What is a box culvert?
A box culvert is a monolithic, flat-sided precast concrete structure with walls at 90 degrees to the floor and roof. Box culverts were introduced to provide an easily-installed conduit for culverting of watercourses where construction can create an obstruction to the natural flow path.
Box culverts can also be used for attenuation of surface water as part of a sustainable drainage system (SuDS), horizontal tunnels and subways, sewers and access shafts. Smaller box culverts can also be used for dry networks including cabling.
Box culverts are available in many different size and shape configurations. Square or rectangular units can be used as single or multi-unit runs, giving excellent structural and hydraulic performance. Extensive design possibilities can be achieved with the use of end walls, access points, vent holes, inlets, outlets, double rungs, splayed ends, starter bars and threaded sockets, a range of different inverts, low-flow channels and dished inverts.