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.
Located near Fisherman’s Wharf in San Francisco, North Shore Pump Station is a part of the North Point Wet-Weather Facility (NPF), which provides primary treatment for disinfection of wastewater. The facility is a two-story building that is completely embedded in soil, and the subsurface conditions include potentially liquefiable sand layers and soft Bay Mud deposits sitting on bedrock sloping toward the east side waterfront. The building is supported by piers extending all the way into the Franciscan Complex bedrock.
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).
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.
Karowe Mine, located approximately 16 kilometers (km) southwest of the town of Letlhakane, is a diamond mine where the second largest diamond ever found on record, with a weight of 1,111 carats, was discovered. This project involved simulating mine dewatering and excavation to evaluate future dewatering requirements, as well as providing guidance for future monitoring borehole and piezometer designs.
As part of evaluation of seismic performance of this 175-foot high hydraulic fill dam located at a confidential site in the southeast Appalachia region, Geosyntec hired Itasca Consulting Group (Itasca) to perform deformation analyses for seismic loading of the dam using numerical modeling. Prior to the deformation analyses, Itasca also assisted Geosyntec with numerical simulations to assess the liquefaction potential of the dam using the cyclic stress ratio approach.
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 binder. A PFC2D model accounting for the microstructure of a baked anode, using the Bonded Particle Model (BPM) has been developed in previous studies.
Boldwing Continuum Architects Inc. has contracted Itasca Consulting Group to perform a liquefaction analysis and evaluate several soil improvement designs for the Langdale Ferry Terminal Project in Vancouver, Canada. The terminal sits on a deltaic granular deposit prone to liquefaction. The new expansion of the ferry terminal has to be designed in compliance with the 2017 Canadian Building Code, which requires the analysis of 11 different earthquake time histories. The most challenging requirement is to design the ground improvement to limit any lateral soil spreading within 100-150 mm.
Investigating the mechanical behavior of a surface repository for low and intermediatelevel short-lived radioactive waste (2017)
Andra operates a surface repository in Aube (“CSA”, North‐Eastern France), where some of the concrete canisters containing low and intermediate‐level short‐lived radioactive waste are stacked in concrete structures, then filled with gravel (Fig 1). ITASCA Consultants SAS, together with EGIS Industries, has studied the mechanical behavior of the assemblies, in the framework of design and safety demonstration programs.
The Björkdal mine ("Björkdalsgruvan"), located 28 km northwest of the town of Skellefteå, is a gold mine with the mineralization typified by Au-quartz veins located within a metamorphic package. The Björkdal mine is operating with both open pit- and underground mining. During spring 2016 the mine experienced local slope instability at one of the open pit walls. The concern was how it would affect safety for the mine workers and future mining, but also if it was safe to remove loose rock mass without endangering workers or interrupt any mining activities.
A baked anode is made of a complex material, obtained by mixing and baking different petrol coke grains, with different size distributions, with a pitch. Hydro PMT needs to study how cracks propagate in such a material – both within and between grains. Representing properly the non-spherical grain shapes, as well as the porosity, both between grains and within the coke grains, are therefore prerequisites.
Fountain Slide has a long history of stability problems. The slope is bounded downhill by the Fraser River and uphill by a highway and a railway. This project stage focused on stabilization of a section of the railway that has suffered extensive damage to its retaining system.
Solution-Mining Modeling (2016)
A confidential mining client was interested in evaluating various potential future solution-mining scenarios using a numerical model in order to assess potential ore recovery, capital costs, and cavern lifetimes, as well as to overall optimize the proposed mine plan. Modeling of solution mining requires that the key processes controlling the mineral dissolution are modeled; however, there are numerous factors that complicate the details of the dissolution process that are impractical or impossible to account for in a model.
At shallow depth, the initial stress state can significantly affect the behavior of the rock mass around excavations, but stress measurements are usually subjected to high levels of uncertainty. This was the case at the Odenplan railway station in Stockholm where unexpectedly large deformations were measured during the excavation.