中国铁道科学2011，Vol.32Issue(5)：43-49,7.
跨河桥梁压缩冲刷数值模拟研究
Numerical Simulation Study on the Contraction Scour of Bridge Cross the River
摘要
Abstract
River-bed scour resulted from the contracted river course by the underwater structure of the bridge endangers the safety of bridge foundations. In this study, the proposed one-dimensional numerical model was adopted to simulate the contraction scour based on the St. Venant equations, and the equations of sediment transport and river bed deformation. In this model, the effective area of flow section was obtained by boundary simplification to consider the recirculation upstream and downstream of the bridge site, and the non-uniformity of sediment was treated by individual fractions. The verification of the numerical model at a bridge crossing in Yangtze River shows that the model is capable of predicting water surface elevations and bed elevations, with absolute error less than 0. 1 and 0. 5 m, respectively. Further results reveal that the contraction scour is noticeable during floods while the river bed would have some minor deposition during low discharge after floods. Furthermore, the proper generalization on the recirculation boundary can have a positive role in the computation of contraction scour which not only makes the results closer to the measured value but also gives a better understanding on the temporal evolution of contraction scour at the near zone upstream and downstream of the contracted flow section under the same water and sediment conditions. Finally, the consideration of sediment non-uniformity is also more reasonable than the previous assumption of uniform sediment in the one-dimensional contraction scour model.关键词
河床/跨河桥梁/压缩冲刷/边界概化/一维数值模拟Key words
River bed/ Bridge cross the river/ Contraction scour/ Boundary generalization/ 1-D numerical simulation分类
交通工程引用本文复制引用
郭辉,齐梅兰..跨河桥梁压缩冲刷数值模拟研究[J].中国铁道科学,2011,32(5):43-49,7.基金项目
国家自然科学基金资助项目(50778018) （50778018）
铁道部科技研究开发计划项目(2007G041) （2007G041）
