Pre-stressed box culvert and methods for assembly thereof

A method for assembling a pre-stressed culvert comprising:

• arranging a first plurality of steel tendons to extend between opposite ends of a mold configured to cast a top slab of a three-sided culvert top section;
• casting the three-sided culvert top section having the top slab that is planar, a first sidewall and a second sidewall, wherein the top slab has a first end and a second end arranged parallel to and opposite to each other and a first side and a second side arranged parallel to and opposite to each other such that the top slab is formed as a parallelogram having two obtuse angles arranged diagonally opposite to each other and two acute angles arranged diagonally opposite to each other, wherein the first sidewall extends orthogonally from the first end of the top slab and the second sidewall extends orthogonally from the second end of the top slab;
• and
• applying a compressive force to pre-stress the top slab via the first plurality of steel tendons.

An apparatus, comprising:

• a first plurality of three-sided culvert top sections each having a pre-stressed top slab that is planar, a first sidewall and a second sidewall, wherein each of the pre-stressed top slabs has a first end and a second end arranged parallel to and opposite to each other and a first side and a second side arranged parallel to and opposite to each other such that each of the pre-stressed top slabs is formed as a parallelogram having two obtuse angles arranged diagonally opposite to each other and two acute angles arranged diagonally opposite to each other, wherein the first sidewall extends orthogonally from the first end of each the pre-stressed top slabs and the second sidewall extends orthogonally from the second end of each of the pre-stressed top slabs, wherein each of the pre-stressed top slabs has a plurality of steel tendons extending between the first end and the second end thereby imparting a compressive force to each of the pre-stressed top slabs, wherein each of the pre-stressed top slabs has a plurality of post-tensioning ducts extending from the first side to the second side, and wherein the plurality of three-sided culvert top sections are arranged adjacent to each other such that the plurality of post-tensioning ducts in each of the pre-stressed top slabs are aligned with each other forming a plurality of continuous channels through the pre-stressed top slabs.