Rockfill materials used for dam construction show obvious stress path dependency during construction process. The constitutive model for rockfill materials are mainly established based on conventional triaxial test. This brings some deviation to the numerical calculation for earth rockfill dam engineering, and it is necessary to develop a constitutive model considering stress paths effect. In the framework of generalized plasticity, plastic modulus can be expressed as the function of dilatancy equation and tangent modulus, hence the influence of stress paths on model can be transfer to the dilatancy equation and tangent modulus. This leads to a new method to describe stress-strain response of rockfill under various loading stress paths. Based on the analysis of large-scale triaxial experiments of rockfill materials with various stress paths, we proposed new dilatancy equation and tangent modulus to better describe stress paths effect and corresponding modified generalized plasticity model is established. Through the prediction and comparison of three groups of rockfill materials triaxial tests, the model established in this paper can simulate behaviors of rockfill materials under various stress paths, using only a set of parameters.

大坝施工堆石料在施工过程中表现出明显的应力路径依赖性。堆石材料的本构模型主要建立在常规三轴试验的基础上。这给土石坝工程的数值计算带来了一定的偏差，需要建立考虑应力路径效应的本构模型。在广义塑性的框架下，塑性模量可以表示为剪胀方程和切线模量的函数，因此应力路径对模型的影响可以转移到剪胀方程和切线模量上。这导致了一种描述堆石在各种加载应力路径下的应力-应变响应的新方法。基于对各种应力路径堆石材料大型三轴试验的分析，我们提出了新的剪胀方程和切线模量来更好地描述应力路径效应，并建立了相应的修正广义塑性模型。通过对三组堆石材料三轴试验的预测和比较，本文建立的模型仅使用一组参数即可模拟堆石材料在各种应力​​路径下的行为。