关键词: 桥梁工程；横流超限；净空宽度；数值矢量图；投影净宽

Abstract: In the context of bridges spanning navigable rivers with cross-currents exceeding a limit of 0.8 m/s, inland navigation standards provide only qualitative regulations without specifying an exact verification method for the clearance width. The reconstruction of the Yuanshui River Bridge right branch navigation hole in the Taoyuan second-line ship lock project served as a case study to explore the verification methods for bridge clearance width when cross-current limit was surpassed. It was suggested that after the cross-current limit was exceeded, the demonstration could be carried out through a triple verification method, including channel width verification, projection net width verification after rotating the bridge axis to prevent cross-currents from exceeding the limit and verification of whether the navigation hole crossed the navigation water area in one hole. Utilizing experimental data in bridge area tested by a 1:100 normal river engineering model, the distribution of current directions and cross-currents, as well as their unfavorable measurement points were displayed in the form of numerical vector graphs, and the clearance width of the reconstructed Yuanshui River Bridge right branch navigation hole was demonstrated and verified. The results indicate that the triple verification method is more suitable for situations where cross-currents exceed the limit.

Key words: bridge engineering; cross-currents exceed the limit; clearance width; numerical vector plot; projection clearance width