超前地质预报在棋盘石岩溶隧道中的应用

Application of Geological Forecast in Construction of Qipanshi Karst Tunnel

研究目的:岩溶隧道因其复杂性、多变性和不确定性成为隧道施工中最容易发生突水、突泥等地质灾害的地方。目前难以准确预报出隧道前方不良地质体的具体类型、位置、规模,为了最大程度地减少岩溶隧道施工中造成的工程投入和人员伤亡,迫切需要提高超前地质预报在岩溶隧道预报中的精度。研究结论:应用地质知识分析了棋盘石隧道出水溶洞的特点、力学性质,推测得知左侧壁存在溶洞的位置及规模;应用地质雷达对左侧壁及隧底进行了探测,探测结果显示左侧壁确实存在一个规模较大的溶洞,与地质知识推断结果大致相符,只是位置上有一些偏差,分析了产生偏差的原因;扎实的地质知识和必要的物探设备是做好超前地质预报工作必须具备的两个条件。

Research purposes： The karst tunnel easily becomes the place where the geological disaster happens during construction of karst tunnel, such as water - inrush and mud - inrush, due to its complexity, changeability and uncertainty. At present, it is difficult to accurately forecast the type, position and size of the unfavorable geological body in front of the tunnel. So it is urgent to improve the accuracy of the geological forecast in order to decrease the construction cost and casualties as much as possible in karst tunnels construction. Research conclusions： （ 1 ） The characteristics and mechanical properties of the karst caves of Qipanshi Tunnel are analyzed with geological knowledge, and the location and size of the caves in the left side of tunnel wall are speculated. （2） The ground probing radar is used to probe the left side of tunnel wall and the tunnel bottom, and the probing result shows that a large karst cave exists in the left side of the tunnel and it conforms to the speculated results, except the deviation in position. The reasons for the deviation are analyzed. （3）The comprehensive geological knowledge and geophysical equipment are two necessary conditions to do the geological forecast perfectly.