Assessment of induced seismicity impact on multi-level mining structures in underground salt exploitation

¹ National Institute for Research and Development in Mine Safety and Protection to Explosion – INSEMEX, general Vasile Milea 32-34, Petrosani, Romania
² Technical University Gheorghe Asachi, Iasi, Romania

^* Corresponding author: stefan.ilici@insemex.ro

Abstract

Underground salt mining frequently relies on blasting techniques that generate shock waves with seismic characteristics. These waves propagate through the geological medium and undergo significant transformations at the boundaries of elastic deformation zones, manifesting as seismic waves capable of inducing dynamic loads on multilevel mining structures. Under such conditions, the structural stability of these works depends on the rock mass’s capacity to dissipate the transmitted energy without exceeding the residual deformation threshold. Modelling the rock mass behaviour under dynamic loading conditions is central to seismic risk assessment. Findings indicate that seismic wave fronts may induce stresses that surpass the elastic limit, resulting in plastic or residual deformations. Repeated exposure to such phenomena, due to sequential blasts, can lead to the accumulation of irreversible deformations, ultimately affecting the structural balance and overall stability. The research underscores the necessity of optimizing the blasting regime to ensure that dynamic loads remain below critical thresholds for residual deformation. This approach aims to safeguard the integrity of multilevel mining structures and support the continued safe operation of underground salt extraction activities. The paper evaluates the seismic risks associated with successive blasting operations in salt deposits and their effects on overlying mining structures.