近距离厚煤层重复采动巷道变形机制及控制技术OA

During the mining process of thick and close distance coal seams,the roadway is affected by multiple mining activities,making support and maintenance difficult.In view of such type of problems,taking the measure roadway of the west wing mining area of the 4th coal in Nanyangpo Coal Mine as the research background,methods of numerical simulation and on-site actual measurement are adopted to study the evolution characteristics of the stress environment of the roadway surrounding rock and the deformation and failure laws of the roadway surrounding rock under their actions.A collaborative control technology of"shallow low pressure-deep high pressure grouting(enhancing the integrity of the surrounding rock)+frame shed reinforcement(passive bearing)+strong anchor rod cable(active constraint)"is proposed to solve the difficult problem of superposition and expansion of the surrounding rock failures under the secondary mining.The research results show that under the disturbance of the primary stoping,the repeated mining deformation roadway exhibits asymmetric deformation and failure characteristics,and goes through three deformation stages,which can be divided into the stage of advanced support pressure influence,the stage of roof activities influence after mining,and the stable stage after mining;The secondary mining roadway is superposed and expanded on the basis of the primary mining failure,manifested as a further increase in the stress peak value of the protective coal pillar to 27.3 MPa,and the asymmetric failure and deformation of the roadway is more significant;The method of deep and shallow grouting is adopted to enhance the strength of the surrounding rock,anchor rod cables are adopted to improve the support force of the support body,and the support is reinforced through the frame shed,realizing collaborative control,reducing the deformation of the roof and goaf sides by 61.8%and 63.5%respectively,meeting the use requirements of the roadway.