Self-anchored suspension bridge
A self-anchored suspension bridge is a suspension bridge type in which the main cables attach to the ends of the deck, rather than directly to the ground or via large anchorages. The design is well-suited for construction atop elevated piers, or in areas of unstable soils where anchorages would be difficult to construct.
- Difference between types of bridges
- Suspension bridge with the main cables attached to the ground (black squares)
- Self-anchored suspension bridge; the main cables are attached to the end of the road deck
Three self-anchored suspension bridges in Pittsburgh | |
| Ancestor | Suspension bridge |
|---|---|
| Related | None |
| Descendant | None |
| Carries | Pedestrians, automobiles, trucks, light rail |
| Span range | Medium |
| Material | Steel rope, steel eyebar, concrete spar, post-tensioned concrete deck |
| Movable | No |
| Design effort | high |
| Falsework required | Usually |
The load path of the self-anchored suspension (SAS) bridge converts vertical loads into tension forces in the main cables which are countered by compressive forces in the towers and deck. The system balances forces internally without external anchorage requirements making it suitable for sites where large horizontal forces are difficult to anchor. This is similar to the method used in a tied-arch bridge where arch member compression is balanced by tension in the deck.