Research on calculation method of incipient velocity for rock-filled steel cage in river closure

DOI：10.7511/dllgxb201804007

 作者 单位 汪淼,周宜红,杨忠勇,刘潋,汪庆元,张淑梅

以工程截流中的单体钢筋石笼作为研究对象，深入探讨了其起动机理．通过对单体钢筋石笼受力分析，推导出其起动流速计算公式，分析了公式中拖曳力系数CD、上举力系数CL的影响因素．通过水槽模型试验，研究了不同摩擦因数条件下多种尺寸的正六面体钢筋石笼、条形六面体钢筋石笼、扁形六面体钢筋石笼起动流速变化规律；定量地分析了CD和CL与钢筋石笼扁度系数λ以及沙粒雷诺数Re*的相关关系，绘制了(λ，Re*，CD)与(λ，Re*，CL)的分布云图．经验证表明，起动流速计算公式和CD、CL分布云图二者结合的钢筋石笼起动流速计算方法的计算值与试验值基本一致，较好地反映了钢筋石笼的起动情况．

The incipient motion mechanism of rock-filled steel cage in river closure is studied. The calculation formula of incipient velocity is deduced through the force analysis of a rock-filled steel cage, of which drag coefficient CD and lift coefficient CL are analyzed. The flume model test is conducted to study the variation of different sizes (regular hexahedron shape, bar hexahedron shape, flat hexahedron shape) rock-filled steel cages′ incipient velocities under different frictional coefficients. And the relationships of CD, CL with the flattening coefficient λ and particle Reynolds number Re* are also quantitatively analyzed, drawn as cloud pictures of distribution of (λ, Re*, CD) and (λ, Re*, CL). It is testified that the calculation method of incipient velocity for rock-filled steel cage, combining the calculation formula with cloud pictures of CD , CL , reflects the incipient case of rock-filled steel cage well through test validation.