开展了反应堆石料尺寸效应的大、中型动三轴试验研究,分析了试样尺寸与堆石料剪切模量和阻尼比的变化关系。基于动三轴试验成果进行了反映堆石料尺寸效应的细观数值模拟研究。首先分析了细观参数对数值模拟结果的影响,得出了细观剪切模量、细观泊松比和细观摩擦系数与试样宏观动剪切模量和阻尼比的变化关系。其次进行了不同试样尺寸的堆石料细观数值模拟研究。数值模拟过程中不同试样尺寸采用的试验级配采用相似级配法进行制备,试验过程中控制试样的孔隙率相等。根据细观参数与颗粒直径之间的变化关系,通过数值模拟分析得出了试样最大动剪切模量和阻尼比随颗粒最大直径的变化的规律,建立了反映堆石料尺寸效应的最大动剪切模量计算公式。
Large-and-middle-scale dynamic triaxial tests are performed to study the relationships between the size of sample rock and dynamic shear modulus or the damping ratio of roekfill materials. Based on the test results, a meso mechanical simulation(MMS) is made to model the rock size effect. By comparing the MMS results of different meso parameters, the relationships between the shear modulus, Poisson's ratio or the friction coefficient and the macro dynamic shear modulus or the damping ratio are established. In addition, a MMS study is conducted for different rock sizes, adopting the similar gradation method with constant porosity. By using the simulation results and the relationships between the meso parameters and the rock diameters, the variation of the maximum dynamic shear modulus and the damping ratio with the maximum rock diameter are obtained, and the formulas of the maximum dynamic shear modulus are established to account for the sample size effect of the rockfill materials.