无砟轨道端刺结构纵向位移的解析算法及应用

考虑高速铁路纵连板式无砟轨道底座板、摩擦板、端刺结构及路基土体的相互作用关系,深入分析了端刺顶部水平力的传递机理,借鉴水平荷载及弯矩共同作用下单桩承载力及变形的计算公式,推导出适用于计算端刺结构纵向受力与变形的解析算法。该方法中,底座板与摩擦板间“两布”滑动层的摩擦力假定为均匀分布,摩擦板和端刺间传递纵向力和弯矩且满足变形协调条件,路基土体对端刺侧面均匀支撑。解析算法的计算结果和基于有限元软件ANSYS 所建立的空间耦合模型具有较好的一致性,说明该文提出的解析算法正确可靠,可实现纵连板式无砟轨道端刺结构纵向位移的快速准确计算。端刺结构计算结果表明:随着大端刺深度、宽度及小端刺数量的不断增加,端刺纵向位移会不断减小,有利于减小底座板的纵向位移及土体的压缩变形。

AN ANALYTICAL ARITHMETIC FOR LONGITUDINAL DISPLACEMENT OF END THORNS IN BALLASTLESS TRACK AND ITS APPLICATION

Considering the interaction among foundation plate,friction plate,end thorns and soil in longitudinal connected ballastless track of high-speed railway,the load transfer mechanism of the horizontal force at the top of end thorn was analyzed.Referring to the formula on bearing capacity and deformation of single pile under horizontal load,an analytical arithmetic for calculating longitudinal force and deformation of end thorn was established.In this method,the frictional force of sliding layer between foundation plate and friction plate is uniformly distributed;longitudinal force and bending moment meet the distortion requirements;the soil acts uniformly on side faces of the end thorn.The analytical arithmetic has a good consistency with the spatial coupling model by general finite element software ANSYS,which proves that the analytical arithmetic is valid and reliable,and can yield fast and accurate calculation of end thorn displacement of longitudinal connected ballastless track.The calculation results show that longitudinal displacement is diminishing with the increasing of thickness,height of main end thorn and the number of small end thorns,which helps to reduce the longitudinal displacement of foundation plate and the deformation of soil.