The selection of model sand is the key problem in the design of a mobile bed model test.

对于研究泥沙问题的动床模型试验，模型沙的选择是模型设计的关键。

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Test results show:for the same grain size groups the flow velocity relating incipient motion of these granite sand grains decreases as the bed slope increases;

实验结果表明，同一粒径组的非粘性花岗岩风化砂粒随底坡坡度的增加其起动流速变小；

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