Study on the wall rock stability of Yantan hydrologic station's underground caverns

Based on the geological investigation, study on evaluation of underground cavern surrounding rock stability with large span and high side-wall is carried out. Systematical analysis is performed on the distribution features of the secondary stress field, strain field and plastic zones in the surrounding rockmass of the underground cavities after the excavation by using of FLAC(3D) numerical modeling technique. And the variation characteristics of stress field, strain field and plastic failure zones in the surrounding rock mass of the underground cavities are summarized. The results of 3DEC and FLAC(3D) numerical modeling show that the underground workshop building chambers are whole stable, but parts of them are unstable and the unstable parts are small and shallow. The results provide basic information and reference for the evaluation of underground cavities stability and project construction.