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Dear clients,

Civil-Geotechnical Engineering design firms will be delighted to know that ITASCA will integrate a new Plastic Hardening (PH) model for soil to the next FLAC and FLAC3D versions. The new PH Model is a shear and volumetric hardening constitutive model for the simulation of soil behavior. We are sure it will become a “standard” model for civil engineering design in many area such excavations, foundations, tunneling and in general, soil- structure interaction. We are fully available to give you more information about this new constitutive model.

Kind regards,

The European Itasca team

Consulting

Itasca Spain has analyzed the stability of an open pit mine in Spain with large problem due to high phreatic levels. Some mitigation measures, as drainage system, were needed to be reproduced in order to increase the stability of the slopes.

Due to the decisive effect of the drainage system in the stability of the slope, it was necessary to model them as accurate as possible. When trying to simulate a drain in a numerical model, a problem arises due to the different scale between the dimensions of the slope (hundreds of m) and the diameter of the drains/wells (10-50cm). A grid that would take into account the required detail to simulate the drains would be unworkable.

For this reason, it was developed a FISH routine to represent a “drainage element”, embedded in a zone, which takes into account the diameter of the well independently of the size of the surrounding mesh.
This drainage element is independent of the grid but linked to it, with a formulation which interacts with the mesh simulating a pore pressure drop and the radial flow from the surrounding zones.

The effect is clearly significant in the pore pressure distribution shown in the slopes in Figure 1 (no drains) and Figure 2 (with drains).

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Figure 1. Slope with no drains


Figure 2. Slope with drains

 

Itasca Germany is performing FLAC3D simulations of deep foundations like pile foundations and combined pile raft foundations (CPRFs) using the newly implemented plastic hardening (PH) soil model.
Settlements of structures have to be realistically assessed for both the serviceability and the ultimate limit states. This includes the assessment of deformations in adjacent buildings and infrastructure units to prevent damages caused by the new building project. The assessment of the evolving deformations has to be carried out by numerical simulations using adequate soil models like the plastic hardening model.

In this context the results of a benchmark simulation of a pile load test with a large diameter bored pile (D = 1,3 m, L = 9,5 m) in stiff clay using the newly implemented plastic hardening model are shown in the figure. The load test was carried out during the construction of a bridge pillar foundation for the highway A 14 near Frankfurt am Main.

 

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Software

  • PFC 5.0 Annual Maintenance
    The latest PFC revision (version 19) is online from 13 May 2015. As PFC 5.0 user, we highly invite you to download this latest sub-version knowing that revisions are included in your annual maintenance contract.

    The next feature PFC 5 will see Python integration, new contact models, including a Smoothed Particle Hydrodynamics contact model, new particle packing and creation/deletion utilities and performance improvements on select commands and plotitems. To benefit from this next revision, do not forget to extend your maintenance contract for an extra year: you will automatically receive the next major upgrade when it will be available.

  • KUBRIX V15.0
    As of April 22nd, KUBRIX Geo V15.0 and KUBRIX BlockRanger V1.1 have been officially released.
    KUBRIX is a family of automatic and interactive grid generation tools for use with Itasca’s FLAC3D and 3DEC geomechanical software products. With the addition of local resolution control in interactive grid generation and geometrical associativity in automatic grid generation KUBRIX is now one of the most versatile grid generation tools available to the geotechnical community.

  • HSM model:
    Civil-Geotechnical Engineering design firms will be delighted to know that ITASCA will integrate a new Plastic Hardening (PH) model for soil to the next FLAC and FLAC3D versions. The model is very easy and straightforward to calibrate and uses familiar properties name and conventions. Calibration is done either using lab tests or in-situ tests. It is well established and would wide used especially for soil-structure interaction problems, excavation, tunneling, and settlements analysis among many other applications.
    The new PH soil is a shear and volumetric hardening constitutive model for the simulation of soil behavior. When subject to deviatoric loading, soil usually exhibits a decrease in stiffness, accompanied by irreversible deformation.

    The main features of the new PH model and example applications available at the following link: PH MODEL.

Current Updates:

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Training & Seminars

Itasca will host introductory training courses in Europe:

Code
Location
Dates
Contact
FLAC3D Gelsenkirchen, Germany June 2015 Itasca Germany
Itasca Info Days Austria and Poland 2nd and 3rd quarter 2015 Itasca Germany
3DEC Sweden September-October 2015 Itasca Sweden
InSite-Lab training course UK To be defined Itasca Consulting Ltd

Conferences

Itasca will be attending the following conferences:

Conference Date Place
Eurock 2015 7-10 October, 2015 Salzburg, Austria
Slope Stability Symposium 12-14 October, 2015 Cape Town, South Africa
Finnish Rock Mechanics Day 29 October, 2015 Helsinki, Finland
Design Methods in Underground Mining 17-19 November, 2015 Perth, Australia
4th Itasca Symposium on Applied Numerical Modeling 7-9 March, 2016 Lima, Perú
7th International Symposium on In-Situ Rock Stress 10-12 May 2016 Tampere, Finland

Recent Publications

J. J. Oetomo, E. Vincens, F. Dedecker, J-C. Morel, "Modeling the 2D behavior of drystone retaining walls by a fully discrete element method", submitted to International Journal for Numerical and Analytical Methods in Geomechanics

J. J. Oetomo, E. Vincens, F. Dedecker, J-C. Morel, "A fully-discrete approach to study the behavior of slope dry-stone retaining walls, submitted to European Young Geotechnical Conference, EYGC 2015, Durham university (10-13 September 2015),

Moreno J., Senis M. and Olalla C. (2015) "Aspectos necesarios a introducir en la modelización numérica 3D de las presas de escollera con pantalla de hormigón para reproducir correctamente las tensiones en el elemento de impermeabilización ", In X Jornadas Españolas de Presas, Spancold, Sevilla (18-20 February 2015)

Graf F., te Kamp L., Auer M., Acharya M. and W. Wu (2015) – “Soil aggregate stability in eco-engineering: comparison of field and laboratory data with an outlook on a new modelling approach”, in Recent Advances in Modeling Land-slides and Debris Flows. Springer Series Geomechanics and Geoengineering, pp. 29-47.

Wu W., Switala BM., Acharya M., Tamagnini R., Auer M., Graf F., te Kamp L. and W. Xiang (2015) – “Effect of vegetation on stability of soil slopes: numerical aspects”, in Recent Advances in Modeling Landslides and Debris Flows. Springer Series Geomechanics and Geoengineering, pp. 163-177.

Amo A., Silvestre A., Prieto V. and P. Velasco (2014) - "Modelling in L.A.", in Tunnels and Tunnelling (October-November 2014), pp. 42-47.

Tran, V.H., Vincens E., Morel J.C., Dedecker F. and HH. Le (2014) – “2D-DEM modelling of the formwork removal of a rubble stone masonry bridge”, in Engineering Structures, 75, pp. 448-456.

Oetomo J., Vincens E., Dedecker F. and J.C. Morel (2014) – “Discrete Element Method to assess the 2D failure of dry stone retaining walls” in Proceedings, 9th IMC (7-9 July, 2014, Guimaraes, Portugal), paper 1432.

Maillot, J., P. Davy, R. Le Goc, C. Darcel and M. Stigsson. (2014) – “Comparison between Poissonian and mechanically-oriented DFN models for the prediction of permeability and flow channeling”, in Proceedings, Discrete Fracture Network Engineering(Vancouver, Canada, October 19-22, 2014).

Le Goc, R., C. Darcel, P. Davy, M. Pierce and M.A. Brossault. (2014) – “Effective elastic properties of 3D fractured systems”, in Proceedings, Discrete Fracture Network Engineering (Vancouver, Canada, October 19-22, 2014).

Davy, P., R. Le Goc and C. Darcel (2014) – “A non-Poissonian, likely-universal, fracture model for hardrock DFN”, in Proceedings, Discrete Fracture Network Engineering(Vancouver, Canada, October 19-22, 2014).

Darcel, C., R. Le Goc, P. Davy and I. Olofsson (2014) – “Including variability into a quantitative DFN modeling approach – application to SKB sites”, in Proceedings, Discrete Fracture Network Engineering(Vancouver, Canada, October 19-22, 2014).

Sjöberg, J. and T. Savilahti (2014) – “Caving in the Fabian Orebody - from Mining Stope to Cave Crater in Malmberget”, in Proceedings 8th Asian Rock Mechanics Symposium. Rock Mechanics for Global Issues – Natural Disasters, Environment and Energy (14–16 October, 2014, Sapporo, Japan), Shimizu, N., Kaneko, K. Kodama, J. (eds.), pp. 1421–1430.

Vatcher, J., S. D. McKinnon and J. Sjöberg (2014) – “Mine-scale numerical modelling, seismicity and stresses at Kiirunavaara Mine, Sweden”, in Proceedings of the Seventh International Conference on Deep and High Stress Mining (16–18 Sept, 2014, Sudbury, Ontario, Canada), Hudyma, M., Potvin, Y,. (eds.), pp. 363–376.

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Itasca Consultants S.A.S
64 Chemin des mouilles
FR-69134 Ecully Cedex
France

© 2015 Itasca Consultants S.A.S.