Electrical Tomography Applied to the Detection of Subsurface Cavities
Electrical Tomography Applied to the Detection of Subsurface Cavities
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DOI：
10.4311/2011es0242
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发表时间：
2013-04
影响因子：
0.9
通讯作者：
J. Martines-López;J. Rey;J. Dueñas;C. Hidalgo;J. Benavente
中科院分区：
文献类型：
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作者：
J. Martines-López;J. Rey;J. Dueñas;C. Hidalgo;J. Benavente
我们已经分析了三个洞切割成不同的地质基底的花岗岩，千枚岩，砂岩，以前的特点是直接的方法产生的地电响应。我们还检查了在花岗岩中挖掘的采矿空洞。在每种情况下，我们采用了三种不同的地电阵列（温纳-斯伦贝谢，温纳和偶极-偶极）和几个电极间距。调查结果表明，电阻率层析成像是一种可行的地球物理工具，用于探测和监测采矿空洞和其他地下空洞。结果因各种因素而异，例如空腔的深度和直径、使用的多电极阵列、电极间间距、地质模型和数据密度。温纳-斯伦贝谢阵列探测这些空洞的分辨能力大于温纳阵列，略优于偶极-偶极阵列。电极间间距与腔体直径之间存在直接关系。一般来说，我们观察到随着电极之间的距离增加，分辨率会降低。当电极间距离小于或等于腔体本身的直径时，实现了最有效的检测。此外，空洞探测随着其在地表以下的深度而变得越来越不精确。用温纳-斯伦贝谢法和偶极-偶极法在4.6米以上的深度找到了半径约为1.5米的洞穴，这意味着可以在洞穴半径3倍的深度进行勘探。
We have analyzed the geoelectric response produced by three cavities cut into different geological substrata of granite, phyllite, and sandstone that had previously been characterized by direct methods. We also examined a mining void excavated in granite. In each case, we applied three different geoelectric arrays (Wenner-Schlumberger, Wenner and dipole-dipole) and several inter-electrode spacings. The survey results suggest that electrical resistivity tomography is a viable geophysical tool for the detection and monitoring of mining voids and other subsurface cavities. The results vary depending on a wide range of factors, such as the depth and diameter of the cavity, the multi-electrode array used, the inter-electrode spacing, the geological model, and the density of the data. The resolution capacity of the WennerSchlumberger array for the detection of these cavities was greater than that of the Wenner array and slightly better than the dipole-dipole. There is a direct relationship between inter-electrode spacing and diameter of the cavity. In general, we observed a loss of resolution as the distance between the electrodes increased. The most efficient detection was achieved when the inter-electrodes distance was less than or equal to the diameter of the cavity itself. In addition, cavity detection became increasingly less precise with its depth beneath the surface. Cavities with a radius of about 1.5 m were located by both the WennerSchlumberger method and the dipole-dipole at depths of more than 4.6 m, which means that prospecting can be carried out at depths 3 times the radius of the cavity.