关键词: 尾矿坝稳定性　季节性冻土　尾矿砂力水热耦合特性　数值模拟

Abstract: During the tailings dam construction in the seasonally frozen areas,the external temperature can easily cause
the formation of seasonal frozen soil layers within the dam,significantly affecting the seepage characteristics and stability of the
tailings dam. To study the influence of the presence and melting process of the frozen soil within the dam on the stability of the
tailings dam,taking a tailings dam in the northeastern region in China as an example,drilling,well temperature testing,and indoor
triaxial shear tests were used to determine the initial temperature distribution within the dam area and the variation patterns
of the mechanical parameters of the tailings soil samples. Based on the thermal-hydro-mechanical coupling characteristics
of the tailings sand,an analysis method suitable for the stability of tailings dams in high-altitude seasonally frozen areas was
proposed. The research results show that the cohesion,internal friction angle,and moisture content of the tailings soil samples
have a relatively obvious negative correlation;the melting of the frozen soil is prone to causing instability and failure of the tailings
dam. During the entire melting period,the safety coefficient of the dam body decreases by approximately 11. 8%. In addition,
the influence of the external temperature on the tailings dam mainly occurs in the upper and middle layers of the dam
body,and the temperature variation range within the dam decreases with the increase in depth. When encountering extreme
weather conditions,multiple layers of frozen soil may exist in the reservoir area,which can easily cause the elevation of the water
table of the tailings reservoir and reduce the stability of the dam body. By conducting ice-breaking operations to break the
integrity of the frozen soil,the rate of frozen soil melting can be accelerated to ensure the stability of the tailings dam. The research
results can provide a theoretical basis for the analysis of the evolution of frozen soil within the tailings reservoir and its impact on the stability of the dam body,and can also provide a reference for other similar engineering studies.

Key words: stability of tailings dams,seasonal permafrost,force-water-heat coupling characteristics of tailings,numerical
simulation