Elliptical Stormwater Pipe Rehabilitation

Chanllenge

City officials in central Texas needed to replace 150 LF of corrugated metal stormwater pipe that had multiple failures and a collapsed section underneath the property of a homeowner on a busy, city street. The 58” x 36” elliptical-shaped pipe was located underneath multiple constituent properties in a densely populated neighborhood, creating a situation where access to the pipe was extremely limited. To dig and replace the pipe would be a messy, time-consuming, and costly task for city maintenance crews and a great inconvenience to the property owners. Further, the elliptical shape of the space reduced the amount of viable trenchless methods to repair the pipe. The rehabilitation process would require a custom-shaped liner engineered to withstand the load in the absence of an existing host pipe.

Solution

Fuquay crews were able to clean and remove debris from the stormwater pipe via man-entry and cut out the failed sections of the pipe. The crews were also able to clean and stabilize the collapsed section of pipe well enough to pull the Alphaliner into place without damage to the liner or equipment. Additionally, they were able to navigate the accessibility issues to get air introduced for inflation. After the curing process, minimal annular space remained between the existing pipe and the new fiberglass liner which dispelled any potential capacity issues. The concrete sections surrounding the pipe were repaired to ensure a smooth transition of flow into and out of the stormwater pipe. Within 48 hours of arrival on-site, Fuquay crews had rehabilitated the pipe and demobilized without disturbing a single property owner.

Key Benefits

• Limited Access

• Minimal Disruption

• Innovative Solution