土层弹性模量对隧道结构受力与变形影响分析

Influence of Soil Elastic Modulus on the Stress and Deformatio of Tunnel Structure

针对杭州市下沙金沙湖绿轴下沉广场开挖工程,分析了基坑开挖对下卧地铁隧道的影响,并进行了不同土层模量取值的敏感性分析。通过ANSYS与FLAC3D建立土层与隧道三维模型,分析了土层弹性模量分别取高、中、低值时,土层与隧道结构的应力及变形特征。研究表明:土层与隧道变形以竖向回弹位移为主,变形对弹性模量取值较敏感并随弹性模量降低而增加。土层最大变形位于基坑底部,隧道最大变形发生于下沉广场圆心位置。开挖过程中及开挖完成后,土层与隧道均存在拉应力区,但拉应力水平较低,且对土层弹性模量取值不敏感。

According to the green axis Sunken Plaza excavation engineering of Hangzhou Xiasha Jinsha Lake,the excavation effects of underlying metro tunnel were analyzed and considered different soil modulus value of the sensitivity analysis. Through ANSYS and FLAC3 D,the 3 D model of soil and tunnel is established,and the variation of soil and tunnel displacement and deformation are analyzed. The analysis results show that the deformation of soil and tunnel is the main displacement and more sensitive to the modulus of soil. The maximum displacement of the soil at the bottom of the pit,and the maximum displacement of tunnel in Sunken Plaza center. After excavation and excavation,the soil and tunnel is in tensile stress area,but the tensile stress level is lower,and it is not sensitive to the modulus of soil.