考虑临界状态的堆石料广义塑性本构模型

Generalized Plastic Constitutive Model of Rockfill Materials Considering Critical State

基于大型静力三轴剪切试验结果,构造了考虑颗粒破碎的塑性模量表达式和考虑临界状态的剪胀方程,建立了适用于堆石料的广义塑性本构模型,并利用本构模型对堆石料三轴试验进行预测。结果表明,考虑和不考虑临界状态的本构模型均能较好地模拟堆石料在高围压下的剪缩性、在低围压下的剪胀性以及由于颗粒破碎引起峰值和剪胀应力比的非线性特性;考虑临界状态的本构模型能模拟应力——应变曲线逐渐逼近临界状态的规律,但其对三轴试验的预测精度略低于不考虑临界状态本构模型。

Based on the results of large-scale static triaxial shear tests, the plastic modulus expression considering particle breakage and the dilatancy equation considering critical state are constructed, and a generalized plastic constitutive model suitable for rockfill materials is established. Constitutive model is used to predict rockfill materials of triaxial test. The results show that considering and not considering the critical state constitutive model could well simulate shear compression of high confining pressure and shear dilatancy of low confining pressure, as well as the nonlinear characteristics of the peak value and the shear stress ratio due to the particle breakage. The constitutive model considering critical state can simulate the law of stress strain curve approaching the critical state gradually, but the prediction accuracy of triaxial test is slightly lower than that of the constitutive model without considering critical state.