Comparison Study of Rock Bursts of Deep Buried Tunnels in the Shear and Compression Tectonic Environments

The geologic tectonic stress field is an important factor that affects the rock bursts. Based on field geological investigation,the actual crustal stress analysis,the laboratory rock mechanics test analysis,and with the example of the deep buried Gaoligong Mt. tunnel,the paper make deeply analysis and research on the deep buried tunnel's rock burst characteristic between the extrusion and shear tectonic environment in the complex geologic tectonic stress field. Using the ANSYS software,the paper has simulated the stress reclassify characteristics at different sections of fold and strike-slip fault geology mass caused by the tunnel excavation,under the current crustal stress field,and made possibly prediction on the rock burst spot and the rock burst intensity. The research indicated that the rock burst has some intensity with the position between the tunnel and the geologic structure body,when the tunnel axis and the axial line of the fold are parallel,and tunnel located at anticlinal shaft and fold limb department,the rock burst possibility is to be the biggest; but when the tunnel axis and the axial line of the fold are vertical,the rock burst possibility is to be low; the strike-slip fault have great affects to the stress redistribution after tunnel excavation,and the partial rock burst possibility is big. The tunnel plan and construction may select the position that the tunnel axis is vertical to the fold axis or the position that far away from the strike-slip,and it is advantageous to weakening influence of the rock burst.