Influence of rub-plate length on forces and displacements of longitudinally coupled slab track for a bridge turnout

Abstract

Because of the successful construction and operation of the Beijing–Tianjin intercity railway line, the longitudinally coupled prefabricated slab track (LCPBT) system has shown its outstanding advantages in both mechanical and structural aspects. With a design speed of 350 km/h, the LCPBT system was also used on the 595.62-m-long, double-track LeiDa Bridge on the Wuhan–Guangzhou passenger dedicated line (PDL) in China. To equably transfer longitudinal force from the coupled concrete base to the subbase by friction, a reinforced concrete rub-plate was placed in transition zones from bridges to the subgrade. A 100-m-long, 0.4-m-thick rub-plate was built at the Beijing–Tianjin intercity railway line, whereas a 50-m-long rub-plate was used at the Wuhan–Guangzhou PDL. This article established an integral finite element model of jointless turnout (crossover)-track slab-bridge-pier taking the LCPBT system on LeiDa Bridge as an example, and researched the proper setting length of the rub-plate in this structure. Calculation conclusions and suggestions were given: the 100-m-long rub-plate used on the Beijing–Tianjin intercity railway line can be shortened; a length of 50–75 m will be appropriate as the case may be; in specific circumstances, it can be designed within the range 25–50 m.