堆石混合料临界状态与颗粒破碎特性

Critical state and particle breakage characteristics of rockfill mixture

文章开展了5组不同混合比的堆石料的大型三轴固结排水剪切试验,研究了随混合比变化堆石混合料颗粒破碎率与临界状态应力比的变化规律。试验结果表明:(1)随弱风化料占比增加,堆石料的峰值强度及临界状态强度均提高,剪胀程度增大。(2)Hardin相对破碎率较好地描述了堆石混合料的颗粒破碎规律,破碎率越大,p′-q平面上临界状态线表现出越明显的下弯。(3)峰值状态内摩擦角随Hardin相对破碎率的增加总体呈线性减小;临界内摩擦角随Hardin相对破碎率Br的增加开始缓慢减小,而后快速减小,最后趋于平稳。

Large-scale consolidated and drained triaxial tests on rockfill mixture were performed to investigate the effects of five mixing ratio of strongly and weakly weathered rockfills on the particle breakage and the critical state stress ratio of the mixture.Findings based on the tests can summarized below:(1)With the increasing proportion of weakly weathered rockfill,the peak strength and critical strength of the mixture conspicuously increase,and the dilatancy increases as well.(2)The Hardin relative breakage ratio can adequately describe the breakage phenomena of the mixture;critical state line in the p'-q plane presents nonlinearity at higher breakage ratio.(3)The internal friction angle at peak state declines with the increasing Hardin relative breakage ratio;while at critical state,the internal friction angle firstly decreases gently,then decreases obviously and finally tends to become stable.