Estabilidade De Canais Fluviais Em Torno De Pontes E Bueiros Na Bacia Hidrográfica Do Paraná Iii, Oeste Do Paraná - Evaluation of the Channel Stability in Bridges and Culverts in Paraná Iii Watershed, Western Paraná State, Brazil

Abstract

RESUMO ABSTRACTThe bridges and culverts alter the natural conditions of rivers, causing changes in fluvial processes. The level of stability of river banks and beds around crossing structures was evaluated in the Paraná III watershed, Western region of Paraná State (Brazil), adopting the methodology of FHWA (2006). A watershed has an area of 7,979.4 Km2 and it predominantly basaltic rocks of the Serra Geral Formation (Cretaceous) that make up the basalt plateau with altitudes ranging between 220 and 725 m. The degree of channel stability was analyzed at 46 structures (18 bridges, 15 culverts box, 7 culverts pipe and 6 small bridges). We selected all crossings structures located in the Paraná III watershed along paved roads, positioned outside the urban area. Among the crossings structure, 13 were classified as excellent level of stability and 33 as good level. It was not registered any points with regular or poor stability. The prevalence of high levels of stability is credited to the outcrop of basalt substrate in bed and the low erodibility of the banks soils (Oxisols and Ultisols) providing greater stability to the channel in the vicinity of the structures.