CAJ | 학술논문

利用双压力室非饱和三轴仪,进行非饱和黏土脱湿、等吸力固结和排水剪切试验,研究非饱和黏土的体变、屈服和强度特性,结果表明:在低吸力范围内,非饱和黏土在脱湿过程中的体积收缩呈弹塑性体变性状,验证了非饱和土本构模型中SI屈服曲线的存在;在等吸力固结试验中,黏土固结屈服应力随着吸力增加而增加,LC屈服曲线呈二次抛物线变化,固结压力的增长比基质吸力的增长对体变性状的影响效应要大.在剪切试验中,非饱和黏土应力应变关系依赖于净围压和基质吸力的不同组合,基质吸力增强土体应力-应变关系的硬化特性;在不同的吸力条件下,固结排水剪的有效内摩擦角基本不变,黏聚力的增长与吸力的增长基本呈线性关系.
이용쌍압력실비포화삼축의,진행비포화점토탈습、등흡력고결화배수전절시험,연구비포화점토적체변、굴복화강도특성,결과표명:재저흡력범위내,비포화점토재탈습과정중적체적수축정탄소성체변성상,험증료비포화토본구모형중SI굴복곡선적존재;재등흡력고결시험중,점토고결굴복응력수착흡력증가이증가,LC굴복곡선정이차포물선변화,고결압력적증장비기질흡력적증장대체변성상적영향효응요대.재전절시험중,비포화점토응력응변관계의뢰우정위압화기질흡력적불동조합,기질흡력증강토체응력-응변관계적경화특성;재불동적흡력조건하,고결배수전적유효내마찰각기본불변,점취력적증장여흡력적증장기본정선성관계.
A series of triaxial tests were carried out using double-cell triaxial system for unsaturated soils to investigate the behavior of volume change,yield and strength of unsaturated clays. The stress paths included drying with isotropic stress,isotropic compression and shearing with controlled suction. The results show that the clay exhibited an elasto-plastic shrinkage upon drying with low suction,indicating the existence of the suction- increase(SI) yield locus. During isotropic compression,the yield stress increases with increase of suction and the loading collapse(LC) yield curve changes parabolically. Increasement of net normal stress has more significant effect on the behavior of volumetric change than that of matric suction. The stress-strain relationship depends on the combinational style of net normal stress and matric suction,and suction enhances the stress-strain stiffness feature during triaxial shear test. Under conditions of different values of constant suctions,the effective friction angle is approximate a constant,and cohesion coefficient versus suction relationship is approximately linear.