Theoretical and experimental research on deformation adaptability of ballastless tracks on long-span cable-stayed bridge in high-speed railway

The application of ballastless track on long-span cable-stayed bridge of high-speed railway can improve the railway smoothness and stability, eliminate potential railway speed restrictions, unify track types, and reduce the maintenance cost of the track, which is an important technological innovation of high-speed railway in China. In this work, based on the first long-span cable-stayed bridge with ballastless track named Ganzhou Ganjiang bridge in Chang-Ji-Gan passenger dedicated line, the refined finite element model of long-span cable-stayed bridge with ballastless track was established, the deformation characteristics of the long-span cable-stayed bridge with ballastless track system were explored, the equivalent scale test model of long-span cable-stayed bridge with ballastless track was designed and produced, and the theoretical and experimental deformation adaptability research of long-span cable-stayed bridge with ballastless track was carried out. Therefore, the effects of different lengths, types of isolation layers and arrangements of ballastless track on long-span cable-stayed bridge were analyzed, and the deformation followability and coordination of ballastless track on long-span cable-stayed bridge under various deformation conditions were studied. The main conclusions are as follows: the beam end rotation and the overall deflection of the main girder can be controlled according to the relevant limits of small and medium-span bridges in current specifications in China, and the local deformation of the main girder should be reasonably controlled to avoid voids between the ballastless track and long-span bridge; The technical scheme of the unit ballastless track with rubber isolation layer laid on the long-span cable-stayed bridge is proposed, and the buffer effect of the rubber isolation layer in ballastless track and the design goal of “separation without separation” at ballastless track interlayer is put forward, so as to significantly improve the deformation adaptability of the ballastless track laid on long-span cable-stayed bridge. Therefore, this work provides a valuable technical support for the application of ballastless tracks on the long-span cable-stayed bridge in high-speed railway. © 2024, Central South University Press. All rights reserved.