不同类型无砟轨道路基动力响应研究

Dynamic response of different ballastless track subgrade

针对京沪高速铁路采用的CRTSⅠ型板式、CRTSⅡ型板式、双块式3种无砟轨道,采用有限单元法软件ANSYS建立有限元模型,计算3种无砟轨道路基的动力响应,并进行对比分析。结果表明:在0～1 m深度范围内,双块式无砟轨道路基竖向动应力幅值明显小于板式无砟轨道;3种无砟轨道路基竖向动位移幅值仅在0～1 m深度范围内有较大差别,且双块式无砟轨道小于板式无砟轨道;双块式无砟轨道基床表层表面与基床底层表面的动应力、动位移在距路基中线约1 m范围内明显小于板式无砟轨道;板式无砟轨道结构垂直于线路方向的刚度小于双块式无砟轨道,CA砂浆层可能是引起这种差异的主要原因。该结果对同类研究具有一定参考价值。

For three kinds of ballastless tracks used in Beijing-Shanghai high-speed railway,including CRTSⅠ slab ballastless track,CRTSⅡ slab ballastless track and twin-block ballastless track,the dynamic response of their subgrade was calculated and compared through finite element models established by ANSYS.The result shows that,in depth ranging from 0 to 1 m,dynamic stress amplitude in twin-block ballastless track subgrade is obviously less than that in slab ballastless track subgrade.The dynamic displacement in three kinds of ballastless tracks subgrade is different only in depth from 0 to 1m,and dynamic displacement in twin-block ballastless track subgrade is less than that in slab ballastless track subgrade.Compared with slab ballastless track,when distance from the subgrade centerline is less than 1m,the dynamic stresses and displacements in surface of upper roadbed and lower roadbed of twin-block ballastless track subgrade are obviously smaller.In the direction perpendicular to the alignment of railway,the slab ballastless track shows a less stiffness than twin-block ballastless track,for which the buffer effect of CA mortar may be responsible.The results have certain reference value for similar researches.