Analysis of earth pressure on retaining walls with limited displacement based on elastic theory

The classical earth pressure theories were established by studying the stress state in an elastic half-space body based on the limit equilibrium condition of soil and the static equilibrium of the wedge. Due to the creep and consolidation characteristics of soil, the active and passive earth pressures have time-dependent features. From a long-term perspective, the earth pressure acting on retaining walls due to the creep and consolidation of soil is under non-limit equilibrium conditions(limited displacement). A calculation formula for calculating the earth pressure acting on the retaining wall under limited displacement is established in this study based on the linear elastic constitution theory. The tangent modulus in Duncan-Chang nonlinear elastic model is introduced to reflect the change of soil modulus with confining pressure, and the boundary strains of Rankine active earth pressure, earth pressure at rest, principal stress direction deflection and Rankine passive earth pressure are derived. According to the four boundary strains, the earth pressure acting on the retaining wall is divided into five state zones as active failure state zone, active earth pressure state zone with limited displacement, passive earth pressure state zone with limited displacement before principal stress deflection, passive earth pressure state zone with limited displacement after principal stress deflection and passive failure state zone. By comparing and analyzing the calculation results by the proposed formula with the model test results, it is concluded that the earth pressure distribution of the wall is always non-linear when the retaining wall moves in a mode of translation displacement (T mode), rotation displacement around the wall base(RB mode) or translation + rotation displacement around the wall base(RBT mode), and that the calculated values of the earth pressure along the wall depth under different displacements are basically consistent with the measured values, which indicates that the proposed can be well applied to the design of retaining walls in practical engineering. © 2020, Science Press. All right reserved.