Box Culverts for Road Construction

A box culvert is a four-sided structure that channels water past an obstacle or to a subterranean waterway. Typically embedded or surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material. Box culverts, specifically, are four-sided concrete culvers made from precast or cast-in-place concrete in the shape of a box.

Box Culverts are used for drainage purposes by controlling the intake and outtake of water. The culvert creates a tunnel which diverts the water without impeding the flow of traffic on a roadway or highway.  The box culvert will also control flooding or avoid destabilizing the surrounding land area with saturated ground water. Therefore, culverts not only offer safety for the public but also do well to prevent property damage of roads, bridges, and buildings. They can also serve as storage for material handling, service tunnels, corridor links, steam tunnels, stormwater management, wastewater treatment plants, utility trenches and even accommodate pedestrian traffic or animal crossings.

Box culverts are usually installed and built underground, under roads, highways, ramps, bridges, railways, buildings, walkways, and on construction sites. Because of the varied uses and purposes of box culverts, they can be installed anywhere under or above ground, wherever there is a need for draining purposes with a high-flow rate.

Once the site has been excavated, a trench is dug, and then a footer is formed by fabricating and placing  rebar (made of reinforced steel to size) inside the formwork to aid the concrete under-tension. Because concrete is strong under compression but has low tensile strength, the rebar provides a tension reinforcement. Cast in place reinforced box culverts are constructed in a sequence so that the concrete has time to cure prior to the next phase.  Footings are constructed first, then the walls and finally the top slab.  Once all concrete has gained the appropriate strength, the structure is backfilled.

If using precast concrete box culverts, the installation is faster and easier by using a gravity set tongue and groove system, each box culvert end is lowered directly into the receiving joint eliminating the need of tugging or hand-cranking the monolithic box culvert, thus resulting in tighter joints free of subgrade aggregates. Once the culvert is in place and the concrete is cured, the dirt is backfilled and/or covered with aggregate rock on top.  Once completed and covered, the site is ready for a safe and stable construction for the roadway or bridge.

• New Construction – 16’x8’ Double Barrel Box Culvert located on the Mountain Parkway
• New Construction – Multiple 4’x6’ box culverts located on the Mountain Parkway with the longest one over 1200’ in length and has over 200’ of roadway embankment fill over it.
• Extension – 13’-9’ Triple Barrel Extension in Pulaski County
• New Construction – Multiple 5’x3’ box culverts averaging 700’ in length located in Russell County