Abstract
Heat hazards in deep-buried tunnels have emerged as a significant challenge constraining their safe construction. This paper addresses the limitation of current tunnel heat hazard research, which primarily focuses on managing high rock temperature and high ambient temperature during the construction period while neglecting associated hazards such as high water temperature and harmful gases. By establishing a heat hazard case-heat hazard response characteristic framework, this study systematically summarizes the effects of tunnel heat hazards. Firstly, based on thermal phenomena in geothermal anomaly zones and extensive engineering practices from heat hazard projects, tunnel heat hazards are redefined to incorporate high rock temperature, high water temperature, and harmful gas outbursts associated with geothermal anomaly zones within the scope of heat hazards. Subsequently, through statistical analysis of 87 domestic and international tunnel heat hazard cases, geothermal anomaly-induced heat hazards are classified into five categories: high rock temperature alone, harmful gases alone, high rock temperature combined with high water temperature, high rock temperature combined with harmful gases, and high rock temperature combined with both harmful gases and high water temperature. The analysis reveals that tunnel heat hazards exhibit strong correlations with surface thermal anomalies and stratum lithology. Finally, the effects of tunnel heat hazards are systematically reviewed, disclosing that heat hazards cause deterioration of the temperature-humidity environment within tunnels, exacerbate surrounding rock deformation and failure, induce cascading failure of support structures, and trigger a multi-dimensional chain generation mechanism of gaseous hazards within the tunnel. This research provides a theoretical foundation for further investigation into the disaster-forming mechanisms and risk prevention and control of tunnel heat hazards.
Full Text
Thermal Disaster Cases and Thermal Disaster Effects in Deep-Buried Tunnels
ZHANG Shishu, ZHAO Xiaoping
PowerChina Chengdu Engineering Corporation Limited, Chengdu 610031, China
Abstract
Thermal disasters in deep-buried tunnels have emerged as a critical challenge constraining safe construction. Current research primarily focuses on managing high rock temperatures and ambient temperatures during construction, while neglecting associated hazards such as high water temperatures and harmful gases. To address this limitation, this paper systematically categorizes tunnel thermal disaster effects by constructing a thermal disaster case-response characteristic framework. First, based on thermal phenomena in geothermal anomaly zones and extensive engineering practice, we redefine tunnel thermal disasters to encompass high rock temperature, high water temperature, and harmful gas outbursts associated with geothermal anomalies. Subsequently, through statistical analysis of 87 thermal disaster cases from domestic and international projects, we classify geothermal anomaly-induced disasters into five categories: high rock temperature alone, harmful gases alone, high rock temperature combined with high water temperature, high rock temperature combined with harmful gases, and high rock temperature combined with both harmful gases and high water temperature. The analysis reveals strong correlations between tunnel thermal disasters and surface thermal anomalies as well as stratigraphic lithology. Finally, we systematically review tunnel thermal disaster effects, elucidating how thermal disasters deteriorate the temperature-humidity environment, exacerbate rock mass deformation and failure, induce cascading failures of support structures, and trigger multi-dimensional gaseous disaster chains within tunnels. This study provides a theoretical foundation for further investigation into the disaster-forming mechanisms and risk prevention of tunnel thermal disasters.
Keywords: tunnel engineering; geothermal anomaly zone; thermal disaster case; thermal disaster effect