Evaluation of chemical grouted region by resistivity tomography

In chemical grouting, a method to evaluate the region improved by the grouting has not yet been established. This problem has been a major obstacle to the enhancement of realibility of chemical grouting. To solve this problem, the author noted that the electrical resistivity of chemical grout is much lower than the electrical resistivities of ground and groundwater. This study investigated the applicability of resistivity tomography to the evaluation of regions improved by chemical grouting through model tests in the laboratory. The resistivity tomography can measure the resistivity distributions of ground before and after grouting. As a result, it was clarified that a relatively high degree of accuracy can be obtained in the evaluation of the improved regions made by chemical grouting. The method proposed to evaluate the improved region in chemical grouting utilizes data on ground resistivities before and after grouting which can be determined by resistivity tomography, and it has been demonstrating a satisfactory applicability.