ERT在西北干旱区隐伏断裂探测中的应用研究

发布时间：2019-03-07 11:15

【摘要】：高密度电阻率成像法(ERT)结合了电剖面法和电测深法的优点,在断裂构造探测方面有其独到的优势.但在ERT实际应用时尚存在电极装置有效性和电极距优化等问题.在西北干旱区还存在接地电阻高而导致无法供电的问题.本文即是针对这三方面问题,选取西北地区一条典型断裂—信泉断裂,开展了实验研究.在垂直于该断裂方向上布设了四条测量剖面,开展了接地电阻降阻、电极装置和电极距实验.实验结果表明:(1)浇入自来水和Na Cl溶液,并使电极与周围介质紧密接触,可以很好的解决新疆干旱地区接地不良的问题(2)ERT不同装置形式和电极距可从不同侧面反应剖面特征,在实际应用中应综合分析不同装置和不同电极距探测结果,以获得丰富的剖面信息(3)信泉断裂的电性特征为:在反演电阻率剖面上有明显的错断,破碎带为低阻板状体异常;断裂上盘低阻层厚度小,下盘低阻层厚度大;断裂西段覆盖层变薄甚至局部地段基岩裸露,断裂中部覆盖层厚度较厚.
[Abstract]:The high density resistivity imaging method (ERT) combines the advantages of electrical profile method and electrical sounding method, and has its unique advantages in fault structure detection. However, there are some problems in the practical application of ERT, such as the validity of electrode device and the optimization of electrode distance. In the arid area of northwest China, there is still a problem of high grounding resistance, which leads to the lack of power supply. In view of these three problems, this paper selects a typical fault in northwest China-Xinquan fault, and carries out an experimental study. Four measuring sections are arranged in the direction perpendicular to the fault, and the experiments of grounding resistance reduction, electrode device and electrode distance are carried out. The experimental results show that: (1) Tap water and Na Cl solution are poured into the electrode, and the electrode is in close contact with the surrounding medium. It can solve the problem of poor grounding in arid areas of Xinjiang. (2) different device forms and electrode spacing of ERT can react profile characteristics from different sides. In practical application, the detection results of different devices and different electrode distances should be comprehensively analyzed. In order to obtain rich profile information (3) the electrical characteristics of Xinquan fault are as follows: there are obvious faults in the inversion resistivity profile, and the fracture zone is low resistivity plate body anomaly; The thickness of the lower resistance layer in the upper disk of the fault is small and the thickness of the low resistance layer in the lower part of the fault is large;
【作者单位】：西北核技术研究所;新疆工程学院;南京大学地球科学与工程学院;
【分类号】：P631.322

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