Stress Around a Shaft or a Drift Excavated in Ground Being in Three-Dimensional Stress State

Abstract

The stress around undeground openings is much affected by the state of stress in the ground in which the openings are made.The present paper describes the results of investigation in the stress distributions around a vertical shaft, an inclined shaft and a drift, taking into account that the ground is in threedimensionalstress state.
First the general method of experimental analysis of stress around a shaft or a drift is discussed, paying special attention to the evaluation of indeterminate stresses. Secondly, the stress around a shaft or a drift with a square or a rectangular cross section having rounded corners is found by two-dimensional and threedimensional photoelastic experiments.The results obtained are illustrated, from which the influence of the state of stress in undisturbed ground upon the stress around a shaft or a drift is discussed.