| This thesis regards 11502 working face haulage gateway in Zhujixi coal mine as research object,through embedded field investigation,based on the measured data of engineering-geological conditions and laboratory test,come to the deformation and destruction characteristics of surrounding rock of drift driving along the gob-side in the mine with the depth over 1000 m.With the theory analysis and numerical simulation of coal stage,confirm the reasonable width of chain pillar.Based on the primary supporting of high prestress and intensive bolting principle,proposing the technology of surrounding rock of 11502 working face haulage gateway and the method of maintain the rock support structure stable.Finally through on-site industrial tests check research results,the main conclusions thrown up the thesis are that:(1)11502 haulage gateway in Zhujixi coal mine is a typical high stress soft rock roadway,this drift often generated remarkable deformation and heavy floor lifts,there are also examples of bolt and anchor-cable supporting failure,steel belt deformed,metal mesh splitting.By the methods of drilling imaging find out the range of surrounding rock loose circle beyond anchorage zones.The primary reason of severe deformation of roadway was revealed,high geostress environment of gob-side entry surrounding rock,the activity law of mined overlying strata,supporting pattern and parameters selection isn't reasonable.(2)In view of strength softening characteristic of surrounding rock of roadway in deep mine under high stress phenome,through establish the mechanics model of coal pillar,deducing theoretic calculation formulas of plastic zone width of coal pillar,getting mathematical formula to calculating reasonable width of coal pillar.According to the engineering geologic conditions of 11502 entry driven along the gob-side,calculating minimum width of coal pillar is 4.6 meter.According to numerical modeling of coal pillar by software FLAC3 D,change regularity of the side abutment pressure is analyzed,studying the distribution characteristics of stresses and displacement of coal pillar driving along gob and integrated coal pillar under different coal pillar width conditions,like the width of coal pillar is 4m,6m,8m,10 m,12m.Finally,a conclusion can be assumed that rational width of coal pillar is 8m.(3)In consideration of geological and mining conditions and deformation characteristic of 11502 gob-side entry,have put forward the primary supporting of high prestress and intensive bolting technique,using high-strength bolt and anchorage to control deformation of gob-side entry.According to the synergetic support principle of bolt and anchor-cable,after theoretical analysis and numerical simulation,an optimal combinations of the bolt prestress and anchor-cable prestress.Be aimed at the prestress loss of bolt and cable,the secondary pre-tensioning method and over tensioning technique is proposed to ensure supporting effect.(4)Studying on how to improve the stability of bolt anchoring and control the slip of wedge and barrel anchorages,have invented a gadget which be installed in bolt body,to be effectively guaranteed bolt anchoring quality in fractured rock;based on the stress present analysis of cable anchor,preventing cable anchor slippage and self-locking device is proposed to reduce occurrences of wedge and barrel anchorages slipping and steel stranded wire eject after it fracture.(5)The industrial test results show that setting 8m width of coal pillar,applying bolting with wire mesh high prestress can ensure the stability of 11502 gob-side entry,come up to the standard no longer repair drift in service period.Research results makes roadway supporting technology in Zhujixi coal mine great progress,achieved the goals of increase economic efficiency and safe and efficient production. |
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