Coupling Simulation of Human-Environmental Safety Risk Factors in Metro Construction Sites

The coupling of human, management, mechanical and environmental risk factors increases the probability of accident occurrence at metro construction sites. This paper exploits the coupling relationship between human and environmental risks to predict the progression in the overall risk level in the construction process at the Rongjiazhai station of Xi'an Metro Line 5. The coupling model and system dynamics (SD) simulation are applied in four steps: develop the coupling model, estimate the weight index for metro construction safety risk factors, calculate the risk level for indicators of risks, and estimate the risk coupling degrees. This paper identifies that the change of coupling coefficients of human-environmental factors has a significant influence on accident risk level. The psychological and physiological quality, natural and working environment, and physiological discomfort and working environment coupling factors have the most obvious influences on the coupling level of human-environmental factor risk. The simulation results argue that the increase of the risk coupling coefficients should be emphasised in engineering practice. To reduce the overall accident risk level of the construction system, the human, machine and environmental risk factors should be identified, coupled and monitored in real time to eliminate potential danger and avoid coupling of multiple risk factors at metro construction site.