- ENGINEERING INFO
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Many utilities throughout the Midwest maintain some amount of cast iron pipe in their water distribution networks. As these cast iron water mains reach the end of their useful lives, utility owners and engineers must determine the best way to replace them. In the Minneapolis metropolitan area, many cities have successfully used pipe bursting, a trenchless construction technique, to replace existing cast iron mains.
The City of Mound, Minnesota is one of the latest communities to embrace pipe bursting technology. In the course of one year, Mound has employed pipe bursting on three separate projects to replace aging cast iron water mains. These projects involved the replacement of 6-inch, 8-inch, and 10-inch water mains along Bartlett and West Three Points Boulevards. Pipe bursting enabled replacement of the water mains with minimal impact to the existing roadways. An additional benefit of pipe bursting rehabilitation is that it utilizes the existing pipeline alignment, eliminating the need to find a new alignment in increasingly crowded utility corridors.
All three of these recent water main pipe bursting projects used Fusible PVC® pipe as the replacement pipe material for the new water main. Fusible PVC® pipe’s successful track record in water main pipe bursting projects across the country, combined with its compatibility with standard ductile iron waterworks fittings, was critical to its selection on these projects. In addition, the high-strength, low-profile fusion joint provides a consistent outside diameter along the entire length of the fused pipeline which facilitates a smoother installation versus segmented pipe products with bells or collars.
Bolton & Menk, Inc. was the design engineer for each of the Mound projects. Bolton & Menk’s engineering professionals understand the value pipe bursting provides its clients when used in the appropriate applications.
Matt Bauman at Bolton & Menk commented on several factors that led to pipe bursting for these projects: “Three Points Boulevard is the only road in and out of a peninsula with hundreds of residents and 3,000 vehicle trips per day. Replacing pipe while maintaining traffic flow throughout the entire construction process was critical to selecting pipe bursting. On Bartlett Boulevard, pipe bursting allowed work to occur at lower overall costs since the entire roadway was not scheduled for replacement.”
The Mound projects involved size-on-size replacement of the existing water mains, which means the existing cast iron pipe was replaced with the same nominal size Fusible C-900® pipe. Although it was not required for these projects, pipe bursting technology also facilitates upsizing the existing pipeline if an increase in hydraulic capacity is desired.
One of the most frequently asked questions when utilities are considering pipe bursting projects is: “How are the existing water services managed during construction?” Water main replacement with pipe bursting typically requires the use of temporary above-ground water lines after the existing services are potholed and disconnected. With many contractors skilled and efficient at running temporary water services, concerns over managing existing water services should not be a reason to dismiss pipe bursting as a potential water main rehabilitation option.
Consulting with local engineers, contractors, and industry equipment suppliers is always a recommended first step when considering a pipe bursting project.
|Pipeline Details and Project Summary|
|Project:||Bartlett Blvd. Water Main Improvements: Lost Lake Bridge to Wilshire Blvd.|
|Project:||Bartlett Blvd. Water Main Improvements: Commerce Blvd. to Lost Lake Bridge|
|Project:||2014 Street, Utility, & Retaining Wall Improvements: West Three Points Blvd. Utilities|
|Length & Pipe Size:||3,600 LF of 6” DR18 Fusible C-900®|
|Length & Pipe Size:||2,070 LF of 8” DR18 Fusible C-900®|
|Length & Pipe Size:||405 LF of 10” DR18 Fusible C-900®|
|Installation:||HDD / Jack & Bore|
|Owner:||City of Mound|
|Engineer:||Bolton & Menk, Inc.|
|GCs:||Widmer Construction LLC, Geislinger & Sons, Inc.|
|Trenchless Subs:||Red Pederson Utilities Inc.,Geislinger & Sons, Inc.|
|UGSI Contact:||Dan Christensen, (715) 206-0518; firstname.lastname@example.org|