Evaluation Of Structural Monitoring Methods For Large Diameter Water Transmission Pipelines

Abstract

The water transmission lines span thousands of miles and form a significant part of the underground infrastructure of United States. The condition of water pipelines deteriorates with time and becomes more vulnerable to catastrophic failures and often results in costly replacement measures. With the advancement of technology, several new techniques have been developed for the condition assessment of water pipelines. However, no unified standards are followed for the selection of these technologies. Moreover, the current decision making methodology followed by water pipeline operators is usually based on individual experience and project requirements and resources. This research presents a comprehensive overview of different structural health monitoring techniques available for continuous observation of the structural performance of large diameter water transmission pipelines. The capability of these techniques to monitor the structural health of a pipeline can be expressed in terms of a condition assessability index. Condition assessability index defines the technical feasibility of inspection technologies to monitor the failure indicators thereby assisting in preventing structural failure. This is accomplished by characterizing the pipe failure modes, mechanism and distress indicators for Steel Pipes (SP) and Prestressed Concrete Cylinder Pipes (PCCP), two main pipes used in large diameter water transmission projects. The condition assessability index, determined in this thesis, provided a basis for development of a decision support system which was used in the selection of a specific inspection and monitoring technique.