The City of Brownwood rented a Grundoburst 800 G static pipe bursting system from TT Technologies providing 100,000 pounds of thrust and 200,000 pounds of pullback. With only four days of training by TT Technologies personnel, work crews completed 14 projects in a six-month span. During that same time, crews replaced nearly a mile (4,692 feet) of 6-inch to 10-inch clay sewer mains.
To compare pipe material performance during installation, the project team used a mix of 10-inch HDPE and 8-inch and 10- inch Certa-Flo PVC pipe. After working with both, crews overwhelming voiced their preference for PVC based on its reduced installation time.
For example, it takes a three-person crew eight hours to fuse the amount of 10-inch HDPE pipe that the Grundoburst 800G is able to pull in one hour. Plus, the Certa-Flo can be installed as the machine pulls it in the ground, thanks to its unique splinelocking joint system which utilizes an integral bell instead of coupling.
For shallow bursts (less than six feet) where there is approximately 50 feet behind the insertion pit, restrained joint PVC pipe can be assembled as fast as the machine can pull. While the speed of a burst is difficult to estimate due to the specifics of any given project, the actual installation of the main has been between two and seven feet per minute.
Static bursting not only allowed the City of Brownwood to replace 6-inch clay mains with 6-inch PVC, it also increased the size of the main by two pipe sizes. Six-inch clay has been replaced by 8-inch and 10-inch while many of the small diameter mains are currently at a minimum grade for their diameter.
City officials say static pipe bursting proved to be a faster, safer and more cost-effective alternative to open cut methods. Moreover, the process dramatically reduced disruption in neighborhoods and business areas while restoring an aging system which once again can service the needs of its citizenry.
