袋装沙枕水下抛投漂移距现场试验研究

近年来,长江水沙变化导致堤岸冲刷加剧,水下抛投护岸成为整治工程的重要环节,新型防护材料袋装沙枕应运而生,其抛投漂距预测的准确性直接影响工程的质量与效率。以长江中下游南京八卦洲河段整治工程为例,分析水深、流速、沙枕质量等对漂移距的作用机理,基于动力学进行漂移距计算公式理论推导,通过在不同流速、水深条件下开展的现场抛投试验确定公式系数。结果表明,采用推导的经验公式计算值与试验值较为吻合,相对误差在20%以内。

Study on field test of drift distance of bagged sand pillow underwater throwing

In recent years,the change of water and sediment in the Yangtze River has led to the intensification of bank erosion,and the underwater throwing revetment has become an important part of the renovation project.The new protective material bagged sand pillow comes into being,and the accuracy of its throwing drift distance prediction directly affects the quality and efficiency of the project.We take the regulation project of Baguazhou reach in Nanjing in the middle and lower reaches of the Yangtze River as an example,analyze the mechanism of water depth,flow velocity and sand pillow mass on drift distance,theoretically deduce the calculation formula of drift distance based on dynamics,and determine the formula coefficient by the field throwing tests under different flow velocities and water depths.The results show that the calculated values derived by the empirical formula in this paper are in good agreement with the experimental values,and the relative error is within 20%.