丁寨防洪排涝隧洞超前地质预报技术应用分析

Analysis on the Application of Forecast Technique for Advance Geology of Dingzhai Flood Control and drainage tunnel

隧道开挖过程中,超前地质预报技术是避免不良地质体诱发地质灾害的有效手段。依托丁寨防洪排涝隧洞工程,针对隧洞施工区域岩体内部存在软弱夹层或岩溶发育、富水等复杂地质条件,采用地震反射波法与震电效应法相结合的方法,对岩体内不良地质体及岩体富水情况进行探测。在接收孔中采集得到与各激发孔对应的波形图。对于存在横波负反射界面,正负反射交替出现,偏移成像图出现密集断层反应的区域,预测此处节理裂隙很发育或存在软弱夹层;根据震电信号反演结果,预测岩体富水区域,并提出相应的工程措施。超前预报成果保障了丁寨防洪排涝隧洞的安全高效开挖,同时也为同类工程施工建设提供参考。

During the tunnel excavation,forecast technique for advance geology is an effective means to avoid geological disasters induced by unfavorable geologic bodies.Relying on Dingzhai flood control and drainage tunnel project,the method of combining the seismic elastic wave method and the seismic reflection method was used to detect the unfavorable geologic bodies and the water-rich condition of the rock body aiming at complex geological conditions such as weak interlayers or karst development and rich water in the rock mass in the tunnel construction area.In the receiving hole,the waveform corresponding to each excitation hole was collected.For the areas where the shear wave negative reflection interface exists,the areas where positive and negative reflections alternately appear,and the areas where dense tomographic response appears in the migration image,it is predicted that the joints and fissures here are very developed or there are weak interlayers.According to the seismic signal inversion result,the water-rich areas of the rock mass are predicted,and corresponding engineering measures are proposed.It ensures the safe and efficient excavation of the Dingzhai flood control and drainage tunnel,and also provides a reference for the construction of similar projects.