Development and experimental validation of a multiscale DEM-FEM model for core overtopping in embankment dams

堤坝核心漫溢多尺度 DEM-FEM 模型的开发和实验验证

• 批准号: 486427-2015
• 负责人: Duhaime, François
• 金额: $ 2.53万
• 依托单位: École de technologie supérieure
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649729
• 关键词: Development; experimental; validation; multiscale; DEM

Core overtopping occurs when the water level rises over the impermeable core, into the filter of zoned**embankment dams. It can lead to internal erosion at the interface between core and filter, and eventually to dam**failure. Core overtopping can be avoided by maintaining a low water level in the upstream reservoir. However,**low reservoir levels can have economic consequences for dam owners. Experimental data on the progression of**contact erosion during core overtopping for complex dam geometries, transient flow and widely graded core**materials are scarce. As a consequence, it is important for dam owners to get a better understanding of the real**impact of core overtopping. The main objectives of this project are to gather experimental data on core**overtopping for realistic geometries, materials and flow conditions, and to develop a numerical model for this**phenomenon. In the first phase of the project, core overtopping will be replicated experimentally with a**laboratory model for different core and filter grain size distributions. The tested materials will be chosen so that**some combinations fail to respect the accepted design criteria for stability against erosion. Combinations**representative of Canadian embankment dams with a widely graded core will be tested. In the second phase of**the project, a numerical model will be programmed to replicate the experimental results. The continuum**models that are widely used in practice perform poorly when modelling phenomena that are dependent on**microscale behaviour, such as internal erosion. The numerical model will be based on a novel multiscale**approach. It will combine particle scale modelling with the discrete element method, where the displacement of**individual particles is modelled (software YADE), and large scale modelling with the finite element method,**where the soil is modelled as a continuum (software COMSOL). There are currently more than 10,000 dams in**Canada. A practical multiscale model and experimental data on erosion threshold and rate of erosion for**realistic geometries and materials will allow appropriate actions to be taken in case of core overtopping. It will**also help design new structures.

当水位上升超过防渗心墙，进入分区 ** 堤坝的过滤层时，心墙漫顶发生。它可导致心墙与反滤层界面处的内部侵蚀，并最终导致溃坝。通过保持上游水库的低水位，可以避免堆芯漫顶。然而，** 水库水位低可能对大坝所有者产生经济后果。对于复杂坝形、瞬变流和宽级配心墙材料，在心墙漫顶过程中接触侵蚀进展的试验数据很少。因此，对于大坝业主来说，更好地了解堆芯漫顶的真实的 ** 影响非常重要。该项目的主要目标是收集关于实际几何形状、材料和流动条件下岩心漫顶的实验数据，并为这种现象建立一个数值模型。在该项目的第一阶段，将用 ** 实验室模型对不同的岩心和过滤器粒径分布进行实验性重复岩心漫顶。将选择受试材料，以便 ** 某些组合不符合公认的抗侵蚀稳定性设计标准。将对具有广泛级配心墙的加拿大堤坝代表性组合进行试验。在该项目的第二阶段，将编制一个数值模型，以复制实验结果。在模拟依赖于微观行为的现象时，如内部侵蚀，在实践中广泛使用的连续介质模型表现不佳。数值模型将基于一种新的多尺度方法。它将把联合收割机颗粒尺度建模与离散单元法结合起来，在离散单元法中，** 单个颗粒的位移被建模（YADE软件），大尺度建模与有限元法结合起来，** 在有限元法中，土壤被建模为连续体（COMSOL软件）。目前加拿大有10，000多座水坝。一个实用的多尺度模型和实验数据的侵蚀阈值和侵蚀率的 ** 现实的几何形状和材料将允许采取适当的行动，在核心漫顶的情况下。它还将有助于设计新的结构。