面板坝堆石料四参数非线性K-G模型研究

堆石料的广泛应用使得对其本构关系的研究至关重要。在热力学原理基础上,由吉布斯自由能函数出发,基于内变量热力学的理论基础,推导堆石料四参数非线性K-G模型,模型理论基础严谨,能够反映堆石料的非线性、压硬性、部分各向异性等主要工程性质,模型参数数量少并独立。针对室内等应力比试验和面板坝的二维应力应变数值模拟,验证了四参数K-G模型的合理性。依托目前世界最高混凝土面板堆石坝233 m的水布垭面板坝,进行了坝体的三维应力变形计算。结果表明：坝体的应力变形分布趋势合理,在填筑工况下,四参数K-G模型计算的垂直位移为2.02 m,较其他非线性模型更接近于实测值,因此四参数K-G模型可以用于面板坝堆石体的应力变形计算。

Nonlinear four-parameter K-G model for rockfills

The researches on constitutive relationship for rockfills are significant because of its wide application. Based on the theory of thermodynamics, a four-parameter K-G model is derived from the Gibbs free energy function. The model is theoretically rigorous and can reflect the nonlinearity, pressure rigidity, partly anisotropy and other engineering properties. Most importantly, only four parameters which are independent of each other are needed in this model. The iso-stress ratio tests and numerical simulations of two-dimensional CFRD validate the reasonability of the model. Furthermore, three-dimensional static calculation of Shuibuya CFRD is performed. The results show that the vertical displacement is 2.02 m, which is closer to the measured value than that of other nonlinear models. Therefore, the four-parameter K-G model can be used to calculate the stress and deformation of CFRDs.