Simulating Spalling With a Flat-Jointed Material (2020)
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.
Modeling of Spalling in PFC3D — A Quantitative Assessment (2020)
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.
Stability Design of Open Pit Walls Using 3D Modelling Approach (2020)
The open pit mine is part of a Greenfield exploration project. Itasca Consultants GmbH in corporation with Itasca Chile were contracted to develop a stability design of the pit. The analysis has been performed using Itasca’s three-dimensional distinct element code, 3DEC (Itasca, 2016).
Influence of former near-surface ore mining on a road construction project (2020)
The road construction department of district Steinfurt, a district in the north of the coal mining area in the Ruhr region, is planning the construction of the new road K 24n. The road axis runs through an area partly affected by old mining operations. These mining operations took place between 1880 and 1921.
Rock mechanical analyses for the Boliden deep repository at Rönnskär (2020)
Boliden AB is constructing an underground repository for final storage of process waste material from the Rönnskär copper smelter facility. The repository is excavated at a depth of 330 m and the main components are storage rooms with a vertical footprint of 16 by 18 m and with lengths varying between 50 and about 200 m. Itasca was contracted by Boliden to carry out rock mechanical analysis to assess the stability in both the short- and long-term (3000 years) perspectives. FLAC3D and 3DEC models were used to study global and local stability as well as the potential for long term effects on flow paths in the rock mass resulting from the excavation of the repository.
Conditioning DFN models by GPR data (2020)
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.
Numerical calculations for the pre-dimensioning of the support lining in a ventilation shaft (2020)
A ventilation shaft in Germany is part of a former colliery and was put into operation in the late 19th century with a depth of approx. 600 m. Since the colliery was closed down, it has been part of the central water drainage system at the site, together with further shafts in the near distance. In the course of technical reconstruction measures, the shaft is to be converted from a ventilation shaft to a well shaft. For this purpose, the current diameter has to be expanded to a clearance of 3.3 m. The shaft, which was previously constructed with approx. 50 cm thick brick masonry, will be secured with a concrete shell after expansion. To evaluate the predimensioning of the shell, a numerical modeling of the secondary stress field is necessary.
Interaction of old near surface coal mining and a road construction project (2020)
The new connecting road K 24n is to be built in the most northern expanses of the coal mining area in the Ruhr region. The road axis runs through an area partly affected by old surface near mining operations. The coal is located in two seams, both dipping north with an angle of approx. 11°. These seams have been mined by three potential drifts, which have been identified by a geophysical field study.
Estimating settlements due to a complex excavation (2019)
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.
Effect of Shear Stresses on Pillar Stability Performance at Troy Mine (2019)
At Troy Mine, a progression of pillar failures led to surface subsidence. Itasca back-analyzed this behavior, using a large-scale numerical model, to understand the level of stresses and failure mechanism leading to the collapse of some pillars. Forward predictions on pillar stability in another nearby deposit, in a similar geomechanical setting, were also done.
Stability during the construction of diaphragm-walls in sand-fills (2019)
For the construction of the diaphragm‐walls of a cut & cover tunnel in sand‐fill, Itasca Consultores S.L. has been analyzing the stability of the slurry walls of an excavation panel
Numerical simulations of shield support for a coal mine (2019)
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.
Seismic Performance of the OPC Puerto Cortes Container Terminal in Honduras (2019)
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.
Pore Pressure Model for Large Open Pit Mine in the North of Chile (2019)
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.
Modelling over-boring and extension of a tunnel with surrounding excavations (2018)
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.