岩溶发育区地铁车站基坑突水涌泥应急处理技术研究

Emergency Treatment Technology for the Water and Mud Gushing from Foundation Pit of A Subway Station in Karst Development Area

岩溶发育区因溶土洞众多、地下水丰富,基坑开挖作业极易引发坑底突水涌泥风险。如何有效应对突涌风险,保证线路施工安全一直是业界难题。以广州某岩溶发育区车站基坑突水涌泥的事故应急治理为例,分析了基坑开挖施工作业引发突水涌泥的原因,针对性地提出了混凝土反压控制涌水量,基坑外四阶段填充式注浆封堵溶土洞及基坑内垂直分层注浆填充裂隙隔断水源的综合治理方法,并总结得出了岩溶发育区基坑突水涌泥应急处理的整体思路。钻孔取芯及变形监测数据表明,基坑内外涌水通道得到有效治理,可为岩溶发育区突水涌泥的应急处理提供技术参考。

Because of the large number of karst caves and rich groundwater, the risk of water inrush and mud gushing at the bottom of the pit is easily caused by the excavation of the foundation pit. How to effectively deal with the surge risk and ensure the safety of the line construction has been a problem in the industry. Taking the emergency treatment of water and mud inrush from a station foundation pit in a karst development area of Guangzhou as an example, this paper analyzes the causes of water and mud inrush caused by the excavation operation of the foundation pit, and puts forward a comprehensive treatment method of controlling the water inrush by concrete back pressure, plugging the dissolved soil tunnel by four-stage filling grouting outside the foundation pit, and filling the fissure in the vertical layer of the foundation pit to block the water source. The whole idea of emergency treatment of water inrush and mud gushing from foundation pit in karst development area is summarized. The core drilling and deformation monitoring data show that the water inrush channel inside and outside the foundation pit has been effectively treated,which can provide technical reference for the emergency treatment of water inrush and mud inrush in the karst development area.