Analysis Of 3D Electric Field Characteristics And Imaging Recognition Technology Of Earth-rock Dam With Hidden Trouble

A variety of hidden troubles affect function and lead to dam break during the long-term operation and management of earth-rock dam.Therefore,quickly,economically and effectively to detect these hidden troubles are important to the dangerous earth-rock dam.This paper is supported by the National Natural Science Foundation of China(51279219),using theoretical analysis,numerical simulation,model experiment and field test,study 3D electric field characteristics and imaging the recognition basis of earth-rock dam with hidden troubles,provided a scientific basis for the management of dangerous earth-rock dam.The main research contents and achievements of this paper are as follows:(1)By establishing a 3D finite difference model,the distribution of electric field characteristics of earth-rock dam with different hidden troubles are analyzed,and the influence of the change of power condition on the electric field characteristics of earth-rock dam,the results show that when the earth-rock dam with hidden body of high or low resistance,around the hidden body electric field changes obviously,in the region of hidden body of high or low resistance will form an abnormal electric field,tthe abnormal area is affected by the power supply condition.And further analysis of the crest electric field characteristics,and the correlation between the type of hidden body and distribution parameters of electric field,the results show that the relationship between the distribution of potential and the location of hidden body.(2)The study of inversion imaging recognition based on electric field simulation,the 3D resistivity imaging inversion model of earth-rock dam is established,and the 3D resistivity inversion imaging features of different hidden danger types of earth and earth-rock dam are analyzed,it is found that there are obvious high and low resistivity anomalies in the 3D resistivity images of earth-rock dam model,and there is a good relationship between the location and the size of the high and low resistivity,the reliability of the simulation results of the forward electric field is verified,and provides the basis for recognition of the high and low resistance body hidden in 3D resistivity images.Through image processing,which can directly observe the spatial distribution of high and low resistance hidden bodies.(3)Through the establishment of physical model earth-rock dam containing hidden,analyzed physical model of voltage distribution characteristics,numerical simulation results and field results are roughly the same.For 3D resistivity inversion imaging of earth-rock dam physical model,it is found that the location of the hidden body is basically consistent with the location of the resistivity anomaly zone in the resistivity image,and the results are basically in agreement with the results of the inversion imaging numerical simulation.(4)Combined with practical engineering,the leakage passage in dam body is detected by 3D resistivity imaging technique.The cause of leakage and the path of leakage are inferred by image processing.The results of numerical simulation and model test are used to guide the field test,which can further improve the detection accuracy of the3 D resistivity imaging technology.