Seismic Response And Control Of A Cable-stayed Pedestrian Bridge

Every year about 150-200 of devastating earthquakes occur with a magnitude of 7.0 and above,this is can be concluded that the destructions cause enormous financial and other losses for the countries.Due to the complexity of the earthquake and the difficulties in earthquake prediction,the vulnerability of modern urban infrastructure requires effective and innovative seismic protection systems.Pedestrian bridge is an important part of city infrastructure,help to relieve the streets of traffic jams,protect pedestrian safety and sometimes it is a place to watch the city.Because this kind of bridge has simple structure,the seismic problem of pedestrian bridges did not cause enough attentions,and most study of pedestrian bridge focused on vibration caused by vehicle and people or its influence on pedestrian bridge comfort.The structural form of the pedestrian overpass is changeable but seismic studies of the pedestrian bridge is remain poorly disclose.From the beginning,this paper aims to obtain some results that can help the design work of many similar bridges in terms of dynamics.As an example,we selected a steel cable stayed bridge with a span a 44.1m.The main work includes:(1)Based on a review of literature,considered earthquake disaster and earthquake damage bridges,especially pedestrian.Also,review the development and research situation of pedestrian bridge engineering,summarize research progress and research situation of conventional bridges seismic response.Analysis the characteristics of different structure pedestrian bridges and its possible problem during an earthquake.(2)Used the finite element software MAIDAS/CIVIL studied the dynamic characteristics and seismic responses of the background bridge,analyzed by the elastic response spectrum method and the dynamic time history method based on modal analysis.(3)Used two methods,method of direct consolidation and "M" method to simulated pilesoil boundary conditions.In order to study the influence of pile-soil interaction,to compared and analyzed the structure stress of the bridge under earthquake used two different methods.(4)A pedestrian bridge model with lead-rubber bearings was established,and dynamic time-history response analysis performed on the model.The results showed that: lead-rubber bearings have no obvious isolation effect on the displacement and internal force of the tower,and they have a good effect on the displacement and internal force of the bridge piers,and the bearings are in a state of linear elasticity.