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?
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.
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.
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.
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 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).
When starting a new mine, whether it's a open pit or an underground mine, the designer faces many challenges! One of these is the understanding of rock mass conditions and how this affects the choice of mining methods and the mine design at an early stage.
Le projet d’extension d’une cave à vin à AMPUIS (69) prévoit la réalisation d’un dallage de 20cm d’épaisseur sur un sol renforcé par des inclusions rigides.
The city of Kiruna is partly located on the hanging wall side of the LKAB Kiirunavaara Mine. In the long-term perspective, it is not possible to have any residential buildings or infrastructure within the fracture zone and cave zone resulting from mining. An urban transformation process for the Kiruna city center is thus currently underway. The current prognosis is empirical based on observations since the early 1960s until today.
In the framework of the development of a subsea tidal turbine, the design of the foundations has to be optimal. Cathie Associates, on behalf of HydroQuest, wanted us to investigate the penetration of a single steel foundation pin in a granitic rock mass by using a discrete numerical approach and follow the state of the damaged zone around the tip during penetration.
Open pit mining often result in high rock slopes, sometimes combined with difficult rock conditions. This is further augmented by large blasting rounds resulting in high vibrations. Reinforcement of pit slope walls is also difficult and many times associated with high costs and loss of production. Bench slope stability is vital for a safe working place for all personnel in the mine as well as for avoiding production loss. Itasca Consultants AB is providing technical, on-site rock mechanics expertise to several open pit mines in northern Sweden.
The Kevitsa open pit mine has been in operation since 2012 and was acquired by Boliden in 2016. A new strategic plan is currently being developed to investigate an increase in production. In conjunction with this, the geotechnical slope design parameters for the final pit depth, including a possibly deeper pit, need to be analyzed.
Boliden Tara Mines is Europe’s largest zinc mine, with an annual production of 2.6 million tones of ore, and has been in operation since 1977. This project was part of the required planning application to the authorities regarding crown pillar extraction in the norther portion of Boliden Tara Mines. It was conducted in two phases – first a continuum model was analyzed in FLAC3D, which was then followed by a discontinuum modelling in 3DEC with included faults.