Impact of in situ stresses on underground cavern design

摘要

The existence of a significant horizontal in situ stress field within the relatively shallowTriassicrnstrata of the Sydney Basin in Australia is well established. The in situ stress state can have significant impacts onrntunnelling conditions and on induced ground movements in the vicinity of underground openings.A parametricrnstudy has been undertaken to assess the impact of this critical in situ horizontal stress state on the performancernof underground caverns. The study included using a constant lateral pressure coefficient, K of 1 or 4, and arnvariable stress profile. Various numerical model complexities were assessed ranging from simple homogeneousrnmodels to fully jointed models with various types of discontinuities. This paper discusses the parametric studyrnundertaken and documents some of the predicted behaviour of the underground openings.