Abstract: Fire safety risk monitoring of tunnel and cavern groups is crucial to ensure the construction and safe operation of underground transportation, energy, and power facilities. This study systematically reviews the research progress of combustion characteristics, monitoring technologies, and intelligent prevention and control systems for fires in tunnel and cavern groups, which located at the pumped storage power stations. By analyzing typical fire cases, the characteristics of tunnel fires are summarized, which includes the strong concealment, the high toxicity of smoke, and the difficulty in evacuation and rescue. In the meantime, the principles and application scenarios of single-parameter fire detection technologies are also sorted, which includes the gas detection, the smoke detection, the flame detection, the temperature detection, and the video detection respectively. The problems existed in the sensors for single fire parameter are pointed out, which includes the high false and missed alarm rates and low data fusion efficiency in complex scenarios, and the multi-sensor networking communication technologies and information fusion algorithms are also discussed, which is conducive to improving monitoring accuracy and anti-interference ability. In the future, it is urgent to build an integrated intelligent monitoring system of "perception-decision-control" by combining digital twin and artificial intelligence technologies, promoting the transformation of tunnel fire monitoring from "passive early warning" to "active prevention and control", so as to provide theoretical support and technical guarantee for the safe operation and maintenance of underground spaces.

Key words: tunnel and cavern groups, fire monitoring, communication networking, information fusion, intelligent prevention and control