Research on the Lateral Resistance of Column Frames in the Tang Dynasty: A Case Study of the Straight Tenon Joints Under Varied Vertical Load Levels

Column frames connected using Tang Dynasty straight tenon joints represent a unique structural system characterized by historical significance and architectural ingenuity. Consequently, an experimental model, resembling the straight tenon joint style of the Tang Dynasty Foguang Temple East Hall, was constructed using two square beams (Fangs) and three columns in this study. Through low-cycle repeated load tests, hysteretic curves, stiffness degradation, energy dissipation capabilities, and certain other indicators were analyzed under four distinct vertical load levels. The results reveal that increasing the vertical load can effectively improve the fullness of the hysteresis curve and the peak restoring force of the column frame. Moreover, a pronounced pinch effect was found in the hysteretic curve of the column frame, indicating that a higher vertical load can strengthen the frame’s restoring force within a specific range of horizontal displacement, thereby maintaining its structural stability. With increasing vertical loads, the maximum restoring force and stiffness of the column frame are elevated, enhancing the structure’s energy dissipation capacity and partially mitigating its stiffness degradation. However, it is noteworthy that as the horizontal load displacement increases, higher vertical loads result in a more rapid decline in the frame’s restoring force, reducing the effectiveness of improving the energy dissipation capabilities of the column frame.