孔隙水-力耦合作用下高速铁路轨道-路基结构动力响应分析

Dynamic Response Analysis of Track-subgrade Structure of High-speed Railway Under Hydro-mechanical Coupling

以某段高速铁路实际运营情况下轨道路基结构为工程背景,建立孔隙水-力耦合有限元模型,计算移动列车荷载作用下高速铁路路基动力响应,进而分析上部列车移动荷载作用下路基内孔隙水对轨道-路基结构动力响应的影响。研究结果表明,在孔隙水渗流和移动列车荷载的耦合作用下,基床表面以下应力分布较均匀,而基床表面以上的支撑层和钢轨承受较大应力;移动列车荷载在钢轨表面加载位置处存在应力扩散,钢轨表面中点位移变化及基床表面中点应力变化存在明显的锯齿状分布;路基内孔隙水头及列车行驶速度均会对路基动力响应产生影响,即路基动力响应主要受孔隙水头和列车行驶速度控制。

The track-subgrade structures of a typical high-speed railway line segment under actual operational conditions are used as the engineering background in this paper. The hydro-mechanical coupled finite element model is established,the dynamic responses of high-speed railway track due to moving train loads are computed,and the effects of pore water pressure in track foundation layers are further analyzed. The results show that with the coupled application of pore water seepage and moving train loads,the stress distribution below the embankment surface is uniform,while the supporting layers and superstructures above the embankment surface exhibit greater stress levels. The stress transmission phenomenon occurs at the loading positions of moving train loads on the rail surface. The trends of the displacement response at the center of the rail surface and the stress response at the center of the embankment surface demonstrate a clear zigzag shape during the entire loading duration. Both pore water pressure level in track foundation and train speed affect the calculated dynamic responses. The track dynamic responses are controlled by pore water pressure and train speed.