Working Through Challenges, Clay Pipebursting Project Exceeds Expectations

By Jeff Griffin, Senior Editor | July 2009 Vol. 64 No. 7

“In one portion of the installation, alignment problems were encountered with an existing 40 year old, six-inch water main composed of asbestos cement pipe (ACP) which meandered adjacent to the sewer alignment. The ACP water main began breaking at multiple locations apparently due to pipe movement caused from soil displacement during the pipe bursting operation. The city decided to relocate the entire portion of the ACP waterline which was within six feet of the existing sewer pipe. The decision to relocate this existing water line would have been the same if an open cut construction method was elected over pipebursting. There were no other major conflicts with utilities and no service disruptions during construction, and all utilities that were in pit areas were supported and maintained at all times during construction.

“Production rates were affected by unknown conditions such as a cementitious cap, dry dense soil conditions adjacent to the existing trench, and the existing sewer pipe alignments.”

Fast turnaround

Haas said the project was completed in nine months, including all pipebursting and one jack and bore segment.

"Production via pipebursting exceeded everyone's expectations," he said. "The contractor estimated that the project would have taken at least 12 months to complete if it had been open cut. Static pull segmented pipebursting technology using clay jacking pipe proved to be very successful and cost effective for upsizing a capacity deficient sewer."

In addition to actual construction cost savings, pipebursting on the project did not interrupt sewer services which were maintained by bypass pumping operations. Pavement removal and replacement costs were reduced by approximately two thirds as only the bursting and receiving pit excavations required pavement removal and replacement which reduced disruption of traffic and inconvenience to local residents and businesses.

FOR MORE INFORMATION:
Project Engineering Consultants (PEC): 602-906-1901, www.pecaz.com
TT Technologies, (800) 533-2078, www.tttechnologies.com
National Clay Pipe Institute, (262) 248 9094, www.ncpi.org.
Mission Clay No-Dig Pipe, (210) 863-3350, www.no-dig-pipe.com
Kiewit Western, (303)979-9330, www.kiewit.com

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