Research On Rapid Hardening Technology Of Coal Slurry Water Floor In Heading Face Of Liangshuijing Mine

The water content in the driving area of Liangshuijing coal mine is large,and the main water source comes from the drainage water and equipment production water.The floor is mudstone,and the crushed coal dropped during cutting and transportation is mixed with water and floor mudstone.After repeated rolling by vehicles,the mixture of "coal-mud-water" is formed,which seriously affects the normal traffic and transportation of the roadway.Before the coal slime water bottom plate hardening,2-3people are needed to dredge and clean about half a shift.The use of hardened concrete on the bottom plate is large,the cost is high,and the hardening speed is slow,which leads to the blockage of vehicle and personnel flow.The hardening speed of the bottom plate does not match the driving speed,which affects the construction period.A material of coal slime water cleaning and floor hardening simultaneously is needed to solve the problem of improper connection between floor hardening and driving surface.The main content of this study includes the following four parts: lithologic characteristics and mechanical analysis of roadway floor,proportioning test and response analysis of new hardening materials,numerical simulation of roadway floor transport load and field construction of rapid hardening of coal slime water floor in underground roadway.Through field investigation and laboratory study,it is found that mudstone of Liangshuijing mine is easy to muddle when encountering water,and the water source is mainly domestic water.A new type of alkali excitation material is selected,and its advantages of fast setting and early strength are used to achieve dredging and hardening of the bottom plate at the same time,which ensures the synchronization with the driving speed.The "liquid cement fast hardening floor structure" is put forward,which is suitable for laying new materials.29 groups of tests were designed by response surface analysis method,and the optimal values of each factor were obtained with the help of Design Expert software: the coal slime ratio was2.2,the optimal mass fraction of coal slime water concentration was 73%,the mass ratio of liquid cement to coal slime was 0.8,and the liquid cement powder liquid ratio was 2.5.The laying thickness of the hardened material is 5 cm and the hardening time is 120 min through the numerical simulation of the hardening material thickness and setting time of the bottom plate.The hardening test of coal slime water floor was carried out on the driving face of Liangshuijing mine,and the strength of the floor after hardening has reached more than 1 MPa.After the vehicle test through,hardening bottom plate strength has reached more than 10 MPa.The setting time and strength of small-scale mold test and large-scale roadway test meet the expected requirements.Compared with concrete,the new alkali-activated hardening material saves more than 50% time and improves economic benefit by more than 35%.The problems such as water difficulty control of coal slime in driving face of Liangshuijing mine and synchronization of hardening speed and driving speed of floor are solved.The thesis has 40 figures,15 tables and 83 references.