作　　者： ; ;

机构地区： 贵州大学资源与环境工程学院

出　　处： 《安全与环境学报》 2019年第2期450-455,共6页

摘　　要： 贵州是全国唯一没有平原的省份,地质情况复杂且岩溶广泛分布,隧道建设过程中因为缺少相关地质资料,经常会发生岩溶突水、冒顶事故等。如何高效地做好隧道超前预测工作是勘察工作面临的一个重大难题,直接影响到设计、施工的有效性和安全性。瞬变电磁超前探测具有高效性、便携性、体积效应小等优点,是目前隧道超前预测预报的主要手段之一。在使用瞬变电磁法进行隧道超前预报的过程中发现了一个比较有规律的现象:隧道巷道两侧的探测反演图像形如蝴蝶的翅膀,即在两侧出现较为明显的对称低阻异常区域。但通过开挖揭露验证,巷道两侧岩体的分布和稳定性往往是正常的。分析出现这种情况是由于测线的旋转角、背景场的差异、金属干扰及信号衰减等原因,是多种因素相互作用的动态表现,可通过改进探测方法和调整参数予以解决。在实践过程中,将掌子面分为左帮、迎头、右帮3个部分,进行分区探测和数据采集,不仅增加了数据量,也方便后期将数据分段处理后叠加在统一的背景场下,以满足探测是基于均匀背景下建构的理论。采用改进的探测方法后,对比常规探测方法,反演图像视电阻率整体较高,且稳定连续,未发现异常现象,与实际地质情况相符。 The paper has found that there exists a more obvious symmetrically low resistivity in the anomalous area on the both sides of the tunnel forecast.And we have analyzed the reasons for the phenomena involved,such as the rotation angle of the measuring line,the difference of the background field,the metal interference and the signal attenuation,etc.,due to the dynamic performance of the interaction of the various factors,which has to be solved by improving the detection method and adjusting the related parameters.In dealing with the problem,we have managed to adopt the method of'semi-circular detection'by dividing the conventional acquisition mode into 3 parts,and the tunnel face into 3 zones:that is,the left side,the front side and the right side.Along the line,we have collected the data involved in the said 3 directions:that is,the 45°of the elevation angle,the horizontal direction,and the 45°of the depression angle,which can not only account for the increase of the data size and varieties,but also include the premise of the background field superimposing and unification through data segmentation.At the same time,it should also satisfy the theory for the detection based on the uniform background construction so as to ensure the relative accuracy of the inversion results.And,then,when the improved detection method has been adopted,and compared with the conventional detection ones,the inversion image apparent resistivity has been found overall higher.What is more,it proves stable and continuous,with no abnormal phenomena found,and consistent with the actual geological conditions.

关 键 词： 安全工程 隧道超前预测预报 瞬变电磁法 岩溶

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