Safety risk assessment of railway tunnel construction by drilling and blasting method in complex and dangerous areas

In view of the safety risk of railway tunnel construction by drilling and blasting method in complex and dangerous areas, comprehensive consideration was given to the geological structure, climatic conditions and construction methods in complex and dangerous areas. The text mining of tunnel construction safety risk literature and safety risk assessment report were carried out by using Python, based on the accident cause theory, risk identification theory and risk factor checklist. The risk factors of tunnel drilling and blasting construction are identified. In view of the safety risk factors, a relatively complete safety risk assessment index system for railway tunnel drilling and blasting construction in complex and dangerous areas was constructed from five aspects, which were construction environment, construction technology, materials and equipment, construction management and construction personnel. The combination of analytic hierarchy process (AHP) and entropy weight method were used to determine the weight of safety risk assessment index. The two-dimensional cloud model was used to construct a safety risk assessment model for railway tunnel drilling and blasting construction in complex and dangerous areas from the aspects of safety risk probability and safety risk loss degree. The method of combining subjective probability with objective probability was proposed to determine the probability of safety risk. The degree of loss of safety risk was determined by radar chart from the aspects of casualty, economic loss, delay of construction period, environmental impact and social impact. Qualitative evaluation and quantitative evaluation were transformed by Matlab, and the concept of close degree was introduced to quantitatively determine the level of safety risk assessment of railway tunnel drilling and blasting in complex and dangerous areas. The safety risk of Z tunnel drilling and blasting method is evaluated, and the grade of safety risk is determined to be grade IV and the degree of safety risk is high. The result proves the feasibility and validity of the model. This paper provides a reference for the safety risk assessment of railway tunnel drilling and blasting in complex and dangerous areas. © 2023, Central South University Press. All rights reserved.