Abstract: To study the active earth pressure of finite soil behind the retaining wall, the cohesionless soil behind the wall is taken as the research object. The fracture surface is assumed as the plane passing through the heel of the wall, and in the translational mode of the retaining wall, the soil behind the retaining wall forms an arc-shaped small principal stress arch. The soil behind the retaining wall is divided into several curve thin-layer elements by the stratification method along the small principal stress. Considering the inhomogeneity of stress distribution on the upper and lower surface of the element, a calculation method is proposed for the active earth pressure of finite soil retaining wall. The expressions of active earth pressure resultant force and the height of its action point are given, and the correctness of this method is verified. The results show that the curve thin-layer element method can accurately consider the complex stress condition of the element, and can better reflect the variation law of the active earth pressure of finite soil behind the retaining wall. The active earth pressure shows a nonlinear distribution along the wall height H, it firstly increases with the soil depth increasing, then decreases monotonically near the bottom of the wall. In parameter sensitivity analysis, the distribution of active earth pressure of retaining wall and the height of combined force applied point are analyzed with different width-height ratios of soil and wall back roughness. The results show that with the increase of width-height ratio n, the active earth pressure gradually increases, the curve of earth pressure distribution becomes more and more nonlinear, the height of resultant force application point gradually decreases, and it is always greater than . It tends to be stable when n is greater than 0.71, so 0.71 can be assumed as the critical width-height ratio of finite soil and semi-infinite soil. The active earth pressure decreases gradually with the increase of the frictional angle ; the curve of earth pressure distribution becomes more and more nonlinear, the height of resultant force application point increases gradually and is always greater than .

Key words: retaining wall, finite soil, active earth pressure, small principal stress trajectory, curve thin layer element