隧道穿越大型充填溶洞超前综合探测与处治技术

Comprehensive Advance Detection and Treatment Technology for Tunnels Passing through Large Infilled Karst Caves

针对隧道穿越大型充填溶洞超前综合探测与处治技术难题,文章结合广西河百高速公路平坎隧道工程建设实践,系统开展补充岩溶地质探测、溶洞处治及效果分析研究工作,提出采用"岩溶地质调查+地震波反射法(TSP)+超前地质钻探+地质雷达探测+地质素描"的综合方法进行超前探测,在探明充填型岩溶腔体发育规模、空间位置、充填性质等特征的基础上,确定采用大管棚注浆、超前小导管注浆等超前加固支护处理之后再进行隧道开挖的总体处治原则,并成功应用于平坎隧道穿越ZK32+989处大型充填溶洞的施工实践。在此基础上,讨论分析了隧道穿越大型充填溶洞预处理方案和突泥灾害发生之后再进行后处理方案的施工工效与安全特征,表明采用预处理方案不仅能够有效控制隧道突泥突石灾害,并具有显著的技术经济优势。

In view of technical problems of advanced comprehensive detection and treatment of the tunnel crossing large infilled karst cave,the studies were systematically carried out for supplementary karst geological detection,karst cave treatment and effect analysis in combination with the construction practice of Pingkan Tunnel Works of Hebai Expressway in Guangxi.Then,it was proposed to perform the advanced detection by the comprehensive method of"karst geological survey+seismic wave reflection method(TSP)+advanced geological drilling+geological radar detection+geological sketch".Based on the exploration of development scale,spatial location and filling properties of infilled karst cave,the following overall treatment principle was determined:tunnel excavation was carried out after advance reinforcement and support treatment,e.g.large pipe shed grouting and advance small conduit grouting.Moreover,it was successfully applied to the construction practice of Pingkan Tunnel crossing the large infilled karst cave at ZK32+989.On this basis,the construction efficiency and safety characteristics were discussed and analyzed for the pre-treatment scheme for the tunnel passing through the large infilled karst cave and the post-treatment scheme after the mud inrush disaster.The results indicate that the pre-treatment scheme could not only effectively control the mud and rock inrush disaster of the tunnel,but also has significant technical and economic advantages.