“两墙合一”地下连续墙在深部高承压水地区超深基坑工程中的应用研究

Research on the application of dual-purpose diaphragm walls for ultra-deep foundation pits in high confined water area

泉州某超深基坑工程,基坑开挖深度约20 m,场地周边建筑及地下管线密集,且场地深部存在复杂的多层高承压含水层。为控制基坑变形,采用“两墙合一”地下连续墙支护结构,其具有墙体刚度大、止水效果好等特点。监测结果表明,此超深基坑工程支护结构变形小,对周边建筑、道路、地下管线影响小,基坑支护设计安全可靠。此外,对施工过程中出现的渗漏、鼓包、露筋问题进行了分析与处理,以期为同类工程提供借鉴和参考。

An ultra-deep foundation pit in Quanzhou has an excavation depth of around 20 m,and it is surrounded by lots of buildings and underground pipelines.Due to the existence of complex multi-layer confined aquifers,lateral leakage and upheaval is likely to occur if without proper groundwater treatment.However,pumping and lowering of the confined water is not suggestive due to its negative impact on the surrounding environment.Therefore,dual-purpose diaphragm walls was adopted as the retaining structures in this project,mainly because of its high stiffness and good water barrier effect,which is also designed as the outside walls of the basement.The monitoring results indicate that the deformation of the retaining structure and the environmental impact are both small,verifying the safety and the rationality of this design.At last,the reasons of leakage and bulge and exposed reinforcement of diaphragm wall were analyzed in this paper and the corresponding measures were also provided,which gave a good reference for other similar projects.