基于高密度电法的抽水蓄能电站地下岩体结构探测

Detection of Underground Rock Mass Structure of Pumped Storage Power Station Based on High-density Resistivity Method

针对抽水蓄能电站地下岩体结构探测存在水下、地形复杂多变、对探测深度和分辨率要求较高等问题,提出了一种适应性强、稳定性高、成果信息丰富,可满足大坝地下岩体结构探测深度和分辨率要求的一种高密度电阻率探测方法。该方法对地下低阻异常具有较高的灵敏度,在探明地下破碎发育带和断层等构造优势显著。通过对西藏永木抽水蓄能电站上水库布设的3条高密度电法剖面进行分析,推断该地段基覆界线、破碎带、断层等分布情况,结合现场钻探验证结果,发现高密度电法反演解译结果与钻孔资料吻合较好,为下一步进行全区断裂划分、基覆界线确认和综合地质解释奠定了基础。结果表明高密度电法在查明抽水蓄能电站地下岩体结构的可行性和有效性。

There are many problems in the exploration of underground rock mass structure in pumped-storage hydroelectricity,such as water-involved,complex and changeable topography and high requirements of depth and resolution.A high-density resistivity detection method with strong adaptability,high stability and abundant information was proposed,which could meet the requirements of the detection depth and resolution of the underground rock mass structure of the dam,this method had a high sensitivity to the low resistivity anomaly,and had a significant advantage in the exploration of underground fracture zones and faults.Based on the analysis of three high-density resistivity profiles in the upper reservoir of Yongmu pumped-storage hydroelectricity,the distribution of the base-overlying boundary,fracture zones and faults in this section has been inferred and verified by field drilling,it is found that the inversion results are in good agreement with the borehole data,which lays a foundation for fault division,subsoil boundary confirmation and comprehensive geological interpretation.The results show the feasibility and effectiveness of high-density resistivity method in identifying the pumped-storagehydroelectricity underground rock mass structure.