泉域承压水地层深大基坑封底加固关键技术研究  

Research on Key Technology of Bottom Sealing Reinforcement of Deep and Large Foundation Excavation in Confined Water Stratum of Spring Area

作　　者：景文琪 JING Wenqi(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57-62,共6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号线一期工程处于泉域承压水地层,工程区域内承压水埋深大、水头高、水量大,深大基坑施工存在较大的安全隐患。基于ABAQUS有限元软件,建立场地-地下连续墙-降水井二维数值模型,分析并指出基坑底下端承压水会导致基坑凸涌及坑底回弹等不利现象;结合基本理论与实际工程经验,提出采用超深三轴搅拌桩加固基底土层与RJP旋喷桩接缝补强的深大基坑封底加固技术。研究表明:该技术可有效控制基底地下水压力并降低基坑横向支撑内力,减小基底回弹的不利影响并保证基坑安全开挖。The first phase project of Jinan Rail Transit Line 4 is located in the confined water stratum of the spring area.The confined water in the project area has large buried depth,high water head and large water volume,and there are great safety hazards in the construction of deep and large foundation excavation.Based on ABAQUS finite element software,a two-dimensional numerical model of site-underground diaphragm wall-dewatering well is established.It is analyzed and pointed out that the confined water at the bottom of the foundation excavation will lead to adverse phenomena such as foundation excavation swell and bottom rebound.Based on the basic theory and practical engineering experience,the bottom sealing reinforcement technology of deep and large foundation excavation is proposed by using ultra-deep three-axis mixing pile to reinforce the base soil layer and RJP jet grouting pile to strengthen the joint.The research shows that the technology can effectively control the groundwater pressure of the basement and reduce the internal force of the lateral support of the foundation excavation,reduce the adverse effect of the basement rebound and ensure the safe excavation of the foundation excavation.

关 键 词：地铁 基坑 降水 加固 有限元分析 施工技术 

分 类 号：TU753[建筑科学—建筑技术科学]