Contribution of Trapped Air, Deck Superelevation, and Nearby Structures to Bridge Deck Failure during a Tsunami
Contribution of Trapped Air, Deck Superelevation, and Nearby Structures to Bridge Deck Failure during a Tsunami
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DOI：
10.1061/(asce)hy.1943-7900.0000855
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发表时间：
2014-05
影响因子：
2.4
通讯作者：
J. Bricker;A. Nakayama
中科院分区：
文献类型：
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作者：
J. Bricker;A. Nakayama
2011年东日本大海啸期间，宫城县南三陆县的宇津混凝土主梁公路桥发生故障，这令人费解，因为桥面并没有被推离桥墩，而是在被汹涌的海啸深深淹没后，从桥墩的陆地一侧翻转而下。为了确定导致这种情况发生的原因，进行了两次模拟。首先是大规模的代尔夫特浅水模拟（从公布的海啸源自由面偏差开始），以确定海啸在桥址的行为（水流深度和速度的时间序列）。第二种是基于Delft模型的边界条件，对桥面流动进行小规模二维（2D）（剖面图）软件流体体积（VOF）模拟。VOF模型允许计算升力、阻力和桥面倾覆力矩。结果表明，导致破坏的因素包括桥梁附近的海堤、甲板向海洋的倾斜（超高程）、水中的沉积物以及梁之间的空气截留。
Failure of the Utatsu concrete girder highway bridge in Minamisanriku, Miyagi Prefecture during the 2011 Great East Japan Tsunami was puzzling because the bridge decks were not pushed off their piers but rather were flipped off the landward side of the bridge piers after being deeply submerged by the surging tsunami. To determine what caused this to happen, two simulations were conducted. The first was a large-scale Delft shallow-water simulation (beginning with published tsunami source free surface deviation) to determine the behavior of the tsunami (time series of flow depth and speed) at the bridge site. The second was a small-scale two-dimensional (2D) (profile view) software volume-of-fluid (VOF) simulation of flow over the bridge deck, with boundary conditions taken from the Delft model. The VOF model then allowed calculation of lift force, drag force, and overturning moment on the bridge deck. Results show that factors contributing to failure included the presence of a seawall near the bridge, inclination (superelevation) of the deck upward toward the ocean, sediment entrained in the water, and air trapped between girders.