摘要
基于"烟圈"效应理论和物理模拟相似性准则,对井下瞬变电磁法沿探测方向上存在多个低阻体时,物理模拟浅层低阻屏蔽体瞬变电磁响应特征。模拟结果表明,在沿探测方向上浅部存在低阻体或低阻薄层时,深部低阻体的瞬变电磁响应会受到表层的低阻屏蔽而被压制或掩盖,在感应电位多测道剖面图上表现为单一低阻体的响应形态及规律,使得隐伏在浅部低阻干扰体背后的目标体难以识别和分辨。矿井瞬变电磁法在实际探测中应尽可能避开巷道附近存在低阻体或低阻岩层位置,避免无法识别远处低阻目标体响应特征。
Assuming that there are multiple low-resistivity bodies in the detecting direction,the transient electromagnetic responses of these shallow ones have been simulated based on the ＂smoke ring＂ effect theory and the similarity rule in physical simulation.The research results show that the transient electromagnetic responses of deeper low-resistivity bodies will be suppressed or even shielded by the shallow ones or thin beds,which are presented as similarly as a single conductive body＇s responses and rules in the multi-channel measurement profile,making the target beneath these shallow interfering bodies difficult to be distinguished.Hence,low-resistivity bodies should be evaded as far as possible in actual transient electromagnetic detection.And attempts to determine these undistinguishable targets in far distance are also suggested to be avoided.
出处
《工程地球物理学报》
2010年第6期661-666,共6页
Chinese Journal of Engineering Geophysics
基金
国家重大基础研究发展计划(973)项目(编号:2007CB209400)资助
关键词
矿井瞬变电磁
物理模拟实验
纵向响应特征
mine transient electromagnetic method（TEM）
physical simulation experiment
vertical response characteristics
