基于地震台阵的矿山爆破当量估算:以安徽滁州地区为例

Estimation of quarry blast equivalent based on seismic array:Case study in Chuzhou,Anhui Province

准确估算矿山爆破当量,可以与起爆装药进行对比,验证是否存在瞎炮、拒爆等遗留药柱,保障矿山安全开采。地震波常被用来估算当量,而区域地震台网检测小震级事件的能力有限,为此我们在安徽滁州地区的郯庐断裂带明龙山-上窑断裂凤阳山段开展实验,布设了6台埋深1米的浅孔短周期地震仪,开展了为期20天的连续监测。使用基于卷积神经网络的地震事件识别方法进行检测,并对检测出的地震事件进行了震源定位、频谱分析、发震时刻、震级、爆破当量和起爆药量统计等处理。经统计该区域在监测期间共发生了42个地震事件,比对发现其中一个地震事件为2022年3月19日宿迁泗洪3.1级天然地震,其余41个地震事件并未被区域地震台网检测到,且震源位置较集中,频谱相对简单,发震时刻集中在当地时间的白天。结合该地区普遍存在的采石场,我们推测这41个地震事件为人工爆破产生。研究表明通过地震台阵监测,可以精确定位矿山爆破,基于地震波能量-爆破当量算法也可准确估算爆破当量。

Accurately estimated quarry blast equivalents can be compared with the quantity of initiated explosives to detect misfires or undetonated explosive remnants,thereby ensuring safe mining operations.Seismic waves are commonly used to estimate the equivalent;however,the ability of permanent seismic networks to detect low-magnitude events is limited.Therefore,we conducted experiments in the Minglongshan–Shangyao fault segment of the Tan–Lu fault zone in the Chuzhou area of Anhui Province in China,deploying six shallow-borehole short-period seismometers at a burial depth of 1 m for continuous monitoring for 20 days.Forty-two earthquakes were detected using a convolutional neural network,and the detected earthquakes were processed based on the source location,frequency spectrum analysis,time of occurrence,equivalent,and magnitude statistics.Through comparison,we found that one of the earthquakes was the M3.1 Suqian earthquake on March 19,2022.Unlike this natural earthquake,the remaining 41 earthquakes have not been reported by any seismic network.The source location is concentrated,the frequency spectrum is simple,and the time of occurrence is concentrated in the daytime.Based on these results and the widespread quarries in this area,we speculate that these 41 earthquakes were caused by artificial blasting.Through seismic array monitoring,the precise locations of quarry blasts can be determined.Furthermore,the seismic wave energy-blast equivalent algorithm can be used to accurately estimate the quarry blast equivalent.