江南地区宋元时期传统木构铺作对结构整体抗连续倒塌性能的影响

为了研究江南地区宋元时期传统木构建筑的抗连续倒塌性能,选择典型实例,通过三维扫描测绘建立实例及对应无铺作大殿的有限元模型,并进行抽柱后结构的空间推覆分析,研究铺作在空间木构架连续倒塌时对结构传力路径及极限承载力的影响。结果表明:对于江南地区宋元传统木构建筑,当某根柱突然失效时,周围的梁、枋、槫、阑额等横向构件可以提供多个方向的拉结,防止结构进一步倒塌;铺作的存在对结构整体抗连续倒塌性能有明显提升,铺作之间的横向构件在倒塌时联合周围构件形成"组合桁架"共同受力,提供了有效传力路径和整体性拉结,使得局部柱失效后结构的极限承载力相对于无铺作结构提升约30%～50%;檐柱和角柱的失效更容易引起木构的连续性倒塌。

Effect of Pu-zuo on progressive collapse of Chinese ancient timber buildings of Jiangnan area in the Song & Yuan Dynasties

To study performance of the Chinese ancient timber buildings of Jiangnan area in the Song & Yuan Dynasties in the progressive collapse resistance, the finite element models of a typical Chinese ancient timber building and a corresponding building without Pu-zuo were established by the three-dimensional scanning survey for further pushdown analysis, through which their main collapse mechanism and the effect of the Pu-zuo against the progressive collapse were studied. The results show that: For Chinese traditional timber buildings of the Jiangnan area in the Song and Yuan Dynasties, when a column suddenly fails, the lateral components around it can provide multi-directional linkages to delay or prevent the progressive collapse.The existence of Pu-zuo improves the progressive collapse resistance of the whole structure. A "truss-like" structure is formed among the Pu-zuo to transfer the extra load when the progressive collapse happens, which effectively enhance the linkage and strengthen the alternative load path in the structure. Thus, compared with the timber building without Pu-zuo, the bearing capacity of the typical Chinese ancient timber building with Pu-zuo significantly rises, with increasing by 30%~50%; Compared with the failure of the middle columns, the failure of the side columns tends to result in the progressive collapse of the building.