Review of Research Progresses and Application of Geothermal Disaster Prevention on Large-Buried Tunnels

Geothermal disaster caused by high geotemperature is a commonly encountered geological problem in tunnel engineering, especially in large-buried tunnels, which is directly related to the safety, technology, and economy of tunnel construction. It seriously affects the personnel security and the performances of construction equipment and building materials, greatly increasing the construction difficulty, and extending the total construction period, which has become a major issue to be urgently solved in the tunnel construction. This paper first briefly introduces the formation mechanism of the high-geotemperature environment of a large-buried tunnel and analyzes the significant influences of high-temperature on personnel, equipment, and materials in the construction process of tunnel engineering. Then, the worldwide research progress of rock mechanics in high-temperature large-buried tunnels is systematically described, including the thermo-mechanical properties of rock mass, the thermo-mechanical properties of shotcrete, and the rheological mechanism and control technology of surrounding rock. Subsequently, the previous geothermal disaster classification of large-buried tunnels is summarized and evaluated. Finally, the research findings of the key technologies of geothermal disaster prevention and control are presented in detail from three aspects of temperature reduction, thermal insulation, and personal protection, which are of great theoretical and practical significance for ensuring the safety design and construction of tunnels in similar geological environment.