Abstract

Investigating the past failures of various geotechnical systems during major seismic events, reveals the importance of developing a robust framework that can reliably analyze complex geotechnical systems. Up to now, fully continuum techniques have been the most popular choice for this type of problems. These methods use sophisticated constitutive models which need careful fine-tuning to successfully mimic the macro-scale dynamic behavior of coupled systems. The discrete element method (DEM) is, by nature, the best option for discontinuous systems such as soil. Furthermore, it has effective means to handle soil-structure interaction. Therefore, many attempts have been made to couple DEM with different computational fluid dynamics (CFD) techniques and extend its application to saturated systems. These coupled approaches can be categorized into two groups: discrete-continuum and pore-scale methods. The continuum-discrete techniques generally use a coarse fixed mesh which is not suitable for setups with movable boundary conditions and, consequently, fluid-structure interaction analysis (the structure basically acts as a movable no-penetration boundary). The pore-scale methods on the other hand while being highly accurate, need huge computational resources and, as of now, are not suitable to be utilized for large-scale problems on normal desktop computers.

In this work, a fully coupled particle-based framework for the seismic response of saturated geotechnical systems is presented. The proposed approach uses DEM to model the solid phase (soil particles and structures) and the smoothed particle hydrodynamics (SPH) to simulate the fluid phase. In addition, the interaction between the two phases is described according to well-established semi-empirical relations. This method is much more efficient compared to pore-scale alternatives and, due to being purely Lagrangian, can easily handle large-strain problems, and deformable boundary conditions required for fluid-structure interaction.

Degree Date

Spring 2022

Document Type

Dissertation

Department

Civil and Environmental Engineering

Advisor

Usama El Shamy

Subject Area

Civil Engineering

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

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