不同应力路径下粗粒料的颗粒破碎试验研究

An experimental study on particle breakage of coarse-grained materials under various stress paths

采用大型三轴试验机,对粗粒料进行了常规三轴、等p和等应力比等不同应力路径的试验,研究了粗粒料在不同应力路径下的颗粒破碎情况,分析了应力路径对颗粒破碎和强度特性的影响,并对颗粒破碎与塑性功之间的关系进行了探讨。试验结果表明,应力路径对粗粒料的强度特性影响并不显著;颗粒破碎主要与加载过程中输入的塑性功有关,颗粒相对破碎率随着输入塑性功的增大而增大,与塑性功呈较好的双曲线关系;颗粒破碎的增加将导致峰值内摩擦角的减小,峰值内摩擦角与颗粒相对破碎率之间呈线性关系。

A series of large-scale triaxial tests under various stress paths for coarse-grained materials were performed,including the conventional triaxial tests,constant p tests and constant stress ratio tests.The particle breakage of these materials was investigated.The impact of stress on particle breakage and strength characteristics was analyzed and the relationship between particle breakage and plastic work was discussed.The test results indicate that the stress path has little influence on strength characteristics of coarse-grained materials,the particle breakage depends on plastic work of the sample during the test.The particle breakage index increases with the increase of plastic work,and the relationship between particle breakage index and plastic work can be expressed by hyperbolic curves.The increase of particle breakage will result in decreasing of the strength of coarse-grained materials,and the relationship between the angle of internal friction and particle breakage index can be expressed as linear function.