Dougong, also known as Dougong, douke, Tuo, Pu Zuo, etc., is a unique structure of Chinese architecture. In the top of the column, between the architrave and the eaves purlin or between the frames, the arched load-bearing structure protruding from the layers added on the architrave is called the arch, and the square wood block padded between the arch and the arch is called the bucket, which is collectively called the bucket arch.
The emergence and development of bucket arch has a very long history. The example of Dougong. The copper scheme of four dragons and four phoenixes unearthed in Zhongshan state as early as the Warring States period.
Function of bucket arch:
1. Load action
It is located between the column and the beam. The load transmitted from the roof and the upper frame should be transmitted to the column through the bucket arch, and then transmitted to the foundation by the column. Therefore, it plays the role of connecting the preceding and the following and transmitting the load.
2. Increase distance
When it is lifted outward, it can lift the outer truss sandalwood out of a certain distance, so that the eaves of the building are more far-reaching, and the shape is more beautiful and spectacular. It is used as the basic measure of component size for a long time after it is formed.
3. Decorative function
It has exquisite structure and beautiful shape, such as bonsai and flower basket. It is also a good decorative component. Later, the bucket arch gradually became decoration (later, the brick wall was adopted, the eaves became closer and the function was reduced), which was also a sign to distinguish the architectural grade. The more noble the architecture, the more complex and prosperous the bucket arch.
4. Seismic action
The combination of tenon and mortise is the key to earthquake resistance. This structure is very similar to modern beam column frame structure. The joints of the frame are not rigid, which leads to the stiffness coordination of the building.