大公山隧洞潘所海段岩溶工程地质问题及应对措施

Karst development law of Pansuohai section of Dagongshan tunnel and countermeasures

大公山隧洞过潘所海段位于复杂岩溶地区,施工中容易发生涌水、突泥、岩溶漏斗塌陷等事故。为了查清潘所海段的地质情况,采用地质测绘、地质勘探钻孔以及与地表物探相结合的综合勘探方法对该段的地质情况进行了深入的研究。根据地质分析成果,调整了隧洞线路,并针对施工中可能出现的问题,拟定了超前地质预报、地表截水、隧洞抽排、临界距离开挖、超前处理、加强支护等措施。实际施工实践表明,综合勘探方法可有效分析岩溶发育规律,所拟定的岩溶隧道施工方案行之有效。

Pansuohai section of Dagongshan tunnel is located at complicated karst area and the accidents of water gushing, mud inrush, karst funnel collapse happened usually in the tunnel construction. In order to identify the geological condition of this section, the integrated survey of geological mapping, geological exploration drilling, surface geophysical prospecting was adopted. According to geological analysis results, the tunnel line was adjusted and in the light of potential accidents in the construction, the measures including geological forecast, surface water interception, water pumping in the tunnel, critical - distance excava- tion, pre - treatment, support reinforcement, etc. were determined. The practical construction shows that the integrated survey method is helpful for effectively analyzing the karst development law and the proposed construction scheme is feasible.