The Aseismic Principle of Chinese Ancient Buildings

    In ancient Chinese architecture, many buildings have experienced many strong earthquakes, which is an earthquake miracle in the history of China and even the world. Flexible frame, platform isolation, bucket arch support and tenons connection are the seismic mechanism of ancient wood structures.
    From bottom to top, the ancient residential wooden structure can be divided into foundation, column frame layer, pavement layer and roof. The wooden frame bears the load of most structures, while the wall only plays the role of division and closure.

    Wood is a flexible material with tensile, bending and elastic resistance. It can well absorb and consume earthquake energy during earthquake, and has strong deformation recovery ability. It can produce large transverse deformation without causing fracture damage under horizontal earthquake.

    The regular and symmetrical layout maximizes the overlap between the center of mass of the building and the center of stiffness of the building, which greatly avoids the torsional effect of the shear effect on the wall when the building is in earthquake. The wooden frame bears and transmits the entire load of the roof, while the wall only keeps the space isolated. Under the action of earthquake, the friction sliding at the joint and the rotation sliding at the bottom of the column reduce the vibration, forming a good isolation and energy dissipation structure system.

    In wood structure buildings, structural members are connected by mortices and tenons. Although the load-bearing area of wood members is weakened and the load-bearing capacity of joints is reduced, the materials in ancient structures are large, which weakens the wood section area to withstand greater loads, thus making full use of the flexibility of semi-rigid joints. The mortise and tenon connection not only changes the characteristics of the structure, but also dissipates the seismic energy due to the friction of the mortise contact surface, which is equivalent to installing a damper on the node, thus reducing the seismic response of the structure.

    Some buildings have multiple columns. When the local seismic force is applied to the buildings, the columns will generate a buffer force between them, so that the buildings will not be damaged by sudden earthquake attacks.
    Some buildings use multi-storey frame, similar to the ring beam of modern buildings, which is a very effective seismic t-section reinforcement method. When the local seismic force is applied to buildings, for multiple groups of triangles, some seismic forces between the support and the beam will be distributed to several small triangles, making the seismic force not concentrated at a certain point.

                                               
    Chinese ancient architecture is a precious heritage of the Chinese nation and an indispensable part of the history of world architecture. The earliest existing ancient wooden structures in China have existed for more than 1000 years, and many buildings still stand after many natural disasters. From the perspective of structural performance, ancient wood structures have important research value. On the one hand, it can improve the maintenance and reinforcement level of ancient buildings, on the other hand, it can also provide some useful references for the design of modern buildings.