How to estimate the modulus of deformation of a block rock masses using discrete element simulations?

The deformation modulus of rock mass is a fundamental parameter in the geomechanics of tunnels, mining, and other geotechnical rock-supported facilities. The mechanical properties of a rock mass, seen as a fractured medium, are determined by the intact rock, the pattern of relative joint-sets, the geometrical arrangement of the joints, and their mechanical properties. Joint sets, acting as planar discontinuities, confer scale and direction-dependent mechanical properties. The critical factor influencing the deformational behavior of a rock mass is the stiffness of its fractures and discontinuities. The present study investigates the anisotropic deformation modulus of blocky rock masses formed by three intersecting joint sets, including two orthogonal sets. This was achieved through discrete element simulations of representative volumes of blocky rock masses. These studies facilitate the estimation of the blocky rock mass deformation modulus in different directions without the need for laboratory and in-situ tests or empirical relationships.

For more information, see the article:

📌 Ahrami O., Javaheri Koupaei H., Ahangari K. Determination of deformation modulus and characterization of anisotropic behavior of blocky rock masses. Mining Science and Technology (Russia). 2024;9(2):116-133. https://doi.org/10.17073/2500-0632-2023-08-143

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We present the articles of the fourth issue of scientific journal "Mining Science and Technology” (Russia) for 2024:

The study assessed the impact of water inflows on the strength characteristics of the rocks of the Lovozero rare-metal deposit developed by the Karnasurt mine. he data on water inflow into Karnasurt mine workings, which exploits two ore bodies of the Lovozero rare-metal deposit, are considered. Statistical processing of the data on water volumes collected by the mine over the latest 4 years was performed, with assessment of their changes during a calendar year. The quantitative indicators of the changes in the strength characteristics of rocks due to water saturation were determined. It was found that the water saturation led to a decrease in the rock strength by up to 10–20%, especially for compressive strength values.

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📌 Kalashnik A.I. Effect of water inflows on the strength characteristics of the Lovozero rare-metal deposit rocks. Mining Science and Technology (Russia). 2024;9(4):387-394. https://doi.org/10.17073/2500-0632-2023-09-160

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#Inenglish #MST #mine #extraction #waterinflows #rocks #pillars #properties #strength #watersaturation #rockbursthazard #Lovozeroraremetaldeposit #Karnasurt #metaldeposit

We present the articles of the first issue of scientific journal "Mining Science and Technology” (Russia) for 2025:

Scientists conducted laboratory tests according to the International Society for Rock Mechanics (ISRM) methodology to investigate fracture toughness at interfaces between gypsum stone and sand-cement mortar. The fracture toughness coefficient K_IC was determined using cylindrical specimens 40 mm in diameter and 150 mm long with a V-shaped notch, tested in three-point bending. Results showed that the average KIC value for the rock-concrete interface was only 0.323 MPa×√m – 4 times lower than for pure gypsum (1.327 MPa×√m) and 2.5 times lower than for concrete specimens (0.858 MPa×√m). Interestingly, the formation of a calibrated fracture during testing caused a 30% increase in the internal mechanical loss factor Q⁻¹, revealing new possibilities for fracture toughness evaluation using resonance methods. These findings have important practical implications for the design, operation and monitoring of industrial mining facilities containing rock-concrete interfaces.

For more information, see the article:

📌 Voznesenskii А.S., Ushakov E.I., Kutkin Ya.O. Fracture toughness of rock-concrete interfaces and its prediction based on acoustic properties. Mining Science and Technology (Russia). 2025;10(1):5-14. https://doi.org/10.17073/2500-0632-2024-10-316

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How to determine the deformation modulus and anisotropy in blocky rock masses?

🔹 In a study published in Mining Science and Technology (Russia), the authors investigated the anisotropic behavior of blocky rock masses. They employed the discrete element method to model and analyze the deformation modulus as a function of loading direction, joint properties, and intact rock characteristics.

🔹 Key Findings:
✔️ The deformation modulus depends on the Joint Roughness Coefficient (JRC) and the Uniaxial Compressive Strength (UCS) of the intact rock.
✔️ The influence of joint roughness on the deformation modulus is three times greater than that of intact rock strength.
✔️ The degree of anisotropy in the deformation modulus ranged from 1.6 ≤ Rₑ ≤ 2.5, with an average value of 1.88.
✔️ During joint sliding failure, the yield strain (0.2–0.4) is independent of the loading angle (θ) and the orientation of the third joint set (α).

🔹 Practical Applications:
The results enable the prediction of rock mass behavior without costly field tests, which is crucial for designing tunnels, boreholes, and other geotechnical structures.

Read the full study in Mining Science and Technology (Russia):

📌 Ahrami O., Javaheri Koupaei H., Ahangari K. Determination of deformation modulus and characterization of anisotropic behavior of blocky rock masses. Mining Science and Technology (Russia). 2024;9(2):116–133. https://doi.org/10.17073/2500-0632-2023-08-143

🔔 Subscribe to our Telegram channel: t.iss.one/MinSciTech

#InEnglish #MST #anisotropy #deformation #modulus #mass #rocks #loading #fracture #stiffness #strength #shear #resistance #stress #displacement #sliding #quartz #modeling #coefficient #index #blocks #deformations #material #surface #structure #boundary #experiment #geomechanics #JRC #UCS #GSI #simulation