聚丙烯纤维对加筋砂力学性能的影响

Influence of Polypropylene Fibers on Mechanical Properties of Reinforced Sand

摘要:

以聚丙烯纤维为研究对象，通过一系列室内排水三轴压缩试验，研究了聚丙烯纤维对加筋砂的力学性能影响，重点研究了其应力应变特性、胀缩性和抗剪强度参数。试验结果表明：在有效围压50、100、150 kPa的条件下，与纯砂相比，聚丙烯纤维加筋砂的偏应力峰值和延性有显著提高，偏应力峰值较纯砂增长了30%、18%、10%，延性分别提升了61%、86%、83%；在胀缩性方面，纤维加筋材料对小应变下的收缩性几乎没有影响，而在较大应变下，纤维加筋材料显著抑制了土体的膨胀性。此外，聚丙烯纤维加筋砂的抗剪强度参数（内摩擦角和黏聚力）较纯砂均有所增加，黏聚力增加了128%，而内摩擦角仅增加了2%。

Abstract:

Taking polypropylene fibers as the research object, through a series of indoor drained triaxial compression tests, the influence of polypropylene fibers on the mechanical properties of reinforced sand is studied, and the focus is on its stress-strain characteristics, expansion and contraction properties, and shear strength parameters. The test results show that under the conditions of effective confining pressures of 50, 100, and 150 kPa, compared with pure sand, the peak deviatoric stress and ductility of polypropylene fiber reinforced sand have significantly improved. The peak deviatoric stress has increased by 30%, 18%, and 10% compared to pure sand, and the ductility has increased by 61%,86%, and 83% respectively. In terms of expansion and contraction properties, the fiber reinforced material has almost no effect on the contraction under small strains, while under larger strains, the fiber reinforced material significantly inhibits the expansion of the soil. In addition, the shear strength parameters （internal friction angle and cohesion) of polypropylene fiber reinforced sand have increased compared to pure sand. The cohesion has increased by 128%, while the internal friction angle has only increased by 2%.