【摘要】 在"功能分离"设计理念基础上,提出减震榫与拉索限位器组合的高速铁路桥梁减震方案,通过减震榫的屈服耗能作用减小桥梁的地震响应,通过拉索限位器控制减震榫的过大变形和防落梁,给出减震榫和拉索限位器在多遇地震、设计地震和罕遇地震下的设计准则和设计方法。以1座高速铁路连续梁桥为例,研究在具有向前方向性效应、滑冲效应和无速度脉冲效应的近断层地震动下,采用组合减震方案桥梁结构的抗震性能。结果表明:仅采用减震榫的桥梁在速度脉冲型近断层地震作用下可能因减震榫变形过大而不安全;加设拉索限位器后,能有效地控制减震榫的变形及墩梁的相对位移,起到了较好减震效果,其减震率在60%以上。更多还原

【Abstract】 Based on the design idea of"functional separation",a new seismic isolation system including steel energy absorbers and cable restrainers was proposed for high speed railway bridges.The steel energy absorbers reduced the seismic response of bridge through yield energy dissipation.The cable restrainers were effective in controlling the excessive deformation of steel energy absorbers and falling-off prevention.The design criteria and methods for steel energy absorbers and cable restrainers under frequent earthquake,design earthquake and rare earthquake were given respectively.Taking a continuous beam bridge for high speed railway as an example,three groups of ground motions with distinct characteristics such as forward rupture directivity,fling-step effect and without velocity pulse were selected as seismic excitation.The seismic performance of bridge with new seismic isolation system was investigated.Results indicate that the bridge isolated with steel energy absorbers alone is not safe due to the excessive deformation of steel energy absorbers under near-fault ground motions with velocity pulse.Cable restrainers can effectively control the deformation of steel energy absorbers and the relative displacement of piers and beams.The seismic performance of the bridge of the new isolation system with steel energy absorbers and cable restrainers is effectively improved,and the decreasing ratio of seismic response can exceed 60%.更多还原