Study on the Characteristics of Surrounding Rock and Design of Backfill Material Parameters for Tunnels Passing through Giant Caverns and Underground Rivers

The influence on tunnel construction of karst and underground rivers is always an important problem in engineering. In order to demonstrate the rationality backfill parameters effectiveness supports under groundwater when a passes through large cave, finite element software FLAC3D was used for numerical analysis. Converting mean values standard deviations mechanical response results surrounding rock multiple sections into ECULID distance from origin point two-dimensional plane as evaluation indexes, reinforcement analyzed by orthogonal experiments. Based fuzzy decision theory, regarding between simulated result each group global optimal value index comprehensive index, parameter design method proposed. By comparing which worst FLAC3D, 10 times 2.5 differences longitudinal horizontal displacement were observed, respectively. Then, applied actual project verification. field monitoring showed that can effectively reduce around tunnel. After constructing diversion river, water flow cave did not rise during rainstorm. This study provides reference other projects future.