The Application Research On Bolt-Mesh Support Technology Of Large Cross-Section Gateway In Sihe Coal Mine

This paper takes the basic theory of gateway surrounding rock stability controlling and the dynamic information method (DIM) of bolt parameters design as instruction, with referencing a large number of domestic and overseas blot-mesh supporting experiences both in theory and practice, carried out a detailed study on the bolt-mesh supporting technology and application of large cross-section gateway in Sihe coal mine.Underground surrounding rock strength testing equipments & strata detecting apparatus were applied to survey the surrounding rock strength, the initial stress & structures of the gateway systematically, and the finite element simulation software FLAC is used for analyzing the gateway supporting effect with multi-schemes contrast using different spacing, bolt length and disposing method in 10201S, the first coalface in Sihe Mine, and the equipment remove gateway(ERG) mining induced whole course is also analyzed. The simulation results demonstrate that the bolt-bar-mesh-cable combined supporting method with the bolt spacing 1000mm, bolt length 2400mm and the cable reinforcing could acquire approved supporting effect. Based on the DIM, the driving method and the ERG support method are adjusted duly. The analysis results of the roof separation and roadway bolt load observation showed that the surrounding rock tends to be stable after drove 15d & the separation is below 18mm, and the maximal bolt load is under 160kN and the change quantity is about 13kN, that is to say, the supporting intensity is enough and could satisfy the acquires of safety & high-effect. The measures, such as installing hydraulic supports, pilling additional cables, spanning single supports and so on, were adopted to reinforce the roof on coalface and ERG in coalface ending course, and achieved the 2302 coalface roof holding steady in whole ending course.The research achievements have been successfully applied and tested in 10201S & 2302 coalface in Sihe coal mine, and acquired excellent technical and economical effects.