Research On Mechanism And Prevention Of Floor Burst For Extremely Thick Coal Seam Roadway In Folded Region

The special thick coal of yanbei Coal Mine is in the fold structure area. Fold zonespecially thick coal seam in the process of mining, significantly influenced by the horizontaltectonic stress, the thick coal seam accumulate a large amount of elastic energy, together withthe critical impact strength of coal is smaller, more easily under the effect of combination ofdynamic and static load instability induced shock of roadway.In this paper, the theoretical analysis, numerical simulation and field application practiceof the comprehensive analysis and research method of combining，Mainly aimed at systematicresearch of the mechanism of the impact of roadway, the appeared rule of gateways, thecontrol measures to train of thought and practice application gateways in yanbei Coal Mine。Using numerical software FLAC2D, respectively, simulation of the roadway surroundingrock stress, displacement, horizontal deformation rate, plastic zone distribution of evolutionlaw of the parameters Under the action of static load and dynamic load disturbance。Bycomparing the simulated different bottom properties and level of the original rock stress andthe influence of different impact energy dynamic load for roadway.Rock-burst monitoring show that the stress concentration zone fracture of coal or rockreleased energy, and the distribution of the mine earthquake focal position to form the goodcorrespondence. Using microseismic monitoring data, the acoustic emission monitoring dataand the analysis of the electromagnetic radiation monitoring data of the rules of the key strata,the key strata breakage during a major energy rock-burst, acoustic emission andelectromagnetic radiation monitoring data to achieve maximum value.Combined with field measured data set during the inkstone north mine250204workingface mining rock-burst monitoring and early warning system, the main stress with thevibration wave CT, online monitoring and cuttings form combination of dynamic and staticmonitoring system. Combining with the monitoring and early warning results formulatecorresponding prevention and control plan, adopting prevention measures such as roof oflarge diameter deep hole blasting, bottom hole pressure relief, coal large diameter deep holeblasting pressure relief，to effectively reduces the risk of the impact of the danger zone.Inprevention and control measures after implementation, strong earthquake activity is reduced,near the working face stress level decreased and cuttings, which shows that make theunloading technology of governance of rock-burst harm has played a significant role.