Experiment Study on Non-limit Passive Earth Pressure of Clay under Different Displacement Modes

In order to reveal the depth distribution law of the non-limit passive earth pressure of clay on a rigid retaining wall under different displacement modes, translation and rotation experiments were carried out using the self-made model box. The influence of the three modes and corresponding displacement on the lateral earth pressure were studied. Firstly, laboratory experiments were carried out, and the basic physical parameters of clay were obtained. Secondly, the model box and test instruments were installed. Finally, earth pressure experiments under three modes of the retaining wall: translation (T-mode), rotation around the top of the retaining wall (RT-mode), and rotation around the bottom of the retaining wall (RB-mode) were carried out. The following conclusions are reached: In the T-mode, the lateral earth pressure generally increased with increasing soil depth except in some local parts, presenting an approximately linear distribution. When the soil reaches the limit state, step-like staggered floors are formed in the vicinity of the wall; In the RT-mode, the lateral earth pressure grow more slowly in the upper wall but more quickly in the lower wall as depth increased, presenting a concave curve. When the soil reaches the limit state, cracks are formed in the vicinity of the wall, and the soil summones up in the middle of the box; In the RB-mode, the lateral earth pressure grow more quickly in the upper wall but more slowly in the lower wall as depth increased, presenting a convex curve. When the soil reaches the limit state, step-like staggered floors are formed in the vicinity of the wall, with the scope smaller than that in the T-mode. The resultant forces of these three lateral earth pressures increase with increasing compressive displacement, reaching the maximum increasing magnitude in the T-mode. When the compression displacement is the same, the ratio of the earth pressure resultant force in the RT-mode and T-mode is between 0.53 and 0.97; the ratio of the earth pressure resultant force in the RB-mode and T-mode is between 0.65 and 0.83.