摘要
滑坡是常见的地质灾害之一,其发生往往伴随着一系列的次生灾害。针对某滑坡中滑动面与上覆地层和下伏地层存在的电性差异,采用半航空瞬变电磁法解析滑坡地区地下的电性结构。通过一维正演研究了K、H模型的地层厚度变化对电磁响应的影响,发现覆盖层厚度的变化对电磁响应的影响集中在前中期,对晚期电磁响应影响较小,而中间层厚度的变化则会对前中晚期电磁响应均产生一定的影响。以中间薄层地电模型为例,计算了薄层相对于围岩分别为高阻和低阻的电磁响应情况,得到了针对高低阻目标层的半航空瞬变电磁探测敏感区域。最后对某滑坡工区采集的半航空瞬变电磁数据进行了反演,取得了与工区地质情况相符合的地电模型。
Landslide is one of the common geological disasters,and its occurrence is often accompanied by a series of secondary disasters.In this paper,the semi-airborne transient electromagnetic method is used to analyze the underground electrical structure under a landslide area in view of the electrical differences between the sliding surface and the overlying and underlying strata.The effect under stratum thickness change on electromagnetic response of K and H models is studied by one-dimensional forward modeling.It is found that the influence of the thickness of the cover layer on the electromagnetic response is concentrated in the early and middle stages,but has little influence on the electromagnetic response in the late stage,while the change of the thickness of the intermediate layer will have a certain influence on the electromagnetic response in the whole stages.Taking the geoelectric model of the middle thin layer as an example,the electromagnetic response of the thin layer with high resistance and low resistance relative to the surrounding rock is calculated,and the semi-airborne transient electromagnetic detection sensitive area for the high and low resistance target layer is obtained.Finally,the semi-airborne transient electromagnetic data collected in a landslide work area are inverted,and the geoelectric model which is consistent with the geological conditions of the work area is obtained.
作者
赵思为
尹小康
张振雄
吕菲
ZHAO Siwei;YIN Xiaokang;ZHANG Zhenxiong;LV Fei(China Railway Eryuan Engineering Group Co. LTD,Chengdu 610031, China;Key lab of Earth Exploration&Information Techniques of Ministry of Education,Chengdu 610059,China;China Railway Design Corporation,Tianjin 300308, China;Sichuan-Tibet Railway Technology Innovation Center Co.,Ltd.'Chengdu 610000, China)
出处
《物探化探计算技术》
CAS
2021年第6期767-774,共8页
Computing Techniques For Geophysical and Geochemical Exploration
基金
中铁二院工程集团有限责任公司项目(KYY2016002(16-19)),四川省科技厅重点项目(KSWC212003),中国中铁股份有限公司项目(KSWQ202006)。
关键词
滑坡
半航空瞬变电磁法
一维正演
地电模型
landslide
semi-airborne transient electromagnetic method
one-dimensional forward modeling
geoelectric model
作者简介
第一作者:赵思为(1982-),男,高级工程师,主要从事工程物探研究,E-mail:44557200@qq.com;通信作者:张振雄(1994-),男,硕士,主要从事地球物理电磁勘探研究,E-mail:1165499169@qq.com。
