A finite element computer model for stress analysis of underground openings

A finite element model for linear elastic analysis of underground openings has been developed for use on microcomputer. The model is designed to serve as a useful analysis tool for the mining engineer to conduct a 2-dimensional analysis of multiple-material domain surrounding a mining excavation for the purpose of predicting areas of potential failure and critical stress. The model accommodates any arbitrary geometry of the opening and allows for a variety of loading conditions and combinations which may be encountered in a mine environment such as in situ stress, gravity loading and boundary tractions. Material failure is checked by means of Drucker-Prager, Mohr- Coulomb and Hoek and Brown criterion. The model utilizes a 4-node guadri1ateral isoparametric element and employs a mesh generating routine to facilitate node and element data preparation. Element stiffness matrix as well as consistent load vectors are evaluated numerically using the Gauss guadrature rulle. The discretized eguilibrium eguations are solved by a banded Gauss solver routine. The use of the model is demonstrated by a numerical example of an underground tunnel opening subject to in-situ stress loading.