Sliplining in Albuquerque

Courtesy HOBAS Pipe USA

Albuquerque was founded in 1706 as the Villa of San Francisco deAlburquerque. The name has changed over the years and in the 19th century became simply Albuquerque. The original villa is now "Old Town," which is preserved as a historic district and major tourist

Mike Rocco, trenchless manager with AUI Inc., Albuquerque construction firm, says, "In the past 10 years, AUI has been called out to repair interceptor sewer lines that have collapsed, resulting in closed the roads. Most of the pipes that are being repaired are old reinforced concrete pipe (RCP) installed in the '60s, '70s and even as recently as the '80s. We are now working on several projects that take a more proactive approach and result in a win-win situation for the installer and city.

"The benefits of sliplining are many. The overall cost, disruption and time to slipline a segment of pipe are less than traditional remove-and-replace methods. AUI can also open-cut and install pipe, but if given the opportunity to slipline, we prefer it and find it more productive and less intrusive than traditional methods," explains Rocco.

Sliplining has been under way for the FY '06 SAS Larger Diameter Sewer Line Renovation project for the city. The first sliplining run of about 180 linear feet was completed quickly in one morning, Sept. 7. The second run of an additional 315 feet of 48-inch sewer line was sliplined on Sept. 8 after cleaning operations were finished and that segment was completed. The entire project of sewer line rehab consists of approximately 495 feet from manhole to manhole. It ranges in size from 30-inch to 48-inch diameter. This sanitary sewer sliplining was made necessary by the corroded state of the existing concrete line.

HOBAS Pipe USA of Houston, Texas, was chosen as the pipe supplier for several reasons: the pipe's superior hydraulics would increase flow capacity, corrosion resistance and ease of installation. HOBAS centrifugally cast, fiberglass reinforced, polymer mortar (CCFRPM) pipe has been performing reliably in the United States since 1984.

Boyle Engineering Corp. of Albuquerque designed the project. Keith Reed, P.E., project manager for Boyle, described the pipe installation and choice of products: "Due to the fact that a reach of sewer involved in the current rehab, known as the Edith Interceptor, is a major sanitary sewer interceptor, which collects much of the flows from the north central portion of the city, capacity was a huge concern.

"If we had used a 42-inch slipliner pipe in the existing 48-inch line, we would have achieved an improvement in line capacity of between 3 percent and 10 percent. This was good, compared to existing capacity, but still inadequate to meet future needs. The severe corrosion in this line made us confident that we could get a 44-inch ID HOBAS sliplining pipe inside the existing 48-inch ID RCP. We determined that the capacity of the line would likely increase 11 percent to 19 percent or more over the existing capacity."

Since the capacity was so critical, the inside diameter of the liner was maximized. HOBAS manufactured a 44-inch-diameter pipe that is not an industry standard but exactly fills the bill for this project.

"HOBAS offers pipe diameters in 2-inch to 3-inch increments for the majority of the product line," says Richard Turkopp, engineering manager for HOBAS Pipe USA. "This often allows for the greatest flow recovery in slipline rehabilitation."

Since the fit was so tight, a mandrel (proof section) of HOBAS pipe was pulled through the line before beginning the relining process. The mandrel was an actual section of the sliplining pipe.

HOBAS has been supplying pipe to the sliplining market since the late '80s and continues to be the pipe employed by many owners, engineers and contactors because of its many unique attributes. The pipe is inherently corrosion resistant, rugged, solid-walled, and provides a long, maintenance-free life. The company has a proven track record in the United States, with nearly a million feet of pipe installed by sliplining around the country.

Prior to installing each new sewer reach in Albuquerque, AUI noted the location of all sewer services and identified which were in service and which were not. Those no longer in service were abandoned and active services reconnected after sliplining. Closed circuit television inspection of the pipeline was completed pre-installation. After sliplining, a final video will be completed.

As part of the contractor's submittals, verification of the design and past performance of the sliplining pipe was required. AUI submitted complete design calculations, joint details and verification of the required 10-year history of successful installations for sliplined sanitary sewers in the United States.

AUI was looking for the best pipe to the company to slipline and complete the project on schedule and within budget. Rocco says, "AUI has experience with several products and prefers the HOBAS pipe because of its stiffness and strength that provides the ability to make long distance pushes.

AUI has been installing HOBAS in Albuquerque since 2004, both by sliplining and by direct bury. As AUI's trenchless manager, Rocco has become familiar with most of these types of jobs and is responsible for overseeing those that are done by AUI's specially trained crews

He explains, "Most of the collapse happens after hydrogen sulfide has eaten the cement away from the inside of the RCP and it fails and collapses.

"Sliplining is a major plus for municipalities because it offers a permanent solution completed in less time and provides a permanent solution to the problem, not just a temporary fix."

HOBAS pipe is manufactured in sizes from 18 inches to 110 inches in pressure and non-pressure classes. For more information, contact HOBAS at (800) 856-7473, via e-mail at info@hobaspipe.com or online at www.hobaspipe.com .