Abstract:
An experimental study is presented on the column foot joints in multi-storey traditional Chinese timber structures, the joints' deformation mechanisms and mechanical properties were investigated and evaluated, respectively. A simplified analytical model was further established upon the load-bearing mechanisms of the column foot joints and the characteristics of rocking rigid body. The research indicated that: the upper floor column foot joint is mainly wood grain embedded deformation and the deformation is significant, while the bottom column foot joint is mainly wood column parallel grain compression deformation, but the deformation is small. With the increase of vertical compression loading, the moment-resisting capacity of the column foot joints increased. However, the hysteresis curves of the column foot joints in upper stories exhibited serious pinching effect, the strength degradation coefficients were between 0.8 to 0.9; the hysteresis loops of the column foot joints in ground storey overlapped each other, and the strength degradation coefficients were greater than 0.95. The energy dissipation capacities of the joints in upper stories increased with the increase of the vertical compression load, and the increase amplitude of the joints with low vertical stress was more significant. The simplified model agreed well with experimental curves and could be utilized in the structural analysis of multi-storey traditional Chinese timber structures.