Based on the progressive rupture mechanism in the backfill

the modified Coulomb's solution of earth pressure against flexible retaining wall is developed; and the nonlinear relationships between the wall movement and the angles of internal friction and wall friction are derived. It is applied to an improved solution for beam on a nonlinear elastic foundation. So that a new calculation of earth pressure against flexible retaining wall considering displacement is obtained. Comparisons of the calculated results with observations from model test show that the calculated results of the earth pressure has a satisfying agreement with the observations. This calculation can give some references to design of flexible retaining wall.