Study On Three-dimensional Electrical Detection And Application Of Earth Rock Dam Leakage

In China,the leakage problem of earth rock dams is widespread,which seriously endangers the stability of dams.In this paper,through theoretical analysis,numerical simulation and field examples,the leakage detection of earth rock dam is studied by using three-dimensional resistivity method,and the following results are obtained:(1)As a geophysical exploration method with high precision and large amount of data,the three-dimensional resistivity method has better detection effect than the two-dimensional resistivity method.It overcomes the observation accuracy problem of leakage around the dam faced by the traditional two-dimensional resistivity method,avoids the influence of side effect and the interference of topographic factors on hidden danger identification,and meets the requirements of three-dimensional expression of leakage,It can scientifically and effectively outline the three-dimensional leakage channel.(2)Through numerical simulation,different leakage channel models are established for comparative observation.The analysis shows that the closer the leakage channel is to the dam abutment,the deeper the buried depth is,the more obvious the abnormal body corresponding to the leakage channel is affected by the volume effect,and the low resistance area gradually diffuses around;The judgment of the penetration degree of the leakage channel is affected by the boundary effect,and the detection effect near the boundary area is poor;The detection results of leakage channels with different deflection angles are good.(3)The three-dimensional parallel electrical method is used to accurately delineate the leakage position in the 38 reservoir,which proves the feasibility of the three-dimensional electrical method for dam leakage judgment.At the same time,the two-dimensional and three-dimensional electrical methods are compared and analyzed,which proves that the three-dimensional electrical method has certain advantages for leakage detection.Combined with numerical simulation and engineering application,the center of low resistance abnormal body is obviously upward offset relative to the center of leakage model.Therefore,in practical engineering,the judgment of leakage channel center should be based on the bottom of low resistance abnormal body.Figure[53]table[7]reference[113]...