弯曲分汊河段江心洲稳定性试验研究

Experiment study on stability of river island in braided river

江心洲的稳定完整是保障长江航道畅通、解决浅滩碍航问题的重要条件。在前人研究的基础上,以长江中游窑监河段为依托进行概化水槽试验,对弯曲分汊河段右汊为主、左汊为主、左右汊平衡3种洲滩形式进行研究。结果表明:流量一定,水深越小,洲头冲刷越严重,洲头向左岸移动幅度越大;水深一定时,流量越大,洲头冲刷越严重,洲头向左岸移动幅度越大。洲尾则主要是处于淤积状态,流量一定,水深减小则洲尾淤积越严重;水深一定,随着流量的增加,洲尾淤积越严重。3种洲滩形式下,江心洲的稳定性从高到低依次为:右汊为主、左汊为主、左右汊平衡时期。

The stability of the river island is an important factor for keeping a good navigation condition and avoiding navigation obstruction.Based on the previous research,the paper carried out a flume experiment of Yaojian reach in the middle Yangtze River.The stability of the river island is studied by the model test.The results show that the island head is scoured seriously as the water level descends in the same discharge,and the island head transfers from the right to the left.The larger the inlet discharge is in the same water depth,the more serous the island head is eroded,whereas the island tail is mainly silted.When the discharge is constant,the island section will be silted more in a smaller water depth.When the water depth is constant,it will also be silted more in a larger discharge.