泉域承压水地层深大基坑降水优化方案研究  

Study on Optimization Scheme of Deep and Large Foundation Excavation Dewatering in Spring-confined Water Area

作　　者：白兆明 BAI Zhaoming(China Railway 21st Bureau Group Rail Transit Engineering Co.,Ltd.,Jinan,Shandong 250010,China)

机构地区：[1]中铁二十一局集团轨道交通工程有限公司,山东济南250010

出　　处：《施工技术（中英文）》2024年第10期51-56,62,共7页Construction Technology

基　　金：中铁二十一局集团重点研发计划(22C-10)。

摘　　要：济南轨道交通4号线一期工程济南西站项目处于泉域承压水地层,该区域内的承压水一般分布于松散地层。由于承压水埋深大、水头高、水量大等原因,对深基坑工程底板及深基坑施工危害较大。为保证济南西站深大基坑降水工程的施工安全,建立了场地-地下连续墙-降水井三维模型,分析降水井数量、间距、深度对降水效率的影响,提出最优的降水井布置方案与地下连续墙深度。研究表明:降水井的数量、间距、单井降水能力对基坑降水工程中降水效率有直接影响,且地下连续墙应尽量插入场地中的承压水地层,隔断基坑内外承压水地层的水力联系。基于此研究,建议实际工程基坑横截面上布置两个降水井,并采用40m深的地下连续墙设计方案以控制承压水的不利影响。通过基坑降水现场实测,进一步验证了方案的可靠性。The Jinan West Station of Jinan Rail Transit Line 4 Phase I Project is in the spring-confined water area,and the confined water in the confined water area is generally distributed in loose strata.Due to the large burial depth,high water head,large water volume in the confined water area,it is harmful to the bottom plate of the deep foundation excavation and the construction of deep foundation excavation.To ensure the construction safety of the deep and large foundation excavation dewatering project of Jinan West Station,the 3D finite element model of the site-underground diaphragm-wall dewatering well is established to analyze the influence of the number,spacing and depth of dewatering wells on dewatering efficiency,and the optimal dewatering well layout scheme and the depth of underground diaphragm wall were proposed.The research shows that the number and spacing of dewatering wells and the dewatering capacity of single well have a direct impact on the dewatering efficiency in the foundation excavation dewatering project,and the diaphragm wall should be inserted into the confined water stratum in the site as far as possible to isolate the hydraulic connection between the confined water stratum inside and outside the foundation excavation.Based on the research in this paper,it is suggested that two dewatering wells should be arranged on the cross section of the foundation excavation of the actual project,and a 40m deep diaphragm wall should be adopted to control the adverse effects of confined water.Through the field measurement of foundation excavation dewatering,the reliability of the scheme is further verified.

关 键 词：地铁 基坑 降水 数值模拟 优化 

分 类 号：TU753[建筑科学—建筑技术科学]