近海岸桥梁下部结构波浪力分析

采用雷诺时均Navier-Stokes（RANS）方程和标准k-ε湍流模型建立波浪水槽，分别针对波浪只作用于下部桩基和波浪作用于整个下部组合结构2种工况，模拟分析波浪特性对波浪力的影响.结果表明：波浪入射角为0°时，近岸条件下各桩柱受力大于平床，且前排桩柱受力随桩间距的增加而增加，后排桩柱受力随桩间距的增加而减小；群桩整体受力随波浪KC数和波高比成幂指数规律增加.桥梁下部组合结构整体所受波浪力随波浪入射方向变化较小，随KC数和波高比变化较大，最大增幅为704%；由于桥梁下部组合结构阻水宽度沿垂向变化显著，与KC数相比，波高比能更好地反映波浪特性对桥梁下部组合结构整体受力的影响.
Abstract: The Reynolds-averaged Navier-Stokes (RANS) equations and standard k-ε turbulence model were used to establish the three-dimensional numerical wave flume. Considering the conditions that the wave only acted on the pile foundation and on the whole composite structure, the influence of the wave characteristics on the forces was simulated and analyzed. Results show that when the angle of wave incidence is zero, the wave forces on the piles in the near-shore are larger than that on the flat bed. And in the near-shore, the wave forces increase with pile spacing when the pile is in the front row, while decrease with pile spacing when the pile is in the back row. Furthermore, the total force on the pile foundation increases with KC number and wave height ratio according to the rule of power exponent. The wave force subjected by the bridge substructure varies little with the incident wave direction, but it varies greatly with KC number and wave height ratio, and the largest rate of growth is 704%. However, due to that the current-obstruction width of the composite structure varies greatly in vertical direction, compared with KC number, the wave height ratio can better reflect the effect of the wave characteristics on the wave forces subjected by the bridge substructure.