基于量纲分析法的分段嗣后充填法采空区顶板稳定性判别

Stability Criterion of Roof of Gob of Sublevel Open Stoping With Subsequent Filling Based On The Dimensional Analysis

随着开采深度的增加,大量铁矿山逐渐由崩落法转为充填法开采,其中分段嗣后充填法是主要的方法之一。正确判别采空区顶板稳定性,是保证采场安全的关键前提之一。以某铁矿为工程背景,总结得到了分段空场嗣后充填法采空区顶板稳定性影响因素,采用量纲分析法,建立了采空区顶板稳定判别数学模型,选取顶板许用应变作为采场稳定性判断标准,根据许用应变得到合理的厚跨比。结合现场实际,运用有限元法计算得到了顶板的应力及应变,进而求得了顶板的厚跨比r的取值为1.16～2.5。试验采场按此厚跨比进行生产,顶板未失稳。工程试验检验了此关系模型的有效性。该方法简单高效,可为矿山采空区顶板参数选取、稳定性判别提供参考。

With the increase of mining depth,the mining method of a large number of iron ore has gradually changed from the caving method to backfill mining and the sublevel open stoping with subsequent filling is one of the main methods.It is one of the key premise to correctly distinguish the roof stability of mined out area,which is one of the key conditions to ensure the stope safety.Taking one Iron Mine as the engineering background,summarized the stability factors of gob roof of sublevel open stoping with subsequent filling.Based on dimensional analysis,a mathematical model for the stability of the roof of gob is established.The roof strain is chosen as the criterion for the stability of stope,and the reasonable thickness span ratio is obtained according to the allowable strain.Combining with the actual situation,the stress and strain of roof are calculated by the finite element method.And then the thick-span ratio r is got and the value is 1.16~2.5.The test stope is produced according to the thick span ratio,and the roof is not lost.The effectiveness of this model is tested by industrial experiments.This method is simple and efficient,which can provide reference for selection of roof parameters and stability of gob.