December 2007

The increasing availability of computers running a 64-bit architecture is beginning to be felt in the world of numerical modeling. We are pleased to announce that the upcoming releases of 3DEC 4.1, PFC2D 4.0 and PFC3D 4.0 will all provide 64-bit versions alongside the 32-bit code. Since the new architecture provides models of practically unlimited size, one previous restriction on modeling capability is removed — although processing speed is still a factor that might prevent contemplation of gigantic models. For an example of work done using the pre-release of PFC3D 4.0, see the writeup on our web site.

– Roger Hart, Director of Software Services


The Gotthard Base Tunnel (GBT) in Switzerland, a double tube single track railway tunnel with a length of 57 km, is currently under construction. In addition to the northern and southern portals, the tunnel is being excavated from three intermediate approaches. Two of these intermediate approaches are constructed as so-called multifunction stations (MFS) for the purpose of containing facilities for operation control and emergency stations. The tunnels' crossovers and the galleries for ventilation and rescue form a complex tunnel system (Fig. 1). ITASCA Consultants GmbH, Germany, has contributed with numerical modelling to investigate the static and dynamic behaviour of the MFS Faido in co-operation with AMBERG ENGINEERING AG (Switzerland).

Fig. 1: Tunnel system of the MFS Faido and geology with fault zone
Fig. 2: Tunnel system of the MFS Faido and geology with fault zone

During the construction an unexpected fault zone was encountered giving rise to high loads and small dynamic events. To investigate these phenomena AMBERG ENGINEERING AG has performed 2D numerical modeling with UDEC. These simulations were later extended into 3D by ITASCA Consultants GmbH using 3DEC. Figure 2 shows the model layout indicating the geological layering and the critical fault zone. The location of the seismic source is indicated in Fig. 3

The modeling has given deeper insight into the origin of heavy support loading and dynamic events and has demonstrated that the applied support measures are sufficient.

Fig. 3: Three components of incoming seismic signal, main fault structure and tunnels

Current Versions updated since August 28, 2007
3DEC 4.1 Note on Availability

With 3DEC Version 4.1 targeted for release by December 31, 2007, the following changes have been adopted for sale and distribution of the code:
PFC2D and PFC3D 4.0, In Detail

In addition to a complete description of the new features available in PFC2D/PFC3D 4.0, there is now additional information available on some of the codes' most important new features. Visit the pages on the 64-bit version, the PFC3D-CCFD fluid analysis option, smooth-joint contact model, and the Enhanced Fishtank to get a full overview of the advancements these new features bring to the codes.

With the recent addition of geomechanics capabilities to the hydrogeologic services they have provided since 1999, HCI (our office in Denver/Lakewood, CO) has changed its name to HCItasca Denver Operations. Dr. Mark Board, who joined Itasca in 1984, has been named the new Managing Director. Mark brings his worldwide experience in mining engineering and the application of rock mechanics to civil structures (including waste isolation facilities) to the international expertise of the groundwater group at HCI. Over the next few months, additional geotechnical personnel will join the Denver office. The integration of groundwater and rock mechanics within one office is intended to better serve our mining clients in the Western United States and around the world.

In addition, Dr. Daniel Stone has joined HCItasca Denver Operations as a Principal. Dan is experienced in aquifer evaluation, well-field optimization, mass transport problems, mining impacts analysis, dewatering feasibility, facilities closure/bonding, and litigation. At the same time, Dr. Lee Atkinson, a founder of HCI, begins his transition from President of HCI. Lee will be diminishing his administrative and managerial responsibilities over the remainder of the year to concentrate on providing dewatering consulting services and marketing HCItasca capabilities worldwide. In April of 2008, Lee will begin his new role as HCItasca Associate working approximately half time on dewatering issues for selected HCItasca clients and promoting HCItasca services globally. All of us at HCItasca greatly appreciate the incredible effort and dedication that Lee has devoted to HCI and HCI clients over the years, and look forward to his continued guidance for many years to come.

Itasca Australia is holding a FLAC Training Course on December 3-5, 2007 and a FLAC3D Training Course on December 6-7, 2007. Both training courses will occur in Melbourne, Australia, and will include discussions on the basic concepts and modeling principles for geotechnical numerical analysis including: grid generation, application of boundary conditions, selection of appropriate constitutive (material) models, solution of the static equilibrium state, simulation of construction stages, installation of structural support, and inclusion of either transient or steady groundwater flow states. Example applications of FLAC and FLAC3D for analysis of practical geotechnical problems will also be illustrated. Both courses will be taught by Dr. Roger Hart. For more information, please contact Itasca Australia.

The Spring 2008 software training courses are approaching. All courses will be held at Itasca Consulting Group's office in Minneapolis.
FLACApril 7-9, 2008
FLAC3D*April 14-16, 2008
3DShopApril 21-23, 2008
UDECApril 28-30, 2008
3DEC*May 5-7, 2008
PFCMay 12-15, 2008
More information and registration forms are available on our Training Schedule page.

* - For FLAC3D and 3DEC, one complimentary registration to the corresponding training course is included with the purchase of a new license.

Deadline is Here!
The submission deadline for final papers was November 15, 2007. All authors who have not submitted their papers should send them to Michele Nelson as soon as possible.

Registration Open
Registration forms are available at the Symposium web site. These forms can be filled out on-screen using Acrobat Reader, then simply printed, signed, and returned with payment.

Venue Information
The Depot Minneapolis, A Renaissance Hotel, located just a block away from the offices of Itasca Consulting Group, Inc., will serve as the main location for the symposium proceedings. Participants are responsible for their own hotel accommodations. A block of rooms at The Depot Hotel has been reserved for Symposium attendees at a special rate. Reservations in this block must be made by July 24, 2008. Due to the Republican National Convention being held in the area the week following the Symposium, we recommend you make your reservation as soon as possible. Once this date has passed or the room block has filled, availability and rates are subject to change. To reserve a room:

Literature by HCItasca personnel recently published or acquired in the HCItasca library.

Aglawe, J. P., and A. G. Corkum. "Application of Distinct Element Analysis in Slope Stability Problems," presented at the Indo-Norwegian Workshop on Seismic Hazard and Risk Assessment (New Delhi, India, March 2006).

Gaffney, E. S., B. Damjanac and G. A. Valentine. "Localization of Volcanic Activity: 2. Effects of Pre-Existing Structure," EPSL, 263, 323-338 (2007).

Hausdorf, A., F. Heinrich, H. Konietzky and N. Mocka. "Numerische Untersuchungen zur Stabilität Geschichteter und Geankerter Kammerfirsten im Kalibergbau (Numerical Studies on the Stability of Bedded and Anchored Roofs in Potash Mining, in German)," Kali & Steinsalz, 1, 20-25 (2007).

Lorig, L. J., A. D. Watson and C. D. Martin. "Rockslide Run-Out Prediction from Distinct Element Analysis," in DEM 07, CD Proceedings of the Discrete Element Model-ling Conference (Brisbane, August 27-29, 2007). Minerals Engineering International, 2007.

Mas Ivars, D., M. Pierce, D. O. Potyondy and P. A. Cundall. "A New Modelling Approach for the Study of Deformation, Yield and Failure of Jointed Rock Masses," in Bergmekanikdag 2007 (Swedish Rock Mechanics Day 2007), pp. 33-41. Stockholm: SveBeFo, 2007.

Potyondy, D. O. "The Effect of Voids on the Mechanical Properties of Rock," in DEM 07, CD Proceedings of the Discrete Element Modelling Conference (Brisbane, August 27-29, 2007). Minerals Engineering International, 2007.

Sainsbury, D. P., and M. B. Revell. "Executive Summary: Advancing Paste-Fill Bulk-head Design Using Numerical Modeling," CIM Mag., 2(5), 81 (2007).

Shimizu, Y. "The DEM Simulations Including Natural and Forced Convection Heat Transfer and Conduction Heat Transfer," in DEM 07, CD Proceedings of the Discrete Element Modelling Conference (Brisbane, August 27-29, 2007).