基于跨尺度精细方法的面板坝面板损伤演化尺寸效应分析

Size effect analysis of face slab damage evolution for high concrete face dam under earthquakes based on cross-scale fine method

中国面板坝建设规模正突破200~300 m级跨越,研究地震面板损伤破坏对特高坝抗震性能和安全控制具有重要意义。引入Quadtree跨尺度建模和非线性SBFEM-FEM耦合分析方法,联合土体广义塑性模型、弹塑性接触模型和混凝土塑性损伤模型,研究了高面板坝面板地震精细损伤演化过程。研究表明:面板损伤区主要发生在高程0.6 H^0.9H区间附近;随顺坡向网格细化,损伤越趋局部化,越能合理地反映面板顶部的损伤破坏现象,建议顺坡向面板尺寸取0.5~1.0 m。面板大部分区域法向划分2层或1层网格可满足计算精度,但对顶部局部区域,可考虑分3层网格。基于Quadtree-SBFEM-FEM的跨尺度分析方法,实现了面板的精细化损伤演化规律研究,可为工程地震薄弱区域的精准定位和抗震安全控制方法的有效性分析提供重要参考和指导。

The construction scale of concrete face dams is breaking through 200~300 m span in China.It is vital for the seismic performance and safety control of super-high dams to investigate the seismic damage of face slabs.Quadtree cross-scale modelling and non-linear SBFEM-FEM coupling analysis method are introduced to study the fine damage evolution process of high concrete face slab dam under earthquake by combining generalized plastic model of soil,elastic-plastic contact model and plastic damage model of concrete.The results show that the damage zone mainly occurs near the elevation range of 0.6H^0.9H.With the refinement of the grid along the slope,the damage tends to be localized,which can more reasonably reflect the damage phenomenon at the top of the face slab.It is suggested that the size of concrete face along slope direction should be 0.5~1.0 m.Most areas of concrete face can be divided into two or one layers in normal direction,which can satisfy the calculation accuracy.However,for partial area of the slab top,three layers can be considered.The cross-scale analysis method based on Quadtree-SBFEM-FEM achieves the fine damage evolution research of concrete face,which can provide important reference and guidance for the precise location of the weak area of structures under earthquake and the effective analysis of the seismic safety control method.