Optimizing data for electrical resistivity tomography in hardened sites through the ratio method

To reduce the shielding effect of hardened layers on electrical resistivity tomography a ratio method based on the distortion correction principle and the isolation coefficient is proposed. The effects of the resistivity and thickness of hardened concrete layers on the detection of target objects are explored. Both numerical simulations and indoor tank tests indicate that when the ratio method is employed to correct the original collected data the maximum allowable error for the isolation coefficient should not exceed 1% . Notably when the ratio of hardened layer thickness to electrode spacing does not exceed 1 correction through this method significantly enhances the recognition capability of target objects. However when the hardened layer thickness is greater than the electrode spacing by a factor of 2 or more the ratio method cannot achieve satisfactory results. The case study of flood control engineering detection in the Zhangxi section of the Huangpen River in Dongzhi County demonstrates that the detection effect after correction by the ratio method is comparable to that for the adjacent unhardened pavement and the influence of the hardened layer is obviously weakened resulting in more reliable results. © 2024 Southeast University. All rights reserved.