The Analysis Of Key Parameters Of Seismic Performance Of Half Through Continuous Tied-arch Bridge

With the high-rapid development of urban construction and the city roadcross-section continuously widening, the importance of bridge landscape is more andmore prominent, and the half through continuous tied-arch bridge, as a bridge to adaptto the requirements of modern building,is more and more used in the city. However, ourcountry is one of the most strong earthquake activity national in the world,due to TiedArch Bridge superstructure self-important and high center gravity, tied-arch bridgeseismic performance becomes increasingly prominent especially in high intensity area;In order to reduce the losses caused by the earthquake, we must demand half throughcontinuous tied-arch bridge has better seismic performance at the design time.The seismic resistance of bridge structure is improved mainly by modifiyng thestructure design parameters and using seismic isolation design. Taking BaHe bridge xi’an shaanxi province as the engineering background,this paper uses time historyanalysis method, according to longitudinal vertical and horizontal vertical input seismicwave, which obtains the seismic behavior law of main control section and analyze theaction of natural vibration characteristics within the scope of conventional designparameters.The main contents are as follows:1.Established the half through continuous tied-arch bridge calculation model ofupper and lower structure under different design parameters, the comparative analysis,ofwhich different rise-span ratio, hanger rod arrangement, arch rib inclination angle, tiedarch stiffness ratio, horizontal contact form, the pier cross-section form and differentpile foundation are parameters, impacts on the free vibration characteristics and seismic performance of half through continuous tied-arch bridge.2.Established calculation model of two-direction arch pier isolation about the halfthrough continuous tied-arch bridge, the comparative analysis,of which differentisolation device layout and dampers different layout position in transverse bridge areparameters, have an influence on the free vibration characteristics and seismicperformance of half through continuous tied-arch bridge.3.Using the maximum deviation method and preparing the corresponding matlabprogram, it calculates the different design parameter weight of upper and lowerstructure and calculates the structural seismic performance evaluation value, to avoidthe blindness and empirical of adjustment parameters and provide a reference for theoptimization design of large span arch bridge.The results show that modified structure design parameters and adapt the two-wayisolation method of arch pier can be in a certain degree to improve the seismicperformance of half through continuous tied-arch bridge;When arch pier is adapttwo-way isolation design and between the capping beam and end floor beam setsviscous dampers, Changes is complex in the structure formation, but it can effectivelyprolong the fundamental period of the structure and achieve higher damping ratio, toensure the degree of seismic safe as the whole and component in each level of seismicfortification;Transverse layout and tied arch stiffness ratio have the most influence onthe seismic performance,for the biggest of the weight of coefficient of variation;In thescheme comparison of seismic performance of this bridge,we should be considered firstthe top displacement of girder and arch,second the shear of the cross-section of arch pierand the pier bottom, third the bending moment of the cross-section arch pier and the pierbottom.