港珠澳大桥岛桥结合跨箱梁波浪力试验研究

Experimental study on wave force of box girder at the junction of artificial island and bridge span of Hong Kong⁃Zhuhai⁃Macao Bridge

通过三维物理模型系列试验,对港珠澳大桥工程西人工岛、岛桥结合跨进行模拟。试验测量了不同波浪入射角度、波高、波周期以及梁底净高等影响因子下的岛桥结合跨箱梁所受的浮托力和水平力,分析了受力随波陡、相对梁底作用高度以及波浪入射角度的变化规律。研究表明,在一定条件下箱梁浮托力和水平力,随波陡的增大而减小,随梁底相对作用高度的增加而增大,波浪入射方向的影响主要表现为与箱梁沿波浪传播方向的有效长度相关。由于岛桥结合跨的特殊性,改进的Douglass公式并不适用于岛桥结合跨箱梁受力的计算。通过主要影响因子的量纲分析,建立针对岛桥结合跨箱梁浮托力和水平力的计算公式。研究成果可为今后同类工程以及数值模拟提供借鉴与参考。

The west artificial island and the bridge span of the Hong Kong⁃Zhuhai⁃Macao Brideg project were simulated through a series of 3D physical model tests.The buoyancy force and horizontal force of the bridge under different wave incidence angles,wave heights,wave periods and net heights of deck bottom were measured,and the variation law of the force with wave steepness,relative deck bottom action height and wave incidence angle was analyzed.The results show that under certain conditions,the uplift and horizontal wave forces of box girder decrease with the increase of wave steepness,and increase with the increase of the relative action height of deck bottom.The effect of wave incidence direction is mainly related to the effective length of box girder along the wave propagation direction.The improved Douglass formula is not applicable to the calculation of the stress of the box girder combined with island bridge due to the particularity of the bridge.Based on the dimensional analysis of the main influencing factors,the formulas for calculating the uplift and horizontal wave forces of the bridge are established.The research results of this paper can provide references for similar projects and numerical simulation in the future.