Study On Pressure Law Of Gob-side Entry Retaining By Roof Cutting Mining Face

In the process of coal mining,a certain safety coal pillar must be kept according to the traditional coal mining method,which causes a great waste of resources.In addition,there are some problems such as stress concentration in the coal pillar.On the basis of the realization of efficient mining,the technology of roof-cutting and pressure-relief and roadway retention along the gob can effectively eliminate the phenomenon of concentrated compressive stress in the safety coal pillar,which has certain advantages in the safety of coal mining.At the same time,the technology of roof-cutting and pressure-relief and roadway retention along the gob can also relieve the continuous tension of excavation to a great extent,so as to meet the requirements of the rapid advance of the working face.In this paper,based on the theory of roof-cutting and pressure-relief and roadway retention along the gob,it explores the possibility of applying the technology of roof-cutting and pressure-relief and roadway retention along the gob in 68310 working face.68310 working face is thick coal seams in Duerping Mine.This article selects 68310 working face as the engineering background.Firstly,simulate the process of coal exploitation by FLAC3 D software.One situation is normal working face,and the other is cut-top working face.The main parameteris is law of coal roof conparing normal working face with cut-top working face.Secondly,analyze the data collected by current exploited working face.By the two ways,we can prove the rationalization of parameters seted in the simulation,and the possibility of the roof cutting effect is proposed through the results of the data analysis.The main conclusions are as follows:(1)The technique of roof-cutting and pressure-relief makes the stress concentration area on the side of the working face and roadway close to the working face shift to the depth,which is conducive to the stability of surrounding rock along goaf roadway;(2)The technique of roof-cutting and pressure-relief makes the advance stress distribution of working face appear asymmetrical and the influence range of stress concentration on roof cutting side becomes smaller;(3)The technique of roof-cutting and pressure-relief reduces the vertical stress of the working face,slows down the collapse velocity of the overlying strata,reduces the pressure of the working face in general,and avoids the long-term high-load operation of the support.