Yang Zhen, Mou Xianyou, Li Hao, Ji Honglan, Mao Yuxin, Song Hongze
College of Water Resources and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China.
Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reach of the Yellow River, Hohhot, 010018, China.
Sci Rep. 2025 Jan 9;15(1):1402. doi: 10.1038/s41598-025-85789-3.
The Inner Mongolia section of the Yellow River is a seasonal frozen soil area, where the freeze-thaw effect can alter soil strength and compressibility, affecting bank stability. This study takes the banks sandy silt of the Inner Mongolia section of the Yellow River as the research object. It systematically investigates the relationship between shear strength parameters and compression index of sandy silt and the initial dry density, water content, and freeze-thaw cycles of the soil. It analyzes the order and significance of influencing factors, establishes prediction models of shear strength and compression index, and evaluates the effects of freeze-thaw cycles on soil cohesion and shear strength. The results show that the shear strength index of sandy silt is proportional to changes in initial dry density and inversely proportional to changes in water content. After 10 freeze-thaw cycles, the cohesion of the soil decreases by 22.53 to 58.85%, and the shear strength decreases by 22.67 to 58.91%. The internal friction angle is less affected by freeze-thaw and tends to be stable overall. The smaller the initial dry density and the greater the water content, the greater the compression index and compressibility of the soil, but freeze-thaw has little effect on compression index. The factors affecting sandy silt shear strength and compression index are ranked as dry density > moisture content > freeze-thaw cycles. The stepwise regression model of soil shear strength and compression index based on initial dry density, water content, and freeze-thaw cycles is effective, providing technical guidance for engineering practice.
黄河内蒙古段属于季节性冻土区，冻融作用会改变土壤强度和压缩性，影响岸坡稳定性。本研究以黄河内蒙古段岸坡粉砂土为研究对象，系统地研究了粉砂土抗剪强度参数和压缩指数与土体初始干密度、含水量及冻融循环次数之间的关系，分析了各影响因素的主次和显著性，建立了抗剪强度和压缩指数的预测模型，并评价了冻融循环对土体黏聚力和抗剪强度的影响。结果表明：粉砂土抗剪强度指标与初始干密度变化成正比，与含水量变化成反比。经过10次冻融循环后，土体黏聚力降低22.53%～58.85%，抗剪强度降低22.67%～58.91%。内摩擦角受冻融影响较小，总体趋于稳定。土体初始干密度越小、含水量越大，其压缩指数和压缩性越大，但冻融对压缩指数影响较小。影响粉砂土抗剪强度和压缩指数的因素主次顺序为：干密度＞含水量＞冻融循环次数。基于初始干密度、含水量和冻融循环次数建立的土体抗剪强度和压缩指数逐步回归模型有效，可为工程实践提供技术指导。
