Experimental Study on the Influence Mechanism of the Structural Plane to Rockbursts in Deeply Buried Hard Rock Tunnels

During the excavation of a large number deeply buried tunnels and mining projects, rockburst disasters occur frequently due to complex geologic environment in deep underground, including high initial geostress, adverse tectonic actions, disturbance. Many rockbursts have been found be induced by some small-scale structural planes area around during construction Jinping II hydropower station. In order study influence mechanisms plane rockbursts, physical simulation tests under biaxial stress conditions are carried out using marble samples considering different relative positions with tunnels, namely, tunnel spandrel, sidewall, at intersection tunnel. The digital image correlation (DIC) technique is used trace evolution deformation on surface process sample. results reveal that three types identified, fault-slip rockburst, split bulking shear rupture their processes reproduced. presence vicinity could one major factors triggering rockbursts. findings provide helpful references for predicting development design burst-resistant measures this type