Figure 1 shows the Mohr’s circle in which point B indicates the vertical stress and point E represents the passive pressure. The wall carries a uniform surcharge q. The circle is tangent to the failure envelope. For this case the relation between P_{a} and Ïƒ_{v} is given by:

P_{p} = K_{p}Ïƒ_{v} + qK_{p} + 2c√K_{p} ———-(1)

Where, K_{a} = (1 + sinÉ¸)/(1 – sinÉ¸) = tan^{2}[45^{0 }+ (É¸/2)]

**Pressure Distribution of passive case in cohesive soil – **Figure 2 given below shows the pressure distribution behind a wall retaining a cohesive backfill. The total resultant passive earth pressure P_{p} is obtained by integrating Equation 1. Thus:

———-(2)

For, É¸ = 0, the equation (2) reduces to:

For soils below the Water table, the submerged unit weight is to be used.