Research on Seismic Mitigation System of the Yellow River Road-Cum-Railway Bridge of Shijiazhuang-Jinan Passenger-Dedicated Line

摘要

The Yellow River Road-cum-Railway Bridge of Shijiazhuang-Jinan Passenger Dedicated Line is a large-span, long connected continuous suspension reinforced steel truss bridge. The seismic performance standard is high, so the internal force of the fixed pier under rarely occurred earthquake is large. It's difficult to conduct seimic design, and the reasonable seismic mitigation system should be studied. Through the setup of lock-up devices in the movable piers, the reasonable scheme is obtained, and the position and caculation parameters are optimized. Research conclusions are as follows: (1) The total stiffeness of the bridge is increased owning to the adopting of lock-up devices. But through the sharing of the movable piers, the good mitigation ratios are all obtained under different setup schemes. (2) For the pier with lock-up devices with relatively low height, and the number of neighboring movable piers without lock-up devices is large, the seimic response could be larger than the fixed pier. (3) For long connected road-cum-railway bridge, the setup position and number should be optimized, considering both the seismic mitigation ratios of internal forces and displacements. Besides, the maximum magnification factors and damping tonnage should also be considered. (4) For the road-cum-railway bridge, the pier-beam relative displacements of the railway and highway floor should both be considered in order to control the displacement value of expansion joints of both floors.