电阻率层析成像技术在官峰水库坝址断裂探测中的应用

Application of resistivity tomography in fracture detection of Guanfeng reservoir dam site

福建漳州地区平和官峰水库坝址区地质构造复杂,且存在多组隐伏于地表之下的断裂。为评估水库坝址区岩性的工程地质性能及断裂对渗透产生的影响,采用电阻率层析成像技术(高密度电法)探明研究区的岩性及断裂展布,结合区域地质调查资料,在平和官峰水库部署了2条高密度电法剖面。探测结果表明,研究区沉积地层在反演剖面上可以划分为3个电性层,与钻孔资料对应良好;同时查明了贯穿坝址区的断裂F_(9)的具体位置,发现1条新的隐伏断裂F_(10),并被地质调查所证实。

The dam site of Guanfeng reservoir,Pinghe County,Zhangzhou,Fujian Province,has a complex geological structure,and there are many groups of hidden faults under the surface.In order to evaluate the engineering geological properties of the reservoir dam site lithology and the influence of the faults on the permeability,resistivity tomography was used to investigate the lithology and fault distribution in the study area.Based on regional geological survey data,two high-density electrical profiles were deployed in Guanfeng reservoir,Pinghe County.The results show that the sedimentary strata in the study area can be divided into three electrical layers on the inversion profile,which correspond well with the borehole data.At the same time,the specific location of F_(9)fault running through the dam site was identified,and a new hidden fault F_(10)was discovered,which was confirmed by geological survey.