ABSTRACT
Utilizing risk matrix systems within tunneling construction projects has become popular within the industry. There are many uncertainties that contractors must consider, which can lead to unexpected risk consequences depending on what type of tunneling method they are using. To combat these risk consequences, a risk matrix is developed to help contractors weigh each risk and know which to prioritize. The objective of this research is to provide the guideline of safety precaution in tunneling projects based on a risk matrix and Probability – Impact Analysis (PIA) to prioritize all risks that may happen in tunneling projects. Almost 81 case studies of tunneling projects are analyzed and summarized for the risk matrix and PIA. PIA is one of the most popular risk management tools used within the industry. It involves “Probability”, which is the occurrence index of risks within the project, and “Impact” which is the intensity of the consequences that each risk poses. In investigating these two factors (entities), a new framework is created by utilizing the number of delays that a project experiences due to various risks. The probability analysis is conducted through risk identification, classification, categorization, prevention, and solutions for consequences using a value scale and color codes. Furthermore, through impact analysis, a money value in terms of liquidated damages is calculated and used as another impact factor within the risk matrix. The research outcome is to assist contractors in ensuring safety precautions are taken at the tunneling site by preventing delays and money loss.
