弹性支承块式无砟轨道支承块破损原因分析

针对在隧道内弹性支承块式无砟轨道运营初期容易出现支承块边角开裂、掉块等问题，运用有限元软件建立弹性支承块局部受力模型，分析了道床顶面混凝土高于橡胶套靴帽时，支承块在列车荷载作用下与道床板顶面碰撞的应力分布。计算结果表明:当道床顶面与支承块靴帽边缘空隙不足时，支承块所受拉应力为2.55 MPa，容易出现受剪开裂等破损现象。施工时，必须保证浇筑道床板混凝土时支承块露出部分底面高于道床顶面1 mm以上，支承块才不会受剪切破坏开裂。

Analysis on Breakage Reason of Elastic Supporting Block Type Ballastless Track Supporting Block

Aimming at several problems of elastic supporting block type ballastless track in the tunnel, such as falling blocks and cracking in the early operation process, the local force model of elastic supporting block was established by using finite element software, and the stress distribution of the impact between the supporting block and the top surface of the track bed under the train load was analyzed when the concrete on the top surface of the track bed was higher than the rubber boot cap. The calcilation results show that when the gap between the top surface of the track bed and the edge of the boot cap of the supporting block is insufficient, the tensile stress of the supporting block is 2.55 MPa, which is prone to shear cracking and other damages. During construction, it must ensure that the bottom surface of the exposed part of the supporting block is 1 mm higher than the top surface of the track bed when pouring the concrete of the track bed, and the elastic supporting block type ballastless track structure will not be subjected to shear failure and cracking.