V. M. Seryakov

Mechanical-electromagnetic transformations in rocks on failure

The authors present energy estimations of mechanical-electromagnetic transformations in rock specimens under compression that can be of use to diagnosing rockburst hazard rate in underground mines.

Stress Redistribution in Ore Block During Breaking

The stress fields are calculated for the pattern of short-delay blasting in ore block with the formation of curved free surfaces. It is established that in all breaking stages, the tension areas favoring the reduction in the energy intensity of failure arise in the massif.

Mathematical modeling of stress-strain state in rock mass during mining with backfill

The article presents a discussion of formulations and methods for solving problems on stress-strain state of surrounding rocks and solidifying backfill developed in the Institute of Mining. As shown, effective algorithms can be obtained with the use of a computational domain that conforms with the rock mass before the first and second mining. The process of driving and backfilling is modeled using the iteration procedures from the initial stress and strain methods. Convergence of the offered iteration procedures is confirmed. Solution of practical problems is exemplified. In the framework of the developed methods and algorithms, the author offers the ways of accounting for incomplete backfill with solidifying mixtures and for rheological properties of surrounding rocks and the backfill.

Calculation of the Stress State of Rocks with Regard for Sequence of Filling Mass Formation

A method is proposed for estimating the influence exerted by sequence of stoping and filling operations on the stress state of rock mass. The stiffness matrix of computational system is invariable for all stages of the solution. The convergence of created iteration algorithm and the possibility of its effective application are shown by the example of a number of problems.

Calculation of rock mass stresses considering rock mass–support interaction in mines

The article describes a proved method to calculate stress state of support and surrounding rock mass, considering roof and wall rocks displacement until the contact with the support. The method is based on the use of the intact rock mass stiffness matrix formed prior to mining. Modeling of drivage using the method of initial stresses allows splitting the problem into two subproblems: the first subproblem is on mechanical state of rock mass during roof and wall rocks displacement, the second subproblem describes joint deformation of roof rock, walls rocks and support. The cases of stress calculation for rocks and support, considering support installation conditions, are described. The stress behavior depending on the value of roof and wall rocks displacement until the contact with the support is determined. The features of the method application in case of greatly different mechanical characteristics of rocks and support are discussed.

Calculating stresses in support and sidewall rocks in stagewise face drivage in long excavations

The issues of calculation of stresses and strains in the elements of support and in rock mass in stagewise drivage of a production face are under discussion. In order to take into account the sequence of mining and support installation, it is required to solve problems on extra stresses due to small cross-section drivage. Geomechanical estimation of support and rocks used the method based on single formation of stiffness matrix to describe rock mass prior to mining start. Sequential drivage of excavations and change of mechanical properties in the calculation system are modeled using initial stress procedure. The author calculates two scenarios of mining with stagewise face drivage under conditions of elastic deformation of rocks and support and analyzes behavior of stress redistribution in elements of support being installed in stages. It is shown that mining sequence considerably influences stresses in the support elements upon the drivage completion. The scenario of mining with initial installation of sideways support elements results in increased tensile stresses in the support as against the scenario when the underroof space is first mined out and supported.

Geomechanical validation of the parameters and technique for damping layer in the vicinity of underground excavation for overburden pressure relief

The data on stress-strain state around an underground excavation in an unstable rock mass are reported. For overburden pressure relief, it is proved necessary to create a damping layer, and the related drilling-and-blasting parameters are determined. Zones of probable fracture of rock mass under camouflet blasting are identified.

Stress State of a Coal Pillar in Fully Mechanized Longwall Mining in Dislocation Zone

Stress state of rock mass during fully mechanized longwalling in dislocation zone is analyzed. In focus is the variant of crossing the dislocation zone with disassembling the fully mechanized longwall system and its re-assembling in a new room. Stress redistribution in coal and host rocks when heading approaches dislocation and in post-dislocation mining from the new assembling room is determined.

Geomechanical substantiation of the resource-saving alternatives of the induced block caving method

The paper focuses on the improvement of the ore blasting efficiency in rock masses under the natural, gravity-tectonic and technogenic stresses. The safe and resource-saving process proposed by the authors for the induced block caving in deep hard rock mining reduces consumption of commercial explosives due to the rock pressure energy in the blasting process.