Study On Surrounding Rock Control And Support Stability In High Mining Height Fully Mechanized Face

High mining height fully mechanized technology is one of the important development inthe thick seam mining, and many mines have been the popularization and application in ourcountry. By yang changwan coal 6.2m high height mining technology research for the fieldconditions, study the ground pressure behavior, rock stress distribution, coal spallingmechanism and stability of support with the methods of similar simulation, numericalsimulation, pressure observation and theoretical analysis ,obtaining the following results:(1) By similar experiment, and combined with the situation of domestic several highmining height face , draw that high mining height face have some characteristics,such as largesupport resistance, small dynamic load coefficient , periodic pressure step isn't very differentfrom normal mining height, support resistance is static load mainly and so on.(2) The analyzsis results of FLAC3D numerical simulation show that the peak ofabutment pressure is reduced, influenced range of abutment pressure is increasing, plasticdamage range of face is widen, roof is prone to fracture ahead, so the degree of rib spallingbecome serious in high mining height face, Rib spalling and roof fracture ahead easilyinduced to roof fall in front of support.(3) Face pressure observation results show, support resistance is large in the top andmiddle of face, this is key to prevent the region. it is reasonable and effective that taking "Bolt- Net - Cable" andΠsteel beam with "a beam and three-column" approach to maintain theadvanced section of roofs; Increase support strength of protection plate to rib, ensureresistance of support, accelerate the speed of face advance and improve operating techniquesare conducive to prevention of rib spalling.(4) Instability of high mining height support with a major focus, such as height ofsupport, angle of seam, roof pressure ,width of support and so on, the greater the angle, the higher center of gravity, the smaller width , the more support occurs dumping easily. Therelationship between limit angle and roof pressure is influenced by mining height, limit anglebecome increased while roof pressure increasing in high mining height.There are some majormeasures to prevent instability of support, for example, lower support's center of gravity andweight, increasing the width of support, reasonable way of moving support, setting anchoragepoints at the bottom of face, installing jack of preventing the dumping in face, scientificmanagement of face and so on.The research achievements of this dissertation supply new views for behavior regularityof ground pressure and reasonably surrounding rock control in the high mining height face, itprovides valuable experience for other similar high mining height face in mining technologyrespect, it is significant of engineering experience and theory that the achievements put highmining height fully mechanized technology into effect promotion application anddevelopment in the coal industry.