Electronic Thesis and Dissertation Repository


Master of Engineering Science


Civil and Environmental Engineering


Zhou, Wenxing


The objective of this study is to develop a quantitative method of evaluating the risk of third party damage (TPD) on natural gas distribution pipelines using available industry data and practical engineering experience. A risk model for TPD of gas distribution pipelines is developed to allow for a more robust decision making process and better prioritization of the allocation of resources for operators of natural gas distribution pipelines. The model consists of likelihood and consequence classification procedures to estimate the severity of TPD events within an area.

The TPD model consists of a fault tree (FTA) model to estimate the probability of hit of a given distribution pipeline by third party excavation activities. The distribution FTA model is developed using TPD and locate records from 2014-2016 and survey data from transmission FTA models. This model is then validated by comparing the predicted and actual 2017 damage records in three municipalities in southwestern Ontario with populations varying from 200,000 to 350,000.

Based on a historical analysis of distribution pipeline TPD consequence, a procedure is developed to classify the consequence of a TPD event within a given area. Methods of collecting and classifying data from sources available to distribution companies are used to allow this procedure to be implemented straightforwardly in an industry setting. In a case study a compromise solution method of evaluation is used to identify areas where focusing damage prevention resource would be most effective.

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License