Figure 2: (a) mine lay-out and selected pillars use in the analysis
Rock pillars can be defined as the in-situ rock between two or more underground openings. However, one aspect that is seldom considered in analysis of hard rock pillars, and indirectly in synthetic rock mass models to determine rock mass strength, is the actual stress level and stress path imposed on the pillar due to the excavation sequence and the location of the pillars within the mine lay out. In this paper we propose to use numerical stress analysis to determine how stresses vary across the excavated pillars in a typical room-and-pillar mine lay out, and thus generate a spatially variable determination of pillar stability. Because of the computational difficulty associated with hybrid modelling of realistic discrete fracture networks, synthetic rock mass modelling is commonly carried out using a 2D approach. By comparing 3D and 2D results for selected cross-sections across, we believe the results of the analysis will provide the opportunity to better constrain the stability implications of a 2D approach to pillar design and synthetic rock mass modelling.
Figure 2: (b) 3D stress model created in PLAXIS.
This article was published in IOP Conference Series: Earth and Environmental Science, Volume 833, Mechanics and Rock Engineering, from Theory to Practice 20-25 September 2021, Turin, Italy (2021), and is available as open access here:doi: https://doi.org/10.1088/1755-1315/833/1/012132IOPS Science link: https://iopscience.iop.org/article/10.1088/1755-1315/833/1/012132
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 3.0. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Citation: D. Elmo et al 2021 IOP Conf. Ser.: Earth Environ. Sci. 833 012132