Arches
Closed Spandrel Masonry Arches
Sprandrel
Retaining
Wall
Arch
Traditional Arch Bridge Construction
Spandrel Retaining Walls
Traditional Arch Bridge Construction
Filled with dirt, up to road level
Traditional Arch Bridge Construction
Spandrel Walls
Filled with dirt, up to road level
Arch
Traditional Arch Problem
• The funicular shape for dead load is a parabola
Traditional Arch Problem
• The funicular shape for dead load is a parabola
• When a point load is applied (say, a horse), it is no
longer funicular. Bending moment is present. Masonry
cannot take tension. It might collapse.
Traditional Arch Solution
• Use A LOT OF DIRT
Traditional Arch Solution
• Use A LOT OF DIRT
• Huge dead loads pre-compress the masonry so much
that the tension from the bending action of a Horse Load
will never overcome the compression
Traditional Arch Solution
• Use A LOT OF DIRT
• Huge dead loads pre-compress the masonry so much
that the tension from the bending action of a Horse Load
will never overcome the compression
• Irony: more dead load strengthens a traditional masonry
arch.
Puzzle
• This arch is indeterminate, yet you can solve it. Why?
Puzzle
• This arch is indeterminate, yet you can solve it. Why?
• It is funicular. M=0, everywhere. So…
Puzzle
• This arch is indeterminate, yet you can solve it. Why?
• It is funicular. M=0, everywhere. So…
You can place pins wherever you want
them, to facilitate analysis.
Puzzle
• This arch is indeterminate, yet you can solve it. Why?
• It is funicular. M=0, everywhere. So…
You can place pins wherever you want
them, to facilitate analysis.