Test Study On Subgrade Load Performance And The Road-Culvert Transition Performance In Suiyu Railway

As the speed and axis load of the train increases, the dynamic action of the railway subgrade is more and more obvious, and the dynamic response rule has obvious influence on the design, construction and maintenance of the railway subgrade. With the cosmically construction of the high-speed railway and the widely speedup of the former railway in our country, the inequality of the road-culvert transition section becomes more obvious than before. If we do not repair it, when the train passes road-culvert transition section, the train usually reel seriously, which reduces the safety and ride comfort of the train in motion swiftly. Therefore, more and more researchers are paying attentions to these subjects.In this thesis, based on the achievements of the previous literature, combined with the SuiYu railway 200km/h speed-increasing test which is organized by railway ministry, the dynamic performance in subgrade and road-culvert transition section of several kinds of train(25t double deck container train, passenger-freight blending train, "Changbai mountain" power train team) are investigated with the methods of field test with train. The main research contents: 1) Introducing the development status of high-speed railway, reviewing the published literature on subgrade dynamic performance and road-culvert transition section dynamic performance. 2) Analyzing and studying the subgrade dynamic response, ascertaining the controlling factors in the subgrade design of the railway which have both freight and passenger transport, evaluating the rationality and validity of the subgrade structure form. 3) Analyzing and studying the road-culvert transition section dynamic performance, finding out the controlling factors in the unevenness of the road-culvert transition section, evaluating the rationality and validity of the road-culvert transition section structure form and length.Analyzing the test data, we get some main conclusions: 1) The axis load of the train the running speed of the train and the dynamic performance of the train have different influence on the the subgrade dynamic stress,the dynamic displacement, the vibration speed of the sleeper and the vibration acceleration of the subgrade.The axis load of the train has the most influence on the subgrade dynamic stress and dynamic displacement, the running speed of the train has the most influence on the vibration speed of the sleeper, the dynamic performance of the train has the most influence on the vibration acceleration of the subgrade. 2)the dynamic stress of the subgrade, which was brought by the 25t double deck container train and heavy freight train, is comparatively big and overtop the control value in newly-built 200km/h passenger-freight blending railway design temporary criterion. Dynamic load standard cannot adapt to the technology policy for the 120km/h freight train and 25t double deck container train, it should be modified. 3) setting a transition section between road and culvert can improve the dynamic performance of the railway. But we also find that: the subgrade dynamic stress on the top of the culvert, is obviously smaller than it of the neighboring transition section, but the dynamic displacement on the top of the culvert, is some bigger than it of the neighboring transition section. This result differs greatly from the dynamic performance of the transition section.