一个考虑颗粒破碎的堆石料弹塑性本构模型

基于广义塑性理论建立了一个考虑堆石料颗粒破碎的弹塑性本构模型。模型采用随平均应力增加而减小的峰值摩擦角和特征点摩擦角来反映堆石料因颗粒破碎而表现出的峰值应力比与剪胀应力比的非线性，在此基础上确定塑性流动和加载方向向量；运用指数型压缩函数建立依赖于体积应变和平均应力的压缩参数 λ ，并构造随平均应力与剪应力水平而变化的塑性模量表达式。模型共有 8 个参数，均可通过等向或单向压缩和三轴压缩试验确定。为验证本文模型的合理性，依据试验资料确定了 3 种不同堆石料的本构模型参数，并对典型三轴压缩试验进行了模拟。 3 种材料的模型预测结果与试验数据均吻合良好，表明本文模型可合理反映了颗粒破碎对堆石料强度与变形特性的影响。

An elastoplastic model for rockfill materials considering particle breakage

An elastoplastic constitutive model considering the particle breakage is proposed for rockfill materials within the framework of generalized plasticity.In the model,both the peak friction angle and the characteristic friction angle decrease with the increase of the mean stress so that the nonlinear dependence of the peak stress ratio and the dilatancy stress ratio on the mean stress is captured.The plastic flow direction and the loading direction are then formulated using the above characteristic stress rat...