The Journal of

  Background: There is no doubt that one of the effective factors in implementation of projects that have potential hazard can cause irreversible losses. Therefore recognizing potential hazards is of paramount importance.

  Method: The present descriptive-analysis study was conducted at Rudbar Lorestan Dam constructional projects. For recognizing potential hazard in tunneling activities, job safety analysis (JSA) was performed according to OSHA 3071 method and for observing this purpose, the risk assessment matrix was carried out on the basis of MIL-STD-882E standard. Combination of severity and probability of each risk makes it possible to determine the risk level and the priority of control measures, qualitatively rating from 1-24.

  Results: Generally, a total of 232 risk factors were identified in different activities. As results show, %15.9 of recognized risks were serious, %17.3 almost serious, %38.4 medium and %28.4 were in low level. Therefore more than one-third hazards are assessed as unacceptable. Work at heights without using proper lifting, lack of equipment of tunneling treatmentolagy, delay in unstable rock mass support can be enumerated as the causative factors.

  Conclusion: A llocating a percentage of the budget of every construction project to provide safety and rescue equipment as well as experienced safety experts can significantly reduce the risk level.

  For assessment criteria, MIL-STD-882E standard was used and four indices were presented for decision making: serious, almost serious, medium, and low.