Research on the Dynamic Characteristics of Road-bridge Transition Sections of High-speed Railway

Based on the site test of the dynamic response of Qinshen railway passenger exclusive Hujiatun Middle Bridge road-bridge transition section, this paper aims to study the relationship between the dynamic stress & dynamic acceleration of road-bridge transition section of graded broken-stone and train speed, as well as the attenuation rule of dynamic response with subgrade depth. With this test as an engineering backdrop, rail-subgrade dynamic analysis model is established to make numerical simulation calculation on dynamic response of road-bridge transition section of graded broken stone. The dynamic response rule concluded from numerical simulation analysis is in conformity with site test result, which indicated that: the peak values of both subgrade dynamic stress and dynamic acceleration increase with the raising of train speed, subgrade dynamic stress & dynamic acceleration decrease with subgrade depth sharply, and the dynamic response the train imposes on the subgrade is mainly on its surface. This study would provide engineering practice experience and theoretical bases for correctly designing high-speed railway mad-bridge transition section and ensuring steady and safe traveling of train.