The point P2 at which the circle cuts the ground line represents the lateral earth pressure. The length OP2 measures 47.5 kN/m2.
1 Hence the active thrust per unit length, Pa =- x 47.5 x 8 =190 kN/m2
11.6 RANKINE'S ACTIVE EARTH PRESSURE WITH COHESIVE BACKFILL In Fig. 11.13(a) is shown a prismatic element in a semi-infinite mass with a horizontal surface. The vertical pressure on the base AD of the element at depth z is
The horizontal pressure on the element when the mass is in a state of plastic equilibrium may be determined by making use of Mohr's stress diagram [Fig. 11.13(b)].