Experimental Study On High-density Electric Method For Detecting Hidden Dangers Of Dikes

During the operation of the dyke,various hidden dangers such as holes,wormholes,and cracks are often generated due to surrounding natural conditions or human factors.These hidden dangers may cause leakage,piping,and landslides of the dyke when the flood season comes or encounters floods.Dangerous situations such as collapse,serious cases lead to the collapse of the embankment.The detection of hidden dangers of dikes is an important part of the operation and management of dikes.As a branch of DC resistivity method,high-density electrical method has been widely used in the detection of hidden dangers of dikes due to its high efficiency,accuracy,simple operation and easy analysis.However,there are still many deficiencies in this method,such as the sensitivity of the electrodes to the material of different dikes;for a more uniform soil,there is a lack of empirical value of the relationship between the index of compaction and resistivity;The unevenness and randomness of the embankment;the background value of the resistivity of different soils will obviously affect the interpretation of the detected data;it will inevitably affect the detection of hidden dangers,resulting in multiple solutions of the detection results.In this paper,the Ziyaxinhe embankment detection is taken as the engineering background.The embankment model is built indoors.The high-density electric method is used to carry out the technical test.The influence of different device forms and parameter settings on the detection results is studied.The change in resistivity was analyzed to compare the effect of different parameter settings on the inversion results during data inversion.It provides a technical basis for actual engineering exploration.The main research contents and results of this paper are as follows:(1)Through the indoor compaction test,particle analysis test and electrical detection under different degrees of compaction,it is found that the resistivity value of silty sand shows a decreasing trend when the compaction degree is gradually increased.(2)Comparing the detection effects of the Wenner device and the Slongberg device,it is found that the response of the Slobe device is more sensitive to the dielectric condition in the horizontal direction,and the Winner device is more suitable for determining the vertical of the hidden danger.Location,for the detection of long-distance dikes,it is recommended to use the Sloanberg device more efficiently.(3)Studying the influence of different isolation coefficients on the detection results,it is found that the maximum detection depth of high-density electrical method depends on the size of the pole distance and the device coefficient of the instrument,but the actual detection depth is determined by the size of the isolation coefficient.The coefficient from large to small,first determine the hidden danger position and then reduce the isolation coefficient to amplify the abnormality,which is convenient for qualitative analysis.(4)When high-density electrical data inversion is used to eliminate bad points,not all higher or lower values are abnormal points,depending on the selection of background values,and continuous abnormal values may be due to poor electrode contact and instrument operation error.Caused by other reasons,need to be considered comprehensively.(5)The phenomenon of local high resistance or low resistance appearing at the boundary of the image in the inversion result cannot be directly defined as an abnormal region.The boundary effect of the inversion is often the direct cause of such phenomenon,which is needed in the inversion process.Try to eliminate the effects of boundary effects to ensure the accuracy of the results.