System for Evaluating Underground Pipeline Renewal Options

Trenchless technology (TT) consists of a wide range of methods to install or rehabilitate existing underground pipelines with minimal excavation of the ground. In the past, excavation was used almost exclusively to restore old and deteriorated sewers and water pipelines. However, as cities become more congested, the disruption and expense associated with excavation becomes less acceptable. The development, selection, and utilization of TT have expanded rapidly over the past ten years. The benefits of TT are quite apparent when compared to the conventional open-cut process. However, it is necessary to evaluate the suitability and appropriateness of any rehabilitation system, trenchless or otherwise, on a project-by-project basis through consideration of all project criteria such as site conditions, geotechnical conditions, condition of existing pipeline, design life of new pipe, etc. This paper presents a decision support system to assist design engineers and sewer system managers in selecting the most appropriate technology for a project by systematically evaluating groups of criteria with respect to the knowledge-based preference of the user and the project-specific situation.