大型压缩试验在堆石坝应力变形分析中的应用

在大坝堆石料大型三轴压缩试验中，剪胀变形在总的体积变形中占有相当大的比例，由其试验结果所确定的模型体变参数通常会夸大剪缩的影响。本文提出了用大型侧限压缩试验结果修正堆石料本构模型体变参数的方法，使用清华非线性解耦KG模型，以茅坪溪心墙堆石坝变形计算分析为例，介绍了大型侧限压缩试验成果在定堆石体本构模型参数过程中的应用。通过与坝体变形实测结果的对比分析，证明使用经侧限压缩试验修正后的本构模型参数，可显著提高坝体变形的计算精度。

Application of large-scale confined compression test to stress and deformation analysis of rockfill dam

In large-scale triaxial compression test for rockfill material, shear dilatancy may have considerable contribution to the measured volume variation. Consequently the influence of the compression is usually overemphasized when model parameters are directly determined by test result. In this paper, a modified method for determining the volumetric model parameter based on large-scale compression test result is proposed. The method is applied to analyze the deformation of the Maopingxi Rockfill Dam. In the analysis, the uncoupled nonlinear KG model suggested by the Tsinghua University is applied. The comparison of numerical calculation result with in-situ monitoring data shows that the parameter correction according to the modified method remarkably improves the accuracy of the calculation of dam deformation.