不同应力路径下绢云母片岩粗粒料力学特性试验研究  

EXPERIMENTAL STUDY OF MECHANICAL PROPERTIES OF COARSE AGGREGATES OF SERICITE SCHIST UNDER DIFFERENT STRESS PATHS

作　　者：秦尚林[1] 杨兰强 高惠[1] 陈善雄[1] 罗伟锦 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]浙江省工程勘察院,浙江宁波315010

出　　处：《岩石力学与工程学报》2014年第9期1932-1938,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51079142);中国科学院重点部署项目(KZZD-EW–05);湖北省交通科技项目(20117003.3)

摘　　要：绢云母片岩粗粒料大量用于谷城—竹溪高速公路路基填筑,为研究不同应力路径下绢云母片岩粗粒料的力学特性,采用大型三轴试验机,对绢云母片岩粗粒料分别进行常围压下的固结排水、固结不排水三轴试验以及等p应力路径下的固结排水试验。研究表明,低围压条件下,应力–应变曲线均表现为应变硬化型,但是在高围压条件下,却出现了应变微软化现象。在整个试验过程中,体积应变均以剪缩为主,并没有出现低围压剪胀的现象;并通过分析该粗粒料的破碎特征阐述了出现这种反常现象的原因。另外,通过对不同应力路径下的绢云母片岩粗粒料进行强度分析,验证了Duncan非线性强度准则对绢云母片岩粗粒料具有良好的适用性。Coarse aggregates of sericite schist are widely used in the construction of Gucheng-Zhuxi expressway as subgrade fillings. In order to study the mechanical properties of coarse aggregates of sericite schist,a series of large-scale triaxial tests under different stress paths were carried out,including the conventional drained triaxial, conventional undrained triaxial and constant p tests. All of the stress-strain curves under the low confining pressures exhibited the strain hardening phenomenon. However,the stress-strain curves exhibited the weak strain softening behavior under the high confining pressures. The volumetric strains were found to be mainly shear contraction under different confining pressures,and no shear dilatancy behavior appeared under low confining pressure. The reason of the abnormal strain change behaviour was explained through the analysis of the breakage characteristics of particles. In addition,it is verified that the Duncan′s nonlinear strength criterion has a good applicability for the sericite schist coarse aggregates.

关 键 词：土力学 绢云母片岩粗粒料 应力路径 力学特性 颗粒破碎 

分 类 号：TU43[建筑科学—岩土工程]