岩爆倾向性巷(隧)道围岩破裂的试验研究

Experimental Study on Fracture of Tunnels'Surrounding Rock with Rockburst Proneness

针对硬岩岩爆问题,研制岩爆倾向性材料和断面围岩成形和卸荷的一体化装置,同时为得到因钻爆法或TBM施工造成的围岩损伤对岩爆破裂的影响,在围岩左侧帮预制与临空面平行的非贯通裂隙,制作物理模型,对具有岩爆倾向性的方形巷(隧)道围岩破裂模式进行物理模拟试验。通过数值试验,对比分析含裂隙(损伤)围岩与完整围岩破裂演化的特点。结果表明:两帮围岩总体表现为以劈裂破坏为主;完整侧帮围岩的局部达到了剪切破坏的条件,形成含有剪切模式的中厚边薄的破裂体;含裂隙侧帮围岩中的裂隙优先扩展并贯通形成劈裂,围岩损伤对岩爆倾向性围岩破裂演化模式的影响明显。物理模拟试验的现象与数值试验结果及已有的岩爆现象基本一致。

For the rockburst problem of hard rock, an integration experiment device of surrounding rock forming and unloading to research rockburst proneness was developed. A physical model was made for physical simulation experiment to study fracture patterns of surrounding rock of square roadway or tunnel. In order to simulate the influence of surrounding rock damage caused by construction with drill - blasting or TBM method on rockburst fracture,nonpenetrative cracks being parallel to the free face in the left side of the physical model were preset. The characteris- tics of failure evolvement of integrate surrounding rock and dam- aged surrounding rock （with cracls ） were compared and analyzed. The results indicated that the damage of surrounding rock at two sides were generally characterized by splitting, local shearfailure appeared in the integrated side surrounding rock, fracture body of which middle part was thicker and fringe was thinner came into being in the integrated side surrounding rock, it presented shear pattern;in the side surrounding rock with cracks the cracks propagated and ran through ,finally splitting occurred, this indicated that the damage of surrounding rock with rockburst proneness had great influence on the evolvement pattern of its fracture. The experimental phenomena occurred in the physical simulation experiment were consistent with the results of numerical simulation experiment as well as the rockburst phenomenon taking place in reality.