Arching effects easily occur for a concrete face rockfill dam ( CFRD) built in a narrow valley. In this paper, the Maerdang power station engineering was used for a case study. 3D finite element models of the CFRD under different valley slope schemes were established. Distributions of the static and dynamic displacement, stress of the dam under different slope angle schemes were obtained by finite element ( FE) analysis. In addition, the effect of slope angles on the stress and deformation characteristics of the dam was analyzed. Meanwhile, the influence of the valley slopes on the structure stability of the dam under earthquake action was studied. Results indicate that the valley slope is approximately 50° when evident stress arch effect occurs inside the rockfill of the dam so that the critical angle of the valley should be 50°. A negative correlation is observed between the slope angles and the dam settlement. In the situation of arching effect, the earthquake action has no significant negative effects on the dam.%以玛尔挡水电站面板坝工程为例,建立了不同河谷坡度方案下的面板坝三维有限元模型,研究不同河谷坡度下高面板堆石坝坝体的静动位移和应力分布情况,分析了河谷坡度对坝体应力变形特征的影响,探讨了地震工况下河谷坡度对坝体结构稳定性的影响.结果表明:河谷坡度为50°时堆石体内部将会出现较明显的应力拱效应现象,河谷边坡陡缓临界值近似为50°;坝体沉降与坡度变化之间呈负相关关系;地震作用未对拱效应存在下的坝体产生显著的不利影响.
展开▼
