Research On Vibration Property Of Jia Yuguan Great Wall Induced By Ballastless Track

Environment vibration induced by high-speed railway brings about great effects cannot be ignored to the historic old buildings around the lines. The track passes through underneath the Jia Yuguan Great Wall, therefore, research on the vibration effect of the Great Wall on every aspect is necessary to protect the historic Great Wall out of the vibration damages. So this paper has theoretical and engineering meanings to do some researches on the vibration effect induced by the track to the Jia Yuguan Great Wall.Firstly, based on former researches, this paper applies the finite element method to establish the vehicle-track-subgrade vertical coupling dynamic analysis model and determine the parameter of the vehicle and track system based on the physical truth. After that, using the finite dynamic analytical software ANSYS/LS-DYNA to figure out the slab support reaction under the train load and analyze the relationship between the reaction and the speed of the train.Secondly, the sensitive frequency of structure damages and degree of the damages have great relationship with the vibration velocity. Therefore, using the vibration resultant velocity and the horizontal vibration velocity of the structure top as the control standards to appraise the vibration effect to the Great Wall, this paper establishes the track-subgrade-Great Wall2-D dynamic analytical model and applies the former slab support reaction to the model and analyzed the vibration propagation law on the horizontal and vertical direction of the Great Wall in time domain and frequency domain respectively, and further get the vibration velocity peak value on every direction of the Great Wall and get these following conclusions:Vibration resultant velocity on every direction of the Great Wall is within the scope of admissible value1.8mm/s, however, the horizontal vibration velocity is excessive of the admissible value0.2mm/s.Finally, as the horizontal vibration velocity is excessive of the admissible value, so system parameters should be optimized to reduce the horizontal vibration velocity. Tunnel depth, track system parameter, tunnel system parameter, train speed and system damping parameter are considered to optimize the vibration effect and get these following conclusions:(1) The depth of tunnel should be increased to23.5meter to reduce the horizontal vibration velocity on the top under the limit.(2) System damping parameter should be increased up to0.05to reduce the horizontal vibration velocity on the top under the limit.