| Each winter,river ice often forms in the cold regions of northern hemisphere which can lead to ice jam.The appearance of ice jam will block the river cross-section by imposing extra boundaries,reduce the ice cover over-current capacity,result in a significant rise of the water level.Rising of the water level or ice jam break up which cause the discharge of the ice flood,often lead to flooding disaster upstream or downstream,bring huge losses to the national economy and the people's livelihood.At the same time,the existence of piers in the river channel further changes the original hydraulic conditions and boundary conditions,which has an impact on the formation and evolution of the ice jam,which exacerbates the security threat of bridges in the river.Therefore,it is very important to analyze the influence of bridge piers on critical condition and thickness variation of ice jam for the prevention of ice disaster.By changing the flow conditions and ice discharge in the flume in the laboratory,the location of bridge pier constantly changes,the ice jam evolution process under different position of bridge piper were studied,The experiment results shows that the presence of bridge piers changes the local flow field characteristics,relatively enhancing the ability of ice conveyance around,under the same flow condition,The ice jam formation requires a greater ice water flow ratio;In the same flow condition,compared with the single pier is placed at the midway between two consecutive bends,when the single pier is placed at the apex of the curve,The ice jam formation requires a greater ice water flow ratio.If bridge piers are synchronously placed at midway between two consecutive bends and the apex of a bend,the balance of ice jam is not smaller than the single bridge pier placed at two different location of pipers,but between the two.Therefore,the adverse effects of the ice jam can be minimized when the pier is placed at the apex of the curve. |
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