【摘要】 采用黏弹性边界方法和地震动输入等效节点力方法,结合通用有限元软件ANSYS,建立地铁双隧道地震响应分析问题的模型。通过与间接边界元方法文献结果比较,对整体模型进行精度验证,结果表明,黏弹性边界方法和地震动输入等效节点力方法可以获得非常满意的计算精度。分别通过平面单元和梁单元对衬砌应力进行数值模拟,结果表明,平面单元和梁单元均可以很好地模拟衬砌应力。以天津市深厚覆盖层场地中某地铁双隧道为例进行地震响应分析,研究表明,隧道间距对衬砌地震应力具有重要影响。当两个隧道相距较近时,隧道之间存在明显相互作用,最大衬砌主应力幅值有明显的提高,且衬砌最大主应力均出现在两隧道相对区域。该模型可以用于复杂场地中地下结构的抗震分析。更多还原

【Abstract】 This paper presented seismic response analysis of metro twin tunnels based on the viscous-spring boundary and equivalent node force of earthquake excitation, combined with general finite element analysis software ANSYS. The model for metro twin tunnels in layered half-space was validated through comparisons with the results by indirect boundary element method in literature. Plane element and beam element were used to simulate liner stress, and the results show that both plane element and beam element can well simulate tunnel liner. Seismic response of metro twin tunnels in Tianjin City with thick soil layers was implemented, and the results show that tunnel interval has significant effect on the seismic stresses in tunnel liner; there is evident interaction between two tunnels when the two tunnels are close, and the maximal principal seismic stresses are increased significantly and located between two tunnels. This model can be used for seismic analysis of underground structures in complex sites.更多还原