In Sweden, the Forsmark site, a sparsely fractured crystalline host rock, is selected to be the future location for building a deeply sited nuclear waste disposal. The use of highly detailed DFN (Discrete Fracture Network) based site models is required for both post-closure safety assessment and construction purposes. DFN-based models are considered the most accurate representation of the fractured system and of the geological context.
Site modeling using DFN.lab (2021)
In Sweden, the Forsmark site, a sparsely fractured crystalline host rock, is selected to be the future location for building a deeply sitted nuclear waste disposal. The implementation of highly detailed, and DFN (Discrete Fracture Network) based, site models is required for both post-closure safety assessment and construction purposes. DFN-based models are considered as the most accurate representation of the fractured system and of the geological context.
The objective of the project is to predict the scaling evolution of rock mass effective elastic properties for conditions relevant to the POSE (Posiva’s Olkiluoto Spalling Experiment) niche surroundings at ONKALO, the Finnish site for underground storage of nuclear waste.
LKAB’s Kiirunavaara Mine is a large, underground, sub-level caving mine that has been seismically active since approximately 2008. With this seismic activity comes associated vibrations. These vibrations can be felt on surface in the town of Kiruna, which is currently located close to the mine on the hangingwall side. The mine is undergoing a national permitting process concerning a desired increased production rate. An important question for this process is: will the increased production rate result in changes to vibrations in the town due to seismicity?
SKB is interested in developing a 3D discrete model to predict spalling on the excavation boundaries of underground repositories for the long-term storage of spent nuclear fuel. This project provided a quantitative assessment of modeling spalling using PFC3D to study both lab- and tunnel-scale behavior.
Long-term storage of spent fuel is critical to the nuclear energy industry. The Swedish Nuclear Fuel and Waste Management Company (SKB) is developing an approach for the storage of spent nuclear fuel in an underground repository in competent crystalline rock. In order to better understand the spalling damage process, an in-situ test involving the drilling of two boreholes was performed in Äspö diorite at SKB’s underground hard rock laboratory in Äspö. Tests and monitoring were performed on the pillar that separated the boreholes. In order to further investigate the damage process, Itasca performed numerical modeling using PFC3D and FLAC3D.
As part of the EU Horizon 2020 ENIGMA ITN project, ICSAS, the CNRS, and SKB proposed a PhD project entitled “Flow and transport in fracture networks: reducing uncertainty of DFN models by conditioning to geology and geophysical data”, to develop and test a methodology for rock characterization that would help in the decision-making process for an adequate location of the nuclear waste canister burying.
In the context of the Greater Paris works, the VINCI-SPIE group builds a future metro station underneath the CNIT centre in Paris, for the westward extension of RER E (EOLE). The West Pre-Station is particularly complex due to its excavation phasing and the presence of many surrounding structures, including among others the T2 tramway line and several foundations.
Dans le cadre des travaux du Grand Paris, le groupement VINCI-SPIE construit la future gare du RER E sous La Défense. Dans ce projet, la zone Avant-Gare (AG) Ouest (Fig. 1) est rendue complexe par son phasage et les nombreuses structures avoisinantes, telles que la ligne T2, les fondations d’un bâtiment emblématique de la Défense, le CNIT, et de son parking.
VINCI a demandé à ITASCA de réaliser un modèle 3D pour le calcul des tassements de surface engendrés par les excavations. Le modèle prend en compte le phasage réel de l’ensemble des travaux prévus.
Itasca conducted a seismic performance evaluation of the trestle‐wharf section of the OPC Puerto Cortes Container Terminal, located in Honduras. A FLAC3D analysis of the soil is performed, including the piles and deck of the terminal. This is a fullycoupled, dynamic, soil‐structure, time‐history analysis that quantifies the performance and potential risks for the structure and slope. The Finn model – Byrne formulation was utilized using data from investigation boreholes.
The development of a subsea tidal turbine requires specific research work concerning the design of the foundation in contact with the seabed. This design stage can be simplified by the use of numerical modelling and more particularly by using discrete modelling. HydroQuest asked Cathie Associates to check their previous calculations regarding the behavior of a single steel foundation pin in a granitic rock mass by using Itasca’s discrete numerical approach and follow the forces applied to the pin as well as the state of the damaged zone around the tip during penetration.
Dans le cadre du chantier 4 d’extension du laboratoire souterrain de Meuse/Haute-Marne, une niche de sécurité (appelée GT1) de section type
S1 sera alésée puis prolongée avec une section S4. L’axe de ce tunnel est à 16m de l’axe du Puit Auxiliaire (PX).
Junction Dam (2018)
Built between 1959 and 1961, Junction Dam is a double-curvature concrete arch dam located on Silver Creek in El Dorado County, California, just downstream from where Little Silver Creek and South Fork Silver Creek merge. The dam is in a relatively narrow canyon with steep sides and retains the Junction Reservoir.
The mine is interested in using the decommissioned open pit for storage of tailings from the underground mine, as this would be beneficial both from an environmental and an economical perspective. The implementation will be a technical challenge since portions of the crown pillar separating the open pit from the underground mining has been extracted.
A baked anode is a complex material, that results from the mixing and baking of different petrol coke grains, with different size distributions, with a pitch. A preliminary study (ICSAS16-CST-MFG-35143-01) developed a PFC2D model accounting for the microstructure of a baked anode, using the Bonded Particle Model (BPM).