Models of rock pressure phenomena

Abstract

The use of models made of equivalent materials is a universally acknowledged method of investigation. Proposed and developed at VNIMI (All-Union Scientific-Research Mine Surveying Institute), it is being used ha scientific institutes doing research on rock mechanics and rock pressure phenomena in varied mining-geological conditions and on a wide range of technical mining problems. The method has recently been increasingly recognized abroad.This book deals with the latest progress in development of this method. It gives a very complete and systematic exposition of the theoretical principles of the method and the techniques for its application. The theoretical principles of equivalent-material models have been developed further, giving a sounder basis for selection of criteria of similarity of materials in work on problems characterized by the mechanical state of the solid rock and the conditions of its fracture. The need for such development of the method is urgent in connection with the extension of its range of application.A thorough going examination of the initial state of the solid rock, its mechanical properties and the parameters and depth of the working has enabled the authors to make quite accurate determinations of the range of application of three-dimensional and plane models. They give an estimate of the errors involved in determining the stresses in roof strata with a plane model, and show how to allow for them.The authors have developed sections dealing with preservation of the initial and boundary conditions in the models, the choice of equivalent materials for solving various problems, selection of model scale, and methods of determining the mechanical characteristics of the material. They give a fairly complete description of the methods developed by themselves for testing equivalent materials for strength, and of the devices used for this purpose.The book explains the methods and apparatus most widely used at VNIMI and other scientific organizations for observing displacements, deformations, and states of stress in the rock and in the model, together with structures imitating the operation of the supports at the face and their interaction with the wait rocks.The authors generalize the methods of investigation based on models, and give methods of processing the results. This generalization of methods of testing models and use of standard methods of processing results is very useful for getting comparable data.Of great value is the development of a method of using models to study phenomena connected with blastings. The book analyses the action of waves on the stability of exposed rocks, and shows the possibility of investigating the influence of wave processes on plane models of limited dimensions. The authors give criteria of similarity which must be observed in making models of the action of blasting and methods of achieving such similarity in models made of equivalent materials. They develop technical methods of setting up the experiment.The provision of a sound basis for model research on the a...

Badanie wpływu kompensacji na stabilność górotworu oraz jakość wydobywanej rudy

“…Such systems are used in our underground mines in conditions of insufficient hardness and stability of both ore and country rocks. Iron ore deposits are mined mainly within the depths of 1200-1400 m with further deepening to 1800-2000 Submission date: 24-01-2023 | Review date: 19-03-2023 m. Considering the above facts as well as negative effects of rock pressure at deep levels, the problem arises of choosing the most rational shape of compensation rooms [5][6][7][8]16].…”

Effect of the charge diameter and type of explosive on the size of the overcrushing zone during an explosion

“…If the load is kept similar, the error incurred by replacing plane deformation in an infinite medium by the planar-stressed state in a plate is less than 5% [1].…”

Use of models to study the breaking-down of banks by crater-blasting

“…Using models made of equivalent materials [6] we have studied the caving of steep slopes when ejection-blasted at the base. The slope caves under gravity after formation of the ejection crater and propagation of compression and tension waves through the bank, i.e., the caving process is the final stage in the motion of the ground during the blasting of a steep slope.…”