基于隧洞超前地质探测和地应力场反演的岩爆预测研究

Rockburst prediction based on tunnel geological exploration and ground stress field inverse analysis

岩爆是高地应力地区影响地下工程施工的主要地质灾害,岩爆预测已成为地下工程的世界性难题之一。地层的岩性条件和地应力的大小是影响岩爆发生的两个最根本因素,对这两个因素的准确判别将直接关系到岩爆预测的成功与否。根据工程的区域地质资料,利用FLAC3D程序建立了该区域的数值计算模型,并结合工程现场实测点的主应力数据,采用径向基函数神经网络,反演了计算区域的初始地应力场。基于现场岩石力学试验和TSP203探测技术,获取了岩爆高风险区域的地层岩性条件。最后结合地应力反演数据和TSP探测结果,对掌子面前面长距离范围内的岩爆强度进行精细预测。工程实际应用表明,该方法可操作性强,岩爆预测结果与实际开挖情况较吻合。

Rockburst is a main geological disaster influencing underground constructions at the high ground stress area. The prediction of rockburst has become one of the worldwide difficulties in underground works. Formation lithology and the value of ground stress are two basic factors that affect the occurrence of rockburst; and the accurate discrimination of them is directly related to the success of rockburst prediction. According to the measured principal stress data of the engineering site, a numerical calculation model of the region is established by FLAC3 D. Using radial basis function neural network, inverse analysis of the initial ground stress field is made. Then based on the rock mechanics in-situ experiments and TPS203 detection technology, formation lithology of the area with high rockburst risks is obtained. Finally, combining inverse analysis data and TSP detection results, the intensity of rockburst within a great distance of the region in front of tunnel face is precisely predicted. The case study shows that the proposed procedure is of high maneuverability; and the rockburst prediction results are well consistent with actual excavation conditions.