极不稳固采场稳定性分析

Stability Analysis on Stope with Extra Unstable Roof

为确定节理发育矿体开采顶板合理跨度尺寸,对岩芯库和井下岩体节理裂隙进行统计分析。首先对顶板跨度进行理论求解,然后利用UDEC软件对4,6,8,10m4种顶板跨度进行应力场和位移场分析。结果用弹塑性力学、厚跨比法和载荷传递交汇线法得到的顶板跨度分别为8.37,9.32和8.08m。数值模拟结果表明顶板跨度8 m较合理。对比理论结果引入修正系数α,其值介于0.86～0.99之间,顶板最大变形位移和跨度之间满足y=aln(x)+b的对数函数规律。改进Potvin法得到采场顶板极限暴露面积为448m^2。现场监测结果发现,靠近上盘顶板下沉相对位移较靠近下盘监测点要大,验证了数值结果的正确性。

In order to determine the reasonable roof span width for the jointed ore body,the statistical analysis on the core base and joint cracks of the ore body was carried out.Firstly,the roof span was theoretically solved,and then the stress field and displacement field of roof spans with width of 4,6,8 and 10 m were analyzed by UDEC.Roof span width obtained by elastoplastic mechanics,thick span ratio method and load transfer intersection line method was 8.37,9.32 and 8.08 m,respectively.The simulated result showed that reasonable roof span width was 8 m.Compared with the theoretical calculation result,a modifying parameterαwas introduced,and its value was between 0.86 and 0.99.The maximum displacement of roof and the span met the law of logarithmic function of y=aln(x)+b.The limit exposed area of stope roof obtained by improving Potvin method was 448 m^2.Field monitoring results showed that the relative displacement of the roof near the upper wall was larger than that near the lower wall,which verified the correctness of the numerical results.