Mechanism Of Water Burst And Grouting Results Test And Simulation Research On Limestone Roof Of Underground Iron Ore Mining

This paper takes grouting curtain and deep mining of Gujiatai iron mine as project background. Basing on abundance investigations and analysis of geological materials of Gujiatai iron mine, various mechanical test, such as triaxial compression, triaxial permeability and general rock mechanics test had be putted up on samples of the grebody roof , grouting roof, floor, ore and filling pulled from spot. Got mechanical parameter's values and got hydraulic parameter's values of all kinds of rocks and backfill separately. Then SURPAC software generates really geological model. The geological model then be leaded into the large-scale geotechnical finite difference numerical simulation software FLAC^3D for calculate. Simulate the disturbance of excavation and filling. Based on analysis of roof stress, displacement, plastic-zone, determine whether the flooding accident would happen.The mainly studies are as follows:(1) After strict investigations and analysis on hydro geological condition of the mine, learning that the ore overlying limestone contains much developed fissures and water. The grebody roof has the most threatening on mining, thus confirmed the keystone of numerical simulation analysis is the roof, the target of the numerical simulation.(2)Through learning the FLAC^3D software, familiar with the theory of fluid-structure interaction, defined the material parameter the numerical simulation would need.(3)Basing on abundance various test on the samples pulled from spot got mechanical parameters and hydraulic parameters all kinds of rock and backfill. Provides material parameters value reliably for the numerical simulation.(4)Take advantage of the excavation and filling functions and powerful computing features fluid-structure interaction provided by FLAC^3D , simulate the real process excavation and filling . (5)Based on the analysis of the coupling model simulate results, grouting limestone mine roof and roof have not be opened up by plastic zone . This means that impermeability can be ensured. So, concluded that water outburst will not occur, the roof is safe.(6)Made a simple comparison with the situation without seepage.