Drainage -Water management

Published on 12 February 2008

Earthworks engineering site management has to deal with the water in different aspects.

Cemented ditch Photo SGTN - Belgian LGV line

Earthworks engineering site management not only has to deal with the water that is contained in the soils, but also that of the water table, and water courses both permanent and temporary, as well as rain water.

Water management has 3 aspects:

•Collection and evacuation of surface water on the access roads of the project, this is mainly rain water

•Collection and evacuation of internal water - in other words, drainage

•Replacement of natural flows, brooks, streams and small rivers

Traversing hydraulic structures: These allow passage of catchment area water from one end to the other of the roadbed. Depending on the capacity needed, these may be large engineering structures, or small structures made of a circular or rectangular channel. They are built on a special foundation and protected by structural infill embankment. They have an upstream structure to collect the water and a downstream one to return it to its natural environment.

Highway drainage: The function of this is to receive and drain the rain water that runs onto the roadbed, as well as the run-off water from the slopes, the catchment area water, and internal water if needed.
Open ditch drains are ditches that are either covered or otherwise with cement, or else curved channels or gutters.
Buried drains are pre-fabricated items, such as traps and pipes: they have a drainage component to collect the water and a component that allows the water collected to flow towards an outlet. These structures need inspection chambers at regular intervals.

Large drainage structures: The function of these is to collect the water that comes from the water tables located in the ground crossed by the earthworks operations

Traversing hydraulic structure Photo SGTN - Belgian LGV