The Study Of Pedestrian Bridge Three-dimensional Seismic Response Characteristic And Collapse-proof Systems

Pedestrian bridge is an important part of city traffic project, and it is also the key link of city lifeline engineering. In order to alleviate traffic pressure, a great many of pedestrian bridges that across traffic trunk roads or expressway were built in recent years. Because of its simple structure, the seismic problem of pedestrian bridges did not aroused enough attentions, and most study of pedestrian bridge at home and abroad were focused on vibration caused by vehicle and people or its influence on pedestrian bridge comfort. The seismic research of pedestrian bridge is still a blank, and related design were draw lessons from the research results of conventional bridge, and the difference caused by its features were ignored. In order to explore the seismic response characteristics of pedestrian bridge, reveal its seismic response mechanism and analysis the effect of its structure parameters on seismic response, pedestrian bridges of different structure were researched and their seismic response characteristics were systematically studied through nonlinear time history method in this paper. In response to the problem that pedestrian bridges’ beams are very easy to drop during an earthquake, different beam falling-off prevention device were designed and its fall prevention effect and influence factors were thoroughly researched through nonlinear time history method, and the main works of this paper are as the follows:.Firstly, based on consulting a large number of literature, review the development and research situation of lifeline and pedestrian bridge engineering. Review and summarize research progress and research situation of conventional bridges’ seismic response and beam falling-off prevention device. Analysis the characteristics of different structure pedestrian bridges and its possible problem during an earthquake.Secondly, review and summarize seismic analysis theories and methods of conventional bridge, including static analysis method, response spectrum analysis method and dynamic time history analysis method. Summarize nonlinear problems of bridge analysis. Summarize seismic analysis key points of different structure pedestrian bridges and its component unit’s simulation in Sap2000.Thirdly, based on a simply supported girder pedestrian bridge, its space dynamic calculation models were established by Sap2000, and its three-dimensional seismic response characteristics and influencing factors were analyzed through nonlinear time history method.Fourthly, based on a beam arch combination pedestrian bridge, its space dynamic calculation models were established by Sap2000, and its three-dimensional seismic response characteristics and influencing factors were analyzed through nonlinear time history method.Fifthly, analysis seismic response characteristics of the simply supported girder pedestrian bridge and the beam arch combination pedestrian bridge, and design their beam falling-off prevention device. Establish space dynamic calculation models with beam falling-off prevention device, researching its fall prevention effect through nonlinear time history method and exploring parameters’ effects through dynamic calculation models of different impact parameters.Finally, summarize the research contents of the article, and point out the further works.