Research, Numerical Investigations and Development of a Methodology for Longwall Mining at a Potash Deposit (2021)
Aim of this R&D project is the development of guidelines for the estimation of the water-conducting crack propagation above mined-out spaces above a potash deposit, using research and numerical modelling methods.
The open pit mine is part of a Greenfield exploration project. Itasca Consultants GmbH in cooperation 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).
The road construction department of the district of 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.
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.
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.
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.
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.
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.