The Experiment And Research Of Prevention And Control Of Floor Heave Of Soft Rock Roadways

In recent years due to the increase in coal demand, makes a higher burden on the yield and efficiency of mining, but also promotes the innovation and progress of mining method and mining technology.Output and efficiency must be prompt with mining equipment and large-scale mechanization degree to increase, thus make coal roadway cross-section size also becomes more and more big, to ensure smooth transportation of large machinery and equipment, production work of ventilation and pedestrian safety requirements. With large cross section of roadway in coal mine production, it is used in production of coal mine more and more, at the same time also brings a lot of roadway surrounding rock deformation and failure problems, in which the problem of floor heave of roadway began to become frequent, especially under the condition of the bottom is weak and broken rock, the problem is more outstanding, and with the constant progress of mining technology and the increase of mining depth, the problem is likely to become more prominent. At the same time, the floor heave will lead to roadway cross section shrinking, the severe cases can make the base plate, to bring many adverse factors to mine ventilation, transportation and work; More strongly at the bottom of the drum makes the whole roadway instability or even the whole roadway scrap, leading to maintenance work is bigger, but also impede the safety production of mine. Therefore, research on the prevention and control of floor heave research, especially in the prevention and the control of floor heave soft rock; especially have important influence and significance for the prevention and control of soft rock bottom drum problem of soft rock mine.In this paper, take a mine in shan-xi return air roadway as the investigate object, Through the analysis of bottom point stress and displacement formulas by using elastic-plastic mechanics and rock mechanics, conduct the stress analysis of the point, Namely:σxe<0, the high stress is tensile stress which lead to roadway, Otherwise, by the downward vertical compressive stress, when stress is equal to zero, it does not stressed.In the direction of σxe<0,σxe>0too excessive, firstly floor is failure by tensile strain, until it is greater than zero compressive stress and the damage caused is relatively large, and then the main deformation of floor heave caused by horizontal stress is to vertical direction. Has occurred at the same time, when|σxe|>σt, caused rock brittleness damage,|σxe|>σR, caused the brittle damage. According to the mechanism of floor heave and the factor analysis of floor heave caused by different conditions, concluded the calculating formula of floor heave.Using similar simulation laboratory and means of FLAC numerical simulation, get the causes of the severe floor heave of roadway floor heave and governance measures through theoretical analysis and research. Based on the geological conditions, compared the analog simulation and numerical simulation analysis under condition of without supporting roadway and the full supporting, concluded that the cause of roadway surrounding rock deformation and failure, and concluded that the type of floor heave. At the same time, also verify whether numerical simulation is reliable.Conduct the simulation analysis under the condition of the original supporting roadway Using FLAC, And proposed two kinds of management measures of floor heave of roadway, the cutting pressure relief control floor heave and the cutting end of pressure relief and anchor combined support control floor heave of two kinds of schemes for numerical simulation analysis. Based on the before and after comparison analysis governance situation of floor heave of roadway, reveals the unloading groove cutting control floor heave of roadway scheme is feasible. In simulated base on different cutting depth analysis, concluded that cutting depth, near the roadway depth through the governance effect of floor heave is more effective. At the same time, through the analysis of the experiment and numerical simulation experiment have confirmed the deposit belongs to squeeze film effect of floor heave of roadway could cause extrusion flow model of the bass drum, to control floor heave scheme adopted by the measures is feasible in theory, can carry on the mine floor heave control of on-site guidance.