Abstract
A method of coupling a boundary element method (BEM) with a finite element method (FEM) is developed to analyze three dimensional elasto-plastic problems of tunnels in infinite ground.
In the proposed method, FEM handles construction sequences and elasto-plastic behavior of the ground surrounding a tunnel, and BEM which is applied to the infinite elastic region takes into account boundary conditions at infinity.
By performing some coupling analyses, the following conclusions are obtained. (1) The coupling method is shown to be a reasonable one in the problems with infinite region. (2) Economical coupling analysis of tunnels can be performed by considering geometrical symmetry proposed here. (3) In an elasto-plastic coupling analysis, it is not necessary to make stiffness matrix of BEM region repeatedly. (4) Applicability of the coupling method to tunnel problems is confirmed.
