In this study, a functional relationship for frozen soil at different temperatures, confining pressures, and triaxial compressive strengths is established through macroscopic and mesoscopic comparative tests. Additionally, a three-dimensional pore network model at the mesoscopic scale is constructed. Morphological characterization parameters are introduced to quantify the pore structure, and the evolution of the pore structure in frozen soil during the stress process is analyzed, as well as the influence of temperature and confining pressure on the pore characteristics and failure morphologies. The results reveal that at the macroscale, frozen soil exhibits a power function relationship with temperature, confining pressure, and triaxial compressive strength. During mechanical loading, frozen soil undergoes compaction, pore development, and pore expansion stages, leading to changes in pore size and connectivity. Additionally, temperature and confining pressure significantly impact the pore characteristics and failure morphologies of frozen soil. At lower temperatures, frozen soil experiences severe bulging and brittle failure, accompanied by increased pore size, enhanced connectivity, and complex morphology. Increasing the confining pressure reduces the degree of bulging and damage, decreases the porosity and connectivity, enhances the complexity of the pore morphology, and results in a denser and more stable internal structure in frozen soil. Through this study, a better understanding of the damage behavior of frozen soil under different temperatures and confining pressures is achieved. Furthermore, this research provides a theoretical basis and reference for addressing related engineering problems.

中文翻译：

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荷载作用下冻黄土三维孔隙结构表征方法及演化规律研究

本研究通过宏观和细观对比试验，建立了不同温度、围压和三轴抗压强度下冻土的函数关系。此外，还构建了介观尺度的三维孔隙网络模型。引入形态表征参数对孔隙结构进行量化，分析应力过程中冻土孔隙结构的演化，以及温度和围压对孔隙特征和破坏形态的影响。结果表明，在宏观尺度上，冻土与温度、围压和三轴抗压强度呈现幂函数关系。在机械加载过程中，冻土经历压实、孔隙发育和孔隙扩张阶段，导致孔隙尺寸和连通性发生变化。此外，温度和围压显着影响冻土的孔隙特征和破坏形态。在较低温度下，冻土会经历严重的膨胀和脆性破坏，并伴有孔径增大、连通性增强和复杂的形态。提高围压可减少膨胀和损伤程度，降低孔隙度和连通性，增强孔隙形态的复杂性，使冻土内部结构更加致密和稳定。通过这项研究，可以更好地了解不同温度和围压下冻土的损伤行为。此外，本研究为解决相关工程问题提供了理论依据和参考。