基于易损性的高墩多塔斜拉桥纵向减震控制研究  

Seismic control for multi-span cable-stayed bridge with high-piers using seismic fragility method

作　　者：胡思聪[1] 李立峰[1,2] 王连华[1,2] 

机构地区：[1]湖南大学土木工程学院,长沙410082 [2]湖南大学风工程与桥梁工程湖南省重点实验室,长沙410082

出　　处：《振动与冲击》2017年第22期149-157,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51278183)

摘　　要：为研究常用的减震控制方式在高墩多塔斜拉桥这种新型结构中的减震效果,以一座墩高178 m的斜拉桥为例,建立了非线性有限元动力分析模型。从PEER强震数据库中选取80条实测地震波进行非线性时程分析;结合结构的特点,定义各关键构件的损伤指标;基于易损性分析理论,建立了关键构件及桥梁系统的易损性曲线;以铅芯橡胶支座和黏滞阻尼器为代表,通过易损性曲线对比研究了不同控制参数和布置形式下,位移型及速度型两类减震控制方式的减震效果;结合桥梁实际情况确定最优的减震方案。分析结果表明:由于高墩的影响,斜拉桥的支座系统、主梁和拉索的损伤概率显著增加,而索塔损伤相对轻微;由于传力机理的差异,不同布置形式下控制参数对减震效果的影响规律不同;无论是位移型还是速度型控制方式,梁端布置形式的减震效果均优于塔梁布置形式;对于相同的布置形式,速度型控制方式较位移型控制方式效果更加显著。In order to investigate the effect of seismic control devices on multi-span cable-stayed bridges with high piers,a cable-stayed bridge with 178-meter piers was taken as an example and the nonlinear finite element model was built. A series of 80 ground motions were selected from the Pacific Earthquake Engineering Research Center database and the nonlinear history analysis was conducted. The damage indexes of various components were defined according to the structure characteristics. Based on the fragility method,components and bridge system fragility curves were established,respectively. The seismic control effect of Displacement-type and Velocity-type control devices,represented by the lead rubber bearing（ LRB） and the viscous fluid damper（ VFD）,with different parameters and arrangement forms was compared and investigated through fragility curves. At last,the optimal seismic control of the bridge was determined. The results show that the damage probability of bearings,the deck and cables increase significantly and one of towers becomes slighter with the height of piers. Due to different transmission mechanism of inertial force,the influence of seismic control parameter presents discrepancy for different arrangement forms. The device installed at the end of deck is superior to those installed between the deck and towers. For the same arrangement form,Velocity-type control device is more effective than the Displacement-type control device.

关 键 词：桥梁工程 多塔斜拉桥 高墩 减震控制 易损性评估 铅芯橡胶支座 黏滞阻尼器 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]