Study On Seismic Response And Elastic Restriction Damping Of Cable-stayed Bridge

Because of constant development of economy and bridge technique, more and morelong-span bridges are built. Cable-stayed bridge develops rapidly for its beautiful appearance,low cost and good mechanics performance. With the growing size of the cable-stayed bridge,the seismic response of the cable-stayed bridge becomes more and more important andsometimes plays a decisive role, so the seismic response analysis of long-span cable-stayedbridge is necessary.The paper presents the analysis and discussion in detail of cable-stayed bridge by meansof Midas/Civil, with the emphasis of influence of longitudinal elastic restriction on seismicresponse.Firstly, on the basis of theory of artificial seismic wave, accordant excitation programASW is generated by Matlab. ASW generates the artificial wave fitting criterion which can beused as the input of seismic time-history analysis.Secondly, the dynamic calculation models are established and the dynamic characteristicof cable-stayed bridge is analyzed. General vibratory rule of float system and semifloatcable-stayed bridge is attained through the calculation of mode and frequency of the bridge.Thirdly, the response spectrum analysis of cable-stayed bridge is carried out to getseismic response extreme of three orthogonal components and combination of threeorthogonal components. Study of longitudinal elastic restriction on cable-stayed bridge ismade by means of response spectrum considering the influence of different site categories toelastic restriction damping.At last, the time-history analysis of long-span prestressed concrete cable-stayed bridge isperformed to consider the nonlinear of seismic response and avoid linear and of balancedrandom process of spectrum response. Also traveling wave effect and longitudinal elasticrestriction on bridge are considered in time-history analysis. It also presents the restrictionresult of different site categories and different high-span ratio.The laws of the paper can be used for directing seismic response analysis of such kindbridge.