Abstract

In this paper, the earth pressure distribution generated behind a 20 m high retaining wall was estimated by the finite element method and compared with that obtained from classical earth pressure theories. Soil behavior was assumed to be elasto-plastic with Mohr-Coulomb failure criterion. The concrete retaining wall was represented by linear elastic model. Two-dimensional plane-strain finite element computer program CRISP was utilized after some modification. The results showed that Dubrova’s method gives greater values than Coulomb equation for all modes of wall movements. Whereas, the results obtained from the finite element analysis indicate that the stress distribution is more or less equal to Coulomb equation and ranging at about 90% of the depth for Φ=25^o and 60% for Φ=40^o. Below this depth, the pressure distribution becomes much greater than that obtained by Coulomb equation.  The finite element analysis shows a clear oscillation in the value of lateral earth pressure caused by line loads in addition to backfill, in the upper half of the wall, this oscillation increases as the line load increases in value and decays as the load goes far away from the wall. In the lower half of the wall height, the lateral earth pressure becomes more close to a linear distribution and its maximum value is at the wall base. The lateral earth pressure distribution will vanish as the position of the line load becomes far away from the wall (m ≥ 0.6 × D QUOTE ).

Key words: Earth pressure, finite elements, soil-structure interaction, retaining wall, line loads.