Study On The Application Of Parallel Electrical Prospecting Method For Seepage Of Earth Rock Dam

In our country,dam reservoir disrepair leakage is a common phenomenon,the exploration of means and methods for this problem there are many,the method as a kind of geophysical exploration method in situ nondestructive,convenient and efficient and reliable detection results have been widely used in reservoir dam seepage exploration work.However,due to the inherent structure of earth rockfill dam in electrical volume effect and side effect of internal and practical exploration in the complex under the influence of external factors,get some time the results of the field test and can not accurately delineate the actual size of the risk can not even effectively identify the true position of the abnormal area,causing the site personnel questioned the exploration of means and personal ability of us.At the same time,the mechanism of formation of dam leakage differences in different regions,the hidden location,size,shape and direction is different,this increases the electrical post processing analysis and explanation of the difficulty of data collected on site.If the existing problems in the work of electrical prospecting is studied more in-depth,and the rules and results for the detection of hidden danger of actual master work,which will improve the scene analysis of line arrangement is reasonable and can provide data basis for the interpretation of the results.First of all,aiming at the problems exist in the field of electrical testing in the relevant literature,on the basis of this,the use of parallel electrical testing technology to solve the three problem which has been studied in-depth study.The author summarizes the whole process of the whole series of experiments of electric field response characteristics and related changes are as follows:(1)The data map of apparent resistivity and resistivity inversion of the triode device in about Wenner was studied.The abnormal body of high resistance under the condition of the left offset device of apparent resistivity ratio after Wenner pole detection of high resistivity body to the left,the right is the right device to detect the shift in interference conditions;under the condition of strong,better effect of Wenner device data left to the right pole resistivity inversion device;both the apparent resistivity data or Wenner pole triode Wenner resistivity inversion data about effect of the ratio of the device after the well.The results show that the apparent resistivity data about the device is easy to make the Wenner pole abnormal body hair A certain offset,after the resistivity data inversion after treatment can be very good to judge the exact position of the abnormal body,in the indoor test,especially in the affected by the external factors is relatively large,can use ratio processing methods to weaken the external interference.(2)Study on the response characteristics of electric field leakage channel of different direction and position.In the process of test selection and test the leakage passage line angle is 30 degrees,60 degrees,90 degrees of three kinds of situations,and change the depth of the leakage passage,the leakage passage is perpendicular to the line direction,by changing the the leakage channel depth and relative to the line level,respectively.The electric field response characters were compared.The results indicate that when the leakage passage and the arrangement of measuring line perpendicular to the direction,the best to detect the depth and size effect,with the angle decreases,the resistivity value at the position of abnormal body becomes smaller but,The resistivity value of the right and left sides of the area is increased,and when the depth of the leakage passage is increased,the response of the geoelectric field is obviously weakened,and the detection effect is different.(3)The side effect problem in electrical in related experiments.Experiment,abnormal body from below different depth and position of the line gradually deviate from the detection section,observe the abnormal body in the process of electric field response,by extracting the center position of abnormal body horizontal and vertical data,get the the whole process of the electricity in the offset section and electric sounding curves.This time through the side effect problem is studied deeply,the basic grasp of anomaly detection section in the process of gradually deviate from the response of geoelectric field variation characteristics,the effective judgment response range of abnormal body position and the form of the use of electrical side effects.This paper through the relevant laboratory tests on problems in the field exploration,obtained under different electric field response characteristics and change rules,provides some guidance for reasonable selection of field line spacing and the results of data analysis and explanation.