ABSTRACT

Due to the unequal self-weight, foundation treatment and anti-deformation ability between different structures, apparent settlement irregularity is easily formed in the HSR track-bridge transition section, and the running safety or ride comfort will be threatened when it accumulates to a certain extent. Taking a soft soil subgrade section in a HSR as the engineering background, the time-irregularity development pattern within recent years has been studied on the basis of measured data, and the key parameters representing track-bridge transition section settlement irregularity are determined by regression analysis, including curve modus, wavelength and amplitude. Then a train-transition section-bridge dynamic analysis model is built, in which the bridge and ballastless track are modeled with beam finite elements and the elasticity of rail pad, CA motar and subgrade are considered. The motion of a four-axle car with two suspension systems is modeled based on multibody dynamic theory with linear springs and dampers. The dynamic responses of passenger cars and track of transition section under settlement influence are studied and the operational performance of the whole system are evaluated. Through the study on settlement irregularity prediction of HSR track-bridge transition section and the dynamic simulation analysis, the early warning limits of settlement irregularity are proposed to ensure the running safety and ride comfort, and eventually some reasonable strategies are put forward for the HSR design and maintenance.