基于流变理论的基坑回填后地下通道变形数值分析

Numerical Analysis of Underground Tunnel Deformation after Foundation Pit Backfilling Based on Rheological Theory

基于流变理论,运用有限元软件ANSYS建立三维有限元模型,并应用EDP弹塑性模型和西原正夫蠕变模型进行模拟分析,研究地下通道回填后时间效应对土体及结构物的变形规律。结果表明:基坑回填完成后,随着基坑支护距离的增大,地表Z向位移逐渐减小,主体上部结构最大X向位移变化不大,约为0.09 mm。土体沉降和上部结构沉降随时间变化规律基本相同,都表现为最大沉降越来越大,变化速率开始很快,随后越来越慢,最后趋于稳定状态。

Based on the rheological theory,a three dimensional finite element model was established by using finite element software ANSYS,and the EDP elastoplastic model and MODIFICAL creep model were used for simulation analysis.The deformation law of soil and structure caused by time effect after backfilling of underground tunnel was studied.The results show that,after the foundation pit backfilling is completed,the surface z-direction displacement gradually decreases with the increase of the supporting distance of the foundation pit.The maximum X-direction displacement of the main superstructure changed little,basically 0.09 mm.The soil settlement and the superstructure settlement change with time are basically the same,both of which show that the maximum settlement becomes larger and larger,and the change rate starts quickly,then becomes slower and slower,and finally tends to be stable.