坑外降水-回灌技术结合在复杂工况超深基坑工程中的应用研究

Study on Application of External Dewatering-recharge Techniques in Complex Working Conditions for Ultra-deep Foundation Pit Projects

在深基坑内降承压水将导致地下连续墙内外侧出现水头差,易使地下连续墙的薄弱部位产生渗漏,甚至涌水涌沙。采用基坑外管井降水减小水头差是较为经济有效的措施,同时采取双止水帷幕和回灌措施可保护基坑周边建筑物,达到既保证基坑安全施工又能减少对周边环境影响的效果。以某地铁车站为工程背景,介绍了Y线车站主体基坑施工过程中,采取基坑外双止水帷幕内降水和回灌技术相结合的方式,降低因深基坑施工降承压水对周边环境的不利影响,为同类型工程提供经验借鉴。

The reduction of confined water in a deep foundation pit can lead to a difference in water head between the inner and outer sides of the diaphragm wall.This can potentially cause leakage in the weaker parts of the wall,and even incidents of water and sand gushing.However,reducing the water head difference is achieved more economically and effectively through the dewatering of the pipe well situated outside the foundation pit.Furthermore,the implementation of a double waterproof curtain and recharge measures serves to protect the surrounding buildings adjacent to the foundation pit.This ensures the safe construction of the pit while minimizing the impact on the surrounding environment.With a subway station serving as the engineering context,the construction process within the main foundation pit of a Y line station is detailed,highlighting the combined application of dewatering and recharge techniques within the double waterproof curtain located outside the foundation pit.This approach not only mitigates the adverse impacts on the surrounding environment,which are typically caused by deep foundation pit construction,but also provides valuable experience for similar projects.