关键词: 高密度电法, 侨城东路, 北延通道, 区域断裂带, 低电阻率

Abstract: To solve the problem of the refined detection of the fracture zone under the complex geological conditions, a case history project of north extension of Qiaocheng East Road in Shenzhen City is presented in this paper. Throughout the analyzing the engineering geological conditions of the site, the high-resolution resistivity distribution image of the site is obtained by using the high-density electrical method. The position and trend of the fracture zone are inferred. The results show that there are four faults within the project limits that have a greater impact on the alignment. The tectonite in the fracture zone is mostly squeezed, with poor rock fracture development and integrity, poor rock structure, rock mineral alteration and cementation, which results in low strength of the tectonite, which is relatively soft rock and soft rock. The geophysical exploration indicates that there are three abnormal areas, all of which are characterized by the low resistivity anomalies. Their resistivity is significantly different from that of the fully weathered granite and the moderately weathered granite layers, which indicating relatively low resistivity. The interface between the geoelectric layers is well defined, and the resistivity of the abnormal area is roughly the same as that of the Quaternary soil layer, with a resistivity range of less than 30 Ω· m, while the resistivity range of the fully weathered granite is 30-50 Ω· m. The resistivity of the moderately weathered granite layer is greater than 50 Ω· m. The interpretation results of the high-density electrical method are consistent with the results revealed by the geological drilling, indicating that the high-density electrical method has the characteristics of high accuracy, high efficiency, and visualization.

Key words: High-Density Electrical Method, Qiaocheng East Road, North Extension Channel, Regional Fracture Zone, Low Resistivity