Use of Rubber Mat to Improve Deformation Behaviors of Ballastless Tracks Laid on Bridges

Weiqi Zheng,Hongqiang He,Ying Yang,Hongyi Xu,Xingwang Sheng

doi:10.1155/2020/8821402

Abstract

The deformation behaviors of ballastless tracks have an important influence on their service performance. In this work, rubber mats commonly used in metro traffic were employed in ballastless tracks laid on bridges to improve their deformation behaviors. In order to research the effect of rubber mat for deformation behaviors, a series of static loading tests were carried out based on two full-scale ballastless tracks with different types of isolation layers. Main conclusion include that, for ballastless track with geotextile isolation layers, gaps and voids are formed at interlayers with the increasing static load. However, for ballastless track with rubber mat isolation layer, the maximum tensile deformation in the thickness direction unexceeds the precompression of rubber mat under the deadweight of its upper structures. Interlayer gaps and voids can be eliminated due to the precompression of rubber mat. Besides, the rubber mat isolation layer is still in the linear elasticity stage under the routine service condition, and the interlayer behaviors of the ballastless tracks perform well. It is a feasible way to use a rubber mat isolation layer to improve the deformation behaviors of ballastless tracks laid on bridges.

Highlights

High-speed railway was developed rapidly in recent years; as a typical track structural pattern, ballastless tracks were widely applied in high-speed railways, especially in China [1]
Stress Level of the Ballastless Tracks. e stress values of each component of the ballastless tracks under different loading conditions are recorded separately. e stress distributions of the ballastless tracks are very simple under static loading, and the most unfavorable stress appears at loading positions
Concrete base plate is connected with bridge deck by embedded steel bars. e connection between the base plate and the bridge deck is firm and can deform together

Summary

Introduction

High-speed railway was developed rapidly in recent years; as a typical track structural pattern, ballastless tracks were widely applied in high-speed railways, especially in China [1]. Higher requirements are put forward for ballastless tracks with the development of high-speed railway technologies [2,3,4,5]. Several modifications of traditional ballastless tracks have been developed to obtain a higher bearing capacity system while increasing its durability [6]. As a kind of railway elastic elements, an isolation layer coordinated the deformation between lower structures and ballastless tracks and achieved isolation for facilitating maintenance [7]. Reasonable adjustment of the isolation layer is a way to improve the structural performance of ballastless tracks. It is of particular importance to identify the effect of using new isolation layers to improve deformation behaviors of ballastless tracks laid on bridges

Methods

Results

Conclusion