AIE provided the prescoping study for the repair and rehabilitation of four culverts in the Henrico and Hanover Counties in Virginia.

The culverts ranged from single barrel to four-barrels and were moderately to severely damaged. The wing walls of three culverts had collapsed and the end portion of one of the culvert barrels had settled and failed. Heavy spalling and scaling were observed in several culverts with exposed reinforcement and delamination. Cracking, rust stains and efflorescence in barrels, head walls, toe walls and wing walls was a common observation throughout. Heavy embankment erosion and undermining had occurred under every toe wall and wing wall. Vegetation had grown around the culverts and drift was obstructing flow into the barrels in two out of the four culverts.

AIE verified the findings at the site and reviewed the latest existing conditions with a site inspection at each culvert. Based on the observations, a prescoping report for each of the culvert was prepared outlining the repair recommendations and the cost estimate for the repair. The structural repairs included, but were not limited to, the following:

• Patching repairs of existing concrete at locations with cracking, spalling, scaling, and delamination; epoxy injection of cracks and coating any exposed reinforcement with epoxy.
• Construction of new wingwall and sections of barrel included constructing new components designed on the basis the latest geotechnical report.
• Recommendations to add a granular, free-draining material with a drainage layer behind the wall to reduce the hydrostatic pressure were added to prevent future occurrences.
• Joint repair between the culvert barrels and the wing walls was recommended at locations where separation had occurred.
• Drilling weepholes along the length of the wing walls was suggested to prevent future occurrences.
• Repair of undermined areas consisted of filling the areas with grout or flowable fill and adding articulated block mattresses below the streambed to prevent any future undermining.
• Channel and slope restoration was recommended using riprap and articulated block mattresses to adjust the channel alignment and facilitate better flow into the culvert.

Other culvert-specific or minor repairs included clearing of drift and vegetation, installation of new security fences, and pipe repair.

AIE provided a preliminary hydrologic evaluation, general plans and sketches showing the existing and repaired condition. AIE minimized the need for new construction or complete replacement, prevented obstruction to traffic and road blockages, and recommended reuse wherever possible to keep the project costs to a minimum.