装配整体式梁柱节点的抗震性能对比研究

Comparative Study on Seismic Performance of Highly Efficient Assembled Beam-Column Joints

目的 研究预制柱纵筋间距放大后装配整体式T型节点和十字型节点的抗震性能,为工程设计提供依据。方法 对5个足尺梁柱节点试件进行低周往复荷载试验,通过对比各试件的滞回曲线、骨架曲线和位移延性等,研究了节点类型、柱纵筋间距和轴压比对梁柱节点抗震性能的影响。结果 装配式节点均发生梁端弯曲破坏,预制柱和节点核心区未见明显破坏,破坏主要是预制梁端底部纵筋屈服和梁端底部混凝土压碎脱落;楼板加强了叠合梁的抗负弯矩能力,叠合梁上部现浇混凝土和预制混凝土交界面出现明显的水平剪切裂缝;柱纵筋间距放大后,与对比试件相比,T型节点的承载力提高了9.2%,十字型节点的承载力提高了1.3%。结论 柱纵筋间距放大试件的延性和耗能能力与对比试件相差不大,柱纵筋间距放大对梁柱节点的抗震性能影响不大;十字型节点和T型节点位移延性系数相差不大。

The seismic performance of precast T-shaped joints and cross-shaped joints after the longitudinal bar spacing of prefabricated column is enlarged is studied,which provides a basis for practical engineering.low cyclic reversed loading tests were carried out on five full-size beam-column joint specimens.By comparing the hysteretic curve,skeleton curve and displacement ductility of each specimen,the effects of three parameters,joint type,longitudinal bar spacing of prefabricated column and axial force ratio,on the seismic performance of the beam-column joint were studied.The beam end bending failure occurred in all the prefabricated joints,but no obvious failure was found in the core area of the prefabricated column and the joint.The main failure was the buckling of the longitudinal bar at the bottom of the prefabricated beam end and the crushing of the concrete at the bottom of the beam end.The floor slab strengthens the negative moment resistance of the superimposed beam,and obvious horizontal shear cracks appear at the interface of cast-in-place concrete and precast concrete in the upper part of the superimposed beam.The bearing capacity of T-shaped joints and cross-shaped joints is increased by 9.2% and 1.3% respectively.The ductility and energy dissipation capacity of the specimens amplified by column longitudinal bar spacing are not much different from those of the contrast specimens.The amplification of the longitudinal bar spacing of prefabricated column has little effect on the seismic performance of beam-column joints.There is little difference in the displacement ductility coefficient between the T-shaped joint and the cross-shaped joint.