A flat-top (versus an arch) is a more versatile profile while a flat-top with a pre-stressed top slab is the most versatile profile.
Flat-Top 3-Sided Geometry
- Superior efficient end area (Hydraulics and full-span headroom
- Greater low and high chord bridge control
- Lower rise to span ratio - longer spans without needing a commensurate rise
- Better "fit" for more long-span/low profile sites
Pre-Stressed Flat-Top Slab
- MAXIMUM end area: Longer spans/much more potential end areas than conventional reinforced flat-tops
- GREATEST low and high bridge chord control than...
- LOWEST rise to span ration than...
- BEST fit for long-span/low profile sites than...