Houman Rahimi - Academic Staff, Islamic Azad University, Shahr Qods Branch
Moshfegh Yeganeh - Graduated student, Geotechnical Engineering Department, Faculty of Civil Engineering, K. N. T. University

The shape of slip surface of the wedge creating lateral thrust on retaining wall plays an important role in the magnitude, distribution, and height of point of application of lateral force. Considering the shape of slip surface as linear, circular, logarithmic spiral, or a combination of them is various conventional assumptions made in the literature review. It is know that the Coulomb method assumes a linear distribution of soil pressure on retaining walls, thus the point of application of total thrust is placed in one third height of the wall supporting granular backfill. However, some experimental studies have revealed non-linear distribution of earth pressures. In addition, the point of application of resultant thrust is placed somewhere upper than one third height of the wall. In the present study, plasticity equations are used and governing equations are derived on the basis of limit equilibrium approach to determine the nonlinear failure surface. For this purpose, a new analytical solution for determining total resultant thrust on the wall is introduced and the distribution of pressures and the point of application of thrust are computed with no simplifying assumptions. The results are compared with data from earlier available research work data. The results obtained from the developed method will be presented in tabular and graph forms for better understanding of the problem of earth pressure theorem.

Retaining wall, Slip surface, Plasticity, Limit equilibrium method, Distribution of earth pressure