Experimental investigation on dynamic performance evolution of double-block ballastless track under high-cycle train loads

Abstract

This paper aims to investigate the dynamic performance evolution law of double-block ballastless track under long-term train load through a full-size laboratory experiment. The experiments are conducted based on a comprehensive test platform of a full-size double-block ballastless track-subgrade system, and the test contents are composed of the fatigue loading test and dynamic performance test. The full-size acceleration test method is adopted for the fatigue test to simulate the fatigue process of the ballastless track under different accumulative loading cycles. Moreover, the fatigue loading stage is divided into several periods according to the accumulative loading cycles, and the dynamic performance test is conducted after each fatigue loading period to study the dynamic performance evolution law of the ballastless track. The test results show that the static rail displacement relative to the subgrade displacement presents a development progress from initial decline to gradual stability along with the increase of loading cycles. However, the accelerations of the ballastless track structure components present a gradual increase trend with the accumulation of loading cycles. The deformation resistant capacity of the double-block ballastless track decreases gradually with the increase of loading cycles. This study may provide useful reference for scientific operation and maintenance of ballastless track in high-speed railway.