Research and Application of Permanent Outburstproof Door for Encased Structures

In order to improve the intensity and service life of the permanent outburstproof door, reduce the revision rate of the outburstproof door, and avoid the expansion of the damage scope of coal and gas outburst accidents caused by the damage of the outburstproof door, the paper analyzes the use of the traditional outburstproof door in the mine and finds out the existing problems. According to the principle of concrete-filled steel tube structure and the experimental comparison results of the compressive strength of structural parts of different materials, the advantages of using concrete-filled steel tube structure to construct permanent outburstproof door are obtained. The technical key points of forming “pressure ring” by anchoring and spraying technology, installing the skeleton of concrete-filled steel tube structural parts, pre-grouting construction parts by using “jacking perfusion method” and finally making the formwork for pouring concrete are proposed. The field application results show that the concrete filled steel tube (CFST) gate can control the deformation of surrounding rock, improve the strength of the wall, reduce the construction cost and prolong the service life.