摘要
地铁车站基坑施工过程中产生的土体变形,往往与降水所产生的土体固结变形耦合在一起,使土体变形更加复杂,因此探明降水诱发的地表沉降对基坑变形控制具有重要意义。以郑州地铁东赵站深基坑降水施工为背景,基于理论分析、现场监测和有限元数值分析方法系统研究了基坑降水对周边地表变形的影响规律;并以降水井间距为控制因素建立3种工况,对比分析不同间距管井降水对地表沉降的影响,进行了管井间距的优化。结果表明:基坑降水过程会形成较为明显的“降水漏斗”,并以基坑为中心向外扩散;地表水平位移相对较小且基坑两侧土体朝基坑方向发生变形;地表沉降由基坑中心位置向两侧呈由大到小的变化趋势;在降水井深度相同条件下,井间距越小,地表沉降越大。研究结果可为地铁车站深基坑管井降水设计及施工优化提供理论及实践参考。
In the process of subway station pit construction,the soil deformation generated by the construction is often coupled with the soil consolidation deformation generated by the precipitation,which makes the soil deformation more complicated,so it is of great significance to investigate the precipitation-induced settlement for the control of pit deformation.Taking the descending construction of Zhengzhou Dongzhao Station pit as the background,the influence law of pit descending on the surrounding surface deformation is systematically studied based on theoretical analysis,on-site monitoring and finite element numerical analysis methods.Three working conditions are established with the spacing of descending wells as the controlling factor to comparatively analyze the influence of three different spacing of tube wells on the ground surface settlement when descending,and the optimization of the spacing of the tube wells is carried out.The results show that the pit descending process will form a more obvious"descending funnel"and spread outward with the pit as the center;the horizontal displacement of the ground surface is relatively small and the soil on both sides of the pit deforms in the direction of the pit;the ground surface settlement from the center of the pit to the two sides shows a trend of change from large to small;under the condition of the same depth of the wells,the smaller the spacing of the wells,the larger the ground surface settlement.The results of the study can provide theoretical and practical references for the design and construction optimization of deep foundation pit tube wells for metro stations.
作者
龙程
方昆
杨东博
郑联伟
孙立光
郜新军
LONG Cheng;FANG Kun;YANG Dong-bo;ZHENG Lian-wei;SUN Li-guang;GAO Xin-jun(China Railway First Group Corp.,Ltd.,Zhengzhou 450000,China;Zhengzhou University,Zhengzhou 450001,China)
出处
《河南城建学院学报》
CAS
2023年第4期1-7,共7页
Journal of Henan University of Urban Construction
基金
国家自然科学基金面上项目(52078469)。
关键词
深基坑降水
地表沉降
数值模拟
deep foundation pit dewatering
surface subsidence
numerical simulation
