南宁地区第三系半成岩地层中超深地铁车站降水关键技术研究

Key technology research on dewatering at ultra-deep metro station in the tertiary semi-diagenetic strata in Nanning area

根据极软岩中大断面暗挖地铁车站施工需要,研究了低渗透性地层中的群井降水施工技术特点,提出了和第三系半成岩地层相适应的降水井井管结构、成井工艺及井位布置原则等。采用了数值模拟、实践验证及反演计算等技术路线,成功解决了低渗透性、大降深群井降水方案设计及降水施工引起的构筑物保护难题等。经实践检验,降水效果显著,极大地降低了工程风险,取得了良好的社会经济效益。

According to the construction need of metro station mining with large - sections in extremely soft rock, the construction technology features of well group in strata with low permeability were studied, the dewatering well tube structure, the well competion technique and the layout principle of well location compatible with the tertiary semi - diagenetic strata were proposed. Techniques like numerical simulation, practical proof and inverse calculation were adopted to successfully resolve the difficulties of low permeability, dewatering scheme design of deep drawdown well group and structure protection provoked by dewatering construction. By practical test, the dewatering effects are significant, the project risks were remarkably reduced, and good economic results were achieved.