Study on Gateway Driving Along Goaf with Thick Compound Roof

Abstract：Taking complex roof condition in Tongchuan Mining Area as an example, based on the stability principle of large and small structures in surrounding rock of the gateway driving along goaf, in combination with the broken arch delta model of the overburden strata, the small pillar width plan of the gateway driving along goat＂ was preliminarily set up from the view of the theoretical analysis. Thus the bolt combined beam reinforcement theory and the anchor suspension reinforcement theory was applied to the preliminary design of the support cross section. The FLAC3D simulation software was applied to the support effect investigation of the gateway driving stage and the coal min- ing influence stage for each plan. Finally the width of the coal pillar was determined as 5 m. A left rotary no longitudinal rib high strength deformed steel bar bolt was applied for the support of the gateway with a row distance of 800 mm. The support effect of the gateway driving along the goat＂ and the mining influence stage showed that with the support plan applied, the stress distribution of the surrounding rock a- long the gateway was rational and the suitability of the bolt support system was excellent.