斜井上部流砂层塌陷空洞纳米瞬变电磁法探测

Research on detecting collapse holes in quicksand layer above inclined shaft by NanoTEM

为了获得斜井井筒流砂层塌陷地下空洞的分布情况,采用新型纳米瞬变电磁法进行勘探。工作装置为中心回线型,垂直于井筒走向共布置17条测线。考虑干旱季节流砂层塌陷空洞呈高阻特征,由视电阻率剖面圈定了井筒流砂层段地下空洞的范围。纳米瞬变电磁法探测结果表明:主斜井与副斜井流砂层段均存在两处空洞异常。结合井筒施工流砂层统计数据,综合划定了井筒区域流砂层塌陷空洞范围,为井筒及周边建筑物稳定性评价及治理提供了依据。

To obtain the distribution of underground collapse holes in quicksand layer above inclined shaft,new NanoTEM（nanometer transient electromagnetic method） was used in detecting.Central loop mode system was taken as the working device and 17 survey lines were perpendicular to the trend of the shaft axis.In view of the high resistance characteristics of collapse holes in arid season,the range of collapse holes in quicksand layer above the inclined shaft was deduced from apparent resistivity profiles.The NanoTEM detecting results indicated that there were respectively two holes in the quicksand layer over the main inclined shaft and auxiliary inclined shaft.Combining the statistic data of the quicksand layer form shaft construction,the ranges of collapse holes in quicksand layer over shaft area were determined,which provided basis for stability estimation and control of shaft and nearby buildings.