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The bracket arm also extends inside the building, where it either supports an interior frame member

or is held in place by one. Often a tie-beam takes the place of one bracket arm and thus ties the

bracket set to an interior part of the structure. Corner bracket sets carry a single or double hip beam.

When sets are connected with transverse and longitudinal ties, they strengthen the frame.

Besides holding up the roof, bracket sets also stiffen and brace the upper wall section. This upper

wall follows the perimeter columns and adds height from the architrave level to the roof. The height

of the upper wall above the architrave is about half of the column height, a 1:2 ratio. A 20-ft.-tall

column means a 10-ft.-tall upper wall. The upper wall is constructed by stacking horizontal beams

on top of each other. Bracket arms and transverse tie-beams perpendicular to the wall plane lap

these upper wall beams and lock the wall in a vertical plane. Bracket sets also connect the upper wall

to the roof structure and to the interior frame. They keep the upper wall from rotating and falling

off of the columns. The second function of brackets is to stay the upper wall section.

Bracket arms under beams transfer loads back to columns and reduce the span of beams between

columns. This third function of brackets is not very obvious visually, but as Chinese forests were

depleted, beam size and span became an important issue.

Bracket arms, blocks, and cross yokes parallel to the wall plane increase the number of bearing

surfaces for framing members such as purlins and longitudinal tie-beams and increase the number

of lateral connections. The cross-yoke looks like a small bracket arm and typically gives three points

of support to the longitudinal member that it holds. Especially where purlins or ties-beams join end

to end, it is helpful to have more bearing surface underneath the joint. The fourth function of

brackets is to strengthen the frame by increasing the number of connections between members.

All these joinery connections unify the frame. They make the frame more resilient without

necessarily becoming rigid. This joinery is flexible and even a bit elastic, partly because wood is by its

nature resilient, and partly because, while small woodwork requires tight-fitting joinery, large-scale

building uses loose joinery. Chinese building philosophy is similar to T’ai Chi. The force of an

attacker, or earthquake, is not confronted or resisted. A person sidesteps the attacker. A building

flexes and lets the force pass by.

Bracket sets in large buildings can number tens of thousands of pieces, all connected by joinery.

Bracket pieces are small relative to the size of framing members. Building with brackets is an

efficient use of materials. Brackets sets may thus offer a shock-absorbing capacity. In a region as

prone to earthquakes as Asia, brackets may help buildings to survive.