纤维参数和围压对纤维加筋风沙土力学特性的影响

发布时间：2018-03-07 16:24

本文选题：土力学　切入点：风沙土　出处：《岩石力学与工程学报》2015年S2期 　论文类型：期刊论文

【摘要】：通过不固结不排水三轴压缩试验研究纤维长度(3~18 mm)、纤维掺量(0.1%~0.3%)和围压(30~300 k Pa)对聚丙烯纤维三维加筋风沙土强度特性的影响。试验结果表明:在试验方案内,纤维长度、纤维掺量和围压的提高均能有效地增强纤维加筋风沙土的破坏强度和残余强度。随着纤维长度和掺量的增加,纤维加筋风沙土黏聚力提升显著,而内摩擦角提升微小。纤维长度的增加可使纤维加筋风沙土应变软化型过渡为应变硬化型,破坏韧性提高微小。随着纤维掺量的增加,3 mm纤维加筋风沙土始终保持为应变软化型,破坏韧性没有提升;9和18 mm纤维加筋风沙土均由应变软化型过渡为应变硬化型,破坏韧性明显提升。随着围压的增加,纤维加筋风沙土破坏韧性和应变硬化程度得以提高。破坏强度与围压关系以临界围压为转折点呈双线性。临界围压前,加筋作用主要体现为内摩擦角的提升;临界围压后,加筋作用主要体现在黏聚力的增强。
[Abstract]:The effects of fiber length (318mm), fiber content (0.1%) and confining pressure (30kPa) on the strength characteristics of polypropylene fiber reinforced sandy soil were studied by unconsolidated and undrained triaxial compression test. The increase of fiber content and confining pressure can effectively enhance the failure strength and residual strength of fiber-reinforced wind-sand soil. With the increase of fiber length and content, the cohesive force of fiber-reinforced wind-sand soil increases significantly. The increase of fiber length can make the strain-softening type of wind-sand soil reinforced by fiber become strain-hardening type. With the increase of fiber content, the sand soil reinforced by 3 mm fiber always remains strain-softening type, and the failure toughness does not increase from strain softening type to strain hardening type, and the failure toughness is not improved by 9 mm and 18 mm fiber reinforced sand soil, and the strain softening type is changed from strain softening type to strain hardening type with the increase of fiber content. With the increase of confining pressure, the failure toughness and strain hardening degree of fiber-reinforced wind-sand soil are improved. The relationship between failure strength and confining pressure is bilinear with the critical confining pressure as the turning point. The reinforcement effect is mainly reflected in the increase of the internal friction angle, and after the critical confining pressure, the reinforcement effect is mainly reflected in the enhancement of the cohesion force.
【作者单位】：哈尔滨工业大学土木工程学院;佳木斯大学建筑工程学院;哈尔滨工业大学交通科学与工程学院;
【基金】：国家自然科学基金重点项目(41430634) 国家重点基础研究发展计划(973)项目(2012CB026104) 神华集团创新项目(201212240384)
【分类号】：TU411

【参考文献】