大直径水底盾构隧道不良地质段及疑似溶洞探测技术的应用

Application of Geological Prediction Technologies in Construction of Large-diameter River-crossing Shield-bored Tunnels

为探明江中盾构段存在的岩溶、裂隙发育带、岩层不整合面等不良地质情况,通过对4种物探方法的场地适应性试验,最终采用水域高密度电阻率法、高频大地电磁法及地震反射波法对过江隧道掘进区域内的不良地质体的赋存情况进行探查。通过对3种物探方法比对分析,基本查明了测区内岩土层的分布情况,查清了裂隙密集带、局部岩体节理裂隙发育区及溶洞可能发育区等不良地质体的分布位置,达到了预期目的。

Tests have been made on the field applicability of 4 geological prediction technologies, including high density resistivity technology, high frequency magnetotelluric technology, seismic reflection wave technology and transient elec- tromagnetic technology. According to the testing results, the former 3 technologies are adopted to predict the geological conditions of the large-diameter river-crossing shield-bored tunnel. In the end, the distributions of soil conditions, frac- tures and potential karst cave are predicted.