| The damage in roadbed-bridge transition section of railway is widespread and serious. ShuoHuang Railway, as a existent heavy-load railway, is also in this condition.In order to meet with the demand of heavier axle load and faster speed, it is necessary to investigate the improvement of roadbed structure. Several methods, including in-situ and laboratory tests, were used to confirm the problems of the test segment. Based on the analysis of the test results, the range and measure and control standard of reinforcement were brought forward.The current finite element software ANSYS has been used to doing analyse of foundation and roadbed structure on the function of heavy-load train.The stress and deformation regularity of roadbed on condition of different material parameter is educed.As can be seen from the results of static analysis:the stiffness of top layer of bedding and filling in transition section has little effect on settlement of top subgrade. The stiffness of bottom layer of bedding has much effect on settlement of top subgrade only when its value is small. The stiffness of foundation has significant effect on settlement of top subgrade.Moreover density of filling has evident effect on settlement.As can be seen from the results of dynamic analysis: the stiffness of foundation has great effect on dynamic deformation of top subgrade,but it has hardly any effect on stress and acceleration. While the stiffness of surface layer of bedding increases, acceleration of the top surface of subgrade declines rapidly, and dynamic deformation has some reduction too. Damping of bedding has great effect on stress and acceleration of the top surface of subgrade. 50 percent vertical dynamic stress of the general roadbed declines in the depth of 0.7 meter, while in the transition section roadbed it needs 2 meters' depth to achieve the 50 percent descent. The higher the stiffness of top layer of bedding increases, the more rapidly dynamic stress declines. |
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