ABSTRACT
Consider a point on pressure surface AB at a depth z from point B (Fig 11.24a). The normal component of the earth pressure per unit area of surface AB may be expressed by the equation,
Ppn = rzKp (11.74) where Kp is the coefficient of passive earth pressure. The total passive earth pressure normal
to surface AB, Ppn' is obtained from Eq. (11.74) as follows,
p =.!.y H2 K p pn 2 sina (11.75)
where a is the angle made by pressure surface AB with the horizontal. Since the resultant passive earth pressure Pp acts at an angle 8 to the normal,
Figure 11 .24 Diagram illustrating passive earth pressure theory of sand and relation between <p, 8 and Kp (After Terzaghi, 1943)
