| The main complications that occur in the underground space are roof rocks collapse,increase of pressure onto the support,bulging of floor or in contrast,increasing of its compliance when the support goes onto the excavation floor.However,as it turns out,all of these types of complications and many others have the same source.The source of this is the influence of tectonic fault zones.Tectonic faults in the form of defects and large thrusts subject rocks to prolonged displacement,overlapping of rocks of different ages,resulting in changes in their structure,composition,physical and mechanical properties,increasing fracturing of rocks,and reducing the stability of geotechnical facilities on the slope.In this thesis,calculations on the choice of optimal parameters of underground roadways in the fields with strong tectonic disturbances are carried out.The issues discussed on the example of the Taldybulak gold mine,which is located in Kyrgyz Republic.The following findings and conclusions were obtained based on the conducted work:1)The Taldybulak gold mine is located in tectonic stress zones of various genesis,and almost all types of metamorphism characterize the properties of the rocks.The mineralization zone's host rocks and rocks have low porosity and low water absorption;the rocks are intense fracturing,shale,and blocking.With depth,there is a change in the values of the strength properties of rocks.2)It is established that combined with the study of rock mechanics,and technical and economic comparison,for the conditions of the mine recommended to use the cut and fill mining method with backfilling the empty space for developing the Taldybulak gold mine.The mining method's final structural parameters should be fully justified by the subsequent analytical calculations of the stability of roadways.3)It is found that reducing the excavation cross-section can improve the mining site walls' safety and stability.Still,it has low economics.Increasing the size can improve the economics of mining,but the mining site walls' safety is lacking.According to the analysis of developing excavation stability process,it is recommended to accept the dimensions of the mining area excavation 4m × 4m,at the same time,different support measures should be applied as the properties of the roadways' roof rocks change,to ensure the safety of the excavation.4)It is established that the analysis of destruction factors at the loss of stability ofroadways approximately allows allocating types of destruction of a gold ore deposit Taldybulak,with an application of various methods of support depending on an operating mode.At this site,a screw anchor of rod option is mainly recommended for anchoring,which is more effective than a tubular seam anchor rod.However,the latter has been applied at the Taldybulak gold mine for many years,which requires continuous optimization of technical anchoring parameters through production practice in the mine to achieve the effective support of different types of the roadways.5)It has been established that in the Taldybulak gold mine,the massif is crushed.The massif quality is inferior;during the mining process,the collapse of the roof quickly occurs and other geological disasters.In this regard,given the current state of development of the crushed ore bodies at many medium-sized mine sites,a mining pressure monitoring program should be investigated to prevent and manage the risk of natural disasters during mining operations.Based on the results of rock pressure monitoring,the rock pressure hazard class can be assessed promptly to provide a basis for developing the anchoring option and an appropriate safe technical action.There are 32 figures,9 tables,and 71 references in this paper. |
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