Dougong

The wooden joinery is one of the earliest examples of modern mortise and tenon joints,[3][4] using precisely cut notches and grooves to allow for a tight fit.

This process can be repeated many times, and rise many stories, each layer of dougong joinery providing a broader, and more stable surface area for the beam.

Adding multiple sets of interlocking brackets reduces the amount of strain on the horizontal beams, creates elasticity, and allows structures to withstand damage from earthquakes.

[1] Over the next several centuries, and with the increasing importance of Buddhism, more emphasis was placed on decorative elements in wooden joinery, and these initial systems began to take on a more consistent form.

It wasn't until the late Song Dynasty, a time of economic prosperity in much of China, that dougong began to take on its rich decorative characteristics.

The capacity for seismic resistance in dougong joints and systems comes primarily from their ability to dissipate energy between column and beam through friction, compression deflection, rotary deformation,[8] and extrusion.

[1] In essence, the dynamic nature of dougong's construction dissipates seismic energy as it travels through the joints, offering a layer of protection for structures that employ it.

Dougong inside the East Hall timber hall of Foguang Temple , built in 857 during the Tang dynasty
Dougong brackets on an Eastern Han (25–220 CE) era architectural model of a watchtower
A stone-carved relief above a cave entrance of the Yungang Grottoes ( Shanxi province ) showing an imitation of dougong brackets, Northern Wei dynasty (386–535 CE)
Stone pillars made in imitation of wooden dougong and "人-shaped gong" (Chinese: 人字栱) at cave entrance of Tianlongshan Grottoes, Northern Qi .
Colourful dougong supporting a structure at Sagami-ji , Japan
Diagram of bracket and cantilever arms from the building manual Yingzao Fashi (published in 1103) of the Song dynasty