摘要
针对城市高架匝道桥,提出仅在矮墩上设置隔震装置的部分隔震设计方案。以上海嘉闵高架某直线匝道桥为例,系统对比了"完全延性"、"完全隔震"与"部分隔震"体系下的结构地震响应。结果表明,相比"完全延性"设计,将固定墩改为活动墩的"部分隔震"设计,能有效降低纵向固定墩的地震强度和变形需求近70%,减小过渡墩伸缩缝的变形需求约21%~34%,降低主梁横向的地震动加速度约20%~39%;同时相比"完全隔震"设计,在墩底内力响应、支座变形以及伸缩缝变形方面基本相当。此外,固定墩改为活动墩的"部分隔震"设计,相较仍设固定墩的"部分隔震"设计,能显著降低纵向固定墩的地震响应以及主梁的纵向地震加速度近56%与38%,具有相对更优的性能。
A partial vibration isolation system in which only short bridge columns are isolated was proposed for the a seismic design of ramp bridges. A parallel ramp bridge on the Jia-min Elevated Route in Shanghai was taken as a study object, and the structural seismic responses under three kinds of seismic resistant systems including a full ductility resistant system, a full vibration isolation system, and a partial vibration isolation system were analyzed. It was shown that compared with the full ductility resistant system, using the partial vibration isolation system in which the traditional fixed pier is changed into a movable pier, the earthquake intensity and deformation demand of the fixed pier along the longitudinal direction are effectively reduced by nearly 70% , the deformation demands of expansion joints at transition piers are reduced by almost 21% - 34% ,and the acceleration of girders under the transverse earthquake input is also greatly reduced by 20% -39% ; compared with the full vibration isolation system, simulation results for the 2nd design and the 3rd one are very close in aspects, such as,internal forces at pier bottom, bearing deformation and longitudinal displacements of expansion joints at transition piers; furthermore, two kinds of partial vibration isolation schemes with and without the arrangement of the fixed pier are compared, the latter has more superior performances, the latter can reduce the longitudinal seismic response of the fixed pier and the longitudinal acceleration of the main girders 56% and 38% , respectively.
出处
《振动与冲击》
EI
CSCD
北大核心
2017年第7期141-148,共8页
Journal of Vibration and Shock
基金
国家自然科学基金(51408359
51378384)
关键词
部分隔震
延性
完全隔震
匝道桥
地震响应
partial vibration isolation
ductility
full vibration isolation
ramp bridge
seismic response
