微动勘探与高密度电法在小尺度老采空区探测中的应用

Application of microtremor survey and high density electrical method in exploration of small-scale old goaf

栾川县赵庄村一带的油页岩老采空区对当地人居环境产生了一定威胁,但其规模小、分布复杂,人员聚居干扰多,探测难度大。为了有效探测该采空区,提出了将微动勘探与高密度电法结合的综合探测方法。通过数据采集与处理获得二维视速度与电阻率剖面,结合实际地质情况,将电阻率剖面上近似层状分布的中等电阻率层推断为油页岩富含层位,将视S波速度剖面上对应该层位处的横向上的低速异常区解释为油页岩采空区。钻探验证结果表明物探解释结果与实际情况基本相符,证明该组合方法可有效探测小尺度老采空区,且抗干扰能力强,施工效率高。

The oil shale old goaf in Zhaozhuang Village of Luanchuan County has posed a certain threat to the local living environment.However,this goaf has small scale,complex distribution,and interference from crowded people,which made it difficult for detection.In order to detect the goaf effectively,the authors in this paper proposed a combined detection method of microtremor survey and high-density electrical method.The two-dimensional apparent velocity and resistivity profiles were obtained through data acquisition and processing.Then,the oil shale rich layer was identified as medium resistivity layer with approximate layered distribution in the resistivity profile,and the oil shale goaf was identified as low velocity anomaly area in the horizontal direction of medium resistivity layer,according to the actual geological condition.The verified results from drilling indicate the inference results of the combination method are basically consistent with the reality,which prove the combination method is feasible for the exploration of small-scale ancient goaf of oil shale,with strong anti-interference features and high-efficiency construction.