ESTIMATIVAS DO PERÍODO DE RETORNO DO COLAPSO DE PONTES EM 2016 EM ITATIBA, SP

Código

ENES20200003

Autores

Fernanda Pires Pinto, José Anderson do Nascimento Batista

Tema

06 - RISCOS E DESASTRES RELACIONADOS AOS SEDIMENTOS

Resumo

Bridge collapses generally result from flood events, as they are subjected to localized erosion and additional loads on the structure. The debris accumulation in the bridge section can aggravate the structure instability scenario in flood events. This work aims to estimate the return periods related to the collapses of two bridges in Itatiba/SP, in 2016, in scenarios with and without debris accumulation, based on inundation and obstruction rates of bridges sections considered in the literature. The triggering flow methodology was used to estimate the collapse flows and the return periods were obtained by the nearest IDF formula from Campinas, with the rainfall intensities modeled inversely by the I-PAI-WU rainfall-runoff method. The results showed that the debris accumulation, on both bridges, was essential to the collapses. The scenarios of 120% inundation rate has been considered as the most probable, once the deck Froude number has been related to drag and lift coefficients peak. Thus, the calculated return periods for this scenario were between 23.65 and 68.90 years on Cruzeiro bridge, and 43.14 and 108.24 years.