摘要
为减少自复位桥墩的摇摆界面可能由压力造成的混凝土压碎和预应力损失,同时加快预制桥墩与承台的连接速度,基于某采用钢筋提供耗能能力及恢复力的可恢复铰(简称RH铰),提出一种新型摇摆机械铰。该新型摇摆机械铰(简称摇摆铰)首先将RH铰的普通钢筋改为无粘结预应力筋和U形耗能器,分别为桥墩系统提供自复位能力和耗能能力,形成球形机械铰(简称球形铰),再增大支点与墩中心线的距离使重力提供稳定力矩。对该摇摆铰与球形铰结构构造进行对比分析,推导摇摆铰桥墩和球形铰桥墩的荷载~位移关系,对比2种桥墩的滞回曲线,并以某四跨连续梁桥为背景,采用非线性时程分析方法对比分析采用摇摆铰和球形铰桥梁的地震响应。结果表明:摇摆铰桥墩的滞回曲线呈典型的旗帜形,而球形铰桥墩的滞回曲线可用弹塑性曲线表示;在相同条件下,摇摆铰桥墩比球形铰桥墩具有更强的水平承载能力和自复位能力;与采用球形铰的桥梁相比,采用摇摆铰的桥梁中墩处主梁峰值位移更大,中墩墩底剪力相近,残余位移更小,自复位性能更优。
In this paper,a novel type rocking mechanical hinge(RMH for short)that is developed from the mechanical hinge(RH for short)that uses reinforcing bars to fulfill the demands of energy dissipation and structural resilience is proposed.The application of RMH can minimize the possible concrete crush and prestress loss in the rocking interface of the self-centering pier that is caused by compression and accelerate the connection of precast pier and abutment.In RMH,the common reinforcing bars in RH are replaced by unbounded prestressing tendons and U-shaped energy dissipaters(to form a spherical mechanical hinge,SMH for short)to allow the pier to have self-centering and energy dissipation capacity,the distances between supports of the hinge and pier center line are enlarged to allow gravity to provide stable force moments.The structural compositions of RMH and SMH are compared to derive the load-displacement responses of the pier with RMH and the pier with SMH,the hysteresis curves of the two types of piers are compared.Based on an existing four-span continuous girder bridge,the non-linear time history method was used to analyze the seismic responses of the pier with RMH and the pier with SMH.It is shown that the hysteresis curve of the pier with RMH resembles a flag,while that of the pier with SMH is similar to an elastic-plastic curve.Under the same conditions,the pier with RMH has better horizontal load bearing capacity and self-centering ability than that with SMH.The peak displacements of the girders over intermediate piers with RMH are bigger,compared with the bridge with SMH,the shear forces in the bottom of intermediate piers are of no big difference,the bridge with RMH has smaller residual displacements and better self-centering ability.
作者
钟学琦
李建中
高浩原
鲍泽华
ZHONG Xue-qi;LI Jian-zhong;GAO Hao-yuan;BAO Ze-hua(State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2023年第2期52-59,共8页
Bridge Construction
基金
国家自然科学基金重点项目(51838010)。
关键词
桥梁工程
自复位桥墩
摇摆机械铰
球形机械铰
滞回曲线
地震响应
非线性时程分析法
bridge engineering
self-centering pier
rocking mechanical hinge
spherical mechanical hinge
hysteresis curve
seismic response
non-linear time history analysis
