Low Level Crossings
The low level submersible bridge is ideal for sites where it is not viable for a bridge to be above the required flood level. These slim profile concrete bridges are built for HNHO-72 loading and withstand being over-topped regularly. They have the advantage of keeping the stream bed clear allowing fish passage which is seen favourably from an environmental perspective.
Low level concrete - Submersible
- Simple installation
- Robust units
- Low profile
- Adaptable to different crossing widths and alignments
- Designed to allow for debris and hydraulic loads
- Can be relocatable in some cases
- Can be installed at low levels to avoid need for building consent
- Can be used (site dependent) in replace of a larger span bridge, which requires to clear flood heights, making it a more cost-effective solution
- Seen as a favourable solution by local Councils as the bridge is designed to maintain flow and fish passage and considered a relatively low risk from a flood hazard perspective.
- Can be designed to full highway HN HO 72 loading providing access to heavier, more frequent traffic.
- Suitable for heavy vehicles 0.85 HN with a maximum axle loading: up to 7.5 tonne single axle and 15 tonne dual axle loading
- Generally over top multiple times per year
- Appropriate for sites with good rock layer (not erodible soil type)
- Appropriate for low catchment areas
- If high catchment area – is there appropriate area for spillway
- Approaches are likely to wash out in flood event
HO HN 72