高速铁路隧道岩溶探测及塌方处理方案研究

Research on the Karst Detection and Collapse Treatment Scheme of High Speed Railway Tunnel

研究目的:以南玉铁路巴山隧道工程为依托,建立适用于复杂地质条件的综合超前地质预报体系,精准判断隧道掌子面岩溶发育的情况。综合考虑围岩级别、岩溶类型、充填情况及地下水情况,研究岩溶隧道拱部塌方的处理措施,保障隧道施工安全。基于综合超前地质预报结果,从而对岩溶进行针对性处理。研究结论:(1)本隧道在DK32+713~DK32+723段落为岩溶发育区,受接触带影响,基岩裂隙水主要沿接触带入渗和侵蚀,水流沿着裂隙面入渗而形成全填充型溶洞;(2)建立适用于本隧道综合超前地质预报体系,探明了岩溶的形态、规模、与隧道的空间位置关系以及地下水的发育情况,探测结果与现场揭示情况基本一致;以超前水平钻为主,综合TSP、地质雷达及地质调查法的综合超前地质预报探测效果较好,准确性高;(3)结合探测结果,对岩溶采取针对性措施,岩溶塌方得到妥善处理,隧道安全通过岩溶发育段,通过围岩监控量测,隧道通过后变形趋于稳定,效果良好;(4)对于岩溶地区的隧道,应进一步加强超前地质预报,提前发现异常,及时采取预加固措施,发挥超前地质预报的作用,避免引发安全事故;(5)本文研究对岩溶区隧道工程的建设具有指导意义。

Research purposes:Based on Bashan tunnel project of Nanning-Yulin railway,a comprehensive advanced geological prediction system suitable for complex geological conditions is established to accurately judge the karst development of tunnel face.Considering the surrounding rock grade,karst type,filling condition and groundwater condition,the treatment measures of karst tunnel arch collapse are studied to ensure the safety of tunnel construction.Based on the comprehensive geological prediction results,targeted treatment of karst is carried out.Research conclusions:(1)The DK32+713~DK32+723 section of the tunnel is a karst development area.Affected by the contact zone,bedrock fissure water mainly seeps and erodes along the contact zone,and then a fully filled karst cave was formed.(2)The comprehensive advanced geological prediction system suitable for the tunnel has been established,and the shape and scale of karst,the spatial position relationship with the tunnel and the development of groundwater have been proved.The detection results are basically consistent with the field findings.The comprehensive advanced geological prediction with advanced horizontal drilling as the main method and TSP,GPR and geological survey method has good detection effect and high accuracy.(3)Combined with the detection results,targeted measures are taken for karst collapse,and the tunnel passes through the karst development section safely.Through the monitoring and measurement of surrounding rock,the deformation tends to be stable after the tunnel passes through,and the effect is good.(4)For the tunnel in karst area,it is necessary to further strengthen the advance geological prediction,find out the anomalies in advance,and take pre reinforcement measures in time.Functions of advanced geological prediction are made best use of to avoid causing safety accidents.(5)The research result is of guiding significance to the construction of tunnel engineering in karst area.