Study on Hierarchical Prevention Method of Heat Hazard in Geothermal Tunnel Construction

When tunneling progresses into the geothermal areas, the high-temperature environment threatens the quality of engineering structures and the health of workers, reduces the work efficiency of staff, or impacts the normal operation of mechanical and electronic equipment. Therefore, it is significantly important to understand the heat transfer characteristics of geothermal construction tunnels for cost-effective heat-hazard-prevention measures. Based on the understanding of the thermal characteristics of geothermal construction tunnel, a method of heat-hazard prevention based on fuzzy comprehensive evaluation of heat hazards is proposed. Firstly, considering the factors of geothermal, construction conditions, subjective and objective construction workers, fuzzy comprehensive evaluations of heat hazards for different stages of tunnel excavation are carried out. Then, corresponding heat hazard prevention measures are formulated according to the heat hazard evaluation results. Finally, heat hazard evaluations and heat hazard prevention measures are constantly updated and iterative throughout construction period. While ensuring the cooling and prevention of heat hazards, the cost of heat hazard prevention measures is reduced, as well as the consumption of energy and resources, that makes the whole process of geothermal tunnel construction safe and economical.