岩溶对桥梁基础影响的综合物探分析

Analysis for Effect of Karst on Bridge Foundation Based on the Integrated Geophysical Exploration Method

古港互通主线跨线桥、B匝道跨线桥基础场地发育溶沟、溶洞及溶蚀裂隙,为了查明岩溶发育范围、规模、埋深状况以及岩溶地质构造和控制因素等,对两桥梁及其附近进行了针对性的工程物理探测及其部分钻探验证工作。准确定位了场地岩溶发育情况,物探工作采用了音频大地电磁法、激发极化法(包括电测深和剖面法)和瞬变电磁法,分析了岩溶对桥梁基础的影响程度,结果表明:场地内岩溶发育,规模较大,且受构造控制明显,采取避绕或适宜处理措施后,场地整体仍处于稳定状态。

There exist developed karren,karst cave and karst fissure in the area of Gugan deck bridge and B ramp bridge,in order to find out the karst development scope,scale,the condition of buried depth and karst geological structure and the control factors,the specific physics detection of engineering and the drilling verification work are done nearby two Bridges.In order to determine the karst development situations from the macroscopic and microscopic,the integrated detection method are adopted,including audio magnetotelluric method,the induced polarization method（including electric sounding and profiling）and transient electromagnetic method,to find out the influence degree of the karst on the bridge.The results show that the ground within the karst development is extensive,local development large water-eroded cave,controlled by the structure,and provides a certain direction,but after maneuver around or appropriate treatment,space is still in the stable state.