General features of strong rock bursts and induced earthquakes in critical-stress areas of the Earth’s crust

The problem connected with rock bursts and induced earthquakes is yet one of the most critical in the mining regions. The manmade nature of disastrous earthquakes induced in the areas of the heaviest impact on the subsoil is being widely discussed. The main argument against the manmade genesis of such earthquakes is their great depths and high energies. The general features of the induced earthquakes are considered. The displacement directions of the walls of large tectonic faults during such events are analyzed. The sizes of focal zones are estimated and related with sizes of geodynamcially active blocks in the Earth’s crust. The location of hypocenters of geodynamic events relative to the manmade impact zones is studied. The found homogeny of strong rock bursts and induced earthquakes is explained by the interaction of local and regional (global) geodynamic processes. The critical stress state of the upper Earth’s crust having hierarchical block structure is considered as the basis of such interaction. When focal zones of rock bursts and induced earthquakes have sizes of hundreds of meters or a few kilometers, the initiation zones of such events reaches many kilometers in size, is commensurable with the Earth’s crust blocks and is larger than the mining impact zone. Therefore, displacements along large faults are the part of a tectonic process, i.e. displacement directions along large faults during strong rock bursts are correlated with the regional stress field.

Of forming loads on the mounting of shaft shafts in the hierarchic block environment under the influence of modern geodynamic movements

The subject of the research is the lining of mine shafts and surrounding rock mass. The subject matter is the features of the stress-strain behavior of lining and adjacent rock mass in shafts and near-shaft underground openings in the Tenth Anniversary of Independence of Kazakhstan mine located in the tectonically high-stress and low-strength rock mass. The loading of the lining in the shafts and near-shaft openings in the Tenth Anniversary of Independence of Kazakhstan mine during construction is investigated, and the damages of the lining in the course of drivage in the nonuniform stress field are analyzed. The long-term periodic in-situ instrumental monitoring of stress variation in the lining of the mine shafts and near-shaft openings revealed the main influences on the process of load formation on the lining in the conditions of post-limiting deformation of surrounding rock mass. It is validated that the surrounding rock mass of the mine has a complex hierarchical block structure and is subjected to modern geodynamic movements. As the depth of mining is increased, surrounding rock mass of the mine shafts transfers to the condition of postlimiting stresses and strains. As a consequence, the lining of the shafts and near-shaft openings at different stages of construction experiences nonuniform concentrated loads, which violates integrity of the lining.