Application Research On Pumped-concret Support Based On Flexible Formwork Of Gob-side Entry Retaining In Deep Mine And Thick Coal Seam

The gob-side entry retaining with safety mining and mining development direction, and has wide application prospect, but the existing research results mostly based on shallow thin and medium thick coal seam roadway retained along the base of the empty, practice has proved that the deep mining and shallow mining in the mine pressure and appearance, gas gushing out there are different. Therefore, shallow coal gob theoretical achievements and practical experience to meet the deep coal roadway along goaf needs.This paper combines theoretical research and on-site industrial test, system of deep and thick coal seam along the moving rule of surrounding rock, empty tunnel support design, ventilation and gas prevention and control technology of Y, and has been successfully applied in Henan Shenhuo Coal&electricity Xuehu Coal Mine2307working face, the results are as following:(1) The first flexible formwork-pumped concrete technology has been applied to the depth of820meters,5.2meters high wall of high pressure coal gob-side entry retaining, leaving roadway roof and floor maximum near72mm, two for maximum near56mm.(2) The gob-side entry retaining direct roof, roadway support and the bottom plate are simplified as elastic different stiffness of the body, has established branches in the system stiffness structure model, analyzed the influence of each part of the system, the stiffness of the research that:improve roadway support stiffness to control the surrounding rock deformation effect is not apparent, must guarantee direct roof stiffness, roadway support stiffness and the bottom plate matching.(3) The adjacent working face open-off cut and slot Y type ventilation, calculation formula of Y type ventilation main side into the airway and air distribution ratio was established, reveals the mined-out area "U" ring leakage channel is the upper corner gas overrun the root cause, is proposed to decrease the mining comprehensive gas control technology of air leakage area and Liu Xiang buried pipe gas drainage combined.(4) Witek proposed "separation of rock block method" of gob-side entry model, has the characteristics of simple principle and easy operation, but this method does not consider the influence of mining depth on gob-side roadway surrounding rock pressure, so the larger error along goaf under the conditions of application in deep well. In consideration of the influence of the mining depth, amendments to the "separation of calculation model of rock block method", the revised formula of roadway surrounding rock pressure along the gob and puts forward.(5) Deep and thick coal seam mining are pressure severe appearance, coupled with the roof test face soft and broken, moving frame post-cast wall caving roof immediately, leading to the construction of gob-side entry. In order to prevent the concrete wall area roof caving, near a proposed in working face coal wall on the left lane pouring wall area roof cable anchor permanent new method of strengthening support; in order to effectively cut off the direct roof, stop the waste rock in goaf into the left lane, put forward a kind of cutting top new technology support gangue branch in advance between frames.