Study On Mechanism And Control Technology Of Vertically Pressing Floor Heave In Mining Roadway

Floor heave is a very common kind of geological phenomenon in the coal mine,and its also a key problem that impacts efficient and safe production of coal mines.Serious floor heave will make the roadway section greatly reduced,ventilation equipment deterioration,tilting,workers impassable,especially in soft rock roadways and dynamic pressure roadways.According to the vertical extrusion type floor heave phenomenon of 10502 fully mechanized coal mine Yitang +560m horizontal transportation lane occurred,by field investigation,theoretical analysis,laboratory experiment and computer numerical simulation methods,in-depth study of the Roadway Floor Heave Mechanism and floor heave process,there are some good conclusions:(1)The main factors influencing the occurrence of floor heave of roadway in soft rock in structure and lithology of floor rock roadway.The occurrence of floor rock mass structure determines the type of floor heave of roadway;floor rock lithology decides the degree of floor heave.(2)The roadway is different from the general roadway,floor heave has its unique characteristics: with the advance of working face,the roadway in a certain distance from the working surface occurs periodically in floor heave;caused by mining abutment pressure,floor heave is large,serious floor heave;the floor heave is accompanied by a tunnel opening digging into the mining face in the whole process,floor heave is changing continuously,it is dynamic.(3)The vertical extrusion of roadway floor heave is the root cause of the ultimate bearing capacity of vertical abutment pressure formation stress exceeded the floor broken rock.The slip line field theory based on soil mechanics,combined with rigid limit equilibrium method of elastic-plastic mechanics,the ultimate bearing capacity of rock bottom,and predict the size of the floor heave.(4)The different floor heave control scheme for supporting effect simulation by using numerical simulation software Flac3 D,the scheme selection of grouting in floor + floor bolts,grouting can be broken rock bottom to cement integration,increasing the cohesion and internal friction angle of the rock bottom,and the bottom anchor that can form "the pin function,cut off the plastic slip line in floor rock,but also can use the cable to mobilize bearing capacity of deep surrounding rock stability.(5)The control scheme is applied in 10502 fully mechanized coal face Yitan transportation roadway,displacement monitoring results show that the support after 2 months,the distance from the working face 130 m monitoring points to the working face passes the monitoring point.The maximum floor heave 86 mm shows that the support effect is good.