Authors: A.G. Protosenya, A.V. Andreeva

Title of the article: Improving the methodology for predicting fracture zones in waterproof strata for deep potash deposits

Year: 2025, Issue: 5, Pages: 117-127

Branch of knowledge: 2.8.6. Geomechanics, destruction of rocks by explosion, mine aerogasdynamics and mining thermophysics

Index UDK: 622.2

DOI: 10.26730/1999-4125-2025-5-117-127

Abstract: The development of potash deposits is associated with the necessity of protect the mine workings from intrusion of fresh water from overlying aquifers. Water can enter the mine workings through water-conducting fractures formed as a result of the deflection of water-bearing strata into the excavated space. To estimate the height of water-conducting fractures in modern deep potash mines, engineering calculation methods based on formulae with empirical coefficients are available. The methodology is based on a combination of analogues for shallow salt deposits and deep coal deposits. In order to calculate the height of fracture formation in relation to a specific working area, it is proposed to use numerical methods that consider real geology of the deposit and rock behavior. In this paper, numerical models of the field area with an average geological section are built, the model parameters are selected according to the average rock properties: for the rocks of water protection layers - concrete model, considering the damage accumulation, for the salt rocks of productive and underlying layers - model, considering their long-term deformation. The models estimate the dependence of the crack height on the working time and the width of the cleaning space. For this purpose, two numerical models were constructed: the model of the chamber-pillar system, with successive development of chambers in chamber blocks and subsequent calculation for 30 years, and the model of the chamber system with constantly increasing cleaning space. It was found that there is a limiting height of fracture formation, above which further increases in working time and cleaning space width do not affect the height of fracture propagation.

Key words: Waterproof strata crack propagation potash mine deep deposit Concrete model numerical modelling

Receiving date: 03.03.2025

Approval date: 22.09.2025

Publication date: 23.10.2025

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