Modelling of Deformation and Instability in Geomechanics

该提案的基本主题是可持续性和管理与潜在危险相关的风险。需要关注的不仅是我们的城市，还有连接城市中心的基础设施。该提案将涉及两条研究路线：一条是加强我们对路面结构中使用的颗粒材料的力学行为的了解，目的是改进考虑到不断变化的环境条件的设计；另一条是开发分析技术，以更好地处理不稳定性的模拟和预测，特别是更好地模拟泥石流滑坡和山体滑坡，以及沿沿海地区或河流岸线发生的水流滑坡中的土壤-水相互作用。水流滑坡有可能破坏自然的水生栖息地，破坏近海管道和基础设施，并对防洪造成负面影响。碎片和山体滑坡是对我们的交通网络和基础设施的直接威胁。 这项拟议研究的目标是： (A)建立再生沥青混凝土(RAP)-天然集料混合物的模型，以研究RAP颗粒与天然集料之间的相互作用，同时考虑循环荷载和温度。骨料相互作用的具体建模将通过基于应力假设的多边形有限元和非线性节理单元的离散单元建模来进行。这个框架将允许自然地考虑各向异性及其对宏观行为的影响。超塑性和高循环累积模型的框架将被用来研究和更准确地评估由于粒状基层导致车辙和疲劳破坏而导致的永久性路面挠度(应变)的发展。申请者过去进行的实验研究已经产生了一个大型数据库(现场和实验室)，将用于模型开发和校准。 (B)建立了明确考虑土-水相互作用和温度影响的二维有限元和材料点法模型。模拟框架将建立在迄今为处理多尺度/多机制现象而开发的技术的基础上，同时考虑到远离平衡的非线性热力学方法。

The underlying theme of the proposal is sustainability and managing risk associated with potential hazards. It is not only our cities that require attention but also the infrastructure joining the urban centers. The proposal will address two lines of research: one dealing with enhancing our understanding of the mechanical behaviour of granular materials used in pavement structures with the purpose of improving design that takes into account changing environmental conditions; and the second is to develop the analytical technology to better deal with the modelling and prediction of instabilities, in particular to better model debris slides and landslides, as well as the soil-water interaction in flow slides that occur along coastal areas or river shorelines. Flow slides have the potential to destroy natural aquatic habitats, damage offshore pipelines and infrastructure and negatively impact flood defenses. Debris and landslides are a direct threat to our transportation network and infrastructure. The objectives of the proposed research, which compliments what has been done in the past, are to: (a) model reclaimed asphalt concrete (RAP) - natural aggregate mixtures to examine the interaction between RAP particles and natural aggregate taking into account cyclical loading and temperature. The specific modelling of aggregate interaction will be carried out via discrete element modelling based on stress-assumed polygonal finite elements and nonlinear joint elements. This framework will allow naturally taking into account anisotropy and its effect on macro-behaviour. The frameworks of hyperplasticity and high cycles accumulation modelling will be used to study and more accurately assess development of permanent pavement deflections (strains) due to granular base layers that lead to rutting and fatigue failure. The experimental research undertaken by applicant over the past has led to a large data bank (insitu and lab) that will be used for model development and calibration. (b) develop two-dimensional finite element (FEM) and material point method (MPM) model that explicitly takes into soil-water interaction, as well as temperature influences. The modeling framework will build on the technology that has been developed to date to tackle multi-scale/multi-mechanism phenomena taking into account a nonlinear far-from-equilibrium thermodynamic approach.