Glossary · T
Thrust line
Also called line of thrust, thrust lines
The line along which compressive force passes through an arch or vault; the structure stands if a thrust line can be drawn within its thickness.
Rules that use the word
An arch stands if its thrust line fits inside it. Trace the path of the resultant force through the stones from crown to foundations. If a line can be found that stays everywhere within the masonry, the arch will stand; where it touches an edge, a hinge will open, and four hinges make it collapse.
Where it appears in the book
In the chapters The Arch, Frame and Skin.
Nearby in the glossary
Thermal mass · Tholos · Tholos tomb · Thrust · Tierceron · Tile-hanging · Tokonoma · Tondo