Upload
mahdi-roozbahani
View
75
Download
1
Tags:
Embed Size (px)
Citation preview
1
Application of gravitational sphere packing method to study the inner structure of packed soil particles
Student: M. Mahdi RoozbahaniAdvisor: Dr. J. David Frost
Geosystem Engineering Group, School of Civil and Environmental Engineering
Georgia Institute of Technology
Oral Portion of the Comprehensive Ph.D. Examination23 January 2015
2
Motivation of the research
• To develop a computationally efficient and rapid technique to pack multi-sized spherical and non-spherical particles.
• To examine boundary effects. Many of the geotechnical experiments are affected by the boundary effects.
• To explore the complex geometrical shape of pore structure.
• To apply artificial intelligence approaches to speed up numerical calculation of soil properties with the high computational demands (permeability, tortuosity, …)
Gravitational Sphere Packing (GSP)
[AR Fuggle, et al, 2014]
Binary Packing with Size Ratio = 2.8
- Non-spherical particles (sphere clump)?
- Shaking process?3
Boundary Effects
[Roozbahani et al, 2014]
Mono-sized packed particles (Container size / Particle size = 10)
Boundary effects in loose and close sphere packing with different particles’ sizes?
4
Complex geometrical shape of pore in a 2D case
• Finding the complex pore geometry in 3D using Euclidean Distance Transform (EDT) ?
• How particle size and shape change pore geometry?
5
Applying an optimized
algorithm of local maxima
Nearest Neighbors Algorithm
EDT
6
Artificial intelligence approach
A graphical abstract how to employ GSP to predict soil properties by considering the comprehensive information attained by spatial statistics.
Intellectual Merit
• Applying GSP to study different properties of packed soil particles.
• Integrating computer science techniques into geotechnics. Such as: Machine Learning, network or graph analysis, …
• To develop rapid and accurate techniques to compute packed soil properties, and validate them with the trivial cases.
7
8
Broader Impacts
• Filter Media (water purification, drainage system)
• Soft Matter (viscosity - rate of motion is a function of packing)
• Agriculture (Fruit Packing)
Thank You!
Publications:
Fuggle, Andrew R., M. Mahdi Roozbahani, and J. David Frost. "Size Effects on the Void Ratio of Loosely Packed Binary Particle Mixtures." Geo-Congress 2014 Technical Papers@ sGeo-characterization and Modeling for Sustainability. ASCE.
Roozbahani, M. Mahdi, Lori Graham Brady, and J. David Frost. "Mechanical trapping of fine ‐particles in a medium of mono sized randomly packed spheres." ‐ International Journal for Numerical and Analytical Methods in Geomechanics (2014).