地铁减振型无砟轨道CA砂浆应力匹配研究

摘要

地铁减振型无砟轨道结构中， CA砂浆层位于轨道板和隔振垫之间，起着支承、传载和调整的功能。由于隔振垫的存在， CA砂浆层极易发生破坏，因此需要全面地研究轨道结构参数对CA砂浆的应力影响规律。基于弹性地基梁体模型，研究轨道板的混凝土等级、CA砂浆弹性模量、隔振垫刚度及轨道板长度4个轨道结构参数对CA砂浆应力的影响规律，并通过应力匹配图得到合理的轨道结构参数匹配。得到的结论是CA砂浆弹性模量是对CA砂浆应力影响最敏感的参数；轨道板的混凝土等级、CA砂浆弹性模量、隔振垫刚度及轨道板长度4个轨道结构参数对CA砂浆最大拉应力的影响远大于对CA砂浆最大压应力的影响；通过应力匹配图，提出较为合理的轨道结构参数匹配：轨道板使用C80等级的混凝土、CA砂浆取中低弹模3000 MPa、隔振垫刚度取0.04 N/mm3、轨道板长度取4.097 m。%CA mortar layer located between the slab and the damping pad of the vibration damping ballastless track in the subway functions for supporting, load transfer and adjustment. Due to the presence of the damping pad, CA mortar layer is prone to failure and it is necessary to study carefully the influence of track parameters on the stress of CA mortar. Based on the elastic foundation beam-solid model, this paper analyses the influence of track parameters such as the concrete grade of slab, the elastic modulus of CA mortar, the stiffness of damping pad and the length of slab on the stress of CA mortar, and identifies reasonable matching track parameters through stress matching map. The research concludes that the elastic modulus of CA mortar is the most sensitive parameter of the stress of CA mortar. The impact of the track parameters, such as the concrete grade of slab, the elastic modulus of CA mortar, the stiffness of damping pad and the length of slab on the maximum tensile stress of CA mortar is much larger than the maximum compressive stress of CA mortar. Based on stress matching map, the paper offers the reasonable matching track parameters:the concrete grade of slab is C80 , the elastic modulus of CA mortar is 3 000 MPa, the stiffness of damping pad is 0. 04 N/mm3 and the length of slab is 4. 097 m.