粗粒料强度和变形的大型三轴试验研究

通过大型三轴试验，对高低围压下粗粒料的应力应变特性、抗剪强度、内摩擦角和颗粒破碎特性进行了对比分析，并探讨了不同泥岩含量对堆石坝料强度的影响。结果表明：中高围压下粗粒料表现出应变硬化特性和剪缩，强度包线和不同围压下的最大主应力比与剪胀率的关系近似为线性，而低围压下主要表现为应变软化和剪胀，抗剪强度包线等表现为非线性。随着围压的增加，主应力比降低、颗粒破碎率增大、内摩擦角减小。泥岩含量的增加使颗粒表面的摩擦阻力与粒间的咬合力减弱，导致抗剪强度降低。

Research on strength and deformation behavior of coarse aggregatesbased on large-scale triaxial tests

The stress-strain relationship, strength and particle breakage properties of coarse aggregates under high and low confining pressures are analyzed detailedly. The influence of the content of mudstone on the strength behavior of rockfill is also studied. Test results indicate that under high confining pressures coarse aggregates are characterized by strain hardening and volumetric compression, Mohr-Coulomb envelope and relationship between peak principal stress ratio and dilatancy approximate to linear, while under low confining pressures they exhibit strain softening, volumetric dilatancy and nonlinear respectively. With the increasing of confining pressure principal stress ratio and internal friction angle decrease, while particle breakage index increases. The increasing content of mudstone results in the decrease of rockfill strength.