小尺寸双柱式桥墩波浪力的数值分析

Morison 方程适用于小直径孤立柱的波浪力计算，对于双柱式桥墩的波浪力计算已不能直接采用 Morison 方程。为了能利用 Morison 方程求解双柱式桥墩的波浪力，定义了双柱式桥墩前柱、后柱及整体结构的波浪力干扰系数。采用线性波浪理论，利用推板式造波方法模拟线性波，将 ANSYS Workbench平台作为 FLUENT 和 ANSYS 的数据传递平台，对深水环境下双柱式桥墩受到的波浪力以及波浪场作用下双柱式桥墩的结构变形进行单向流固耦合数值模拟。数值模拟结果表明，双柱式桥墩前、后柱波浪力的干扰系数在一定柱距范围内均随柱距的增大近似的成线性增大，当柱距超过一定值后趋于稳定。由于双柱间存在相位差，双柱墩波浪力的总干扰系数以及双柱墩的结构变形却随着双柱中心距的增大而减小。这些变化曲线为实际工程中深水桥梁双柱式桥墩的波浪荷载计算提供了一种更为简便的算法。

Numerical Analysis of Wave Force of a Small-scale Double Column Pier

The Morison formula is suitable to the calculation of wave forces on the isolated column with small diameter and can’t be used to double column pier .By defining the wave force interference coefficient ,Morison formula can be used to solve the wave force of double column pier .This study adopts the linear wave theory and simulates linear wave by utilizing the push-pedal wave-generating method .By considering ANSYS Workbench as the data transfer platform between FLUENT and ANSYS ,the numerical simulation about one -way FSI for wave forces on double-column pier in wave field were performed .The results show that interference coefficient of two columns’ wave force approximate linearly increased with the increase of column distance within certain range .When exceed this range it tends to be stable .Because of the phase difference between two columns ,the total interference coefficient of wave forces and the structure deformation of the double-column pier decreases with the increase of column distance .And these results can provide reference to wave load calculation of double column pier of the deep-water bridge in practical engineering .