Research on the Correlation of Mechanical Performance and Construction Dimensions Between Chinese Song-Dynasty Official Norms and Locally Constructed Buildings

To investigate the correlation between construction dimensions and seismic performance of Song-dynasty official and local timber structures, two scaled models were subjected to horizontal cyclic quasi-static loading tests. One model is the Goddess Mother Hall of Jinci, and the other is the 7th-grade timber frame described in Yingzao Fashi. The models have similar vertical-layer proportions but differ in bay width, E-fang cross-sectional dimensions, Dou-gong cai-height, and column-top tenon cross-sections. The relative ratio method was used to mitigate the effects of material and scale differences and to focus on the relative contributions of the column-frame and Dou-gong layers to the overall frame. For the Goddess Mother Hall model, which is characterized by a wide bay and thin E-fang, the ratio of the equivalent viscous damping coefficient of the column-frame layer to that of the overall frame remains above 1.0, indicating greater energy dissipation efficiency than the overall structure. However, its stiffness degradation is more pronounced under high vertical loads. The enlarged column-top tenon cross-section and slightly reduced cai height produce a stable increase in the stiffness contribution of the Dou-gong layer, whereas its relative contribution to energy dissipation proportion is smaller than that in the Yingzao Fashi model. The results show that dimensional differences are associated with distinct trends in the stiffness and energy dissipation of the column-frame and Dou-gong layers and that these trends vary with vertical load. This study reveals the coupling relationship between dimensional adjustments and structural performance in official norms and local construction practices, providing a basis and directions for further research on the mechanical effects of dimensional variations in ancient timber structures.