This paper presents a hierarchical fault tree model for analyzing the effectiveness of measures for the prevention of third-party mechanical damage to underground pipelines. The model consists of a high level failure model that provides an overall indication of the effectiveness of a damage prevention program; and lower level fault tree models that detail the effectiveness of individual damage prevention measures. The model developed in this paper is consistent with current damage prevention and data collection practices, and it presents information in a simple and intuitive format that facilitates analysis and interpretation.
The hierarchical fault tree approach developed in this paper is shown to be a useful tool for evaluating the effectiveness of various measures to prevent third-party damage and for identifying weak links in current damage management practices. It can also serve to inform the development of new damage prevention techniques and to identify information priorities relevant for future data collection and interpretation efforts aimed at reducing the frequency of third-party damage events.