Study On The Dynamic Response Properties Of The Foundation Structure In Heavy-Haul Railway Tunnel

Abstract:Since the1980s, many heavy-haul railway lines have been constructed, such as Daqin line, Shuohuang line, heavy-haul railway in central south of Shanxi et. But, with the increase of the axis Load, more and more diseases of cracks, damage, sag and mud pumping, apper in the base structure of tunnels, which affect the safety and economy of heavy haul traffic. Therefore, it is necessary to study the dynamic priorities of base structure of heavy haul railway tunnel. This dissertation studies the dynamic priorities of the base structure of heavy haul railway tunnel with the numerical calculation method systematically. This dissertation is granted from the National Natural Science Foundation of China (NO:51278494) and Coal Joint Foundation (NO:U1361204). The main contents and conclusions are as follows:(1) Based on the paraters of exisiting heay haul train and train track, the train-track coupling model is established. The time history curve of the load applied on the base structure of tunnel by the heavy haul train is obtained.(2) Based on the design parameters of exisiting heavy-haul tunnels, the dynamic priorities of base structure of single and double heavy haul railway tunnel are analysised from the aspects of displacement, accelera-tion, stress of the base structure with the three-dimensional dynamic model. Meanwhile, the influence rules of axis-load are also acquired.(3) According the dynamic response of the invert and filling structure, the influence rules of span ratio, filling thickness, invert thickness on the dynamic priorities of base structure are analysised with the method of numeric calculation.(4) According the dynamic response of the base structure, the influence rules of soft bedrock and void on the dynamic priorities of base structure are obtained.