The Evolution and Comparative Assessment of Flexible Close-fit Liner Design Approaches based on North American and Global Practice

Abstract

Since Insituform released their first Design Manual in North America in 1983 (based on UK research), the design of close-fit flexible liners has been continuously evolving to better capture liner performance in various geometrical configurations with enhanced confidence. While there was little change in liner design in North America from the 1989 release of ASTM F1216 until the mid-2000’s, the evolution of design practices globally advanced considerably and came to a head within North America with the release of the ASCE PINS Committee Report in 2007. Accordingly various international design methodologies including WRC (UK), ASTEE (France), and ATV (Germany) were advanced over that timeframe to assess liner performance and structural behavior under different loading conditions in a wide range of host pipes. The ASTEE 3R Standard in France (2014) formed much of the basis for the ASCE MOP 145 which was released in 2022 This presentation will trace a history of research and design implementation to tackle various liner design challenges and provide a comparative analysis of these global approaches, focusing on their fundamental design principles, key assumptions, and the variations in calculated results. By understanding these global perspectives, attendees will gain insight into best practices and emerging trends that influence the future of close-fit liner rehabilitation design as well as insight into the strengths and limitations of various design approaches.