【摘要】 冻融损伤是寒区工程研究的关键问题。岩堆体是一种特殊岩土混合体，为更好地了解寒区岩堆体的力学性质和冻融侵蚀引起的细观损伤，开展了不同冻融条件及不同含水率作用下岩堆体的三轴压缩试验。提出孔隙损伤增量模型，利用颗粒（孔隙）及裂隙图像识别与分析系统（particles(pores) and cracks anlysis system，简称PCAS）深入研究冻融过程中孔隙结构的变化趋势。以孔隙度分形维数为核心，建立冻融-损伤模型系统地分析冻融循环次数对岩堆体损伤的关系。结合材料的细观与宏观参数变化趋势，验证模型合理性及全面揭示岩堆体在冻融作用下的损伤模型。结果表明：（1）在冻融循环过程中细观损伤对宏观强度的影响显著，孔隙损伤增量增加导致应力峰值下降，两者呈负相关；（2）岩堆体的峰值应力随着冻融循环次数的增加而降低，且降低幅度在冻融循环次数为4次前逐渐增大，随后幅度逐渐减小；（3）利用孔隙度分形维数建立的孔隙增量模型，从细观层面有效地验证了岩堆体的冻融损伤是随着冻融损伤次数的增加而增加，该模型的参数数据与实测数据高度一致，且相比传统模型计算更简便。更多还原

【Abstract】 Freeze-thaw damage is a critical issue in engineering research in cold regions. Rock piles is a unique type of rock-soil mixture. To investigate the mechanical properties of rock piles in cold regions and the meso-scale damage induced by freeze–thaw erosion, the triaxial compression tests were conducted under varying water contents and freeze–thaw conditions. A pore damage increment model was proposed, and the particles(pores) and cracks analysis system(PCAS) method was employed to analyze the evolution of pore structure during the freeze–thaw process. Based on the fractal dimension of porosity, a freeze–thaw damage model was developed to systematically examine the relationship between freeze–thaw cycles and damage in rock piles. Combined with the variation patterns of meso-and macro-scale material parameters, the model’s rationality was verified and the damage mechanisms of rock piles under freeze–thaw action were elucidated. The results indicate that:(1) Meso-scale damage significantly affects macro-scale strength during freeze–thaw cycles. An increase in the pore increment parameter corresponds to a decrease in peak stress, indicating a negative correlation.(2) The peak stress of the rock pile decreases with increasing freeze–thaw cycles. The rate of decrease rises until approximately four cycles, after which the rate gradually declines.(3) The pore increment model, based on the fractal dimension of porosity, effectively confirms that freeze–thaw damage in rock piles increases with the number of cycles at the meso-scale. Model parameters show high consistency with measured data, and its calculations are simpler than those of traditional models.更多还原