Proper Prep, Execution Cures First-Time Bursting Butterflies

16th In A Series From The IPBA
By Matt Timberlake, President, Ted Berry Trenchless Technologies Team LLC | November 2012, Vol. 67, No. 11

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In the design stages, the owner called an IPBA contractor and asked simply "How can this be done by pipe bursting, what are the considerations, and what could go wrong?" This was a very straight forward question and one that deserved a comprehensive review of the project and burst plan. In the site evaluation, it was clear to the contractor that pneumatic pipe bursting would be the preferred method and using the IPBA guideline was able to show in detail the process and considerations that would be part of the planning of a Class C pneumatic pipe burst. The 24-inch pipe required a new 24-inch HDPE pipe be put installed and the owner had not installed HDPE pipe before in a continuous application. Therefore, it was very important to review the area needed for fusing and staging of the pipe as well as insertion into the pit which would be located in a way to minimize disruption to the site.

Picture clears
Through the preliminary design and planning, the owner began to get a picture of what the project would look and feel like and what benefits and challenges he would need to be prepared to deal with. Contingency plans were discussed and risk properly allocated in the contract documents.

On day one of the project the owner began to gain a sense of reality as 50-foot pieces of 24-inch HDPE pipe was unloaded and fused into a continuous 400-foot pipe alongside the roadway. The winch and hammer was delivered to a small receiving pit being excavated on one end of the jobsite and another machine excavated a 20-foot pipe insertion pit at the other end. Set-up was completed and the next day would be important for the owner and project team.

Early the following morning final preparation included pulling the pipe into place, attaching the hammer, setting the final configuration of the winch and support equipment such as an air compressor and mud system. The owner was amazed that the 24-pipe pipe could be maneuvered in a way to enter the insertion pit and make a 90 degree turn out to the city street. Neighbors started asking many questions and at this point the owner was easily able to explain the process and why the city chose it. As the pipe was inserted, the hammer and winch started and the pipe burst was officially underway. At this point, the owner was anxious to see the pipe successfully exit almost 400-feet away. The pull, which ran under four properties, was completed in about one hour and 20 minutes. Once in place, the owner’s crew was able to make final connections back to the existing structures and sewer flow restored early on the third day.

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