Reasonable seismic isolation measures of intercity railway viaduct simple supported beam bridge under strong earthquake
Intercity railway viaduct(IRV)is the core hub of engineering in urban traffic.At present,the seismic design of IRV is mainly based on the ductility seismic design of highway bridges.However,the minimum volume stirrup ratio of IRV piers in the standard is the same as that of high-speed railway piers,which is 25%smaller than that of highway piers.Therefore,it is necessary to learn from the principles of seismic isolation design for high-speed railway bridges and study the reasonable seismic isolation system of IRV.This paper takes an IRV three-span 32.7 m standard span simple supported beam bridge as the research object,firstly,puts forward a variety of measures under strong earthquake for vibration reduction and isolation,studies the constitutive model of various measures,and then establishes a 3D IRV elastic-plastic model based on OpenSees,and verifies it.Secondly,the effects of various seismic isolation measures for IRV under strong earthquakes are compared and analyzed,and the optimal seismic isolation system is proposed.The results show that both spherical steel bearing and friction pendulum bearing can reduce the pier bottom internal force and the displacement of the pier top under strong earthquakes,but cannot limit the relative displacement of the pier beam,and it is easy to fall beam.It is necessary to cooperate with the limiting device(such as a shock-absorbing clamp)to limit the excessive seismic displacement in the upper structure and alleviate the vertical ground motion in the strong earthquake area.The relative displacement between piers and beams can be limited effectively by using"spherical steel bearing+shock-absorbing clamps"or"friction pendulum bearing+shock-absorbing clamps",but the effect of"spherical steel bearing+shock-absorbing clamps"on the pier bottom internal force and the pier top displacement is poor.Therefore,it is suggested to adopt the"friction pendulum bearing+shock-absorbing clamps"as the optimal vibration isolation system for IRV in strong earthquake areas.
intercity railwayfriction pendulum bearingshock-absorbing clampanti falling beanreasonable seismic isolation system
万方数据
维普
