Home – Home – Jornals – Advanced Search

The effect of stiffness of shock-absorbing pads of a real explosion chamber on the degree of vibration damping and maximum stresses in the body of the camera is experimentally and numerically investigated. The results are analyzed. A relation between the seismic effect on the foundation after a charge explosion inside the chamber and durability of its operation is revealed.

The article gives the experimental proof of effective use of the kinematic criterion χ, derived by Oparin for “apparent” velocities of pendulum waves based on deterministic description of seismic energy release in the Norilsk mine fields, for assessment of stresses and strains in coal beds in terms of the Polysaevskaya Mine, Kuzbass.

Based on numerical modeling of stress–strain state of rocks and the in situ deformation monitoring of rocks mass surrounding underground excavations, the authors determine limit criteria of geomechanical stability of mine structural elements in terms of the Aikhal Mine where mining has been transferred under the worked-out open pit bottom. Using the determined criteria, the stress–strain state and subsidence of the crown pillar are assessed, considering current stage of the water table in the open pit. The article gives predictive estimate of the change in the stress–strain state and subsidence of the crown pillar upon the water level raising.

The regular patterns of initiation and show of acoustic emission memory effect in a composite are experimentally obtained using cloth laminate. The authors illustrate capacity of cloth laminate as an absolute sensitive stress-to-acoustic emission converter. The designed and tested downhole sensor enclosing this converter provides indication of incremental stress excess over pre-assigned critical limit.

The article reports the integrated assessment of natural stresses in rock mass in the Nurkazgan Mine. The visual observation of underground excavations and instrumental measurements of effective stresses denote the hydrostatic stress state within the studied minefield

The issues of physico-mechanical properties of ore and rocks, measurement of displacements in rock mass around underground excavations, stability of the excavations, selection of types and parameters of supports are studied in terms of the Yakovlevsky iron ore deposit

Out of aspects of modeling mathematically deformation of rock specimens, the article analyzes soft and rigid loading. The authors formulate an inverse problem on identification of mechanical properties, boundary conditions and geometry of weak areas using overspecified conditions using data on measured displacements and acoustic-electromagnetic emission that characterizes rock failure under loading.

Based on the review of the strongest mining-induced rockbursts with the same seismic characteristics recorded in underground mines in Russia, the author compares the events based on their energy parameters. It is shown that the mining-induced seismic events on the Kola Peninsula are still the strongest events.

The article presents and discusses a quasi-brittle rock failure model, analytical expressions constructed for limit stresses using necessary and sufficient criteria of structured rock failure, normal tensile stresses in rock mass with fracture, quasi-brittle failure diagram constructed using approximation of two-section kinked stress–strain curves obtained in coal under tension, and critical stress estimates.

Mining complexes can contain multiple mines operating simultaneously along with multiple processing streams, stockpiles and products. Stochastic optimization methods developed to date generateonly local optimal solutions in the sense that they do not consider the entire mining complex. This paper presents an extension of a multi-stage method used for generating long-term risk-based mine production schedules, to operations with multiple rock types and processing streams. The developed method uses a simulated annealing based algorithm during the optimization stage, seeking to minimize deviations from production targets for waste and different ore processing streams. The proposed approach is applied at Escondida Norte copper deposit, Chile, in which sulphide, oxide, mixed and waste materials are present with milling, bio-leaching and acid-leaching being the available processing streams. The stochastic schedule generates expected deviations from mill and waste production targets smaller than 5%, which avoid indirect costs associated to idle capacities. A schedule generated conventionally exhibits expected deviations of the order of 20%.