Effect of shape of opening on the stability of caverns: An experimental analysis

摘要

Sustainable development requirements made it necessary that underground space shall be used with larger size openings. This is to ensure a greater transportation demand and for preserving environment quality. The need for underground space technology has increased significantly during the past few decades in India. The deep mining and civil engineering applications need to perform rock stability analysis during the excavations. These analysis are closely related with stresses and deformations in the excavation contours. Five key parameters required for stability analysis of any underground excavation are namely; a) in-situ state of stress, b) induced stress fields, c) shape of the opening, d) size of the opening and e) related allowable deformation when the openings are made. The study is focused on changes in the stress regime of a cavern in elasto-plastic rock mass and its impact on the stability. Four different shapes of caverns are considered to study the behavior of the shapes in a particular ground conditions. Commercial numerical code RS3 has been used for the analyses of the problem. Full 3D numerical model has been developed for the analysis. The effect of parallel openings on the stability is also analyzed. An optimum shape for the underground opening is suggested based on the study under the particular rock mass condition.