装配式桥梁下部结构的抗震性能

Seismic performance of prefabricated bridge substructure

为研究装配式桥梁的抗震性能,制备12组灌浆套筒试件进行单向拉伸试验,根据现浇结构钢筋混凝土黏结应力-滑移本构关系式拟合套筒黏结滑移曲线,拟合黏结滑移曲线与试验黏结滑移曲线基本相同;采用软件ABAQUS建立2组装配式桥梁下部结构有限元模型和1组现浇桥梁下部结构有限元模型,设定参数,对装配式桥梁下部结构进行数值模拟,从破坏形态、滞回曲线、骨架曲线、累积耗能、刚度和延性多角度对比分析装配式桥梁下部结构的抗震性能。结果表明:灌浆套筒连接的装配式桥梁下部结构的破坏形式主要为弯曲破坏,3组模型的滞回环形状为梭形或弓形,骨架曲线下降段斜率相差较小,刚度退化和延性系数基本一致,表明灌浆套筒连接的装配式桥梁下部结构具备良好的抗震性能。

To study the seismic performance of prefabricated bridges,12 groups of grouted sleeve specimens are prepared for unidirectional tensile tests.Based on the fitting of the bond stress-slip constitutive relationship of cast-in-place reinforced concrete structures,the bond slip curve of the sleeves is obtained,which closely resembles the experimental bond slip curve.Software ABAQUS is used to establish finite element models for 2 groups of prefabricated bridge substructures and 1 group of cast-in-place bridge substructures.Parameters are set to numerically simulate the prefabricated bridge substructures.The seismic performance of the prefabricated bridge substructures is analyzed from multiple angles,including failure modes,hysteretic curves,skeleton curves,cumulative energy dissipation,stiffness,and ductility.The results show that the failure mode of the prefabricated bridge substructure connected by grouted sleeves is mainly bending failure.The hysteretic loops of the three models are shaped like a shuttle or an arch.The slopes of the descending segments of the skeleton curves differ only slightly,and the stiffness degradation and ductility coefficients are basically consistent,indicating that the prefabricated bridge substructure connected by grouted sleeves possesses good seismic performance.