椰壳纤维土的三轴试验研究

摘要

Laboratory triaxial tests are carried out to study the stress-strain relationship and strength property of coir fibre-reinforced soil.The reinforcement effect and the change rule in different reinforced cases are investigated.The experimental results showed that: mixing coir fibre in the red clay can improve the ability of deformation resistance.Only when the strain is big enough can the reinforced effect of coir fibre shows, and stronger effect at the bigger axial strain with the increase of triaxial strain.The stress-strain curve of coir fibre-reinforced soil is similar to a hyperbola, whose main damage mode is shown as ballooning destruction.It was shown that not only the cohesion but also the internal friction angle are improved when mixing coir fibre in the red clay.And the cohesion increases obviously, but the internal friction angle increases less.The reinforcement effect of coir fibre-reinforced soil improves gradually with the increase of dosage in the same conditions.The reinforcement effect of coir fibre-reinforced soil turns better with the lower confining pressure in the same conditions.%采用室内三轴试验的方法,研究了椰壳纤维土的应力-应变关系及强度特性.探讨了不同加筋情况下椰壳纤维土的加筋效果及变化规律.试验结果表明:在红黏土中掺入椰壳纤维,能够提高土体抵抗变形的能力;椰壳纤维的加筋作用只有当试样的应变足够大时才能发挥出来;且随着轴向应变的增加,椰壳纤维土的加筋作用越来越明显;椰壳纤维土的应力-应变曲线近似呈双曲线,其试样的主要破坏形式表现为鼓胀破坏;在红黏土中加入椰壳纤维后,纤维土的黏聚力c值和内摩擦角φ值均有一定的提高;其中黏聚力c值提高明显,而内摩擦角φ值变化不明显;相同条件下,随着椰壳纤维掺量的增加,椰壳纤维土的加筋效果逐渐提高;相同条件下,围压越低,纤维土的加筋效果越好.