秸秆纤维加筋固化土物理力学特性与抗冻融性能试验研究

Experimental Study on Physical and Mechanical Properties and Freeze-Thaw Resistance of Straw Fiber Reinforced Solidified Soil

为有效解决高寒地区开挖边坡冻融侵蚀严重、生态修复等难题,结合多雄拉工业广场开挖边坡气候特征,在传统改性材料固化砂土的基础上,通过掺入不同比例的秸秆纤维,对秸秆纤维加筋固化土的渗透性、抗剪强度和抗冻融性能进行测试,分析加筋固化效果,探寻最优配比,并揭示加固机理。结果表明:与纯砂土相比,加入改性材料和秸秆纤维后,降低了土体渗透性,增加了土体的黏聚力,内摩擦角基本保持不变;含水率是土体渗透性能的主要影响因素,秸秆纤维是土体黏聚力的主要影响因素;此外,加固土抗冻融性能明显优于纯土,当改性材料、水、秸秆纤维分别占砂土质量0.234%、15%和0.3%时,秸秆纤维加筋固化土的抗冻融性能最佳。研究成果对于明确秸秆纤维加筋固化土的内在机制有参考价值。

To effectively address the issues of severe freeze-thaw erosion and ecological restoration of excavated slopes in alpine regions,our study focused on the excavation slopes in the Duoxiongla Industrial Plaza as a case study.In view of the climatic characteristics and based upon traditional solidified sand with modified materials,we investigated the effects of adding different proportions of straw fiber on the permeability,shear strength,and freeze-thaw resistance of straw fiber reinforced solidified soil.Our analysis aims to examine the effectiveness of reinforcement and solidification,explore optimal ratios,and reveal the underlying reinforcement mechanism.Results demonstrate that the addition of modified material and straw fiber reduced soil permeability and increased soil cohesion when compared to pure sand.Moreover,the internal friction angle remains essentially unchanged.Moisture content is the primary factor that affects soil permeability,while straw fiber is the main contributor to soil cohesion.In addition,the freeze-thaw resistance of reinforced soil is significantly better than that of pure soil.The highest level of freeze-thaw resistance can be achieved when modified material,water,and straw fiber account for 0.234%,15%,and 0.3%of sand mass,respectively.