中-弱透水互层深基坑降水方案优化研究  

Optimization of Dewatering Scheme for Deep Foundation Pit with Medium-Weakly Permeable Interbedded Layer

作　　者：王强 WANG Qiang(Design and Research Institute of China Railway Construction Bridge Engineering Bureau Group Co.Ltd.,Tianjin 300300,China)

机构地区：[1]中国铁建大桥工程局集团有限公司设计研究院分公司,天津300300

出　　处：《铁道建筑技术》2022年第6期151-155,共5页Railway Construction Technology

基　　金：中国铁建大桥工程局集团有限公司科技研究开发计划项目(2020-B14)。

摘　　要：伴随我国城市轨道交通建设高速发展,复杂地层环境条件下深基坑降水问题日益凸显。中-弱透水互层由于层间渗透系数差异较大,降水不当极易引起基坑及周边环境破坏,严重影响施工安全和工程成本。本文针对榆安1号隧道明挖段深基坑开挖降水施工,利用数值模拟与工程监测相结合的方法,系统分析降水井数量、止水帷幕深度及滤水管插入含水层深度等因素对深基坑降水效果的影响,并在此基础上对降水方案进行优化。研究结果表明,本项目降水井单井控制面积宜在180 m^(2);止水帷幕深度插入比宜控制在1∶0.9~1∶1;滤水管插入含水层深度宜控制在0.6~0.8倍含水层厚度。With the rapid development of urban rail transit construction in China,the problem of deep foundation pit dewatering in complex stratum environment is becoming more and more prominent.Among them,the permeability coefficient between intermediate and weak permeable layers varies greatly.Improper dewatering of foundation pit is very easy to cause damage to the foundation pit and its surrounding environment,which seriously affects the construction safety and project cost.Aiming at the dewatering construction of deep foundation pit excavation in the open excavation section of Yu’an No.1 Tunnel,using the method of numerical simulation and engineering monitoring,this paper systematically analyzes the influence of the number of dewatering wells,the depth of waterproof curtain and the depth of filter tube inserted into aquifer on the dewatering effect of deep foundation pit,and optimizes the dewatering scheme on this basis.The research results show that the single well control area of the dewatering well in the project should be 180 m^(2),the depth insertion ratio of the waterproof curtain should be controlled at 1∶0.9~1∶1,and the depth of the filter tube into the aquifer should be controlled at 0.6~0.8 times the thickness of the aquifer.

关 键 词：深基坑 中-弱透水互层 井群降水 降水井数量 止水帷幕深度 滤水管深度 方案优化 数值分析 

分 类 号：U455.45[建筑科学—桥梁与隧道工程] TU473.3[交通运输工程—道路与铁道工程]