岩土工程学报2013，Vol.35Issue(z1)：44-51,8.
基于库仑定律的CU总应力切线和割线强度指标数理意义释义和适用性研究
Mathematical and physical significances and applicability of tangent and secant strength indices of total stress of consolidated undrained triaxial tests based on Coulomb's law
摘要
Abstract
Most of the strength criteria for soils should satisfy the Coulomb's law on the failure surface,and the effective stress strengh indices of isotropic soil are unique under different drainage conditions.The mathematical and physical meanings of triaxial total stress strength indices are investigated based on the relationship between the excess pore pressure at failure in Coulomb's law under undrained conditions and that in consolidated undrained (CU) triaxial tests.The results show that,in view of the linear envelope of the Coulomb's law under drained and undrained conditions,the pore pressure coefficient Df is proved to be constant,which is related to the normal stress state on the failure surface.The existence of linear total stress failure envelop of CU is based on the certain relationship among Skempton's pore pressure coefficients Af,Dr,cohesion and deviator stress at failure.The corresponding expression is also obtained.Furthermore through the strength parameters of CU tests,the secant strength indice.s,(φ)R and cR,are obtained.It provides more reasonable and operational method for engineering problems with known sliding surfaces.However if the total stress tangent strength indices of CU are used,the strength will be overvalued by more than 10％,which will cause great security risk.关键词
库仑定律/原状黏土/三轴压缩试验/总应力强度指标/孔压系数Key words
Coulomb's law/ undisturbed clay/ triaxial compression test/ total stress strength index/ pore pressure coefficient分类
建筑与水利引用本文复制引用
沈扬,葛冬冬,徐海东,张超波..基于库仑定律的CU总应力切线和割线强度指标数理意义释义和适用性研究[J].岩土工程学报,2013,35(z1):44-51,8.基金项目
国家自然科学基金高铁联合项目(U1134207) （U1134207）
"长江学者和创新团队发展计划资助"(IRT1125) （IRT1125）
