接顶对充填体-围岩相互作用影响的声发射监测试验

Acoustic Emission Monitoring Test for the Effect of Top Filling on Filling Body-surrounding Rock

运用相似原理,进行充填体与围岩相互作用的室内试验,借助声发射仪进行声发射点定位、声发射振铃数、声发射能量等相关数据的监测,引入强度占比系数和损伤变量,提出建立损伤变量与强度占比系数的关系,表征充填空区未接顶、接顶、接顶(充填厚度大小改变)三种工况的内部损伤及整体稳定性。同时借助超声波仪测试三种工况加载破坏前后的声波值变化。结果表明,充填空区未充填接顶时,在加载作用下,声发射点主要发生在充填空区界面以及充填体与围岩的接触面。当充填空区充填接顶后,声发射点主要发生在充填体与围岩接触面。当充填区面积减小时,增大了围岩的整体稳定性,声发射点主要发生在充填体存在区域。相较未接顶,充填空区接顶充分的充填体-围岩共同体的储能能力更强,相应的抵抗应力集中产生的内部破坏及能量释放的能力也更强。

The indoor experiment of the interaction between the filling body and the surrounding rock was simulated through the similarity principle.The position of the acoustic emission(AE)point,the number of the AE rings and the AE energy and other related data were monitored by the AE instrument.The relationship between the strength ratio coefficient and the damage variable were proposed to characterize the internal damage and overall stability of the filling space in unattached,topped,and topped(filled thickness changes)respectively.At the same time,the ultrasonic wave value changes before and after failure were tested by means of a sonicator.The results show that when the filling space is not filled,the AE point mainly occurs at the interface of the filling space and the contact surface between the filling body and the surrounding rock under loading.When the filling area is filled,the AE point mainly occurs at the contact surface between the filling body and the surrounding rock.When the filling area is reduced,the overall stability of the surrounding rock increases,and the AE point mainly occurs in the area where the filling body exists.Compared with the unstacked,the filled filling body-surrounding rock community has a stronger energy storage capacity,and the corresponding internal stress and energy release capacity against stress concentration is stronger.