عنوان مقاله [English]
Extensive construction projects such as dam construction, road construction, water transfer, land leveling, and railways are active in the country, and in all these projects, manpower and equipment play an important and decisive role. The purpose of this research is to identify the ergonomic hazards of the office environment and the activity of machinery in the workshop of section 6B of the Chabahar-Zahedan railway project. In order to collect information, questionnaires were compiled and distributed among workshop experts who were a group of senior managers and middle managers of the workshop. After completing the questionnaire, the obtained data were analyzed using the FMEA technique, and three indicators of probability, severity and probability of risk detection and finally the rank of each risk were determined. The results of the risk assessment of the office environment, including the technical office, HSE, human resources and the warehouse, show 17 ergonomic risks in the office environment, the highest risk is related to the warehouse unit with a risk rating of 196 and the risk of moving equipment. Examining the risks of machinery activity shows 18 risks related to excavators, dumpers, rollers, graders and loaders. The highest risk rating is related to the excavator with a risk rating of 192 with the risk of rock fall from the trench. All identified risks are placed in the group of risks with a low risk rating.
The trend of accidents in industrial environments has also increased due to the increase in industrial activities, the development of technology and the increase in the use of machines. In traditional systems, investigating the causes of accidents after the occurrence of accidents, irreparable damage is determined, in other words, system or process defects are determined after the accident. Today, due to the existence of different methods of hazard identification and risk assessment, it is possible to determine critical and accident-prone points before an accident occurs and take necessary measures to prevent accidents and control measures. To identify and prioritize risks, the method of risk identification and risk assessment, which is a structured method, can be used. Risk assessment is a logical method that measures the quantitative and qualitative assessment of risks and the investigation of the potential consequences of possible incidents on people, materials, equipment and the environment. In fact, in this way, the effectiveness of the existing control methods is identified and valuable data is provided for making decisions in the field of reducing risks and hazards, improving control systems and planning for them. The information obtained from the risk assessment has three basic uses, which include prioritizing the degree of importance of risks in order to allocate risks for limited financial, technical and human resources in eliminating defects and improving conditions, determining points that need optimization in terms of occupational safety and health, and Their risk should be reduced to the minimum tolerable level, and finally, the content of classic trainings should be determined while working in the field of occupational health and safety. Among the different methods for risk assessment, there is a useful risk assessment method that, in addition to being simple, should be appropriate to the nature of activities, processes, culture, and other characteristics of the organization in question. Among the existing risk assessment methods, there is the method of analysis of failure modes and their effects (FMEA).
The present research is an evaluation-analytical method; And it is survey type. To collect and compile information, the method of library studies and compiling a questionnaire was used. Questionnaires were distributed and completed among 20 senior personnel of the workshop, including the workshop manager, deputy workshop manager, machinery manager, HSE manager and other unit managers located in the Chabahar-Zahedan railway workshop complex, workshop 6B. The accuracy and reliability of the questionnaire developed in this research was confirmed by the experts of the workshop, and the reliability of the questionnaire with the analysis done in SPSS software and the use of Cronbach's alpha coefficient to measure the reliability was about 0.85. It has been stated that the evidence of optimal and reliable conditions was compiled with a questionnaire. After completing the questionnaire and data analysis, the data was analyzed using the FMEA technique, and three indicators of probability, severity, and probability of risk detection were determined, and finally, the rank of each risk was determined. Then, the ergonomic risks of office personnel and the risks related to the operation of machines were compared. Analyze the identified hazards by considering the risk factors of occurrence (O), severity (S) and detection (D). The main purpose of FMEA is to allow analysts to identify the failure modes of a system, design, process, product or Prioritize services to allocate limited resources to high-risk cases.The prioritization of failure modes in FMEA is determined through the risk priority number (RPN), which is the coefficient of risk factors D, S, and O for each risk, where O stands for the probability of occurrence, S is the severity of the risk, and D is the probability of detecting the risk. and RPN represents the risk priority number. The three risk factors are presented in Tables 1. As mentioned, the RPN number is obtained from the product of the three components of risk probability, risk intensity and risk detection capability according to formula number 1. According to the obtained risk number formula, they are divided into three levels of low risk, risks 1-300, medium risks including risks 301-600, and high risks with RPN 601-1000. The overall flowchart of the study is shown in Figure 2. The steps of the research are:
1. Distribution of questionnaires among experts
2. Forming a working group of data analysis experts
3. Using FMEA technique for risk assessment
4. Comparison of ergonomic risks and machines
The purpose of this research was to identify the risks in the two fields of ergonomics and machines activity using the FMEA method. The obtained results indicate that 17 identified ergonomic risks have a higher probability of risk and 18 risks related to the activity of machines have a higher risk intensity. The highest risk rating in the two evaluation cases belongs to the risk of moving equipment and tools of ergonomic activity in the warehouse with a risk number of 196 and the lowest risk rating also belongs to ergonomic activities and the potential risk of inappropriate lighting with a risk number of 60. A total of 35 identified risks are in the group of risks with a low risk rating, which is evidenced by the low number of workshop accidents. At the end, suggestions on control measures for ergonomic risks and machinery activity are presented in Table 4.