新型装配式预应力混凝土框架梁柱节点抗震性能试验研究

Experimental study on seismic behavior of novel prefabricated prestressed concrete frame beam⁃to⁃column joints

新型装配式预应力混凝土框架结构,通过后张预应力钢绞线和预应力螺纹钢筋产生的预压力实现梁柱节点连接。为研究该节点的抗震性能,设计并制作了4个试件,对其进行拟静力试验,分析了其破坏形态、滞回特性、刚度退化、变形能力、承载力及耗能能力,探讨了剪跨比、截面预压应力对其抗震性能的影响,并建立了梁端接缝截面受弯承载力计算方法。研究结果表明:各试件均发生了梁端弯曲破坏,滞回曲线呈反“S”形或饱满“弓形”,位移延性系数均大于3,强屈比在1.07~1.33之间,整体表现出较好的耗能能力、变形能力;剪跨比对节点的抗震性能影响不明显;截面预压应力分布对节点抗震性能有一定的影响,梁端接缝截面均匀受压时,其耗能能力、位移延性等综合抗震性能相对最优。

The novel prefabricated prestressed concrete frame structure realizes the connection of beam⁃to⁃column joints through the pre⁃compress generated by post⁃tensioned prestressed steel strands and prestressed twisted steel bars.In order to study the seismic behavior of this joint,the pseudo static test is carried out on four specimens to examine the failure modes,hysteretic characteristics,stiffness degradation,displacement ductility,bearing capacity and energy dissipation capacity,and the influences of shear span ratio and section prestress on its seismic performance are also discussed.A calculation method for the bending bearing capacity of the connection is established.The test results indicate that all specimens have bending failure at the beam end.The hysteresis curve is inverted“S⁃shaped”or plump with“bow⁃shaped”.The displacement ductility coefficients are greater than 3 and the strength yield ratio of each specimen is between 1.07 and 1.33,which show that the specimens have excellent energy consumption ability and deformability.The shear span ratio has no obvious effect on the seismic behavior of the joints.The distribution of section prestress has a certain influence on the seismic behavior of the joints.When the connection is under uniform prestress,the comprehensive seismic performance such as energy dissipation capacity and displacement ductility is relatively optimal.