FEM modeling method for anchored slope stability analysis and discussions on anchoring effect

Soil and anchor structure are under the condition of deformation compatibility in anchored slopes.The nature of the combined action between soil and anchor structure can not be considered by the slice method due to the rigid body assumption of soil.Thus,the results by slice method often underestimates the anchorage effect.A stability assessment method for anchored soil slope was proposed using FEM.In FEM modeling,point anchored truss elements and full-length bond truss elements were used to simulate the substantial reinforcement effect according to different parts of anchorage,namely,free part and anchored part.Based on the stress field given by FEM analysis with the reinforcement effect contained,unfavorable slip surface of anchored slopes could be obtained utilizing the safety factor concept of slice method where the ultimate shear strength of soil and anchor structure were considered.The unfavorable slip surface given by the method was deeper than that of the slice method and the safety factor was increased.The characteristics of the difference of effective anchorage length between the slice method and the proposed FEM-based method were studied.