立交匝道桥地震响应及合理抗震体系研究  

Seismic response analysis and reasonable aseismic system design for a viaduct ramp bridge

作　　者：张菊辉[1] 管仲国[2] 

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《振动与冲击》2015年第13期189-194,共6页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(51378384)

摘　　要：以上海嘉闵高架桥为依托，分析了不同曲率半径、地震输入方向对立交匝道桥地震响应的影响，指出小曲率半径下的匝道桥地震响应较为复杂，地震最不利输入方向与墩柱切线、法线方向仍存在20°～30°的偏差，墩底弯矩偏低约10％～20％，大曲率半径下则可简化为直线桥。基于新规范体系，评估了立交匝道桥在两级地震作用下的性能，指出匝道桥较容易满足 E1地震下的强度要求，在 E2地震下，顺桥向固定墩以及横桥向高墩均会进入屈服，其中矮墩固定墩较容易发生剪切破坏。对直线匝道桥分别采用延性抗震体系与减、隔震体系进行设计，并评估其适用性，指出单独采用任何一种抗震体系都难以满足结构性能要求，建议高墩区采用延性抗震体系，矮墩区采用减隔震体系。A viaduct ramp bridge for the Jiamin Elevated Route in Shanghai was taken as a study object,the effects of curve radii and earthquake input directions on seismic response of a ramp bridge were analyzed.The results showed that the seismic response of a ramp bridge with a smaller curve radius （R =50m）is very complicated;a deviation of 20°to 30°exists for the angle between the tangential or normal direction of pier columns and the worst earthquake input direction and the bending moment is on the low side by nearly 10% to 20% at the pier bottom;when its curve radius is larger than twenty times of bridge width,the seismic response of a ramp bridge is nearly consistent with that of the straight bridge;a simplified straight bridge model can be used to model a larger curve radius ramp bridge.Base on the new two-level seismic fortification criterion,the seismic performance of the ramp bridge was evaluated.It was shown that the ramp bridge is easier to meet the strength requirements under E1 earthquake;while under E2 earthquake,both the fixed piers along the longitudinal direction and the higher piers along the transverse direction of the bridge yield,the shear failure easily occurs on the lower fixed pier.Then,the ductility seismic-resistant system and the seismic mitigation and isolation system were selected and applied in aseismic design of a straight ramp bridge.The applicability of these two aseismic systems was evaluated and the results showed that only using one kind of aseismic system cannot meet the requirements of structural performances;the ductility seismic resistant system is suggested to be used in higher piers area of the ramp bridge,while the seismic mitigation and isolation system is suggested to be used in the lower piers area of the ramp bridge.

关 键 词：匝道桥 曲率半径 地震动输入方向 抗震体系 延性 减隔震 

分 类 号：U448.17[建筑科学—桥梁与隧道工程] U442.55[交通运输工程—道路与铁道工程]