宋、清式斗栱低周反复荷载试验研究

Experimental study of low-cycle loading test on Song-style and Qing-style dougong

对六朵宋式斗栱及一攒清式斗栱足尺模型进行了低周反复荷载试验研究。由试验结果可以看出,斗栱像球形铰一样具有较好的转动能力,而且层间滑移现象并不明显。大部分斗栱模型发生了斗底的脱榫或折榫破坏,而上部构件的整体性较好,基本未发生破坏。试验得出了斗栱的滞回曲线、骨架曲线,由于里跳和外跳不对称,所以横向加载时的滞回曲线不对称。还探讨了不同形制及铺作数对斗栱抗震性能的影响,宋式斗栱横向的抗侧刚度和水平承载力略大于纵向的,且随着出跳数增加而减小;清式斗栱由于尺寸较小,抗侧刚度和承载力均较小。

Experimental study was carried out on low-cycle loading test of seven full-scale dougong models, including six Song-style dougong models and one Qing-style dougong model. Results show that dougong has well rotation capacity as spherical hinges, which seldom slip interfacial. Most dougong models failed due to pulled out or broken of nethermost tenon; while the upper members worked as a whole and hardly got broken. The hysteretic curves and skeleton curves of these models were obtained. Due to asymmetry of inside and outside parts of dougong, hysteretic curves under horizontal loads were asymmetrical. The influence of different forms and layers of dougong on its seismic performance was also discussed. The lateral stiffness and load-bearing capacity of Song-style dougong, which decreased as the layers of dougong increased, were slightly larger when under horizontal loads than under vertical loads. Lateral stiffness and load-bearing capacity of Qing-style dougong were small due to its small size.