聚丙烯纤维改良粉土剪切性能的研究  

THE SHEAR PERFORMANCE OF SILTY SOIL IMPROVED WITH POLYPROPYLENE FIBERS

作　　者：李儒潼 LI Rutong(Liaocheng University,Shandong Liaocheng 252000,China)

机构地区：[1]聊城大学,山东聊城252000

出　　处：《低温建筑技术》2025年第1期126-128,137,共4页Low Temperature Architecture Technology

摘　　要：为改善粉土路基强度较低、容易松散、稳定性差的状况,使用聚丙烯纤维改良粉土并开展直接剪切试验,研究9 mm聚丙烯纤维改良土在掺量为0.25%、0.5%、0.75%加筋条件下,对土体抗剪强度及剪切参数的影响。试验结果表明,加筋土抗剪强度在掺入0.5%纤维之前,随着纤维掺量的增加不断增强,250 kPa垂直压力下最大抗剪强度达到63.54 kPa;超过0.5%掺量后,抗剪强度开始降低;0.5%掺量的聚丙烯纤维改良土内摩擦角相较素土提高了3.44°。聚丙烯纤维改良粉土剪切性能的最优掺量为0.5%,聚丙烯纤维通过增强土体之间的摩擦力,有效提高了土体的抗剪强度,但土体间黏聚力不受影响,研究可为粉土路基的加固与改良提供科学依据。Polypropylene fibers are used to improve silty soil to address the issues of low strength,looseness,and poor stability of silty subgrades,in which direct shear tests are conducted.We investigate the effectiveness of 9 mm polypropylene fibers with reinforcement content of 0.25%,0.5%,and 0.75%on the shear strength and shear parame⁃ters of the soil.The results indicate that the shear strength of the reinforced soil increased continuously with the fiber content before reaching 0.5%,achieving a maximum shear strength of 63.54 kPa under a vertical pressure of 250 kPa.When the fiber content is beyond of 0.5%,the shear strength is prone to decrease.The internal friction angle of the soil improves by 3.44°comparing to unreinforced soil at a fiber content of 0.5%.The optimal fiber content for im⁃proving the shear performance of silty soil is determined to be 0.5%.Polypropylene fibers effectively enhance the shear strength of the soil by increasing the friction between soil particles,although the cohesion of the soil remained unaffected.This study may provide a scientific basis for the reinforcement and improvement of silty subgrades.

关 键 词：纤维加筋土 聚丙烯纤维改良土 内摩擦角 直接剪切试验 抗剪强度 

分 类 号：TU521.3[建筑科学—建筑技术科学]