摘要
本文以南宁市地铁3号线心圩车辆段出入段线U型明挖深基坑工程为例,通过变形监测技术对基坑墙顶水平位移、墙顶竖向位移、墙体水平位移和支撑轴力等重点监测项目进行实时监测,根据地下连续墙+内支撑的支护形式,分析基坑围护结构的变形规律。监测结果表明:墙顶水平位移量随时间迅速增大后逐渐减小;墙顶竖向位移累计量由零开始迅速减小,随时间呈振荡式增大;墙体水平位移沿深度方向呈中间大两边小的“大肚子”形,最大水平位移几乎位于墙体中部;支撑轴力逐渐增大,一定程度上抑制了墙体侧移。最后应用有限元软件Midas/GTS对基坑开挖过程进行了数值计算,将数值计算结果与监测数据进行对比,数值计算与现场监测数据变化趋势基本上一致,但数值模拟结果较小,模拟结果与监测数据较为吻合,可为日后类似工程的设计、施工及研究提供有益的借鉴。
This study focuses on the deformation characteristics of a subway foundation pit supporting structure in Nanjing,specifically examining the horizontal displacement of the foundation pit wall,the horizontal displacement of the wall top,and the axial force of the wall and support.By analyzing the deformation patterns of foundation pit retaining structure,which consists of an underground diapharagm wall and internal support,valuable insights are gained.The findings reveal that the horizontal displacement of the wall top initially increases rapidly over time before gradually decreasing.Additionally,the cumulative vertical displacement on the top of the wall experiences a rapid decreases from zero,followed by oscillating increases as time progresses.Notably,the horizontal displacement along the depth direction of the wall exhibits a prominent bulging effect,with the maximum displacement occurring near the middle of the wall.Moreover,the axial force of the support gradually increases,effectively restraining the lateral movement of the wall to a certain extent.To further validate the research,excava⁃tion process of the foundation pit was simulated using the finite element software Midas/GTS.The simulation results were then compared and analyzed alongside the field monitoring data.While the numerical simulation results were slightly smaller than the monitoring data,the overal trend was consistent.These results provide valu⁃able references for the design,construction and future research of similar project.
作者
赵蕊
邓飞
魏燃
李小林
付宏岐
ZHAO Rui;DENG Fei;WEI Ran;LI Xiaolin;FU Hongqi(School of Civil Engineering,Weinan Vocational&Technical College,Weinan 714026,Shaanxi,China;College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,Guizhou,China;North China Institute of Science and Technology,Langfang 065201,Hebei,China;Southwest China Railway Institute of Science and Technology Co.,Ltd.,Chengdu 610031,Sichuan,China)
出处
《矿产勘查》
2023年第9期1713-1721,共9页
Mineral Exploration
基金
渭南市科技计划项目(2020ZD YF-SFG G-95)
渭南职业技术学院校级重点科研项目(WZYZ201902)
陕西省职业技术教育学会教育教学改革研究课题(2023SZX418)
陕西省重点研发计划项目(2018NY-113)
渭南市基础研究计划项目(2019-ZDYF-JCYJ-150)联合资助。
关键词
变形监测
地铁基坑
围护结构
数值计算
有限元
monitoring data
subway foundation pit
supporting structure
deformation law
finite element
