Abstract:For the long-span cable-stayed bridges, there are many influential factors on the seismic calculation. It is required to base on its own characteristics for the special study. Taking Minpu Bridge III in Kunyang Road as the study object, the response spectrum method and time-procedure analysis method are used to compare and analyze the structural seismic response of semi-floating single-pylon cable-stayed bridge. The suitable seismic wave and damping parameters are selected. Under the E2 earthquake, the time-procedure analysis method is used to analyze two different stress systems before and after the bad shear of the vertical restraint support between the pylon and beam. The result shows that the main pylon supports bear the large horizontal force for the vertical restraint system before the bad shear of support. The displacement at the top of the main pylon and the longitudinal displacement at the end of the main girder are all large for the vertical activity system after the bad shear of the supports. Aiming at the scheme characteristics of long-span single-pylon cable-stayed bridge, the composite system of seismic mitigation and absorption is used to greatly reduce the longitudinal stress of pylon bottom and also to control the vertical displacements of the pylon top and beam end within the reasonable range, which is the ideal seismic isolation restraint system.
