基于钻探约束的瞬变电磁解释方法及应用

Application and interpretation method of TEM data based on drilling constraint

随着我国城镇建设的飞速发展,城镇建筑用地范围不断扩大,所面临的近地表地质构造越来越复杂,常规钻探法难以满足地基勘查的需要。为此,基于优势互补理念,将瞬变电磁法空间采样率高、地质信息丰富、地质体横向边界刻画准确等优势与钻探垂向测深精度高、分层定位准确等优势相结合,提出基于钻探约束的瞬变电磁法解释新方法,较好地克服了常规瞬变电磁法计算深度精度不足的局限,提高了视电阻率剖面的纵向解释能力。通过浩金元住宅建设区采空区探测的应用试验,圈定了测区中东部存在一个面积约0.01 km2的采空积水区,中部存在一个面积约0.009 75 km2的非采空区,其他部分均为采空区,取得了良好的应用效果。

With the rapid expansion of the scope of urban construction,the near-surface geological structure is more and more complex.The conventional drilling method is difficult to meet the needs of the foundation exploration.For this reason,based on theory of complementary advantages,a new idea inversing apparent resistivity by the transient electromagnetic data under the constraint of drilling data is put forward,which combines the advantages of the transient electromagnetic method(TEM),such as high space sampling rate,rich geological information,accurate determining of lateral boundary of geological body and so on,and the advantages of drilling,such as high precision vertical sounding,accurate layering and so on.A new interpretation method of TEM data based on drilling constraint is given,which can better overcome the limits of traditional TEM method to get high accuracy depth results difficultly and improve the depth explain ability of calculating apparent resistivity section.The goaf detection results in Haojinyuan house construction area show the new interpretation method can obtain good effect,which determine a coal goaf water area about 0.01 km^2 in the central section,and a non-goaf area about 0.009 75 km^2 in the mid-east region,and infer other region are coal goaf area.