Study On "Support-surrounding Rock Relationship" In Mining Faces Backfilled With Bags Of Super-high Water Materials

Many coal reserves are trapped under building structure,railway and water body in Chinese coal mines.The traditional mining methods caused by mining damage and serious environmental pollution and other issues.Super-high water material filling and mining is an effective way to solve the traditional mining methods of water resources,The bag filling method has the advantages of strong adaptability,intuitive filling effect and no water Influence and many other advantages,to achieve the "three under" the scale of coal mining.In this paper,the characteristics of the structure of the overlying strata are taken as the basic starting point.According to the different filling rates of the bag filling and mining,the physical similarity simulation,numerical simulation and theoretical analysis are used to study the effects of the ultra-Stope-surrounding rock "and the feasibility of light stenting.The main research results are as follows:(1)Based on the factors of overlying control of the stope,the ultra-high water material bag filling and mining is divided into three control stages.The influence of the filling and mining parameters on the overburden activity is analyzed,and the key to control the overlying movement and the surface subsidence factor.(2)Using the physical similarity simulation experiment and numerical simula t io n analysis,the law of overburden movement of ultra-high water material bag fil ing and mining was studied,and the relationship between "bracket-surrounding rock" under different fil ing rate was analyzed,The effect of the change of the working resistance on the amount of the roof sinking is revealed.When the working resistance increases from 4500 kN to 6600 kN,the fil ing force is increased by the change of the working resistance.When the rate was 77%,86%,92%,the roof sinking volume decreased by 3.4%,2.7% and 1.4% respectively.(3)Based on the composition of the surrounding rock of the brackets,the brackets are divided into three parts: the direct top Z,the unstable direct top B and the high basic E,When the filling rate is high,the brackets need to control the strata mainly to fall directly to the top Z,and the instability of the direct top B,the filling rate is low,the stent control rock layer also includes the high basic top E,and put forward Calculatio n Formula of Support Strength under Bag Filling Condition.(4)Using FLAC3 D to verify whether the scaffold can be lighted under the condition of ensuring a certain filling rate,the working resistance of the stent is 4200 kN and 6600 kN,respectively.The variation law of rock deformation is obtained,and the control effect of surrounding rock and the effect on the mining roadway are small,and the stent can choose the light specification.