Analysis of the effect of orientation of a buried hemispherical excavation on the surrounding stress distribution

An investigation of the stress around a buried hemispherical excavation, using finite-element methods, was undertaken to analyze and compare the effect of orientation relative to an assumed in situ stress field. Measured values for physical properties of the rock and for the assumed in situ stress were obtained from nearby locations. This analysis deals only with stress considerations and does not include geologic factors such as joints, joint frequency, and joint orientation. The most stable orientation of the hemispherical excavation is that in which the base is perpendicular to the direction of the minimum principal stress axis of the assumed in situ stress field. For this orientation the base strikes N. 150 E and dips 780 NW and the curved portion of the hemispherical excavation could be located on either side of the base