Study On Seismic System Of Prestressed Concrete Simply-Supported Bridges With Continuous Slab-Decks In Soft Soil Area

China is a country with frequent earthquakes.The economic losses and casualties caused by the earthquake are also among the top of the disasters.Bridges,as part of the infrastructure,are the life channels connecting the disaster areas to the outside world.Therefore,bridges with earthquake resistance are crucial.In the eastern coastal areas of China,the bridges are not only affected by the earthquake hazard,but also because of their special soft soil sites and the earthquake resistance of the bridges at other sites.Therefore,based on the related research at home and abroad,through the finite element analysis,the bridge seismic system analysis of the bridge with the first simple supported rear bridge deck is applied.The following research is carried out:(1)Through the literature survey,the current research status of commonly used bridge seismic systems is summarized.According to the earthquake damage of bridges at home and abroad,the paper draws lessons from it and points out the design criteria that should be followed for small and medium span bridges.(2)The basic theory of seismic analysis of bridges at home and abroad is introduced in detail,and the finite element model considering pile-soil interaction,block constraint and bridge deck continuous constraint is established by finite element software CSI Bridge.And the time-history analysis results verify the correctness of the model and ground motion parameters.(3)The incremental dynamic calculation and analysis of the plate rubber bearing considering the slipping and non-slip conditions,the results show that the working condition considering the bearing slip is significantly reduced compared with the non-slip working condition,but The displacement of the support has increased significantly.The effects of the plate rubber bearing,LNR bearing and HDR bearing on the seismic performance of the bridge were studied.The results show that the plate rubber bearing scheme is more suitable for engineering than other solutions.(4)Summarize the regulations of national regulations on the block and the problems in the design of the block in China.The initial stiffness and initial clearance of the block were analyzed parametrically.This paper intends to use a block arrangement with a stiffness of 10~5kN and an initial clearance of 10 cm.(5)Summarize the regulations of the national standard for the vertical limit device and the design method of each limit device.Firstly,the cable form is preliminarily designed by the1.5 times dead load method,and the limit effect of the three limit devices of the lock-up limit device,the beam type limit device and the beam-to-beam limit device is compared.The results show that the beam-to-beam limit device is more suitable for this project.Through the parameter analysis,the cable arrangement with the stiffness of 8×~4and the initial clearance of 10cm is determined.(6)Established a fortification concept of“multi-channel fortification,step-by-step energy dissipation”and a design method that considers the limited damage of the support.