Gap‐graded granular soils are common natural soils composed of cohesionless granular matrix and rock aggregates. Since they are widely used as construction materials worldwide, their deformation behavior is crucial for the design of civil infrastructures. There have been rare constitutive models reported for gap‐graded granular soils in the literature. This study presents a homogenization‐based state‐dependent model within the elastoplastic framework. The model features a homogenization equation with a structure parameter and a novel state‐dependent dilatancy function to describe the behavior of granular matrix. Simulations of the model reveals that the initial stiffness and peak shear strength of gap‐graded soils rely on both the coarse fraction and the initial density of granular matrix. The structure parameter is related to the internal structure of gap‐graded soils, and it varies with the particle shape, and particle size distribution of rock aggregates. A higher value of the structure parameter indicates a more distinct coarse fraction effect of rock aggregates, that is, higher initial stiffness, higher peak shear strength, and higher residual shear strength. For a given coarse fraction, the critical states can be well fitted by a straight line through the origin, and the critical state strength parameter M_m increases with the rising rock fraction. A practical method is further proposed for the critical state line of gap‐graded granular soils in e‐p′ compression plane. The proposed model is validated by using experimental data from the literature, including the soils with various densities of sand matrix, different particle size, and particle size distribution of rock aggregates. Comparison between measured data and model predictions indicates that the proposed model can well reproduce the stress‐strain relationship and volumetric deformation behavior of sand‐gravel mixtures and soil‐rock mixtures.

中文翻译：

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基于均质化的状态决定模型，用于具有精细控制结构的间隙分级颗粒材料

间隙分级的粒状土壤是常见的天然土壤，由无粘性的粒状基质和岩石聚集体组成。由于它们在世界范围内广泛用作建筑材料，因此它们的变形行为对于民用基础设施的设计至关重要。文献中已经报道了针对间隙分级的粒状土壤的稀有本构模型。这项研究提出了弹塑性框架内基于均质化的状态依赖模型。该模型具有均质化方程，该均化方程具有结构参数和新颖的状态相关剪胀函数，用于描述颗粒矩阵的行为。该模型的仿真表明，间隙分级土壤的初始刚度和峰值剪切强度取决于颗粒基质的粗粒分数和初始密度。结构参数与间隙梯度土壤的内部结构有关，并且随岩石团聚体的颗粒形状和粒径分布而变化。结构参数的值越高，表示岩石聚集体的粗级分效应越明显，即，较高的初始刚度，较高的峰值抗剪强度和较高的残余抗剪强度。对于给定的粗分数，临界状态可以通过原点的直线和临界状态强度参数很好地拟合M _m随着岩石分数的增加而增加。一种实用的方法还提出一种用于在间断级配粒状土的临界状态线ë - p '压缩平面。所提出的模型是通过使用来自文献的实验数据进行验证的，这些数据包括具有不同密度砂土，不同粒径和聚集石粒径分布的土壤。实测数据与模型预测值的比较表明，所提出的模型可以很好地再现砂砾混合料和土石混合料的应力-应变关系和体积变形行为。