软土区地铁深基坑降水设计及数值分析  

Dewatering design and numerical analysis of deep foundation pits for subway construction in soft soil areas

作　　者：王金奎 WANG Jinkui(China Railway 11th Bureau Group 4th Engineering Co.,Ltd.,Wuhan 430070,China)

机构地区：[1]中铁十一局集团第四工程有限公司,武汉430070

出　　处：《低温建筑技术》2024年第11期104-108,共5页Low Temperature Architecture Technology

基　　金：国家重点研发计划项目(2021YFF501004);中国铁建科研课题(2022-B02)。

摘　　要：软土地区富水地层的深基坑降水是基坑工程的重大难题,常采用地连墙+素混凝土墙的止水帷幕方案。但在基坑开挖过程中,若内侧地连墙存在缺陷,止水帷幕极易在高水头压力下出现侧壁渗漏、管涌等工程问题。文中依托南京某地铁风井深基坑工程,基于数值模拟和现场实测分析了基坑止水帷幕部分失效情况下的降水效果。研究结果表明,在实际工程中地连墙及素混凝土墙均可能存在瑕疵,坑外地下水可能对坑内地下水进行补给,此时开启两墙之间降水井能够有效降低地下水水位,同时能够合理控制基坑降水对地面沉降的影响,研究结论可为类似工程提供参考。Deep foundation pit dewatering in water-rich soft soil areas presents significant challenges in pit engineering,often using a combination of diaphragm walls and plain concrete walls as a water barrier.However,if defects occur in the inner diaphragm wall during excavation,the water barrier is prone to issues such as sidewall leakage and piping under high hydraulic pressure.This study is based on a deep foundation pit project for a subway ventilation shaft in Nanjing,employing numerical simulations and on-site measurements to analyze dewatering effectiveness when part of the water barrier fails.The findings indicate that both the diaphragm wall and plain concrete wall may have flaws in actual projects,and the groundwater outside the pit may replenish the groundwater inside.In such cases,activating dewatering wells between the two walls can effectively lower the groundwater level while reasonably controlling the impact of dewatering on ground settlement.The conclusions drawn from this study provide valuable references for similar engineering projects.

关 键 词：软土地区富水地层 深基坑降水 地面沉降 

分 类 号：TU441[建筑科学—岩土工程]