【摘要】 为研究聚丙烯纤维掺入长度、含量以及分布形式对黄土加固效果的影响，通过均匀和不均匀加筋方案的室内大型直剪试验(其中，不均匀加筋分三层夯入加筋土，通过改变剪切盒两侧的加筋含量实现),得到加筋黄土的抗剪强度-剪切应变曲线及其抗剪强度指标。研究结果表明：(1)聚丙烯纤维的掺入能有效提高黄土抗剪强度，加固效果受到纤维长度、掺量以及法向应力耦合影响；(2)在均匀加筋方案中，纤维长度12 mm、掺量0.5%的加固效果最佳；在不均匀加筋方案中，当法向应力为50 kPa,剪切面影响范围<15 mm,当法向应力为100 kPa,剪切面影响范围略>35 mm,当法向应力为200 kPa,剪切面影响范围进一步增大；(3)纤维的分布形式对加固效果具有明显影响，相比于整体0.8%含量加筋组，将两侧加筋含量降低为0.5%后的不均匀加筋加固效果更好，因为避免了高含量纤维导致的成团现象，从而保证土颗粒和纤维间的粘结。研究成果有望为黄土纤维加筋优化布筋方式提供参考。更多还原

【Abstract】 To investigate the effects of polypropylene fiber length, content, and distribution on loess reinforcement, a large-scale indoor direct shear test was designed for both uniform and non-uniform reinforcement schemes. In the non-uniform reinforcement, the fiber content was varied on both sides of the shear box and rammed into the soil in three layers. The curves of shear strength versus shear strain and shear strength indices of the reinforced loess were obtained. The results indicate: 1) Incorporating polypropylene fibers significantly enhances loess shear strength, with the reinforcement effect influenced by fiber length, dosage, and normal stress coupling. 2) In the uniform reinforcement scheme, a fiber length of 12 mm and a content of 0.5% achieves the best reinforcement effect. In the non-uniform reinforcement scheme, the influence range of the shear plane is less than 15 mm at normal stress of 50 kPa, slightly greater than 35 mm at 100 kPa, and further increased at 200 kPa. 3) The distribution pattern of fibers significantly impacts the reinforcement effect. Compared to a uniform 0.8% content group, non-uniform reinforcement with 0.5% content on both sides yields better results, as it avoids fiber agglomeration and ensures soil-fiber adhesion. These findings are expected to provide valuable insights for optimizing loess fiber reinforcement.更多还原