Analysis on Lateral Seismic Performance of Inverted Y-shaped Concrete Tower for Long Span Cable-stayed Bridges

To research on lateral failure mechanism and elastic-plastic performance of the inverted Y-shaped concrete tower for long span bridges,a typical long-span cable-stayed bridge with inverted Y-shaped concrete tower was taken as the prototype,and based on OpenSees nonlinear finite element platform,a nonlinear finite bridge model,considering the main tower's elasticplastic performance,was established.Three observed seismograms were taken as seismic input.Dynamic incremental analysis(IDA)was used to analyze.The results show that under different observed seismic inputs;the lateral yield in the concrete tower of cable-stayed bridge is found at the top section of the beam,which is controlled by tensile strain of reinforcement at the side of core concrete,while the lateral damage in the concrete tower is found at the top section of the beam or at the bottom section of the tower,which is controlled by compressive strain of concrete at the side of core concrete.For an inverted Y-shaped concrete main tower,three plastic zones are formed during the earthquake on the transverse direction.Confinement effect of transverse reinforcement in different sections of the main tower shall be taken into consideration,which can improve the lateral plastic performance and lateral seismic performance of the concrete tower.