Values of CRR predicted by the model and compare very well to semi-empirical curve (left) as do curves of CSR versus number of cycles in undrained DSS cyclic simulations (right).

CRR versus (N 1) 60 and number of cycles.Single-zone FLAC3D models were used to test and evaluate this new liquefaction constitutive model considering the following: The following table compares a number of factors for selected liquefaction constitutive models. preserves the feature that one set of model constants is used to simulate different responses with different initial relative densities and initial stress states.requires only the initial soil relative density (Dr) and initial stresses to match the semi-empirical relation of CRR versus some in-situ parameter such as (N 1) 60 or q c1N when using the default parameters*.switches all void-ratio related formula, including the elastic modulus, plastic hardening modulus, and critical state, to be relative density related.retains the general 3D formulation, considering Lode angle effect, and thus can be used for general 3D boundary value problems.

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. 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. Itasca is pleased to announce P2P-Sand (Practical Two-Surface Plasticity model for Sands), our new practice-friendly 3D liquefaction constitutive model for FLAC3Dbased on the DM04 (Sanisand) model (Dafalias & Manzari, 2004).

While all of the aforementioned models have merit they also have some notable limitations and many of them are not formulated for 3D modeling. 2003), DM04 (Sanisand) model (Dafalias & Manzari 2004) model, UBCSand model (Beaty & Byrne 2011), and PM4Sand model (Boulanger & Ziotopoulou 2015), to name some. 2001) to the relatively complex effective stress-based models like the PDMY02 model (Elgamal et al. 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. 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.

Flac3d simulation of triaxial test