Calculation of nonlimit active earth pressure of retaining walls based on curved sliding surface

The shape of the sliding surface and the displacement of the wall have important effects on the earth pressure of retaining walls. Taking the cohesive backfill behind the inclined retaining wall as the research object, the relationship between the displacement ratio of the wall and the internal friction angle, the external friction angle, the cohesion and the wall-soil adhesion were build up. The potential slip surface behind the wall was assumed to be a cycloid curve, establishing the force balance and moment balance equations of the horizontal differential soil element, the distribution of the non-limit active earth pressure was obtained. The reliability of the proposed method is verified by two model tests and some theoretical results. The parametric research indicates that with the increase of displacement ratio and internal friction angle, the range of potential sliding body decreases gradually, and the non-limit active earth pressure decreases accordingly, presenting a convex curve distribution with the peak value in the middle and lower part of the wall; With the increase of cohesion, the range of potential sliding body increases slightly, and the non-limit active earth pressure near the wall bottom gradually transitions from positive value to negative. With the increase of the inclination of the wall back, the range of potential sliding body increases, and the shape of non-limit active earth pressure curve gradually transitions from convex curve to concave curve. The theoretical method proposed in this paper can provide reference for the research of earth pressure of retaining walls under translational mode.