冻融循环是季节性霜冻地区建筑物破坏和不稳定的主要原因之一。在这个过程中,土的力学性质受到影响,导致定居,cracking,或基础设施的变形。减轻或减少季节性霜冻地区建筑物霜冻破坏的发生已成为研究的重要课题。冻融(F-T)作用会影响加筋土内部水分的分布,改变冻融土的强度,与主要影响因素密切相关,例如初始水分含量,压实度,钢筋间距,冻融循环次数(FTC),冻结温度,和有效的垂直应力。粘合力是决定粘土抗剪强度的重要指标,这对分析F-T后内聚力的变化很重要。同时,粘合力与土壤水分含量密切相关。本研究通过FTC试验对这些主要影响因素(5个水平的6个因素)进行了正交实验,三轴试验,和含水率测试,以确定FTC后粘土的不排水内聚力和含水率,从而确定冻融条件下钢筋对土体强度的影响。根据实验结果,利用SPSS软件拟合了不同高度黏土下主要影响因素所表达的不排水内聚力和含水率的回归方程。当最高不排水内聚力值6.8、10.6、8.9kPa和最低含水率值24.0%时,利用Matlab软件获得了主要影响因素的优化方案。24.3%,26.2%出现在上部,分别测试粘土结构的中部和下部,在-15°C的冷冻温度和5倍FTC的条件下。并确定了水分含量的最佳组合,钢筋间距,压实密度,和垂直载荷在不同的高度。减少粉质粘土中的加筋间距有利于F-T后的液体水下渗流。土壤样品中内部水分的重新分布增强了其不排水的凝聚力,从而提高土壤的抗剪强度。比较不同位置的加固条件,发现当它们之间有3层间距为150毫米的钢筋时,这个间距是最佳的。在提高土体抗剪强度和提高其承载力方面发挥了重要作用。对于增强粘土本身,F-T后影响土体不排水黏聚力的主要因素顺序,从高到低,是初始水分含量,钢筋间距,和压实度。
The freezing and thawing cycle is one of the primary causes of damage and instability to buildings in seasonal frost regions. During this process, the mechanical properties of soil are affected, leading to settlement, cracking, or deformation of infrastructure. Mitigating or reducing the occurrence of building frost damage in seasonal frost regions has become an important subject of study. Freeze-thaw (F-T) action will influence the distribution of moisture inside the reinforced soil and change the strength of thawing soil, which is closely related to the main influencing factors, such as initial moisture content, compaction degree, reinforced spacing, number of freeze-thaw cycles (FTC), freezing temperature, and effective vertical stress. Cohesion is an important index to determine the shear strength of clay, which is important to analyze the change in cohesion after F-T. Meanwhile, cohesion is closely related to soil moisture content. This study conducted orthogonal experiments on these primary influencing factors (6 factors at 5 levels) through FTC tests, triaxial tests, and moisture content tests to determine the undrained cohesion and moisture content of the clay after FTC, thereby establishing the influence of reinforcement on soil strength under freeze-thaw conditions. Based on the experimental results, SPSS software was used to fit the regression equations of undrained cohesion and moisture content expressed by the main influencing factors at different heights of the clay. Optimization options for the main influencing factors were obtained with Matlab software when the highest undrained cohesion values 6.8, 10.6, 8.9 kPa and lowest moisture content values 24.0%, 24.3%, 26.2% appeared in upper, middle and lower parts of the testing clay structure respectively, in conditions of - 15 °C freezing temperature and 5 times FTC. And determined the optimal combinations of moisture content, reinforcement spacing, compaction density, and vertical load at different heights. Decreasing reinforced spacing in silty clay was beneficial for liquid underwater seepage after F-T. The redistribution of internal moisture in the soil sample strengthened its undrained cohesion, thereby increasing the soil\'s shear strength. Comparing reinforcement conditions at different locations, it was found that when there were 3 layers of reinforcement with a spacing of 150 mm between them, this spacing was optimal. It played a significant role in improving the soil\'s shear strength and enhancing its bearing capacity. For reinforced clay itself, the order of the main factors influencing the undrained cohesion of soil after F-T, from high to low, was initial moisture content, reinforced spacing, and compaction degree.