溶洞发育区超深地下连续墙施工处理技术

New Treatment Technology for Super-Deep Diaphragm Wall Construction in Rich Karst Cave Geology

:清远枢纽二线船闸围堰与基坑采用超深地下连续墙+内支撑支护结构,由于该工程地下连续墙施工需克服遭遇场地表层覆盖砂层厚、岩溶发育强烈的富溶洞工程地质问题,保证北江大堤安全及一线闸不断航,超大型深基坑防渗及处理等技术难题。通过采用边界探测和溶洞新型处理技术,在地下连续墙内预留灌浆管高效解决墙底止水帷幕的施工对策。实践验证了在溶洞埋藏较深的区域施工地连续墙进行溶洞预处理技术的可行性,取得了良好的效果和经济效益,项目的建设经验对其他大型船闸或类似工程建设有示范作用。

The cofferdam and foundation pit of the second-line Shiplock of Qingyuan junction adopt the super deep diaphragm wall+internal support structure.Because the construction of the underground diaphragm wall of the project needs to overcome the engineering geology of the rich karst cave with thick sand layer and strong karst development on the surface of the site,ensure the safety of the Beijiang Levee and the navigation of the first-line lock,and the anti-seepage and treatment of the super large deep foundation pit.In this paper,based on the construction of super deep diaphragm wall,through the use of boundary detection and new treatment technology of karst cave,the grouting pipe is reserved in the diaphragm wall to effectively solve the Construction Countermeasures of water stop curtain at the bottom of the wall.The practice has verified the feasibility of pretreatment technology of diaphragm wall in the construction site with deep karst cave,and achieved good results and economic benefits,The construction experience of the project can be used as a model for other large ship locks or similar projects.