passage
A passage or a dole is generally a place that allows passage through something obstructing, i.e. a passage through a wall, a railway embankment or the like. leads through. In particular, passage refers to a structure in the embankment of a traffic route (mostly in railroad embankments ) that enables the flow of water or the passage of animals.
Passages are built to allow smaller streams to pass through a dam, but also to prevent the water that accumulates during precipitation from accumulating on one side of the dam and thus possibly undermining the traffic route. By definition, culverts have a clear width of less than 2 meters and thus differ from overpasses and bridges .
According to the guidelines for the construction of roads - Part: Drainage (RAS-Ew) , culverts should have the following minimum dimensions:
| Under farm roads | DN 400 |
| Under roads (except federal trunk roads) | DN 500 |
| Under overpass ramps on federal highways | DN 500 |
| Under federal highways | DN 800 |
A culvert is a sub-type of passageway that enables a level crossing between watercourse and traffic route. A passage, on the other hand, runs empty when no more water flows in from above.
An eco passage (or eco tunnel ) is a passage through a flood retention basin that is passable for fish and small organisms. They have been built for a number of years to make the waters passable and thus to meet the requirements of the Water Framework Directive, which demand a “good status” of the waters. It can be a closed tunnel or a structure that is open at the top. With normal drainage, the channel remains open. The passage is only closed at high water.
The ecological passage should create somewhat natural conditions. It should have a large cross-section and be sufficiently bright. The flow rate is limited, a minimum water depth is maintained, the bottom profile is rough, and there is a berm (or even two) for animals to roam.
Web links
- Ecological continuity of flood retention basins (PDF file; 371 kB)
Individual evidence
- ↑ DIN 1076 - engineering structures in the course of roads and paths - monitoring and testing . German Institute for Standardization / Beuth-Verlag. 1999.