Decision aids for the selection of installation technology for undergroundmunicipal infrastructure systems

Sewer systems form a vital component of the municipal infrastructure in the US. Many of the municipal utility systems in the US were constructed durin g the turn of the 20th century and are reaching the end stages of their des ign life. Municipal utility systems are eroding due to aging, excessive dem and, misuse, exposure, and neglect (National Science Foundation (NSF), Janu ary (1993),(8), March (1995).(9)) Trenchless technology (TT) consists of a wide range of methods, materials, and equipment to install new or to rehabi litate existing underground pipelines and utility systems with minimal exca vation of the ground. The development, selection, and utilization of trench less technology (TT) has expanded rapidly over the past 10 years. The reaso n for this exceptional growth is the desire to install or rehabilitate unde rground pipeline systems with minimum impact on society and the environment . The benefits of trenchless technology are quite apparent when compared to the conventional open-cut process. However, it is necessary to evaluate th e appropriateness of any technology, trenchless or otherwise, on a project to-project basis by considering all the criteria and subcriteria important for the decision task. This paper presents a framework for a Decision Suppo rt System (DSS) to assist design engineers and system managers in selecting the most appropriate technology for a project by systematically evaluating five groups of criteria and subcriteria with respect to the knowledge base d preference of the user and the project specific situations. (C) 2001 Else vier Science Ltd. All rights reserved.