摘要
以甘肃黑方台地区非饱和黄土的多种强度测试数据为主,辅以其他地点的黄土强度测试结果,反算了吸应力和广义有效应力,实现了非饱和黄土强度包络线的归一化;进一步验证了基于吸应力特征曲线和土水特征曲线对广义有效应力原理的合理性和实用性.结果表明:当有效饱和度(S_e)<80%时,基于吸应力的强度理论公式对同一批次的散点数据拟合度很高;当S_e>80%时,其拟合的精确度较差,统一饱和标准和饱和方法可提高拟合度;表明常规强度试验反算的吸应力和广义有效应力,或者直接用吸应力理论公式计算的广义有效应力,从而获取抗剪强度,实现非饱和土强度理论的实用化思路是可行的;吸应力计算结果更接近实际、更实用,而基质吸力测试偏离实际且复杂.
Supported mainly by multiple types of strength test data on unsaturated loess in Heifangtai,Gansu,as well as results from other locations,suction stress and generalized effective stress were computed inversely,realizing the aim of normalization of the strength envelope of unsaturated loess.The theoretical equation of suction stress was utilized to fit the scattered suction stress data derived from an inverse calculation from strength test data.The results demonstrated that,when the effective degree of saturation,S_e<80%,the theoretical equation gave a high fitting degree of scattered data from the same batch;when S_e>80%,it had an unsatisfactory fitting degree;unifying saturation standard and saturating method could improve the fitting degree.Inversion of suction stress and generalized effective stress of the conventional strength test,or a direct calculation of suction stress theory formula of generalized effective stress,so as to obtain the shear strength,was feasible for the unsaturated soil strength theory in a practical sense.And the suction stress calculation results were more close to the actual ones and of more the utility,and the matrix suction test deviated from the actual and complex.This paper has successfully verified the workability and validity of suction-stress-characterized principle of generalized effective stress in the practical use of strength theory concerning unsaturated loess.
作者
冯立
胡炜
张茂省
朱立峰
Feng Li;Hu Wei;Zhang Mao-sheng;Zhu Li-feng(Key Laboratory for Geo-hazards in Loess Area,Ministry of Land and Resources,Xi'an Centerof Geological Survey,China Geological Survey,Xi'an 710054,China)
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
2018年第5期619-625,共7页
Journal of Lanzhou University(Natural Sciences)
基金
国土资源公益性行业科技专项经费项目(201511056-4)
国家自然科学基金重点项目(41530640).
关键词
非饱和土
强度理论
吸应力
广义有效应力
unsaturated loess
strength theory
suction stress
generalized effective stress
