A probabilistic approach for safety risk analysis in metro construction

This paper presents a probabilistic decision approach for safety risk analysis for metro construction in complex project environments. An expert confidence index is proposed for the fuzzy probability estimation of basic events, aiming to ensure the reliability of collected data during the expert investigation. An approach for defuzzification is developed in a precise way based on the representation theorem, attempting to overcome the limitations related to fuzzy linear approximations. A sensitivity analysis technique is utilized to evaluate the percentage contribution of the basic events to the failure of a top-event. A possibility based importance index, fuzzy importance measure, is deployed for the sensitivity analysis of basic event to reveal the critical basic events for reducing the risk limit. A typical hazard in tunnel cross passage construction (TCPC) on the example of Wuhan Yangtze Metro Tunnel construction is presented in a case study. The results demonstrate the feasibility of the proposed method and its application potential. The proposed method can be used as a decision support tool to provide guidelines for safety management in metro construction, and thus increase the likelihood of a successful project in a complex environment. (C) 2013 Elsevier Ltd. All rights reserved.