高速列车荷载作用下水泥乳化沥青砂浆层的应变速率研究

水泥乳化沥青砂浆主要承受列车垂向荷载,且处于动态加载过程。为研究CRTSⅠ型板式无砟轨道CA砂浆层的应变速率,基于车辆-轨道耦合动力学理论,采用ANSYS/LS-DYNA有限元软件建立列车-CRTSⅠ型板式无砟轨道-路基垂向耦合振动模型,研究CA砂浆层的应变速率及其影响因素。结果表明:路基上板式无砟轨道CA砂浆层的应变速率大于其他基础。随着CA砂浆层和列车速度的增加,CA砂浆层的应变速率增大。CRTSⅠ型板式无砟轨道CA砂浆层的应变速率在4.763×10-3/s~2.025×10-2/s范围内变化。与仿真得到的应变速率相比,规范规定的应变速率不能完全反映CA砂浆层的实际应变速率。

Research on Strain Rate of Cement Asphalt Mortar Layer under High-speed Train Load

Cement asphalt mortar is mainly under the vertical load and in dynamic loading process. In order to study the strain rate of cement asphalt mortar layer of China Railway Track System( CRTS) type I slab track,the finite element software ANSYS / LS-DYNA is used to establish a vertical vibration model for train-CRTS type I slab track-subgrade coupling system to analyze the strain rate of CA mortar layer and its influence factors based on wheel-rail coupling dynamic theory. The results show that the strain rate of CAM layer of CRTS I type slab is bigger than those of other foundation types,and with the increase of train speed and the thickness of CAM layer,the strain rate of CAM layer is increased. The strain rate of CAM layer of CRTS type I slab ranges from 4. 763 × 10-3/ s to 2. 025 × 10-2/ s under different conditions. Compared with the simulation strain rate,the strain load stipulated by Chinese regulation could not fully reflect the actual strain rate of CAM layer.