Analysis of Risk-Response Measures for Tunneling Projects

Tunnel construction involves complex projects that encompass various types of risk. To achieve project goals, contractors need to adopt appropriate risk management strategies from project inception to project completion. In this paper, we present and analyze the risk-response measures employed by tunneling contractors in Thailand and their major criteria for choosing such measures. Thirty-nine risk factors proposed by previous research as borne by tunneling contractors were compiled and verified by experienced tunneling engineers. Alternative risk-response measures for each risk factor employed by tunneling contractors were identified, including risk-retention, risk-reduction, risk-transfer, risk-avoidance, and contingency allowance. It was found that the most commonly used risk-response measures were risk-reduction, risk-retention, risk-transfer, and risk-avoidance, in that order. We also identified the major criteria that contractors consider when choosing the appropriate risk-response measures for each risk factor, such as cost, project delivery system, and project payment method. Tunneling contractors can use these results as a guideline for developing appropriate risk management plans for future projects.