移动荷载作用下半无限弹性空间中地铁隧道动力响应的频域—波数域比例边界有限元法分析

发布时间：2018-10-21 13:09

【摘要】：基于比例边界有限元法与傅里叶积分变换,分析移动荷载作用下半无限弹性空间中地铁隧道动力响应。考虑到移动荷载运动方向与地铁隧道轴线方向的一致性,将半无限弹性空间动力控制方程进行频域—波数域的傅里叶积分变换;在变换域内,隧道径向采用比例坐标系,环向采用有限元意义离散,在计算域内利用Galerkin法,建立频域—波数域内的比例边界有限元方程,进而推导出半无限空间动力刚度的一阶微分矩阵方程;再利用高频渐近展开和傅里叶积分逆变换,得到时间—空间域系统的动力响应。该方法极大地减小了计算分析量,同时避免了无限边界的计算误差。利用该方法进行实例计算的结果表明:随着荷载移动速度的增大,地铁隧道振动波传播到土体表面,引起的土体振动有放大增强的现象,将会对地铁隧道上部结构的安全性造成一定影响。
[Abstract]:Based on the proportional boundary finite element method and Fourier integral transform, the dynamic response of subway tunnel in semi-infinite elastic space under moving load is analyzed. Considering the consistency between the direction of moving load and the axis of subway tunnel, the dynamic control equation of semi-infinite elastic space is transformed by Fourier integral in frequency-wavenumber domain, and in the transform domain, the radial direction of tunnel adopts proportional coordinate system. The finite element method is used to discretize the circumferential direction. The Galerkin method is used to establish the finite element equation of the proportional boundary in the frequency-wavenumber domain. The first order differential matrix equation of the dynamic stiffness of the semi-infinite space is derived. Then the dynamic response of time-space domain system is obtained by using high-frequency asymptotic expansion and inverse Fourier integral transform. This method greatly reduces the amount of computational analysis and avoids the calculation error of infinite boundary. The results show that the vibration wave of subway tunnel propagates to the surface of soil with the increase of load moving speed, and the vibration of soil is magnified and enhanced. It will affect the safety of the superstructure of subway tunnel.
【作者单位】：华东交通大学铁路环境振动与噪声教育部工程研究中心;南昌工程学院土木与建筑工程学院;
【基金】：国家自然科学基金资助项目(51269021,51478184,51569016) 江西省自然科学基金重点资助项目(20133ACB20006) 江西省教育厅科技项目(GJJ14755)
【分类号】：U451;U231

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