基于混凝土不均匀性面板堆石坝面板损伤分析

将混凝土面板堆石坝中面板混凝土视为宏观上均质、细观上不均匀的材料,结合统计学原理,考虑材料参数分布的随机性,通过二维有限元数值分析,研究了混凝土的弹性模量和抗拉强度随机性对面板堆石坝面板动力损伤分布规律的影响。计算结果表明:不考虑面板混凝土材料参数随机性时,(0.65~0.85)H(H为坝高)处面板顺坡向应力较大,拉损伤主要发生在0.8H(H为坝高)附近的面板处;随着混凝土材料不均匀性增大,发生拉损伤的部位趋于分散,但主要集中在(0.4~0.9)H范围内的面板。因此这部分面板应该是抗震设计的重点区域。采用混凝土弹脆性细观损伤模型,考虑材料参数的随机性,能够直观地阐明混凝土面板的地震破坏过程和损伤分布,便于了解面板薄弱环节,研究成果可以为混凝土面板堆石坝抗震设计提供参考。

Slab damage of concrete face rockfill dam based on heterogeneity of concrete

Considering the heterogeneity characteristics of concrete materials, the method of the mesoscopic mechanics is used to investigate the dynamic damage of slabs of concrete face rockfill dam (CFRD) combined with the statistical principle. The mechanical properties, including the elastic modulus and tensile strength, of concrete are assumed to conform to the Weibull distribution law. The elastic-brittle damage model is adopted to simulate the whole deformation and failure process for concrete on a meso-scale through 2D finite element analysis. The results show that the maximum slop-direction tensile stresses in the slabs mainly occur at the height of 0.65 H to 0.85H (H is the height of the dam), and the tensile damage of slabs mainly occur at the height of 0.8H when the randomness of concrete materials is neglected. With the decrease of homogeneity index, the region of the dynamic damage of slabs is scattered, but it is mainly concentrated at the height of 0.4H to 0.9H. Thus, this part of the slab should be the key area of seismic design for CFRD. The micromechanical damage model for concrete can reflect the damage process of slabs precisely. The research may provide guidance for the seismic design of CFRD.