Utilização do método de eletrorresistividade (ERT) em investigações geotécnicas em um parque eólico, localizado no município de Jandaíra/RN

Abstract

In the engineering field, geophysical methods have become popular since the 1990s and continue to be applied in conjunction with geotechnical investigations, such as in monitoring risk areas, detection of pipelines and tunnels and in installation works of Wind Farms. Among the main methods used, the geoelectric methods can be mentioned, especially the electroresistivity method. In this context, the work in question aims to use the electroresistivity method, throughthe technique of Electrical Resistivity Tomography (ERT), aiming to acquire data to assist in understanding the local geology, by imaging possible structures and lithotypes in the subsurface, and obtaining information about the thickness and laterality of the geological unitspresent in the area of a wind farm in the municipality of Jandaíra/RN. The data acquisition wasdone with a Dipole-Dipole arrangement, using 48 electrodes equally spaced at 4 meters. The software RES2Dinv and SURFER 10 were used for processing and better visualization of the 8 resistivity sections obtained. The distribution of resistivity in the subsurface, in 7 of the 8 sections, varied between 3 and 682 Ωm (in one of the sections the resistivity values exceeded 40000 Ωm). The results obtained after interpretation enabled the identification of two geological units and their respective thicknesses, as well as the presence of possible faults and/or cavities. Comparing the results to rotary drilling data, ERT's efficiency in imaging structural features and lithotypes in the subsurface was confirmed.