Comparison

# 9038 THE ADVANTAGES OF TRENCHLESS TECHNOLOGY IN COMPARISON TO OPEN CUT EXCAVATION METHODS Steven Sachs, 0012, Bursic, 2 PM Jake Lightner, 0012, Bursic, 2 PM Favre, Tracy. August 2002. “Pipes: Choosing the Right Rehabilitation Method.” Water & Wastes Digest. Vol. 42, pp. 7 – 8. This article, from a peer reviewed journal for water and wastewater professionals, looks at the most cost effective and efficient use of resources to update this country’s aging water and sewer infrastructure. The author, a professional engineer, examines each trenchless method explaining not only the process of pipe repair or replacement, but the cost effectiveness of each method. Information from this article will allow us to compare the cost effectiveness of each rehabilitation method. Harbuck, Robert H. “Economic Evaluation of Trenchless Technology.” 2000 Association for the Advancement of Cost Engineering. Risk.12. Vol. 1. Pittsburgh, Pennsylvania: University of Pittsburgh. This paper, from the leading international association for engineering cost analysis’ annual conference, gives an excellent overview of trenchless technology. The paper, written by a professional civil engineer, goes on to economically evaluate each of the trenchless technologies before comparing those costs to the open-cut method. The methodology from this paper will allow us to perform an economic evaluation of trenchless versus open-cut methods. Mohamed, Rayman, Mohammad Najafi, Behnam Hashemi. “Cost Comparison of Open-cut and Trenchless Methods for Renewing Sewer Lines.” Underground Infrastructure Management Online. October 2008. http://www.uimonline.com/index/webapp-stories-action?id=182archive=yes&Issue-2008. Accessed 7 January 2009. This article, from an online peer-reviewed journal specializing in underground infrastructure management, examines the costs of a trenchless technology, pipe bursting, versus an open-cut excavation method for replacing sewer pipes. The article shows how the trenchless method provides considerable savings for municipalities seeking to renew underground utilities. This article is also important in that it provides us a template for comparing the costs of other trenchless technologies with open-cut methods. Najafi, Mohammad. 2004. Trenchless Technology Pipeline and Utility Design, Construction, and Renewal. New York New York: McGraw-Hill. This textbook, the most comprehensive book on trenchless technology in North America, contains an overview and comparison of trenchless technologies, and an exhaustive description of the direct and social costs of utility construction. This comprehensive resource examines each trenchless technology and compares its application to that of open-cut excavation in terms of both direct and social costs. Information from this reference will allow us to present pertinent information about each of the trenchless technologies. Purlee, Larry. November 2007. “Relining vs. Replacement: The Need to Understand and Evaluate Alternatives.” Trenchless Technology. Vol. 91, pp. 31 – 32. This featured article, from the country’s most popular trenchless technology magazine, shows how trenchless technology offers many benefits over traditional open-cut excavation methods. The author, who is the vice president of one of the largest relining companies in the United States, does a side-by-side comparison of a cured-inplace pipe repair versus an open-cut replacement method, which will allow us to weigh the pros and cons of each method.

“Resources.” nastt.org. http://www.nastt.org/resources.html#5. Accessed 7 January 2009. This website, from the leading professional society for trenchless technology, contains the largest resource center of information pertaining to the advantages and disadvantages of the various trenchless technologies. The website’s resources page clearly describes each trenchless method from pipe bursting to sliplining. The website pays particular attention to the environmental and social costs of trenching to help us define trenchless technologies’ advantages over open cut excavation methods.

Steven Sachs, 0012 Bursic, 2 PM Jake Lightner, 0012 Bursic, 2 PM

THE ADVANTAGES OF TRENCHLESS TECHNOLOGY IN COMPARISON TO OPEN CUT EXCAVATION METHODS Traditional methods of construction, repair, and replacement of underground utilities generally employ conventional trenching or open cut excavation methods, but over the last fifteen to twenty years, cutting edge advances in trenchless technology have emerged in the utility industry. Trenchless technology is a broad term for the subsurface installation and renewal of pipelines or utilities where no continuous trenches are required to be dug. The elimination of surface excavation or digging is accomplished through various methods of tunneling, drilling, or boring which causes minimal disruption to the surface area. The rapid advancement of trenchless technology is directly related to the fact that open cut excavation methods are generally more expensive because of the need to restore ground surfaces such as sidewalks, pavement, bricks, and landscaping. Municipalities and utilities could save millions of dollars and also prevent untold social problems through the use of trenchless technology in the renewal of their underground utility infrastructure. Much of the cost of utility renewal is associated with the backfilling, compaction, and reinstatement of the ground surfaces. The return of the surface area to its original condition accounts for seventy percent of the total cost of an open cut excavation project [Najafi]. Taking into account these added restoration costs along with the fact that conventional trenching is often more time consuming, it is no wonder more and more utilities are examining the use of trenchless technology [Mohamed]. Furthermore, open cut methods have adverse impacts on community members, businesses, and commuters due to air pollution, traffic disruption, and business loss. In addition, trenchless technology has been shown to increase worker safety and productivity on the job site. Trenchless technologies are divided into trenchless construction methods and trenchless renewal methods. Trenchless construction methods consist of the following advanced technologies: pipe ramming, microtunneling, auger boring, impact ramming, directional drilling, guided boring, and impact moling. Trenchless renewal methods can be categorized into the following types: cured-in-place pipe, coatings and linings, grouting, thermoformed and thermoplastic pipe, and sliplining [nastt.org]. A thorough technical description and explanation of these trenchless technologies will be presented in this conference paper. To objectively study the benefits of trenchless technology versus open cut excavation, this conference paper will research leading trade magazines, current websites, and the standard authoritative textbook to locate information on cutting edge trenchless technology. The objective of this conference paper is to describe the current methods of trenchless technology and to compare direct and social costs of this technology with that of open cut excavation methods during underground pipeline construction. REFERENCES

Mohamed, Rayman, Mohammed Najafi, Behnam Hashemi. “Cost Comparison of Open cut and Trenchless Methods for Renewing Sewer Lines.” Underground Infrastructure Management Online. October 2008. http://www.uimonline.com/index/webapp-stories-action?id=182&archive=yes&Issue=2008. Accessed 7 January 2009. Najafi, Mohammad. 2004. Trenchless Technology Pipeline and Utility Design, Construction, and Renewal. New York New York: McGraw-Hill. “Resources.” nastt.org. http://www.nastt.org/resources.html#5. Accessed 7 January 2009.