Geomechanical substantiation of pillar dimensions between unloading boreholes during the development of rockburst-hazardous deposits

The article discusses methods for reducing hazardous stresses during the development of rockburst-hazardous mineral deposits. The main focus is on the technology of using unloading boreholes, which, compared to alternative methods (such as under-mining and over-mining), offers significant advantages – high implementation speed and minimal labor costs. The authors provide a detailed analysis of the key borehole parameters that determine the efficiency of rock mass unloading: diameter, spacing, spatial orientation, and cross-sectional shape. Particular attention is paid to investigating the influence of the borehole's geometric shape on the stability of inter-borehole pillars. A comparative numerical analysis of rock mass deformation for circular and square cross-sections showed that circular boreholes increase the load-bearing capacity of pillars by 34.8% due to a more favorable stress distribution. Based on the classical Turner-Shevyakov methodology, an improved calculation formula has been developed, incorporating a new correction coefficient Kskv, which accounts for the borehole shape. This allows the application of proven analytical methods for designing borehole unloading systems, simplifying calculations for practical application and eliminating the need for complex software. The research results are of significant practical importance for mining enterprises, enabling the optimization of unloading borehole parameters to achieve a balance between technological efficiency, mining safety, and economic feasibility. The prospects for applying the obtained results to room-and-pillar mining systems are also considered.

Shabarov A. N., Andreev A. A. Geomechanical substantiation of pillar dimensions between unloading boreholes during the development of rockburst-hazardous deposits. MIAB. Mining Inf. Anal. Bull. 2025;(12-2):180-193. [In Russ]. DOI: 10.25018/0236_1493_2025_122_0_180.

A.N. Shabarov¹, Dr. Sci. (Eng.), Director of the Research Center for Geomechanics and Mining Issues, e-mail: shabarov_an@pers.spmi.ru, ORCID ID: 0000-0001-7925-3163,
A.A. Andreev¹, Project Lead of the Administration Office of the Research Center for Geomechanics and Mining Issues, e-mail: andreev_aa@pers.spmi.ru, 
¹ Empress Catherine II Saint-Petersburg Mining University, 199106, Saint-Petersburg, Russia.

A.A. Andreev, e-mail: andreev_aa@pers.spmi.ru.

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