深层承压水降水引起地层沉降的多工况数值模拟  

Numerical Simulation of Various Conditions of the Formations Settlement Induced by Dewatering in Deep Confined Aquifer

作　　者：郭栋[1] 杨潇[2] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]岩土及地下工程教育部重点实验室,上海200092

出　　处：《佳木斯大学学报（自然科学版）》2015年第6期912-915,共4页Journal of Jiamusi University：Natural Science Edition

摘　　要：基于上海某地铁换乘枢纽地下综合体工程背景,借助Geo Studio2007岩土工程有限元数值分析软件,针对上海地区第二层承压水降水及其引起的地层沉降进行数值模拟,考虑了两种降压井布置方式,设置了原位无基坑、单个基坑和多个基坑三种工况,并对各工况下降水后的地层沉降作了对比分析.研究表明,在对第二层承压水设定相同的水位降深时,三种工况下地表沉降值的相对大小关系随距离降压中心位置的变化而变化;基坑围护结构对于地表沉降存在隔断作用,有利于地表沉降的收敛;降压井的不同布置形式影响着三种工况的最大地表沉降值;对第二承压含水层实施降压,只会在该土层引起压缩变形,其上覆各土层的地层沉降基本相同.本文的研究成果对于软土地区多基坑遭遇深层承压水降水问题具有一定的指导价值和借鉴意义.On the basis of underground complex engineering of Shanghai metro junction hub,a numerical simulation was carried out on dewatering in the second confined aquifer and the formations subsidence. With the utilization of finite element numerical software Geo Studio2007,the simulation took into consideration two different arrangement forms of dewatering wells in three various working conditions,i. e. no pits dewatering,single pit dewatering and pits dewatering. Subsequently,a comparative analysis among three conditions was conducted. The results indicate that with the same drawdown of confined aquifer,the relative magnitude of surface settlement proves various in three conditions as the position changes. There exists break effect of retaining structure in surface settlement,which is in favor of the convergence of surface settlement. The maximum of surface subsidence is influenced by different arrangement forms of wells in three conditions. Under dewatering in the second confined aquifer,compression deformation of soil layer only appears in the second confined aquifer,so that the overlaying soil layers share almost the same subsidence value. The achievements of this paper can provide certain aids and references for engineering problems in soft areas as dewatering in deep confined water in multiple excavations.

关 键 词：深层承压水 降水 地层沉降 多工况 数值模拟 

分 类 号：TU473[建筑科学—结构工程]