深埋长大隧道岩爆倾向性多指标评价

The Multi-criteria Evaluation of Rockburst Proneness on Deep Buried Large Tunnel

研究目的:高铁北武夷山隧道是一座单洞双线隧道,隧道最大埋深达1 100 m,属于高应力区,开挖过程中可能会出现岩爆现象。通过对隧道高应力地区采集的岩样进行室内岩爆倾向性实验,并结合声发射监测技术,得到岩石单轴抗压强度等性能参数,先采用强度脆性系数法、变形脆性系数法、弹性应变能指标法、切向应力准则四种单指标评价方法进行岩爆倾向性评价,然后运用四指标模糊数学综合评价法进行评价。研究结论:(1)结合声发射监测技术进行岩石力学实验,获得的变形脆性系数、弹性应变能指标系数相比常规实验更加精确;(2)根据岩体性质和围岩的应力情况,在传统综合评价方法基础上增加了变形脆性系数法评判指标,结果表明采用模糊数学综合评价方法得到的评价结果与单指标评价相比,更加符合隧道岩爆的实际情况;(3)本研究成果为隧道岩爆预测提供了可行方法,对于类似工程提前防治岩爆有借鉴意义。

Research purposes：North Wuyi Mountain of high-speed railway is a single hole bidirectional tunnel,and the maximum depth of the tunnel is as deep as 1100 meters,so it belongs to high stess area that may cause rockburst in the process of excavation.The indoor experiments about rockburst proneness of rock samples which were collected in high stress area of the tunnel are recorded in this paper,and some property parameters of rock like the uniaxial compressive strength were got combining acoustic emission testing.Four kinds of single index evaluation method were used to evaluate rockburst proneness firstly,including the intensity of brittleness coefficient method,the deformation brittleness coefficient method,the elastic strain energy method and the tangential stess criterion.Then the comprehensive evaluation method of fuzzy mathematical was used to evaluate.Research conclusions：（1） Combined with acoustic emission monitoring technology,we can get two indexes more accurately than conventional experiment.（2） According to rock properties and surrfounding rock stress,we increase the evaluation indicator of deformation brittleness coefficient method.It showed that the results from the comprehensive evaluation method of fuzzy mathematical are more in line with the actual situation of the rock burst of tunnel compared with the single index evaluation.（3） The research result provides a feasible method to predict rockburst and it is significant to prevent and control of rockburst in advance for similar engineering.