详情

原文传递 Impacts of a Floating Structure on the Residence Time in a Poorly Flushed Estuary, Golden Horn

题名：	Impacts of a Floating Structure on the Residence Time in a Poorly Flushed Estuary, Golden Horn
正文语种：	eng
作者：	Olgay Sen;Sehriban Saçu;Tarkan Erdik;izzet Oeztuerk
作者单位：	Faculty of Civil Engineering Division of Hydraulics Istanbul Technical Univ. Maslak Istanbul 34469 Turkey (corresponding author);Faculty of Civil Engineering Division of Hydraulics Istanbul Technical Univ. Maslak Istanbul 34469 Turkey.;Faculty of Civil Engineering Division of Hydraulics Istanbul Technical Univ. Maslak Istanbul 34469 Turkey.;Faculty of Civil Engineering Division of Environmental Engineering Istanbul Technical Univ. Maslak Istanbul 34469 Turkey
关键词：	3D modeling; Estuaries; Residence time; Golden Hom
摘要：	Pontoon bridges are preferable structures when bridges supported by piers are not economically feasible. However, bridges that are built on floating pontoons act as a barrier and can block water flow, thus affecting the transport timescales of the estuaries. The Golden Hom (GH) Estuary in the Bosporus in Turkey suffers from poor circulation conditions and is susceptible to water quality problems due to the Valide Sultan Bridge (VSB), which was built on floating pontoons in 1912, and was later relocated out of the estuary to enhance circulation. However, the Istanbul Metropolitan Municipality is currently reconsidering reinstalling the VSB in the GH, which could potentially reduce the density of traffic in Istanbul. In this study, a three-dimensional (3D) numerical model was performed to determine the best bridge altemative that would cause the minimal negative impact on the water residence time in the estuary. Toward this aim, various hydrological (high-flow and low-flow) and structural scenarios (pontoon layout and location) were developed and compared with each other. Results of the study showed that the pontoons impacted the flow fields and changed the water exchange of the estuary. In low-flow conditions, in the upper and middle estuary, pontoons caused an increase in residence time up to 30 h; however, modification in the pontoon layouts considerably benefited the renewing of the water. In addition, in the case of placing the bridge at the shallow zone, local decreases in renewal times was een, and this altemative was found to be more applicable than the deeper altemative for the bridge location. The findings of the study also revealed the importance of analyzing residence time spatially.
出版年：	2022
期刊名称：	Journal of Waterway, Port, Coastal and Ocean Engineering
卷：	148
期：	4
页码：	05022002.1-05022002.14