Application of the thin-layer interface element to geotechnical problems

Many geotechnical problems involve interaction between structure and soil or rock. If numerical methods are applied to obtain solutions to this type of problems, proper modelling of the contact zone strucure-soil may be important. Many formulations of joint and interface elements have been proposed by a number of researchers but an easy to handle, robust element for routine anylyses has not yet been presented. In this paper the application of a thin-layer element which is a combination of the thinlayer element proposed by Desai and the Multilaminate model introduced by Pande is discussed. The element is implemented into a commercial finite element program and a viscoplastic algorithm is used to solve the nonlinear equations. Investigations concerning optimum time step lenghts are briefly presented. Examples of a buried pipe, a diaphragm wall and an avalanche protection tunnel demonstrate the applicability of the element.