Development and validation of particle models for DEM simulations of the dynamical behavior of saturated soils

土壤建模在更好地理解土壤液化等自然现象方面发挥了重要作用。土壤液化是指水饱和沉积物的结构由于动力荷载（如地震）而失去强度的过程，可能造成灾难性后果：建筑物、挡土结构或堤坝倒塌，以及在粘土地区发生滑坡（Saint-Jean-Vianney，魁北克，1971年）。因此，这是魁北克省的一个主要问题，因为该省有大量的水电大坝。然而，目前的国家的最先进的不允许一个正确地预测土壤液化。该研究项目的总体目标是在颗粒尺度上开发和验证用于描述沙粒之间相互作用的改进模型，将涉及来自蒙特利尔理工学院和位于魁北克瓦雷恩的魁北克水电研究所（IREQ）的合作者。更具体地说，它的目的是改进和验证椭球模型的颗粒，在提供高分辨率的自适应表示的颗粒，并在开发和验证随机接触模型来描述任意形状的颗粒。新模型将在高性能计算机平台（SiGran）中实施和测试，以模拟颗粒和孔隙尺度下静态和动态载荷下颗粒介质与流体流动之间的相互作用。该研究计划将涉及三个博士学位。学生，两名硕士学生和几名本科生，他们将接触到计算工程和科学的当代挑战，并在数值分析，科学计算，数学建模，概率，贝叶斯推理和模型验证方面进行培训。开发先进的建模和仿真工具，以更好地了解液化过程，将为加拿大和世界各地在土壤沉积物附近建造的抗震结构的设计和维护提供宝贵的技术。

Soil modeling has played an essential role in order to better understand natural phenomena such as soil liquefaction. Soil liquefaction, which refers to the process by which the structure of water-saturated sediments loses its strength due to dynamical loadings such as during earthquakes, can have catastrophic consequences: collapse of buildings, retaining structures, or embankment dams, landslide in quick clay areas (Saint-Jean-Vianney, Quebec, 1971). It is therefore a source of major concerns in the province of Quebec due to its large number of hydroelectric dams. Yet, the current state-of-the-art does not allow one to correctly predict soil liquefaction. This research project, whose general objective is the development and validation of improved models at the grain scale for describing the interactions between sand particles, will involve collaborators from Ecole Polytechnique Montreal and Hydro-Quebec's Research Institute (IREQ) in Varennes, Quebec. More specifically, it will aim at improving and validating ellipsoidal models of grains, at providing high-resolution adaptive representations of grains, and at developing and validating a stochastic contact model to describe particles of arbitrary shape. The new models will be implemented and tested in the high-performance computer platform (SiGran) for the simulation of interaction between granular media with fluid flow under static and dynamic loading at the particle and pore scale. The proposed research program will involve three Ph.D. students, two M.Sc. students, and several undergraduate students, who will be exposed to contemporary challenges in computational engineering and sciences and trained in numerical analysis, scientific computing, mathematical modeling, probabilities, Bayesian inference, and model validation. Development of advanced modeling and simulation tools, for a better insight of liquefaction processes, would provide an invaluable technology for the design and maintenance of earthquake-proof structures constructed near soil deposits in Canada and around the world.********