水电能源科学

为研究寒区土石坝边坡冻结粉土力学特性，在4种环境温度和3种固结围岩条件下开展三轴剪切试验，测定应力-应变曲线与强度指标。结果表明，冻结粉土剪切破坏形式呈现明显的剪切带破坏特征，低温下粉土表现出更强的刚度和更高的强度；随着温度降低，冻结粉土的应变软化现象增强，屈服应变降低，粘聚力和内摩擦角正切值均呈线性函数的增长趋势。冻结粉土抗剪性能的变化归因于低温下冰晶的骨架作用和体积膨胀效应。

Triaxial shear experiments were conducted to investigate the mechanical properties of silt in the slope of an earth-rock dam in a cold area, with testing carried out at 4 freezing temperatures and 3 different levels of consolidated surrounding rocks. The stress-strain curves and strength indexes were measured, revealing that frozen silt exhibits distinct shear zone failure characteristics and demonstrates increased brittleness and strength at lower temperatures. Furthermore, as temperature decreases, the strain softening phenomenon is intensified, leading to higher strength and yield strain. Additionally, it was observed that the cohesion and the tangent of the internal friction angle increase in a linear function with decreasing freezing temperature due to the influence of ice crystal formation and volume expansion at low temperatures.