Study On Gob-side Entry Retaining Tchnology In Medium-thick Seam Of Kaiyuan Coal Mine

For gas outburst mines and mining working face gas is the main reason that restricts safe production,for the realization of Y type ventilation,effectively solve the problem of working face gas overrun,but also to avoid the "double u-shape ventilation way,reduced the quantity of roadway,alleviate the pressure mining cohesion,also to avoid the loss of hundreds of coal resources.But along the empty left lane roadway influenced by mining,lateral and lag of mining pressure,surrounding rock of roadway affected by dynamic pressure effect performance than ordinary extraction tunnel is more intense,the choice of the support as well as within the lane on the roadway support is very important,and thus develop along the roadway for the reasonable supporting research has important practical significance,and has achieved the following research results:(1)The reasonable arrangement of the roadway location was determined by numerical simulation.By analyzing the trap column tectonic stress on the stress distribution,deformation amount and plastic zone development of the tunnel surrounding rock,finally the width of coal column with the trap column between 15 m was used for the tunnel arrangement;(2)The influence of tectonic stress on roadway layout and entry retention is analyzed.The structural stress can be approximately regarded as the horizontal stress in the buried depth of about 400 meters.In order to achieve the effect of active support,the roadway must be supported by high preloading force system,changing passive support into active support,improving the tensile and shear strength of surrounding rock,and laying the foundation for retaining roadway in the later stage;(3)The structural characteristics of the roof plate along the hollow stay lane in the tectonic area were analyzed.During the recovery period,under the dual influence of mining and trap column tectonic stress,the initial incoming pressure step of 3903 short working face reaches about 25 m through field practice experience and calculation,and the mineral pressure at the working face appears more moderate,which has a positive effect on the stability of the filling body and overlying rock layer beside the lane;(4)The comprehensive analysis determined that the basic support in the lane adopts the joint support technology system of high preload,high strength and high stiffness anchor rod and anchor cable,and the filling body width was determined to be1.5m,taking into account the service working face time,later role and comprehensive economic benefits of 3903 bypass lane,which successfully guided the practice of Kaiyuan along the hollow stay lane project.The paper has 45 figures,12 tables,and 66 references.