摘要
为解决我国铁路重力式桥墩在地震中延性不足的问题,通过在墩底设置无粘结钢筋来改善桥墩的延性性能。制作了1个完全粘结钢筋混凝土桥墩模型和2个不同无粘结钢筋长度的桥墩模型进行拟静力试验。对比分析3个桥墩的破坏状态、滞回曲线、骨架曲线、刚度退化、耗能能力及位移延性等抗震性能。结果表明:完全粘结钢筋混凝土墩身和墩底均出现裂缝,而2个不同无粘结钢筋长度的桥墩只是在墩底形成一条主裂缝;在同一加载位移下,完全粘结钢筋混凝土桥墩的累积耗能大于无粘结钢筋混凝土桥墩,且无粘结钢筋长度越长,桥墩的累积耗能越少。但是桥墩最终破坏时,无粘结钢筋混凝土桥墩的累积耗能大于完全粘结钢筋混凝土桥墩,且无粘结钢筋长度越长桥墩累积耗能越大;在墩底设置无粘结钢筋可以提高铁路重力式桥墩的延性性能,且无粘结钢筋长度越长,对桥墩延性提升越大,只是刚度略有下降。
In order to solve the problem of insufficient ductility of railway gravity piers in China during earthquakes,the ductility of piers was improved by setting unbonded reinforcement at the bottom of piers. A fully bonded reinforced concrete bridge pier model and two pier models with different lengths of unbonded reinforcement were made for quasi-static tests. The failure state,hysteresis curve,skeleton curve,stiffness degradation,energy dissipation capacity and displacement ductility of the three piers are compared and analyzed. The results show that there are cracks in both the pier body and the pier bottom of fully bonded reinforced concrete,but only one main crack is formed in the pier bottom of the two bridge piers with different lengths of unbonded reinforcement.Under the same loading displacement,the cumulative energy consumption of fully bonded reinforced concrete pier is greater than that of unbonded reinforced concrete pier,and the longer the length of unbonded reinforcement is,the less the cumulative energy consumption of pier is.However,when the pier is finally damaged,the cumulative energy consumption of unbonded reinforced concrete pier is greater than that of fully bonded reinforced concrete pier,and the longer the length of unbonded reinforcement is,the greater the cumulative energy consumption of pier is.The ductility of railway gravity bridge pier can be improved by setting unbonded reinforcement at the bottom of the pier,and the longer the length of unbonded reinforcement is,the greater the ductility of railway bridge pier will be improved,and the stiffness just decreases slightly.
作者
秦训才
丁明波
鲁锦华
刘德安
郝岩
QIN Xuncai;DING Mingbo;LU Jinhua;LIU De′an;HAO Yan(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)
出处
《自然灾害学报》
CSCD
北大核心
2022年第6期134-141,共8页
Journal of Natural Disasters
基金
国家自然科学基金项目(51768036)。
关键词
重力式桥墩
无粘结钢筋
位移延性系数
拟静力试验
抗震性能
gravity bridge piers
unbounded reinforcement
displacement ductility factor
quasi-static test
seismic performance
