Projeto de instrumentação, monitoramento por imagens e retroanálise de pavimento

Abstract

Railroads have gained national prominence due to the large investments and network expansions planned for the coming years. Brazilian methods for analyzing the behavior of railways, however, present outdated simplifications inspired in countries with soils with climates distinct from the 5 climatic regions of Brazil. Thus, this master thesis, an integral part of the Decentralized Execution Term (TED) between the National Department of Transportation Infrastructure (DNIT) and the University of Brasilia (UnB) in partnership with the Federal University of Juiz de Fora (UFJF), collaborates with the execution of an experimental section (TE) composed of specific instrumentation to measure the stresses, strains, and modifications in the conditions of the railway materials resulting from traffic actions. To this end, the instruments that will integrate the TE were defined, with reference to the few national and international experiences. Of the instrumentation designed, only the measurement of deflections by means of image treatment was used when the train was passing, leaving a legacy for future research. In comparison to these experiences, the monitoring of deflections by means of digital images, used in the research, presented itself as a differential. The instrumentation project was guided by a previous numerical modeling, using the SysTrain software. Thus, we proceeded with the monitoring of the potential stretch to be instrumented, filming the displacement of targets located on rails and ties. Next, a back analysis was performed in SysTrain, starting from the rail deflection, and validating it with the sleeper displacements, once there was agreement between the modeled and field results. The back analysis showed a resilience module with a value indicating an advanced subgrade degradation process. This is a reasonable condition considering the track's operation time. Through sensitivity analysis of the parameters that can affect the behavior of the railway, the influence of the resilience modulus, especially of the subgrade, on the displacements mobilized in the rail was verified. On the other hand, there was no significant impact of the ballast condition on the behavior of the analyzed structure. Thus, the results highlight the importance of the iteration between the layers of the structure and the condition of the subgrade for a better performance of the railway.