南京江北新区地铁盾构开挖引发地面沉降三维数值模拟预测  

Three-Dimensional Numerical Simulation of Ground Settlement Caused by Metro Shield Excavation in Jiangbei New District,Nanjing,China

作　　者：徐成华 何政宇 刘刚 施威 骆祖江[2] Xu Chenghua;He Zhengyu;Liu Gang;Shi Wei;Luo Zujiang(The First Geological Brigade of the Bureau of Geology and Mineral Resources of Jiangsu,Nanjing 210041,China;School of Earth Sciences and Engineering,Hohai University,Nanjing 211100,China)

机构地区：[1]江苏省地质矿产局第一地质大队,南京210041 [2]河海大学地球科学与工程学院,南京211100

出　　处：《吉林大学学报（地球科学版）》2024年第4期1316-1325,共10页Journal of Jilin University：Earth Science Edition

基　　金：江苏省地质科技创新项目(2022KY01);江苏省地质工程环境智能监控工程研究中心开放基金(2021-ZNJKJJ-13);国家自然科学基金项目(41874014)。

摘　　要：为研究地铁盾构施工引起的地面沉降问题,首先以Biot固结理论为基础,将土体本构关系拓展为黏弹塑性,考虑土体渗透性的动态变化,建立了地铁盾构引发地面沉降的三维全耦合数值模型;然后以南京地铁11号线江北新区马骡圩站至石塘公园站盾构施工区间为例,模拟预测了该盾构区间的沉降量,并完成了模型的校准;最后利用该模型模拟预测了地铁盾构开挖所引起的地面沉降规律,并模拟了盾构拱顶上方土体和盾构底部下方土体的参数变化。结果表明:实测地面沉降量与计算值吻合较好,模型可靠;以模型第二区间段为例,东线轴线处沉降量在52.41~54.52 mm范围内,西线沉降量在53.28~55.60 mm范围内;东线盾构隧道沉降以隧道轴线为中心对称分布,西线隧道开挖后,最终引起累积地面沉降量在轴线之间较大;随着开挖的进行,上方土体孔隙度、渗透系数及泊松比变小,变形模量增大,下方土体变化则相反。In order to study the ground settlement caused by subway shield construction,firstly,based on Biot consolidation theory,a visco-elastic-plastic constitutive relation of soil mass and the dynamic change of soil permeability is considered,a three-dimensional fully coupled numerical model is established.Then,taking the shield construction section from Maluowei Station to Shitang Park Station of Jiangbei New District of Nanjing Metro Line 11 as an example,the settlement of the shield section is simulated and predicted,and the model is calibrated.Finally,the model is used to simulate and predict the ground settlement law caused by shield excavation,and the parameter changes of soil above the shield arch and under the shield bottom are simulated.The results show that the measured ground settlement is in good agreement with the calculated values,and the model is reliable.Taking the second section of the model as an example,the settlement of the eastern line is in the range of 52.41-54.52 mm,and the settlement of the western line is in the range of 53.28-55.60 mm.The settlement of shield tunnel in the eastern line is symmetrically distributed in the center of the tunnel axis,and the cumulative ground settlement of the tunnel in the western line is larger between the axes after tunnel excavation.With the progress of excavation,the porosity,permeability coefficient and Poisson’s ratio of the soil above decreased,and the deformation modulus increased,while the change of the soil below was opposite.

关 键 词：地面沉降 BIOT固结理论 盾构施工 三维全耦合 地铁 隧道 

分 类 号：P641[天文地球—地质矿产勘探]