Guanjiao Sun (管脚榫): The Column-Foot Tenon of Chinese Timber Buildings
Guanjiao sun · Column-foot tenon
Chinese timber columns usually stand on a stone base rather than in the ground. A small tenon at the foot keeps each one in place.
It is the guanjiao sun, literally the tenon that “manages the foot”.
- Chinese
- 管脚榫 · guǎnjiǎo sǔn
- Joins
- Column foot to stone base
- Found in
- Timber-frame buildings
- Size
- About a third of the column diameter
How it works
A short round tenon
The foot of the column is cut to a short round tenon, about a third of the column diameter.
Into the base stone
It drops into a socket (海眼) cut in the top of the stone base (柱顶石). The column’s weight keeps it down and the tenon stops the foot sliding.
Through-base version
Where columns need extra anchoring, a much longer square tenon (套顶榫) passes through the base stone into the foundation below.
How it's made
Step 1Cut the tenon
Cut a short round tenon on the column foot.
Step 2Size
About a third of the column diameter.
Step 3Socket the stone
Cut a socket in the base stone.
Step 4Set the column
Lower the column onto the stone.
Step 5Located
The tenon stops the foot shifting.
Step 6Hidden
Once in place it can’t be seen.
Variations
Through-base tenon (套顶榫)
A long square tenon through the base stone into the foundation, for columns that need more anchoring.
Related joints
Questions
What is a guanjiao tenon?
A short tenon at a column foot fitting a socket in the stone base.
How big is it?
About a third of the column diameter.
Is the column buried?
No, it stands on the stone; the tenon only keeps it from sliding.