Cable Truss Support On a Large Span Set-up Coal Entry Based On Ground Stress Measurement

There are no stable upper rock strata available to suspend if conventional bolts (cables) are used to support the large span set-up entry with thick coal roof, and the roof caving accident is prone to occur. According to the field observation results of rock stress, a stress distribution model of the surrounding rock is built to analyze the relationship between rock stress and roadway damage. In this paper, the active multidimensional support technology of cable truss is put forward, and its control principle is discussed, and the physical simulation experiment is done to verify the effect. After the support scheme is applied in field, the surrounding rock is controlled successfully. The thick seam (more than 3.5 m) occupies an important place in the current coal industry of China. Its reserves, in total, account for about 44% of all coal deposits and more than 40% of all volume of production. As the coal market improves and the urgent need for high capacity and efficient exploitation, the caving method has made great progress and been a primary method in the mining of thick seam. However, the fully mechanized caving method is bound to cause the problem of large span set-up entry timbering with thick and friable coal roof. The comprehensive mechanized caving method is adopted to mine No. 10 coal seam in Pangpangta Colliery. There are 1–3 levels of carbon mudstone dirt band with a thickness of 0.10–0.38m in the seam. The roof is grayish black mudstone or sandy mudstone with a thickness of 1.00–7.00m and the bottom is grayish black mudstone and sandy mudstone that thick about 1.00–8.00 m. The set-up entry of No. 10101 fully mechanized caving mining face is a rectangular figure at 3.5m high by 6.8m wide.