Safety analysis using finite elements

A finite element based method for determining safety factors which has certain advantages over conventional limit equilibrium methods is described. The stress field produced by a finite element analysis is used in conjunction with a conventional limit method to determine the safety,factor. It is shown how the stress values at the finite element integrating points may, be interpolated to points on a potential slip surface selected by trial as in the conventional method. This involves three basic problems: (a) identification of the element which contains a chosen point on the slip surface; (b) determination of the local co-ordinates of this point, and (c) determination of the element nodal stress values. Procedures to solve these problems are described. The problem of a vertical cut in clay is analysed and the results are compared with analytical solutions, (C) 1998 Elsevier Science Ltd. All rights reserved.