摘要
为了进一步研究横观各向同性非饱和重塑黄土在复杂应力路径下的变形及强度特性,采用不同试验仪器(非饱和真三轴仪及非饱和三轴仪)对横观各向同性非饱和土体进行了3组共计39个固结剪切试验。结果表明:在真三轴剪切试验中,试样的应力-应变关系曲线呈现出应变硬化特征,并具有双曲线形态,应力也随吸力的增加而提高;随着剪切过程的持续,真三轴试样的含水率不断减小,相同b值、净围压条件下,吸力越大,含水率-轴向应变关系曲线斜率也越大;真三轴试样、K_(0)CD试验试样及K_(0)′CD试验试样在剪切试验中始终呈现剪缩状态;3种不同初始条件下试验试样的破坏应力大小依次为真三轴试验试样最大,K_(0)CD试验试样次之,K_(0)′CD试验试样最小;K_(0)CD试验试样的初始切线模量最大,K_(0)′CD试验试样次之,真三轴试验试样最小。研究成果对于推动横观各向同性非饱和黄土的力学性质研究、完善相关理论和准则、以及指导工程实践具有指导意义。
In order to further investigate the deformation and strength characteristics of transversely isotropic unsaturated remolded loess under complex stress paths,three sets of 39 consolidation shear tests were conducted on transversely isotropic unsaturated soil using different experimental instruments(unsaturated true triaxial apparatus and unsaturated triaxial apparatus).The results show that:In true triaxial shear tests,the stress-strain relationship curve of the specimen exhibits strain hardening characteristics and has a hyperbolic shape,and the stress also increases with the increase of suction force.As the shearing process continues,the moisture content of the true triaxial specimen decreases continuously.Under the same b value and net confining pressure conditions,the greater the suction force,the greater the slope of the moisture content axial strain relationship curve.The true triaxial specimen,K_(0) CD test specimen,and K_(0)′CD test specimen consistently exhibit a state of shear shrinkage during the shear test.The magnitude of the failure stress of the test specimens under three different initial conditions is highest for the true triaxial test specimen,followed by the K_(0) CD test specimen,and lowest for the K_(0)′CD test specimen.The initial tangent modulus of the K_(0) CD test specimen is the highest,followed by the K_(0)′CD test specimen,and the true triaxial test specimen is the smallest.The research results are of great significance for promoting the study of mechanical properties of transversely isotropic unsaturated loess,improving relevant theories and criteria,and guiding engineering practice.
作者
郭楠
贾世宁
杨校辉
陈正汉
Guo Nan;Jia Shining;Yang Xiaohui;Chen Zhenghan(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,P.R.China;Department of Military Installation,Army Service University,Chongqing 401311,P.R.China)
出处
《地下空间与工程学报》
北大核心
2025年第6期1935-1945,共11页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(42462028,52168051,52368049)
兰州市青年科技人才创新项目(2023-QN-52,2023-QN-27)
兰州理工大学红柳优秀青年人才支持计划(04-062214)。
关键词
横观各向同性
非饱和重塑黄土
真三轴试验
力学特性
中主应力系数
transverse isotropy
unsaturated remolded loess
true triaxial test
mechanical properties
intermediate principal stress ratio
