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实测资料显示,长江三峡水库变动回水区末端段床沙质以卵砾石夹沙为主,消落期出现的碍航特性主要由卵砾石推移质运动造成,对三峡库尾段航运造成很大影响,有必要对库尾水流条件下的卵石输移规律进行研究。库尾水流通常是非均匀减速流,目前对非均匀流的研究多把局部近似为均匀流。通过库尾非均匀流减速流的卵砾石输移水槽试验,观测减速流卵砾石运动输移过程,并确定非均匀系数对卵砾石输沙强度的影响,再与已有推移质公式对比,根据已有相近的输沙强度公式结构形式,结合水槽试验结果,拟合得出含有非均匀系数的适合于减速流态下的卵砾石输移的输沙强度公式,并通过计算值与实测值的对比验证公式的合理性。
The measured data show that the sandy bed of the end section of the fluctuating backwater area of the Three Gorges Reservoir in the Yangtze River is dominated by gravel and sand, and the obstructing behavior during the fall-off period is mainly caused by the push-slip movement of pebbles and gravel, resulting in great shipping to the Three Gorges Reservoir Influence, it is necessary to study the law of pebbles transport under the condition of tail water flow. The tail water flow is usually non-uniform deceleration flow, the current non-uniform flow of more local approximation for the uniform flow. Through the pebble-gravel transfer tank experiment with non-uniform flow reduction at the end of the tail, the transport process of slow-flow pebble gravel was observed, and the effect of non-uniform coefficient on the sand transport strength of gravel was determined. There are similar structural forms of sand transportation intensity formula. Based on the experimental results of the flume, the formula of sand transport intensity with non-uniform coefficient suitable for the transport of gravel in the decelerating flow regime is obtained. Based on the calculated values and the measured values Compare the rationality of the verification formula.