基于Flow-3D的圆柱形桥墩局部冲刷及防护研究
Study on Local Scour and Protection of Cylindrical Pier Based on Flow-3D

桥梁基础的局部冲刷是导致桥梁水毁的主要因素之一，需要采取一定措施进行防护处理。本文基于Flow-3D软件的水动力学模块和泥沙输运模块，采用RNG k-ε湍流模型对圆柱形桥墩开展了局部冲刷防护三维数值研究，分析了安装护套对圆柱形桥墩局部冲刷防护的效果。计算结果表明：护套装置能够大幅降低最大冲刷深度，最大冲刷深度仅为无防护情况的13%；安装护套装置后，河床冲刷形态较无防护时发生了较大变化，桥墩迎水侧未发生冲刷，最大冲刷深度位置位于护套侧前方距离护套边缘很小距离的位置；在护套两侧冲刷坑后方，形成了与无防护工况类似的较大面积的沙丘拖尾，但由于冲刷程度较小，水流中的泥沙含量较低，沙丘的高度和面积均远小于无防护工况。
Local scour of bridge foundation is one of the main factors leading to water damage of bridges, and certain measures need to be taken for protection treatment. In this paper, based on the hydrodynamic module and sediment transport module of Flow-3D software, the RNG k-ε turbulence model is used to carry out a three-dimensional numerical study on the local scour protection of cylindrical bridge piers, and the effect of installing sheaths on the local scour protection of cylindrical bridge piers is analyzed. Calculation results show that the sheath device can greatly reduce the maximum scour depth, the maximum scour depth is only 13% of the unprotected condition; after the installation of the sheath device, the scour pattern of the riverbed changes greatly compared with the unprotected condition, and the waterward side of the abutment is not scoured, and the location of the maximum scour depth is located in the sheath side of the forward side of the sheath at a very small distance from the edge of the sheath; in the sheath on both sides of the back of the scour crater, a large area of sand dune trailing is formed, similar to the unprotected condition. In the back of the scour pits on both sides of the sheath, a large area of sand dune trailing similar to the unprotected condition is formed, but due to the smaller degree of scour and lower sediment content in the water flow, the height and area of the sand dune are much smaller than that of the unprotected condition.