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?
In general, analysis performed on wind turbine foundations focus on the effects of the foundation’s rotational stiffness and deformation for a range of overturning moments. This project stage focused on the performance of the foundation and, given the local soil condition, its bearing capacity. To evaluate the behavior of the soil-structure interaction, a detailed numerical model of the concrete foundation and its steel reinforcement (i.e., rebar) was built and analyzed in FLAC3D.
For pile groups with a relatively large pile cap, the geotechnical failure is generally not the controlling failing mechanism of the system. It is almost always settlements, rotation, or performance that controls the design.
In this project, the effects of deformation and rotation with regards to the pile length were observed. Specifically, four piles of a pile bridge were driven through an intermediate sandy layer and may have encountered a local anomaly (Figure 1). A safe assumption was to consider the anomaly to be clay. Additionally, the benefit of any additional helping elements to balance the stiffness distribution of the pile under the pile cap were evaluated.
The development and mining of a deeper seam in a coal mine, located in southern Siberia is planned. ITASCA was tasked with assessing the minimum support pressure and maximum unsupported distance between shield and coal face required to ensure stability of the roof. Also the stress state, displacement field and excavation damaged zone in the roof of the seam were analyzed.
For over five years, Itasca Chile SpA (Itasca) has developed and continuously updated, the 3D numerical groundwater flow model for this open pit mine in Chile. The model is primarily used to estimate pore pressure distributions for past, present, and predictive stages of the pit excavation. These are subsequently used for 3D slope stability analysis. With the new and updated model, new predictions for future stages were made, and new mining and drainage plans were evaluated from a hydrogeological point of view.
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.
Numerical Investigation of the Mechanical Response of Dual-Purpose Canisters to Internal Pressurization (2019)
Dual purpose cannisters (DPCs) are used for temporary storage and transportation of spent fuel rods. The U.S. Department of Energy is investigating the performance of DPCs for direct geological disposal of spent nuclear fuel.developed a numerical modeling methodology to better understand how a DPC will respond to a criticality event.
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.
Itasca Chile SpA was retained to develop a numerical 3D groundwater flow model that would allow the assessment of potential environmental impacts over the aquifer due to the infiltration associated with the expansion of the Tailings Storage Facility (TSF). Additionally, it was requested to study the potential influence of infiltrations on the mine pit located about 3 km of the TSF.
As part of phase four in the extension of the ANDRA Meuse/Haute-Marne Underground Research Laboratory, a safety niche (called GT1) will be over-bored into a larger section, then extended. The tunnel axis is 16 m from an auxiliary shaft (named PX). Two perpendicular drifts, called GLN and GLE, connect these 2 excavations.
With concurrent open-pit mining and sub-level open stoping under way at Rampura Agucha, the goal of this work was to gain insight into how blasts should be designed to better protect underground excavations. FLAC3D models were used to link the small-scale detonation and crushing behavior to the mine-scale stress wave propagation behavior.
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.
In the context of a wine cellar extension project, a 20cm thick concrete slab is to be constructed on a soil reinforced by rigid inclusions. Itasca France has been called by the design office to verify the mechanical resistance of the concrete slab and assess its settlement under a uniform load.
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.