Over the last couple years, we’ve teamed up with the Virginia Council of Trout Unlimited to aid in projects related to their I-81 CARE program. This program started in an effort to conserve, protect, and restore cold-water streams in the valleys and mountains in the I-81 corridor. Reducing pollution in these streams improves the habitat for trout in five major rivers: Shenandoah, James, Roanoke, New, and Upper Tennessee.
So far, we have designed aspects of four bridges in the I-81 corridor. With our two most recent bridges, things got a little fishy when we were asked to design bridge abutments – typically built with concrete – in an area that concrete trucks could not reach. While this challenge initially felt like swimming upstream, we tapped into one of our main priorities when it comes to projects: innovation! By getting creative and thinking outside the box, we found solutions that did not require cast-in-place concrete and could be brought to site on a truck or made on site.
What: Two bridges and box culverts were designed and constructed by others and brought on site. Engineering Solutions was contracted to design the bridge abutments to support the prefabricated bridges/box culverts.
The Challenge: Site location limited the materials that could be used for design purposes. A typical bridge abutment would require a cast-in-place concrete footing and sometimes a concrete retaining wall. However, a concrete truck would not be able to drive to the location of the pour in the allotted 90 minutes after mixing.
Unnamed Tributary (UNT) to Little River – This is a prefabricated box culvert. The box culvert is supported by Redi-Rock retaining wall. The wall/abutment is supported by a compacted stone reinforced with geogrid. All these materials could easily be brought onsite by a truck.
Fox Run – This is a prefabricated steel bridge, designed by others. The bridge is supported by a precast concrete beam on top of a Redi-Rock retaining wall. The wall/abutment is supported by a compacted stone reinforced with geogrid. All these materials could easily be brought onsite by a truck.
To read more about our first bridge design for Trout Unlimited in Pendleton County, WV, click here.