For large underground cavern established in bank slope with ‘V’ shape valley, estimation of in-situ rock stress and failure of wall rock is very signification, not only for prevention from potential failure, large deformation, and instability of caverns, but also for the optimizing design of rock supporting. As a typical example, the relationship between valley rock stress field of Yalong river and rock failure of underground caverns is discussed. Firstly, the differences between elastic simulation method and elasto-plastic simulation method of in-situ rock stress field at ‘V’ shape valley are analyzed, which shows that the rock stress field calculated by elasto-plastic constitutive model is more reasonable. Then, the subfield of valley's stress field is marked out according to the ratio between maximum principle stress and vertical stress, which is useful for position design of cavern in bank. What's more, the comprehension about rock failure of Jining I underground caverns and in-situ rock stress filed of Yalong river valley is discussed and the conclusion is that the in-situ initial rock stress condition in stratum, including value and direction of stress, is the basic force source of rock failure in underground engineering.
In underground construction of large cavern or tunnel, determination of in-situ rock stress and failure of wall rock is very important, not only for prevention from potential failure, large deformation, and instability of caverns, but also for the optimizing design of rock supporting (Rajmeny 2002, Xia 2007, Li Shouju 2008). However, many outside factors, such as historical tectonic stress, encroach of valley bottom, degradation of bank slope el al., had affected the primal self-weight rock stress and leaded to the complicated current rock stress of bank slope at ‘V’ shape valley (Hudson 2003, Tan 2004, Li 2006).