岩爆是一种典型的地质灾害,如何对岩爆进行预测已成为地下工程领域研究的热点和难点问题.为评价南水北调西线工程深埋隧洞岩爆发生的可能性,提出采用岩性分析、地应力实测及有限元分析相结合的方法进行岩爆预测.在研究中,从工程地质的角度,基于隧道围岩岩性分析、现场地应力实测及地应力场的反演分析,对隧道开挖后应力场进行了有限元数值模拟,综合分析了西线工程隧道初始地应力场沿轴线分布规律以及隧道开挖后不同埋深处岩爆发生的等级.结果表明,该工程岩爆等级大部分为中等岩爆.
Rock burst is a typical geological disaster, how to forecast rockburst has become a hot and difficult issue in the research field of underground engineering.In order to evaluate the possibility of rockburst, based on the deep buried tunnel in West Route of South-to-North Water Transfer Project, combined with stratum litho logy analysis, in-situ stress measurement and the stress field inversion analysis, the stress field of tunnel after excavation was studied with finite element numerical simulation, tunnel initial in-situ stress field distribution along the axis also was researched, then the stress distribution of the tunnel surrounding rock after excavation was analyzed.In the end, the tunnel rockburst grade at different depths was analyzed and predicted.The results show that, the level of rockburst can be predicted accurately with this method, which will provide technical support for tunnel excavation supporting scheme and construction measures.