不同减隔震措施下平板支座抗震性能试验研究

Experimental study on seismic behavior of roof joint with different seismic isolation measure

为探究不同减隔震措施对短边距混凝土网架平板支座的抗震性能和破坏模式的影响,分别针对不同混凝土边缘距离以及采用不同减隔震措施的四个平板支座缩尺试件进行拟静力加载试验,对平板支座破坏模式、滞回曲线、箍筋应变进行分析。试验结果表明:平板支座的运动伴随着平动和转动。当混凝土边距不足时,边缘混凝土在压剪作用下,会发生冲切破坏。开长孔支座能较好的释放水平位移,并且对锚栓约束较弱,使其受力较小,从而减轻了边缘混凝土的受力。对采用橡胶垫板的支座,混凝土边缘未发生破坏,原因是橡胶垫具有良好的变形能力,可以释放支座的位移和转角,使得边缘混凝土受力较小。因此,针对混凝土边缘距离较短的平板支座节点,为防止混凝土发生边缘破坏,可采用开长孔支座,但需要对孔长进行合理的设计。采用橡胶垫支座也可避免混凝土发生边缘破坏,橡胶垫板可按照我国相关设计规范进行设计。

In order to investigate the effect of different seismic isolation measures on the seismic performance and failure modes of roof joint with short edge concrete,four specimens with different concrete edge distances and different seismic isolation measures were designed.Quasi-static loading tests were carried out to analyse the failure modes,hysteresis curves,and stirrup strains of roof joint.The test results show that the motion of roof joint is accompanied by the translational motion and rotation.If the edge distance of concrete is too small,edge concrete will be punched and destroyed under pressure and shear force.The roof joint with loose hole of base plate can release the horizontal displacement of the roof joint.The stress of anchor rod with loose hole of base plate is smaller,thereby reducing the edge damage of the concrete.The edge concrete was excellent without damage if roof joint using rubber bearing.The reason is that the rubber bearing can release the displacement and rotation of the roof joint,and the stress of edge concrete is small.For the roof joint with small edge distance of concrete,the hole length of base plate can be reasonably designed in order to prevent edge failure of concrete.And rubber bearings can also be used,which can be carried out in accordance with relevant design specifications in China.