Chinese joinery----Dougong (Bracket set)

Chinese joinery can be traced back to 7000 years ago. There are so many kind of Mortise and Tenon joint structures. Pictures showed below are just a few types.

Dougong  or Bracket set

Main function: transferring the weight, increasing the distance, decorative effect and anti-seismic effect
The bracket set is a unique shape in ancient Chinese architecture and is the transition between the pillars and the roof of larger buildings. Its function is to bear the eaves that are spent on the roof, and to concentrate its weight directly on the column, or indirectly to the forehead and then to the column. In general, the construction of bracket set is a very important or monumental building.

The combination of “dougong” is the key to earthquake resistance. This structure is very similar to the modern beam-column frame structure. The nodes of the frame are not just connected, which ensures the stiffness coordination of the building. In the event of a strong earthquake, the spatial structure combined with “dougong” will be “loose” but not “scattered”, consuming the energy from the earthquake, which will greatly reduce the seismic load of the entire house and play a role in earthquake resistance. The roofs of Chinese ancient buildings are more provocative in the form of arches than those without arches, and the seismic capacity is much stronger under the same seismic intensity. The bracket set is a standard component of the combination of the raft and is the intermediary of force transmission. In the past, people have always thought that the arch is an architectural decoration, and the research proves that the arches hold the weight of the eaves evenly, which plays a balance and stability.

Evolution:  3 stages

1, (420-581) The first stage is the Western Zhou Dynasty to the Northern and Southern Dynasties. At the top of the column, there is a bucket arch to support the raft, the beam or the floor raft, and the arch of the outer end of the girders supports the rafts, and the arches are not connected to each other. After the Han Dynasty, he began to use the arch between the columns. It was originally a kind of arch in modern times called the herringbone arch, that is, a fork hand was placed on the forehead, and a bucket was placed on the forehead.

2，The second stage is from the Tang Dynasty to the Yuan Dynasty. The main feature of the arch in this period is that the beams supported by the studs are inserted into the arches, so that the arches and beams are integrated, and the arches become the reinforcing nodes at the intersections. At this time, the bucket arch is no longer an isolated support frame or a provocative component, but an inseparable part of the horizontal frame. This horizontal frame, now called the “laying layer”, is used on the column of the hall structure to play a key role in maintaining the integrity of the timber frame. The existing arch of the Buddha Temple of Wutai Mountain (following pic) in the Tang Dynasty is a typical example of this practice

3, The third stage was from the Ming Dynasty to the Qing Dynasty. Since the Ming Dynasty, the bracket set has become smaller and the outer eaves has become shorter. This is because of the shortage of timber, and also with the improvement of the building technology, the forehead between the studs and the use of the beam slabs enhance the integrity of the frame, so the arch is no longer a force component, but a decorative component.

Applied in modern furniture, using the similar principle in below. Coffee Table

Also derived Luban Lock which traditionally for puzzle game toy, from Luban Lock, applied in modern furniture.