考虑地震行波效应的高铁连续梁桥梁轨互制

摘要

为研究行波效应下高速铁路连续梁桥与无缝线路的非线性互制作用，采用带刚臂的梁单元模拟梁体，用非线性杆单元模拟梁轨间的互制作用，建立了考虑纵向和竖向地震动行波效应的梁轨相互作用模型。以我国沪昆线上某（60＋100＋60）m连续梁桥为算例，分析了轨道结构对梁体和墩台地震响应的影响，研究了纵向和竖向行波效应下钢轨和墩台的受力特点。研究表明：轨道的存在可提高系统基频，降低连续梁桥地震响应；但在地震动的行波效应下，钢轨纵向力最大值可达一致激励下的1．2倍；减小线路纵向阻力，增加桥墩刚度可减小地震作用下的钢轨应力；在检算钢轨时，还应累计竖向行波效应对钢轨受力的影响。%In order to study the nonlinear interaction between CWR(continuously welded rail)and continuous beam bridge carrying high-speed railway under traveling wave action,the beam element with rigid elements was used to simulate the beam and the nonlinear bar element was used to simulate the longitudinal interaction between the beam and tracks.A track-structure interaction model was established,considering the longitudinal and vertical seismic traveling wave effect.Taking a (60 +100 +60)m continuous beam bridge on Shanghai-Kunming line as an example case,the response analysis was carried out,it was shown that the track makes an impact on the seismic response of the beam and pier.The force characteristics of the track and pier were studied under the longitudinal and vertical traveling wave action. The results showed that the track can raise the system natural frequencies and reduce the seismic response of the continuous beam bridge;the maximum longitudinal stress in the track under seismic traveling wave action can be up to 1 . 2 times of that under uniform excitation;when calculating the track stress,the impact of the vertical traveling wave effect should be also considered.