Application Of Flexible Model Gob Side Entry Retaining In A Mine Of Shendong Mining Area

Coal is an important energy guarantee for the rapid development of China's economy,but it is non-renewable resources.Given the limited reserves,how to exploit more efficiently and effectively,and extend the overall service life of the mining area are not only the inherent requirement for the high-quality development of coal industry,but also the endogenous driving force for the sustainable development of enterprises.Taking the modern high-yield and highefficiency mine as an example,the mechanized longwall mining method is widely used,and the fully mechanized mining recovery rate has almost reached the limit.At the same time,in order to ensure safety,the protective coal pillar with a width of about 20 meters will still be left between the working faces.This not only increases the preparation time of tunneling,but also causes the waste of resources.By using gob side entry retaining can greatly reduce the amount of roadway excavation and improve the recovery rate,Y-type ventilation can also protect the occupational health of workers,which is in line with the concept of green mine,so it has high economic value and research significance..This paper takes the gob side entry retaining project of 22301 working face in a coal mine as the background,and comprehensively uses the methods of theoretical analysis,numerical simulation,field practice and actual measurement to conduct in depth research on the transportation tunnel gob-side entry retaining project of 22301 fully mechanized working face in a coal mine.In this paper,the fracture,movement and stress distribution characteristics of overlying strata of gob-side entry retaining roof after mining are analyzed theoretically,and then the feasibility of roadway retaining engineering in a coal mine is discussed.Then,by means of numerical simulation,it analyzes the stress distribution of Roadway after mining under different support parameters,and the support effect after building three kinds of flexible formwork walls with different widths.Based on the simulation results and practical experience,it puts forward the support parameters of roadway strengthening support,roadside support and delayed temporary strengthening support.The optimized overall support parameters of gob side entry retaining are put forward,the bearing capacity of flexible formwork concrete wall is checked,and the 1m wide wall which is safe and economical is selected.Then,taking the working resistance of the support at the typical position of the working face as the monitoring object,the paper analyzes the influence of retaining roadway on the mine pressure behavior of the working face,monitors and analyzes the surrounding rock deformation of the roadway after mining,and studies the relationship between the mean stress of the bolt(cable),the deformation of the surrounding rock,the deformation rate and the advancing distance of the working face.It is fully verified that the surrounding rock of the roadway can maintain a stable state and the flexible formwork wall can keep normal after the optimized support parameters are adopted.Finally,the field engineering practice of 22301 transportation tunnel gob side entry retaining is analyzed.The results show that the application of the research results has good economic benefits.The research results of this paper can provide some reference for the application of gob side entry retaining technology in Shendong mining area.