预应力平板-异形柱结构抗震性能试验研究

Experimental study on seismic behavior of structure having prestressed slabs and columns with special section shape

目前关于混凝土异形柱、短肢剪力墙及节点的抗震性能研究工作已开展得较为充分,但对它们与无黏结预应力平板所组成的整体结构的抗震性能还不甚清楚,为此采用拟静力试验方法对2个六柱一板单层整体结构模型在水平低周反复荷载作用下的开裂破坏全过程,以及各项抗震性能指标进行了试验研究。模型缩尺比例为1∶2.5,2个试件的板采用了不同的预应力筋布置方式,异形柱和短肢墙采用了不同的抗震等级、截面尺寸和配筋率。结果表明:2个试件的各构件开裂时间和裂缝程度有所不同,但各构件的屈服破坏顺序是一致的,都形成了梁端塑性铰-板屈服铰线屈服机构,最终为延性破坏。滞回环具有典型的梭形特征,后期抗力与刚度下降平缓,变形和耗能能力良好,梁柱节点构造措施可靠,一字形短肢墙的早期裂缝控制应进一步研究,建议对其采用较高的抗震等级设计。

Now the study on the concrete column with special section shape, the short-leg wall and the joint is extensively developed. However, when they are considered with the unbonded prestressed slab together, the seismic performance of the whole structure has not been enough clarified. So we adopted the pseudostatic test to study and analyze the whole cracking-failure process and each seismic performance index, based on two 1： 2.5-scale single - floor structure models of six columns-one slab under low-frequency reversed cyclic loading. The prestressed reinforcements in two specimen slabs were adopted with different collocations. The column with special section shape and the short-leg wall have different seismic grades, section dimensions and reinforcement ratios. The result indicates that the crazing time and the crack degree of each member for two specimens are different, but the yield fail- ure order of each member is same, all form yield mechanism with beam end plasticity hinge and slab yield hinge line, and finally is ductile failure. The hysteretic loops present the typical shuttle-form character, the resistance and the rigidity decline gently, and the deformation and the capacity of dissipating energy are all right. The tectonic measure of beam-column joint is dependable ; the control of forepart crack should be more studied fol ＂--＂ shaped short-leg wall, and the authors suggest adopting higher seismic grade to design it.