急倾斜极薄矿脉削壁充填法开采采动压力监测

二道沟金矿为急倾斜极薄矿脉,采用削壁充填法与浅孔留矿法开采,随着采深的增加,发生了多起采场岩爆。为研究岩爆发生所需高应力的来源,特对开采过程进行了采动压力监测。采用巷道变形收敛监测的方法,实测了1530采场削壁充填法回采过程中,穿脉监测巷道顶底板和两帮的收敛变形。监测结果表明:随着回采高度的增加,监测巷道顶底板间距呈减小的趋势,而两帮间距则呈增大的趋势,且两帮的变形幅度比顶底板的变形要大。并根据两帮各监测点最大收敛值,绘制了采动压力特性曲线。由该曲线可知,采动压力在距上部采场上盘回采边界约7 m的范围内形成波峰,再往上盘侧则趋于平缓。对于这种比较集中的采动压力分布特点,适合采用卸压的方法对其进行控制,从而达到阻止岩爆发生所需外部高应力条件的形成。

Monitoring of Mining Pressure in Exploitation of Steeply Inclined and Extremely Thin Vein with Resuing Stoping Method

The orebody of Erdaogou gold mine is steeply inclined and extremely thin，which is caved by the methods of resuing stoping and short-hole shrinkage.With the increase of mining depth，stope rockburst occurred seriously.In order to study the source of high stress needed by rockburst，the author carried out the mining pressure monitoring to mining process.With the method of tunnel convergence deformation，the convergence deformation of roof-floor and two sides was monitored in the process of the No.1530 stope caved by resuing stoping method.The monitoring results showed that with the increase of caving height，the space of monitoring tunnel roof and floor tends to decrease while the space of two sides tends to increase.Besides，the deformation magnitude of two sides is larger than the roof and floor.What's more，according to maximum convergence value of each monitoring point of two sides，the author drew the mining pressure characteristic curve.It is found that mining pressure formed peak value in the area of 7 m distance from the upper stope boundary，then after that tend to level off.For this relatively concentrated distribution characteristics of mining pressure，it is suitable to adopt the stress-relief method to control，so as to prevent the formation of external high stress condition needed by rockburst.