Design and implementation of a quantitative risk assessment software tool for Singapore road tunnels

This paper presents an interesting approach to develop a quantitative risk assessment (QRA) software tool for road tunnels. It first introduces a QRA model for road tunnels, consisting of event trees, fault trees and consequence estimation models. The model is developed by taking into account the unique characteristics of Singapore road tunnels. The paper proceeds to describe design of the QRA software tool based on the QRA model by means of the object oriented design (OOD) method and eXtensible Markup Language (XML) technique. The XML files are used to store the numerous tree structures in the proposed model thus making the programming much more efficiently and effectively. The QRA software tool is robust and flexible such that users can easily add or modify the event trees, fault trees and the consequence estimation models. An application to Singapore road tunnels has been carried out to assess the robustness and effectiveness of the QRA software tool.