Interactive Lining : A Mains Rehabilitation Solution That Is Set To Become A Key Element Of Cost-effective Asset Management

摘要

Interactive lining of water mains is a structurally efficient method for extending theservice life and asset value of partially deteriorated mains, which form the greatmajority of the mains in need of rehabilitation in North America.AWWA Manual M28 defined four classes of rehabilitation. The great majority ofsolutions currently available fall into Classes I (non-structural) and IV (fullystructural). In many cases the need for rehabilitation is driven by localised corrosionof cast or ductile iron mains which causes either leakage or structural failure at onepoint. Class I liners are insufficient to deal with this and Class IV liners are oftenused unnecessarily because there is no effective alternative. This results in excesscost due to the use of Class IV liners in situations where they are not justified on thebasis of pipe condition.Interactive lining can fill this gap. Its use to date has been limited by lack ofexperience and also of a clear design methodology. This paper will explore thedesign approach of creating a composite of pipe and liner so that the liner resistsinternal pressure while the host pipe resists external loading, resulting in a moreelegant and efficient engineering use of all elements of the rehabilitated pipe. Theresult is an asset that has an extended service life equal to that of a fully structurallyrehabilitated pipe and in which this is achieved more cost-effectively because theresidual structural capacity of the partially deteriorated host pipe is not simplyignored. Understanding and using the solutions most appropriate to the problems tosolve them at the optimum balance of cost and risk is good engineering and isessential to maximise the benefits from the expenditures made.The paper will include case studies from international experience with interactiveCIPP linings which will show the technology used and the resulting benefits to theasset owners and operators.