Experimental study on the seismic performance of a full-scale two-story traditional timber frame on sloped land

In traditional timber structures built on hilly areas, columns of varying lengths are utilized to accommodate sloped terrain. This structural feature renders these structures more susceptible to seismic damage than structures built on flat land. To investigate the seismic performance of traditional timber structures on sloped land, the quasi-static test was conducted on a full-scale two-story timber frame on sloped land (FSL), while an identical frame on flat land (FFL) was served as a comparative reference. This study analyzed the deformation characteristics, bearing capacity, and energy dissipation capacity of the frame on sloped land, as well as its weak positions and failure mechanisms. The test results indicate that the frame on the upper ground is the weak position compared to the frame on flat land. Short columns of the upper frame have greater inclination angles, leading to larger pull-out lengths of the mortise-tenon joints, and the column foot becomes more susceptible to slipping and lifting. Although the FSL has a greater bearing capacity than the FFL under the same horizontal displacement, it experiences a more significant deformation and is more prone to tenon failure and column foot sliding out of the foundation stone. With excessive deformation, gravity becomes a detrimental factor for structures on sloped land to resist horizontal overturning moments, which would accelerate the collapse of the structure.