theories are known as classical earth pressure theories. Rankine’s made the following assumptions while deriving his earth pressure theory. The assumptions are: The soil mass is homogeneous Read more […]

## Earth Pressure at Rest | Coefficient Earth Pressure at Rest

When a soil mass gets deposited naturally or artificially, the coefficient of earth pressure attains a value known as coefficient of earth pressure at rest (K0) which is intermediate between coefficient of active earth pressure (Ka) and coefficient of passive earth pressure (Kp) values. In this case the horizontal stress is given by, —————————–(1) Where, = Vertical Stress at depth ‘z’ = Unit weight of soil z = Depth Read more […]

## Yield | Relation Between Yield and Magnitude of Earth Pressure

The amount of movement is called yield. The relationship between the yield and magnitude of the earth pressure is illustrated in Fig.1. As the earth pressure largely depends upon the flexibility of the wall, the earth pressure problem is a case of soil structure interaction. The soil in the region beyond the active and passive state of failure will be in plastic state while the soil in the region within the active and passive state will be in the Read more […]