Study of slope stability in Petropolis (RJ) through the geophysical methods GPR andERT

Abstract

The sliding of slopes is a natural phenomenon that occurs all over the world and that can cause loss of human and material lives. Being the possibility of evaluating these risk areas through geophysical methods. In this study, Ground Penetration Radar (GPR) and Electrical Resistivity Tomography (ERT) methods were used on Rua Mato Grosso, in the Quitandinha neighborhood, Petrópolis (RJ), which is susceptible to slopes. The GPR is based on the propagation of electromagnetics waves with frequencies between 10 and 6000 MHz, in the data acquisition a 200 MHz antenna was used and the data processing performed in the REFLEXW program. The ERT is based on the electric potential difference of natural or artificial electric fields, 24 electrodes were used for data acquisition, with data processing in the RES2DINV program and a data simulation in the RES2DMOD program. In the results obtained, a difference between consolidated and unconsolidated soil at approximately 1.5 m depth that can generate future land displacements, the presence of blocks of different sizes scattered throughout the area were found, indicating that the area has already suffered from landslides, drainage points and water accumulation, increasing the risk of slipping. The use of geophysical methods contributes to the analysis of slope instability and helps to avoid future disasters.