Mechanism Of Staged Control And Key Supporting Technology Of Roadway Under Repeated Mining Influence In Baode Mine

The engineering background of this paper is based on the supporting of roadway underrepeated mining influence on the condition of large deformation and rapid mining face. Toconduct a systematic study on the law of deformation and failure, the mechanism of stagedcontrol and the key technology about secondary reinforcing supporting of roadway underrepeated mining influence in Baode mine, an integrated research method about theoreticalanalysis, numerical simulation and field test is used. The following main results are obtained:(1)The characteristics of the second mining roadway and deformation and failure on supportare achieved, it is mainly showed that the deformation of roadway surrounding rock isaffected by the environment of stress and surrounding rock, and almost has no relationshipwith the increasing of the support-strength. This conclusion changes the difficult situation thatwe can not avoid the breakage of large number of anchor cable although we try our best toincrease the quantity and strength of anchor cable.(2) The system of secondary coordinatedsupporting technology is formed in Bao de mine, the supporting form of long bolt which canbe connected, rigid long screw bolt should be respectively adopted for roof and roadway, soroadway deformation can be coordinated, support resistance can be continued, thedisadvantages about low anchor cable elongation and fracture failure after roadwaydeformation can be overcome, and the danger of roof fall can be eliminated.(3)Themechanism of staged control is revealed, the conventional suspension theory can be used forthe design of primary control during excavation and the roadway under repeated mininginfluence during the first mining, the secondary reinforcing supporting can use the supportingform of long bolt instead of anchor cable to adapt for the deformation of roof and roadwayand avoid the danger of roof fall because of anchor cable breakage.The supporting form canincrease the speed of tunneling for reducing the time of supporting while tunneling.