软索连接装配式混凝土圆孔墙抗震性能试验研究

Experimental simulation on seismic behavior of prefabricated concrete circular-hole wall connected by flexible cables

为研究软索连接装配式圆孔剪力墙的抗震性能,分析翼墙对主墙的影响,设计一字形、L形、工字Ⅰ形和工字Ⅱ形4类共8个足尺装配式圆孔剪力墙试件,进行拟静力试验,通过对试验现象和数据进行分析,研究构件的破坏形态、特征荷载、变形性能、受剪承载力等特性。结果表明:采用软索连接的翼墙能有效提高主墙的抗裂性能,有效避免主墙沿圆孔的竖向裂缝,同时能改变主墙的应力分布和破坏形态;翼墙能够有效提高主墙的屈服荷载和极限荷载,但对屈服位移、延性的影响不明显;墙体弹性层间位移角能够满足我国规范中对剪力墙的要求,弹塑性层间位移角较小,宜提高软索锚固设计;墙体中的圆孔会大大降低墙体的受剪承载力;通过规范公式对该类型墙体进行受剪承载力计算,发现多数墙体的计算值远大于试验值,基于试验结果,建议将规范公式进行0.5倍折减后,再用于该类型墙体的受剪计算。

In this study,the seismic performance of prefabricated reinforced concrete(RC)shear walls with circular holes and flexible cable connections is investigated,with focuses on the wall flange to web effects.Totally eight full-scale walls of typical line shape,L-shape,Ⅰ-shaped type-Ⅰ and Ⅰ-shaped type-Ⅱ are tested under quasi-static loading schemes for their failure mechanisms,characteristic loads,ductility,and shear capacity.The results show that with flexible cable connections,shear wall flanges can improve the crack resistance of the webs which specifically mitigates vertical cracking along the circular holes in the web,and shear wall flanges change the stress distribution and failure mechanism of the web which effectively improve the web’s yield and ultimate capacity of the walls.However,wall flanges have negligible effects on the yield displacement and ductility.Even though the resultant elastic story drift is small enough and meet the code requirements,flexible cable anchorage in prefabricated RC circular-hole walls still needs being optimally designed.Since circular holes can significantly reduce the in-plane shear capacity of shear wall,the experimental shear capacity is 50%lower than the code-specified shear capacity,which shall be reflected by the current Chinese code.