| Coal mining area of South Wuxia Formation in Malan Coal Mine is affected by large mine pressure and mining dynamic pressure.910 east roadway and preparation roadway are seriously deformed,and there are problems of roadway bottom drum and original support failure.At the same time,these roadways are full-coal roadways with extra-large cross-sections,which are difficult to support and face the mining influence on the mining areas on both sides.These problems may cause these roadways to face more serious deformation and damage in the future and frequent repairs.Considering that these roadways have a long service life and bear the important functions of transportation,pedestrians and ventilation in the future production of the mining area,corresponding measures must be taken to ensure the long-term strength and stability of the roadway.Aiming at the serious deformation of the No.8 coal seam preparation roadway in Malan Mine,this article takes the No.8 coal seam preparation roadway as the research object,and adopts the methods of experimental testing,numerical simulation and on-site measurement to study the many influence factors of the roadway deformation,And optimize the roadway support plan accordingly,and carry out field tests.The main research work and conclusions are as follows:(1)Conduct detailed investigation on the failure of the support of the prepared roadway in the No.8 coal seam,and study the in-situ stress and surrounding rock in the area where the prepared roadway is located,using drilling TV and on-site coring,etc.Observation of the properties and joint development,the range of surrounding rock loosening circle and the surrounding rock failure morphology were obtained.At the same time,the physical and mechanical properties of rocks are obtained in combination with laboratory physical and mechanical tests to provide a reference for support design.And to deal with the problem of large changes in the in-situ stress of the valley terrain,the magnitude and direction of the in-situ stress are tested to provide a reference for the optimization of the roadway layout.(2)The numerical simulation method is used to study the stress distribution law of the protective coal pillars on both sides of the prepared roadway under the influence of mining.The influence of the excavation on the protection coal pillars under different protective coal pillar widths is discussed.The simulation results show that when the width of the protective coal pillar of the prepared roadway is 70 m,the prepared roadway is less disturbed by the stress of the stope and the change of the surrounding rock of the roadway tends to be stable.(3)Research on the deformation of the roadway caused by the stress superimposed by the adjacent roadway excavation,and obtain the deformation characteristics of the large coal roadway under the influence of mining in the adjacent roadway.At the same time,the deformation law of the roadway under the influence of the stopes on both sides was studied,and measures such as high-prestressed resin full-length anchoring bolt and cable combination support,and steel belt joint support roof between the anchors were proposed.(4)A long-term study of the test roadway is carried out using on-site observation methods to obtain the length of time the prepared roadway enters the stable phase from the violent activity stage,and the final deformation of the roadway before and after mining influence is obtained.According to this result,the optimized design plan is evaluated,and the result shows that this design plan can effectively ensure the service requirements of the roadway from driving to the completion of mining area recovery,and has engineering reference value.There are 30 figures,12 tables and 61 reference paper in this thesis. |
PDF Full Text Request