Modeling Landslide-Induced Flow Interactions with Structures using the Material Point Method

Thesis (Ph.D.)--University of Washington, 2013Landslides cause significant damage and loss of life around the world each year. To help protect people, infrastructure, and lifelines against such disasters, it is critical to: a.) control the path and/or redirect flow when potential interaction with the built environment exists, and b.) have engineered structures that are capable of resisting the loads imparted by a landslide. Capturing the mechanical behavior and structural interaction is challenging---as these flow events are highly dynamic, unpredictable, and inherently complex in nature. This dissertation presents the Material Point Method (MPM) as a continuum-based tool for modeling landslides and other flow-like events, with an emphasis on capturing the force interaction between the flow and rigid structures. Key challenges arising in this context are the ability to: a.)~model the transition between solid and fluid-like behavior within a single numerical environment, b.)~develop constitutive frameworks that can accommodate extremely large deformations while remaining computationally efficient and numerically stable, and c.) account for the different phases and constituents that comprise these events This research addresses these challenges and includes an anti-locking enhancement designed to improve kinematics and the quality of the stress field, a volume constraint for multiphase simulations, and an evaluation of different elasto-plastic material models suitable for large deformation analyses of granular materials. The current implementation is used to model several examples from both the solid and fluid mechanics regime, including incompressible fluid flow, the response of an elastic cantilever beam, three fully saturated porous media analyses, a ductile hyper-velocity Taylor bar impact, a parametric investigation of planar granular flow, snow avalanche simulation, and three landslide applications evaluating the nature of the force interaction with structures