摘要
利用一种特殊颗粒材料-玻璃珠进行了一系列室内直剪试验,研究颗粒大小对颗粒材料力学行为的影响。试验一共考虑了3条近乎平行的级配曲线和4种颗粒摩擦情况:干燥状态、水浸润状态、水淹没状态和油浸润状态。试验结果表明,颗粒大小对颗粒材料的力学行为有显著影响,剪胀性随着粒径的增大而增强。为考虑颗粒大小对剪胀性的影响,提出了一种新的剪胀关系式。在该剪胀关系式中,剪胀系数为依赖于颗粒大小和颗粒摩擦等颗粒基本性质的变量。试验研究同时表明临界状态摩擦角随着颗粒大小的增加而增加。此外,从颗粒细观运动的角度提出了颗粒滑动的功能模型,推导出了功能方程,并以此揭示了颗粒大小对临界状态摩擦角影响的细观机制。
A study of the effect of particle size on mechanical behavior of granular materials is reported, by conducting a series of direct shear tests on a special granular material-glass bead. In this investigation, three approximately parallel grading curves are taken into consideration;and also four types of inter-particle friction conditions are concerned, including dry state, water-lubricated state, flooded state and oil-lubricated state. The test results indicate that particle size exerts a pronounced effect on mechanical behaviors of granular materials and that dilatancy is enhanced with the increase of particle size. On the basis of test results, a stress-dilatancy relationship is brought forward to appropriately take into account the effect of particle size on the dilatancy of granular materials. The dilatancy coefficient in this proposed relationship is revealed to be a variable dependent on particle size, inter-particle friction and other basic particle attributes. In the meantime the critical state friction angle is found to increase with the increasing particle size. In addition, an energy-work model of particle sliding behavior is proposed from a perspective of mesoscopic particle motions. Based on this proposed model, the energy-work equation is derived and the essential mesoscopic mechanisms underlying the effect of particle size on critical state friction angle are accordingly elaborated.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2014年第7期1878-1884,共7页
Rock and Soil Mechanics
基金
香港大学基础研究基金(No.10208227
No.10400889)
国家自然科学基金(No.51209237
No.41030747
No.51108472)
关键词
颗粒大小
直剪试验
剪胀关系
临界状态
功能模型
particle size
direct shear test
stress-dilatancy relationship
critical state
energy-work model
