基于弹性薄板理论,分析矿石顶板破坏的主要规律,推导矿石顶板的厚度求解公式.研究结果表明:矿石顶板中心的拉应力是矿石顶板破坏的主要原因,根据该点的极限破坏条件推导出矿石顶板的厚度求解公式;以某铝土矿第10采场为工程案例,经过求解,该采场最优矿石顶板厚度为0.36 m,考虑安全系数为1.3,设计矿石顶板厚度为0.5 m;在整个工业试验过程中,顶板动态报警仪未启动报警,矿石顶板未发生破坏;相比类似条件的采场矿石顶板减少0.1~0.3 m,矿石顶板回收率提高16.7%~37.5%.
Based on the elastic thin plate theory, the main law of the ore roof failure was analyzed and the formula of the ore roof thickness was deduced. The results show that the tensile stress in the roof center accounts for the roof failure. According to the limit failure conditions of the point, the formula of the ore roof thickness was derived. Taking No.10 stope of a bauxite mine as an engineering case, the optimal thickness of the ore roof was 0.36 m. The safety factor was taken as 1.3, therefore the design thickness was 0.5 m. In the whole industrial test process, the dynamic alarm devices did not start the alarm and the ore roof was not damaged. Compared with other stopes under similar conditions, its thickness was reduced by 0.1?0.3 m. The recovery rate of the ore roof was increased by 16.7%?37.5%.