流固耦合下隔水帷幕对深基坑的变形特性研究  

Study on the Deformation Characteristics of Deep Foundation Pits by Water Barrier Curtain Under Fluid-Solid Coupling

作　　者：郭安宁 金作栋 GUO Anning;JIN Zuodong(School of Traffic and Transportation,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China)

机构地区：[1]兰州交通大学交通运输学院,甘肃兰州730000

出　　处：《汕头大学学报（自然科学版）》2023年第2期71-80,共10页Journal of Shantou University：Natural Science Edition

摘　　要：本文以某软土区止水帷幕深基坑监测为背景,使用COMSOL Multiphysics对基坑分层建模并建立二维渗流-固结耦合模型,研究流固耦合模型在软土地区基坑数值模拟的可行性,基坑渗流模型的建模方法,并分析不同隔水帷幕建模方法对基坑水平位移及坑外地表沉降的影响.研究表明:COMSOL Multiphysics模拟基坑变形数值与实际监测数值较吻合,降水渗流作用对基坑变形具有很大影响.止水帷幕对于减少坑外水位下降和控制地表沉降有显著作用.设置隔水帷幕后,地面沉降量减小,而缺点是导致围护结构变形增大.最后模拟了不同深度隔水帷幕对坑外地表沉降的影响,认为隔水帷幕对坑外沉降改变量有先增大后减小的规律,深度过小或者过大对沉降量的控制效果不好.弱透水层交界处有沉降改变量的极大值,弱透水层处沉降量改变量有明显骤减.In this paper,the monitoring of a deep foundation pit with water barrier curtain in a soft soil area is taken,and COMSOL Multiphysics is used to model the pit in layers and establish a two-dimensional seepage-consolidation coupling model to study the feasibility of the flow-solidity coupling model in the numerical simulation of foundation pits in soft soil areas,the modelling method of the foundation pit seepage model,and to analyze the effect of different water barrier modelling methods on the horizontal displacement of the foundation pit and the settlement of the ground surface outside the pit.The study shows that the COMSOL Multiphysics simulated pit deformation values are in good agreement with the actual monitoring values,and that the effect of precipitation seepage has a great influence on the pit deformation.The water barrier curtain has a significant effect on reducing the water level drop outside the pit and controlling the surface settlement.The installation of the water barrier curtain reduces the amount of ground settlement,while the disadvantage is leading to an increase in the deformation of the enclosure structure.Finally,the effect of different depths of the curtain on the ground settlement outside the pit is simulated,and it was concluded that the curtain had a pattern of increasing and then decreasing the amount of settlement outside the pit,and that too small or too large a depth had not a good effect on the control of settlement.There is a great value of settlement change at the junction of aquitards,and there is an obvious abrupt decrease of settlement change at aquitards.

关 键 词：软土 流固耦合 水平位移 隔水帷幕 弱透水层 沉降量 

分 类 号：TU46[建筑科学—结构工程] TU924[建筑科学—土工工程]