本文選題：細(xì)沙補(bǔ)給 + 粗化層��； 參考：《泥沙研究》2017年02期

【摘要】：結(jié)合Venditti關(guān)于細(xì)沙補(bǔ)給對河床活動(dòng)性影響的分析,引用修正后的Einstein-Barbarossa方法對河床阻力進(jìn)行劃分,探討了細(xì)沙補(bǔ)給對砂卵石河流沖刷粗化完成后河床阻力變化的影響。研究結(jié)果表明:在一定量細(xì)沙補(bǔ)給的條件下,沙粒阻力與床面阻力的比值先減小后增大,形狀阻力與床面阻力的比值先增大后減小;水流克服表面阻力損失的能量隨沙粒阻力減小而減少,進(jìn)一步導(dǎo)致水流損失的機(jī)械能減小,河床上大顆粒泥沙獲得的能量增大進(jìn)而導(dǎo)致其活動(dòng)性增強(qiáng);河床上活動(dòng)的泥沙顆粒與裸露大顆粒泥沙之間不斷接觸碰撞形成局部能量交換,裸露大顆粒泥沙通過水流方向的動(dòng)量交換所產(chǎn)生的顆粒剪應(yīng)力增大,這可能也是河床上大顆粒泥沙活動(dòng)性增強(qiáng)的一個(gè)原因。
[Abstract]:Based on Venditti's analysis of the effect of fine sand recharge on river bed activity, the modified Einstein-Barbarossa method is used to divide the river bed resistance, and the influence of fine sand recharge on the river bed resistance after the completion of sand cobble erosion is discussed. The results show that under the condition of a certain amount of fine sand recharge, the ratio of sand resistance to bed resistance decreases first and then increases, and the ratio of shape resistance to bed resistance increases first and then decreases. The energy of water to overcome the surface resistance decreases with the decrease of sand resistance, which further leads to the decrease of the mechanical energy of water flow, and the increase of energy obtained by the large sediment on the riverbed, which leads to the increase of its activity. The local energy exchange is formed between the active sediment particles and the exposed large sediment on the riverbed, and the particle shear stress caused by the momentum exchange in the direction of the flow is increased. This may also be one of the reasons for the increase of sediment activity on the river bed.
【作者單位】： 四川大學(xué)水利水電學(xué)院水力學(xué)與山區(qū)河流開發(fā)保護(hù)國家重點(diǎn)實(shí)驗(yàn)室;
【基金】：國家重點(diǎn)研發(fā)計(jì)劃項(xiàng)目課題(2016YFC0402302) 國家自然科學(xué)基金重點(diǎn)基金項(xiàng)目(51539007)
【分類號】：TV143
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本文編號：1791805