Water Resources Engineering (WRE) connects engineering hydrology and hydraulics with global, economic, environmental, and societal issues. Our student, Ashley Miller, makes this connection here…
The news entitled, “Current Trends in Pipe Bursting for Renewal of Underground Infrastructure Systems in North America,” was reported in an online journal, Underground Tunneling and Space Technology, in January 2014 in a special issue Underground Infrastructure Research 2012. This article reports on the hydraulics issue of renewing underground pipe infrastructure through pipe bursting by presenting survey data gathered from companies who specialize in pipe bursting. Pipe bursting is a technique for replacing underground pipe infrastructure by breaking the original pipe and replacing it with a new pipe. However, there are many risks and limitations associated with this technique. To burst a pipe, a conical shaped bursting head is pushed through the pipe. This bursting head creates radial expansion in the pipe causing it to crack and split. As the pipe breaks an annulus, or ring shaped opening is formed underground. The pieces of the old pipe break off into the annulus, and new pipe is immediately pushed through the opening to replace the old pipe. Although this seems like a simple concept, there are several risks associated with this procedure and it is expensive. The burst length, host pipe material, upsize diameter of the new pipe, and geological conditions are just a few considerations. The technique is usually only successful in straight pipes between 91-137m or the typical length between manhole covers. From the surveyed companies it was determined that 98% of replacements were done with high-density polyethylene (HDPE) pipe. A common risk associated with pipe bursting is surface heave. Unfortunately, there were no cost estimates presented in the article, and I think this could be an important factor in determining how practical the technique is. The process seems very cost intensive and it is only practical for small, straight sections of pipe. On average, companies interviewed only performed 13 projects a year. It would be interesting to compare this method to other methods of pipe replacement. Overall, the process is broken down into four stages: pre-site planning, on-site planning, bursting, and site restoration.
These stages are time and money intensive, but replacing piping infrastructure is becoming more crucial because many pipe systems in place today are reaching their age of expiration.
Water resources engineering influences societies all over the world since it deals with the hydrology and hydraulics issues associated with water, a substance that sustains all life. WRE issues affect economic, environmental, and social issues across the globe. A broader context area affected by pipe bursting is economics, specifically how cities have to create budgets to maintain and replace underground infrastructure. I included a second article link in this blog to a New York Times article entitled, “A Severe Winter Breaks Budgets as Well as Pipes.” According to the article, Syracuse has reported over 100 main pipe breaks since the beginning of the year, and Detroit has experienced 353 water main ruptures in January alone. A representative from the National League of Cities stated that there have been “many years of disinvestment in things like roads, bridges, water and sewer systems, which makes them more vulnerable when something like this happens,” referring to the severe winter conditions that have been occurring in the North Eastern United States in 2014. Water maintenance has been put on the back burner for too long, and I think we will see an increase in pipe infrastructure problems if cities do not address these issues. Pipe replacement, such as pipe bursting is an expensive process, but it is necessary and it is time states started being proactive regarding replacing pipe infrastructure.
Figure 1. Regions of Pipe Bursting Activity (2007-2010).
Figure 2. Technical Envelope Developed to Determine the Risk Associated with Pipe Bursting Based on Upsize Diameter
References:
Ariaratnam, S.T., Lueke, J.S., Michael, J.K. Current trends in pipe bursting for renewal of underground infrastructure systems in North America. Journal of Tunneling and Underground Space Technology. 2014;39:41-49.
McKinley, J., Perez-Pena, R. A Severe Winter Breaks Budgets as Well as Pipes. New York Times. February 15, 2014.
ERENGINEERING 