Construction geophysics investigation with direct currentresistivity method: Three dimensional visualization of support structure element

The multi-electrode and multi-channel resistivity measurement systems used in the Direct Current Resistivity (DCR) method allow the method to be applied on structures as well. Although small-scale DCR studies are generally preferred in laboratory research, they are also used in the examination of structural system elements of reinforced concrete engineering structures such as buildings, bridges, etc. In this thesis, a new data collection mechanism which is suitable for investigation of the reinforced concrete structure were developed for the DCR method. In addition, using this data collection mechanism, the most suitable electrode array set was determined by taking into account the measurement time and the inversion results of synthetic data. Firstly, three-dimensional modeling studies were carried out to determine the data set suitable for data collection on reinforced concrete structures with the multi-electrode measurement system. By performing the three-dimensional inversion of the data obtained from the modeling studies, the forward responses obtained when the electrodes are positioned on a single surface, opposite surfaces and adjacent surfaces on a columnar structure were examined for different electrode arrays. In these studies, the change in the three-dimensional resistivity models in case the concrete structure contains iron reinforcement, cracks and a moist region was examined and the suitable mechanism for taking practical measurements was developed. After three-dimensional modeling and inversion studies, the DCR measurement was taken on the column structure with the developed measurement mechanism and suitable electrode arrays. The results obtained from synthetic data showed that it is possible to determine the concrete cover thickness of the element, the distribution of reinforcement within the element and possible fracture/crack/humidity conditions by applying the DCR method on the structural load-bearing elements.