聚丙烯纤维加筋绍兴非饱和黏土的剪切特性研究  

Study on Shear Characteristics of Shaoxing Unsaturated Clay Reinforced With Polypropylene Fibers

作　　者：吴瑞潜 项祺辰 杨光 吴早生 WU Ruiqian;XIANG Qichen;YANG Guang;WU Zaosheng(School of Civil Engineering,Shaoxing University,Shaoxing 31200,Zhejiang,China;Huahui Engineering Design Group Co.,Ltd.,Shaoxing 31200,Zhejiang,China)

机构地区：[1]绍兴文理学院土木工程学院,浙江绍兴312000 [2]华汇工程设计集团股份有限公司,浙江绍兴312000

出　　处：《力学季刊》2023年第1期172-180,共9页Chinese Quarterly of Mechanics

基　　金：浙江省教育厅项目(Y201839206,FG2018148)。

摘　　要：为了研究纤维加筋非饱和土的剪切特性,以绍兴地区广泛分布的非饱和黏土为研究对象,聚丙烯纤维为加筋材料,通过一系列非饱和直剪试验,探讨了纤维长度对加筋土剪切变形特性、抗剪强度及其指标的影响规律,并简要分析了聚丙烯纤维的增强机理,最后得出了0.2%掺量下补强效果最佳的纤维长度.研究结果表明:随着净法向应力的增大,土体的剪应力-剪切位移曲线由软化型逐渐向硬化型转化,纤维长度L为12 mm的加筋土样表现出的剪切硬化特性最明显;不同净法向应力下,纤维加筋非饱和土的抗剪强度均高于素土;随着纤维长度的增加,纤维加筋土的黏聚力呈先增加后减小,内摩擦角先增加后趋于平缓;当纤维长度L为12 mm时,聚丙烯纤维对土体抗剪强度指标的补强效果能够最大程度得到发挥.In order to study the shear characteristics of fiber reinforced unsaturated soil,the widely distributed unsaturated clay in Shaoxing area is taken as the research object,the polypropylene fiber is used as the reinforced material.The effect of fiber length on the shear deformation characteristics,the shear strength and its indicator of reinforced soil is discussed through a series of unsaturated direct shear tests,and the strengthening mechanism of polypropylene fiber is briefly analyzed.In this way,the optimal fiber length with the best reinforcement effect under 0.2%addition is obtained.The results show that with the increase of net normal stress,the shear stress-shear displacement curve of soil gradually transforms from softening type to hardening type,and the shear hardening effect is most obvious for the reinforced soil with fiber length of 12 mm.The shear strength of fiber reinforced unsaturated soil is higher than that of plain soil under different net normal stress.With the increase of fiber length,the cohesion strength of fiber reinforced soil first increases and then decreases,and the internal friction angle first increases and then tends to smooth.When the fiber length is 12 mm,the reinforcement effect of polypropylene fiber on the soil shear strength indicator can be maximized.

关 键 词：纤维加筋土 纤维长度 非饱和黏土 抗剪强度 

分 类 号：TU447[建筑科学—岩土工程] TU43[建筑科学—土工工程]