多装置矿井直流电法巷道超前探测研究及应用
Research and application of multi-array mine DC electrical method for road-way advanced detection
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摘要: 为了提高矿井直流电法在掘进巷道超前探测精度,通过分析不同观测装置类型下的超前探测效果,优化数据采集装置,建立一套适用于掘进工作面超前探测施工方式及数据处理体系。首先利用ANSYS有限元软件建立4个全空间地电模型,分别对直流电法二极装置“U”型观测方式与三极AMN,MNB装置进行数值模拟,然后进行反演计算,综合分析2种装置超前探测效果,并将优化后的装置应用到现场探测中去。结果表明:无巷道与有巷道含异常体模型相比,视电阻率形态特征均相似,有巷道模型比无巷道模型的整体视电阻率增大,影响三极AMN装置探测结果中异常体的圈定与识别;有巷道含异常体模型与现场实际情况最为相似,AMN装置整体阻值较大,异常反映不明显,难以响应掌子面前方低阻体,MNB装置可以响应该低阻体,但响应范围和位置误差较大,并随低阻体远离掌子面,异常信号反映越来越不明显,异常强度及异常中心越来越弱化,异常体难以圈定,且与异常体实际位置及大小偏差越来越大;二极装置“U”型观测方式一定程度上能够有效响应掌子面前方低阻体及其位置,响应信号反映较强,异常幅值强度和中心较明显,低阻体远离掌子面达到50 m时,仍可以识别低阻异常体。采用直流电法二极“U”型装置对某矿掘进巷道前方断层富水性进行探测,探测结果表明该断层呈低阻异常,后经钻孔揭露其为泥质充填的弱富水性断层,从而验证了二极装置“U”型观测方式在巷道超前探测中的应用效果。Abstract: The ANSYS finite element software is used to establish four full-space geoelectric models, and to per-form numerical simulations to the “U” observation mode of the pole-pole array, pole-dipole AMN and MNB arrays respectively.Then the inversion is carried out.The advanced detection effect of the two arrays is comprehensively analyzed, and the optimized device is applied to the field detection.The results show that the morphological char-acteristics of apparent resistivity are similar by comparing with the model with abnormal body in roadway.The overall apparent resistivity of roadway model is larger than that of model without roadway, which affects the delineation and identification of abnormal body in the detection results of AMN array.The model with abnormal body in a roadway is the most similar to the actual situation.The overall resistivity of AMN array is large, and the abnormal reflection is not obvious, so it is difficult to respond to the low resistivity body in front of the roadway.MNB array can respond to the low resistivity body, but the response range and position error are large.With the low resistivity body far away from the face, the abnormal signal reflection becomes less and less obvious, and the abnormal intensity and abnormal center become weaker and weaker.It is difficult to delineate the abnormal body, and the deviation from the actual position and size of the abnormal body is increasing.To a certain extent, the “U” observation mode of the pole-pole array can effectively respond to the low resistivity body and its position in front of the roadway.The response signal is stronger, and the abnormal amplitude intensity and center are more obvious.When the low resistance body is far away from the face and reaches 50 m, it can still be recognized.Through the detection of the water rich property of the fault in front of the driving roadway in a mine, the detection results show that the fault presents low resistivity anomaly.After drilling, it is a weak water rich fault filled with mud.Thus, the application effect of the pole-pole “U” type array is verified in advance detection of driving face.