Calculation and distribution of active earth pressure against flexible retaining walls

The previous studies have shown that the resultant and distribution of active earth pressures against flexible retaining walls vary with the modes and magnitudes of wall movement, and the distribution of earth pressures is significantly different from that of rigid walls. Based on the previous experimental and numerical results, a model to calculate the earth pressures on the flexible retaining walls is proposed, which can consider the effect of wall movement. A middle-state coefficient is introduced to reflect the influence of the modes and magnitudes of wall movement. The formulae of the coefficients of the resultant earth pressures on the flexible wall under any lateral deformation are presented. Then the soil behind the wall is simplified as the combination of nonlinear springs and a rigid plasticity object and the unit earth pressures and the heights of points of application of resultant forces are obtained. The comparisons among the proposed formula, previous methods and the experimental observations show that the results of the proposed method are more satisfactory than these of the previous methods. With the increase of the wall movement, the resultant active pressures decrease and the nonlinearity of the distribution of earth pressures augments gradually. The heights of points of application of resultant forces change with the mode of wall movement. The distribution of earth pressures exhibits a “R” shape under the drum deformation of the wall.