Study On Mechanism Of Floor Heave And Control Technology Of Shallow Depth Seam Roadway In Anshan Coal Mine

Floor heave is the common phenomenon of roadway deformation in coal mining.The field measured data shows that most coal mining roadway floor in China has not taken any protective measures.In this case,about 65%of the roof and floor movement of roadway iscaused by the rise and deformation of the floor,and more than half of the roadwaymaintenance expenses are used to control the floor heave.How to control the roadway floor heave has become the main problem faced by many coal mines.Floor heave is the common phenomenon of roadway deformation in coal mining,which makes roadway cross-section deformation and hinders the safe and efficient production of coal mine.The main causes of floor bulging are analyzed in order to take effective measures to control floor heave.In view of the problem of floor bulging in 31 coal seam roadway belt conveyor haulage of Anshan Coal Mine,this paper analyzes the main reasons of floor hea establishes the mechanical model of roadway bottom drum,and puts forward the measures of preventing floor heave by slotting on bottom plate.The practice shows that the slotting of the bottom plate can effectively prevent and control the bottom drum.The paper are as follows:(1)According to the engineering geological conditions of 31 coal seam roadway belt conveyor haulage in Anshan coal mine,the mechanical experiment of surrounding rock of roadway is carried out.From the experiment,it can be concluded that the floor rock laver of 31 coal seam roadway belt conveyor is low in strength,softened after water absorption and accompanied by volume expansion.This is the main reason leading to the floor heave of th roadway.In addition,the v is located between the return wind roadwav and the ausiliarytransportation roadway,and the stress of the two sides of the coal pillar of the roadway belt conveyor haulage is superimposed,resulting in a strong pressing effect,which is also one of the reasons for the occurrence of the bottom bulge in the roadway belt conveyor haulage.It is found that the type of floor heave is the compound type of the extruded flowing bottom drum and the water swelling type.(2)The treatment measures of bottom drum can be divided into reinforcement method and pressure relief method.The reinforcement method mainly installs the anchor rod in the floor,aiming at strengthening the floor and enhancing its bearing capacity,considering that the lithology of the floor in roadway belt conveyor haulage is soft rock with water swelling.The soft rock in the anchor range will produce flow deformation,which can not effectively control the floor deformation.Therefore,the pressure relief method is adopted to treat the floor heave,that is to say,the floor is cut to release the pressure in order to form a stable structure of "strong-weak-strong" so as to achieve the purpose of controlling the floor heave.(3)Through the numerical simulation software,the position and depth of the cutting groove are simulated.The simulation results show that,for 31 coal seam roadway belt conveyor of Anshan coal mine,the middle groove of the floor can control the floor heave more than the sidewall groove of the roadway,and with the increase of the depth of the cutting groove,The smaller the floor heave is,the greater the depth is,which is not conducive to the stability of the roof and the help of the roadway,and the size of the slot is 0.4m(width)×2.0m(depth)is the optimum parameter.In order to achieve the optimal control effect of roadway deformation,the cutting parameters should be reasonably selected according to the characteristics of surrounding rock of roadway when adopting the measures of cutting groove to control the floor heave.