Application Study Of Active Advanced Support In Longwall Mining

In the process of longwall mining of coal mine,advanced support pressure is generated in a certain range in front of the working face.In order to ensure the safety and stability of the roadway,the advanced working face section of the mining roadway needs to be reinforced during the mining period,and the supporting process is the advanced support of the mining roadway.At present,the most commonly used advanced support forms in China are the single hydraulic pillar with articulated roof beam and advanced hydraulic support.However,due to the complex mining conditions in coal mines,the above supporting forms are not applicable in some tunnels and have certain limitations.With the continuous development of support technology,a new type of active advanced support has been put forward in recent years,and has been successfully applied in many mining areas in China.However,the research on this advanced support form is still in the preliminary stage,and the active advanced support form is mostly selected in the field based on engineering experience,which lacks reasonable scientific basis.When using grouting anchor cable,it has not been determined which grouting theory is more reasonable to guide the design of grouting parameters,and there is no mature system for active advanced support design.Based on the 12219 working face transportation roadway of Binhu Coal Mine as the engineering background,this paper studies the application of active advanced support in longwall mining by using field measurement,theoretical analysis,numerical simulation and other research methods.The main research results of this paper are as follows:(1)For data mining technical conditions of field research,fully understand the field condition of a roadway,and master the conditions of roadway with active forepole,secondly through the study of the field measurement of the roadway,get the crack evolution characteristics of the roadway roof roadway to select the suitable for the active forepole forms provide the design basis,And through theoretical analysis to understand the action mechanism of grouting in surrounding rock control,finally clear the tunnel using anchor cable support combined with grouting reinforcement of the active advanced support form.(2)Through the state of a two-dimensional discrete element software to simulate the process of the mining face,according to the stress of the roadway roof over the evolution characteristics in the process of working face advancing,get forepole minimum range,according to space-time evolution law of roof cracks,grouting time to choose the best,according to the above results finally determine the active forepole scope and grouting time.(3)According to the field conditions of the roadway,the anchor cable of the active advanced support was selected.Through the three-dimensional finite element software FLAC3 D to simulate the prestress diffusion under different support schemes,the reasonable design of the hollow grouting anchor cable support technology scheme was completed,and then the reasonable selection of the grouting parameters was completed by COMSOL Multiphysics.Finally,the numerical simulation proves that the advanced support scheme is suitable for field application.(4)Will study the active forepole forepole of technology scheme is applied to the site,in order to understand the supporting effect,on-site measured during mining,get appeared during stoping roadways pressure,the results show that the support scheme successfully guarantee the stability of roadway,heralding the active forepole successful application in the project,the design idea of this paper may provide reference for similar projects,this paper research is of great significance to promoting intelligent mining process.There are 53 figures,9 tables and 102 references in this paper.