Box culvert without rib stiffeners

DETAILED DESCRIPTION OF THE INVENTION The instant invention comprises a unique, unreinforced structure for box culverts with curved corners having a width (span) which greatly exceeds the height (rise) of the culvert.
Such culverts are formed from corrugated metal sheets having deep vertical corrugations and sufficient wall thickness wherein additional stiffening members are not required.
Further description of the invention may be facilitated by reference to the attached figures.
FIG.
5 is an elevational view of a box culvert having a width which is about two to three times its height.
The box culvert of this invention may be up to about 20 feet or more in width (span) with a height (rise) of up to about 10 feet.
Corrugated box culverts of this invention, as well as conventional rib-stiffened box culverts are designed for low, wide openings with periodic large water flow requirements.
Box culvert heights (rises) of from between about 11/2 to about 5 feet are typical.
The rise may be greater, however, a more conventional arch-type culvert will generally be utilized when the span-to-rise ratio requirement is not restricted.
The box culvert illustrated in FIG.
5 is unique inasmuch as the structure is made from deeply corrugated metal sheets which do not require additional stiffening ribs.
The corrugations of the sidewall members 10 and 11 run vertically.
The roof member 12 is also made from the same type of metal sheet with deep corrugations which nest into those of the sidewall members 10 and 11.
Sidewall members 10 and 11 are preferably inclined inwardly towards one another at a slight angle from the vertical, i.
e.
, the span is greater at the base of the vertical members than at their top.
The sidewalls comprise a lower foundation engaging section 13 which is essentially linear and a corner portion 14 which is a curved or curvilinear portion.
The roof member 12 has a slightly curved margin portion 15 which overlaps the free end of the curved portions 14 of sidewalls 10 and 11.
The roof member 12 is, similarly to the sidewall members, composed of a number of sheets of corrugated metal bolted together to form an essentially flat roof