软土区某地铁深基坑施工过程数值模拟及现场监测  

Numerical simulation and monitoring on construction process of deep pit of subway station in soft clay

作　　者：徐江[1,2] 龚维明[1,2] 穆保岗[1,2] 刘博韬[1,2] 张琦[1,2] 戴国亮[1,2] Xu Jiang;Gong Weiming;Mu Baogang;Liu Botao;Zhang Qi;Dai Guoliang(Key of Laboratory for Concrete and Pre-Stressed Concrete Structure of Education of Ministry , Southeast University , Nanjing 210096,China;School of Civil Engineering, Southeast University, Nanjing 210096, China)

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096 [2]东南大学土木工程学院,南京210096

出　　处：《东南大学学报（自然科学版）》2017年第3期590-598,共9页Journal of Southeast University：Natural Science Edition

基　　金：中央高校基本科研业务费专项资金资助项目;江苏省普通高校研究生科研创新计划资助项目(KYLX16_0238);国家重点基础研究发展计划(973计划)资助项目(2013CB036304)

摘　　要：为研究软土区地铁深基坑围护结构变形及周边土体位移特性,运用ABAQUS软件对软土区某地铁深基坑施工过程进行建模分析和安全监测,并将计算结果与实测数据进行对比分析.结果表明:采用摩尔库伦模型模拟基坑施工过程得到的地连墙水平位移结果准确,墙体最大水平位移的平均计算误差为实测值的15%,周边土体沉降计算值与实测值相比偏小;开挖最后一层土体且开挖面附近无支撑作用时,墙体水平变形明显增大,长边中点断面及端部断面变形增量分别为9.1和10.5 mm,安全监测应以开挖面附近地连墙水平位移变化速率为控制指标;狭长型深基坑长边中点断面及端部断面地连墙变形差异较大,应针对不同位置分别制定变形监测预警值;支撑轴力在开挖下一层土体时会出现较大突变,设计应充分考虑该突变对支撑安全储备的影响,监测应重点关注突变前后支撑轴力的变化.To study the deformation of deep pit and surrounding soil displacement in the soft soil area,the software ABAQUS was used for modeling analysis and safety monitoring of the construction process of a subway deep pit in soft soil area.The calculation results were compared with the measured data.The results show that when the Mohr Coulomb model is used to simulate the construction process of pit,the horizontal displacement of the wall calculated is accurate and the average calculation error of the maximum displacement of the wall is15%of the measured value.The calculated settlement of the surrounding soil is smaller than the measured value.When the last layer of soil is excavated and there is no supporting action near the excavation surface,the horizontal deformation of the wall increases obviously.The increment of the deformation of the long-side mid-point section and that of the end section of the long-side are9.1and10.5mm,respectively.The change rate of the horizontal displacement of the diaphragm wall near the excavation surface should be taken as the control index of safety monitoring.The mid-point section of the long-side and the end section of the long-side have different wall deformation in long deep pits.The warning values of the deformation monitoring should be set for different positions.The axial force of the support exhibits a large mutation when the next layer soil is excavated.The impact of the mutation on the support safety reserve should be taken into account in the design,and the change of the axial force before and after mutation should be focused on during monitoring.

关 键 词：软土区地铁深基坑 有限元分析 现场监测 围护结构变形 

分 类 号：TU476.3[建筑科学—结构工程]