堆石流变试验及双屈服面流变模型的研究

通过对两类不同岩性的堆石料作室内三轴流变试验,研究了堆石料的流变特性,试验结果表明流变体积应变和广义剪应变随时间均呈双曲线变化。殷宗泽曾以椭圆–抛物双屈服面弹塑性模型为基础,提出了一个综合反映堆石料瞬时变形和流变的双屈服面流变模型的初步框架。结合堆石流变试验规律,将该模型用于模拟试样在不同应力状态下的流变变形的发展,确定了模型参数的计算方法,初步验证该模型的合理性和有效性。该模型能反映复杂加载情况,反映剪胀、剪缩特性和流变特性。

Creep tests of rockfill and double-yield surface creep model

Creep tests were done to study the creep characteristics of two kinds of rockfill materials by use of triaxial-rheometer.It was concluded that the time dependent volumetric strain and generalized shear strain were fit for the law described as hyperbola respectively.Based on the elasto-plastic constitutive model with oblong-parabola double-yield surface,Yin Zong-ze proposed the preliminary framework of a creep model with double-yield surface to consider creep characteristics of rockfill.According to the creep characteristics of rockfill,the model was applied to simulate the shearing creep tests and the method of determination of model parameter was also proposed.As compared with the test results,the propased constitutive model was proved to be reasonable and effective.It was shown that the proposed model could reflect the visco-elasto-plastic behaviors,dilatation and shrinkage of rockfill materials,and it was also applicable to all kinds of loading conditions.