2) Determination of the active earth pressure to retaining wall under explosion loading.
and equations (14, 17 - 19, 24, 26) we calculated the active earth pressure to retaining wall in the same place (point).
A modified procedure to evaluate active earth pressure at high seismic loads.
The cone-shaped area (area I) at the pile head is the active earth pressure zone.
Area AOC is the active earth pressure zone, while area ADH is the passive earth pressure zone.
where [M.sub.p1] is the moment of the active earth pressure, [p.sub.1] = Q [tan.sup.2] ([alpha]) is the active earth pressure, and [alpha] = [pi]/4 - [psi]/2 is the angle of EAD.
Seismic active earth pressure considering c-[phi] backfill has been already evaluated by Prakash and Saran  as well as Saran and Prakash .
This effect is quite important in active earth pressure on retaining wall for cohesive soil backfill .
where [K.sub.a] is the active earth pressure coefficient, K0 is the at-rest earth pressure, and [beta] is an empirical factor.
Of course, [beta] = 1.0 corresponds to the active earth pressure state and will obviously underestimate the earth pressure for soil at depths near [z.sub.1].
This paper attempts to use the ultimate strain method to solve the limit height of vertical slope and the active earth pressure acting on the retaining wall.
Without considering the tensile effect between soil and the upper part of retaining structure, when retaining structure does not separate from slope soil, Rankine active earth pressure can be calculated as