Steep Slope Outlet Armoring

Tied Concrete Block Mattress was specified by West Virginia Division of Highways for outlet armoring on a section of roadway with a steep embankment. This was part of a rockfall mitigation project. Stormwater outlets discharge onto a steep 1:1 slope draining into the Tygart Valley River immediately below. Flexamat Plus rolls were manufactured to custom lengths to match the slope lengths. Earth percussion anchors were incorporated throughout the mat.

Concrete was used to transition from the precast headwall to the Flexamat armor. Prior to installing the mat, the area was seeded with a site specific grass seed mix. Within the first growing season, the Flexamat armor will be covered in vegetation.