纤维含量及长度对纤维加筋土强度的影响研究

Impacts of Fiber Content and Fiber Length on the Strength and Deformation of Fiber Reinforced Soil

纤维能随机分布在土体中,有助于增强纤维土复合体的力学性能,将其应用于路堤边坡处理工程中已取得良好效果,但目前关于纤维加筋土配合比的研究还难以量化。选取纤维含量和纤维长度(纤维含量为0%、0.1%、0.2%、0.3%,纤维长度为1.5cm、2.0cm、2.5cm)两个参数开展纤维加筋土无侧限抗压强度试验、直剪试验,研究聚丙烯纤维加筋土的抗压、抗剪和变形特性,揭示纤维含量和纤维长度对加筋土变形特征、强度特征和抗剪强度指标的影响规律,并研究纤维加筋土的最优配合比。结果表明:纤维的加入能改善土体的抗压、抗剪和变形特性,纤维能提高土体的内聚力,但对内摩擦角几乎没有影响;当纤维含量为0.2%、纤维长度为2.5cm时,纤维的加筋效果得到最大程度的发挥。该研究可为采用纤维加固路堤边坡工程提供设计依据,具有重要的工程意义。

Fiber can be randomly distributed in the soil,and can help to enhance the mechanical properties of fiber composite soil. The application of fiber to the embankment slope treatment project has a good effect, but the mix proportion of fiber reinforced soil is difficult to quantify. This paper carries out an unconfined compressive strength test and a direct shear test to research compressive properties,deformation properties and shear properties of polypropylene fiber reinforced soil. Fiber content is 0 %, 0.1 %,0.2 %, 0.1 %, and fiber length is 1.5 cm,2.0 cm,2.5 cm. These tests reveal the impact laws of the fiber content and fiber length of reinforced soil on the deformation characteristics, strength characteristics and shear strength indexes of reinforced soil; and the fiber optimal mixture ratio are studied. Results show that the addition of fiber can improve compressive, shear and deformation characteristics of the soil; fiber can improve the cohesion of the soil, but has little influence on internal friction angle;when the fiber content is 0.2 % ,length is 2.5 cm, reinforcement effect gets maximum. The study provides the design basis for the fiber reinforced embankment slope engineering,and has engineering significance for similar projects.