Ecology, Environment and Conservation Paper

EFFECT OF RELEASING STRESS IN TUNNELS ON THE STABILITY OF SLOPES

Ashkan Fallah Vazirabad and Vahid Hosseinitoudeshki

Abstract

One of the most important problems in geotechnical engineering is slope stability of rocks. In this paper we have studied various radius tunnels modeled in basaltic slopes with different gradients. In a specified slope first the stability of various slopes were analyzed by 2D finite element program and in case of slopes stability, stress was released in tunnels with various radiuses step-by-step modeled in that slope. Effect of changes in radiuses on slope stability and strength reduction factor (SRF) behavior was observed. Rock Mass Rating (RMR), Tunneling Quality Index (Q) and Geological Strength Index (GSI) were used in classification of local rock masses. Initial data of 2D finite element analysis program have been provided by information and classifications mentioned above. The results show that an increase in gradient, radius and releasing stress, decreases SRF and slopes stability.