Dr. Potyondy has developed and applied both continuum and discontinuum models to represent damage and flow processes on both a macro- and a micro-scale.
FLAC3D TMis a numerical modeling code for advanced geotechnical analysis of soil, rock, and structural support in three dimensions. FLAC3D is used in analysis, testing, and design by geotechnical, civil, and mining engineers.
This FLAC3D V7.0 training course accommodates new and experienced users. It will be based on examples that attendees will develop and run by themselves to better grasp the mechanics of using FLAC3D V7.0, the key underlying calculation principles and the spectrum of available features. Attendees are encouraged to bring one of their specific cases that may be discussed.
The upcoming 70th annual Highway Geology Symposium will be held in Portland, Oregon, October 21st through October 24th, 2019.
Dr. Russell is a software engineer with a background in mechanics and fluid dynamics, both theoretical and computational. He has participated in the design of Itasca software for more than 10 years.
Fully nonlinear methods can be formulated in terms of effective stresses and the fluid-mechanical interaction behaviors can be simulated before, during, and following dynamic shaking. Multi-dimensional nonlinear constitutive models are being used increasingly to simulate the phenomenon of liquefaction for sand-like geotechnical materials in earthquake engineering practice, e.g., from the relatively simple uncoupled models like the cyclic-counting Dames & Moore model (Dawson et al. 2001) to the relatively complex effective stress-based models like the PDMY02 model (Elgamal et al. 2003), DM04 (Sanisand) model (Dafalias & Manzari 2004) model, UBCSand model (Beaty & Byrne 2011), and PM4Sand model (Boulanger & Ziotopoulou 2015), to name some. While all of the aforementioned models have merit they also have some notable limitations and many of them are not formulated for 3D modeling.
Itasca is pleased to announce P2P-Sand (Practical Two-Surface Plasticity model for Sands), our new practice-friendly 3D liquefaction constitutive model for FLAC3D based on the DM04 (Sanisand) model (Dafalias & Manzari, 2004). By revising some formula without destroying the conciseness of the original DM04 (Sanisand) model, the modifications improve the comparative results between model simulations and various laboratory and field observations with various initial and loading conditions. In addition, Itasca's new liquefaction model embraces an easier and more practical calibration procedure in terms of in-situ data, instead of experimental data, greatly reducing the laboriousness of calibration.
Itasca's enhanced model:
The following table compares a number of factors for selected liquefaction constitutive models.
Single-zone FLAC3D models were used to test and evaluate this new liquefaction constitutive model considering the following:
The following engineering and laboratory scale simulations using the new liquefaction model are performing very well and behaving as expected.
For more details about Itasca's new liquefaction model, P2P-Sand, please see the following paper:
Cheng, Zhao (2018). "A practical 3D bounding surface plastic sand model for geotechnical earthquake engineering application," Geotechnical Earthquake Engineering and Soil Dynamics (GEESD) Congress V, June 10-13, 2018, Austin, Texas, United States.
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