Unified View of the Mechanics of Debris Flows and Sediment Laden Flows

泥石流和泥沙流力学的统一观点

• 批准号: 09450190
• 负责人: EGASHIRA Shinji
• 金额: $ 4.42万
• 依托单位: Ritsumeikan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09450190/
• 关键词: debris flow; sediment gravity flow; med flow; flow with bed-load; flow with suspended load; sediment transport rate formula; constitutive equations; 浮游砂流

This study has attempted a unified treatment of the following themes : the constitutive relationships of flowing water-sediment mixture, the profiles of sediment concentration and flow velocity from debris flows to flows with both bed-load, and "clear" water lagers to calculate the reference concentration of suspended flows. In this study, the constitutive relationships proposed by Egashira et al. include some physical parameters : the sediment size, the interparticle friction angle and specific weight of sediment etc.The effects of interparticle friction angle on debris flows have been investigated experimentally and theoretically for two years. The following results were obtained : in debris flows over rigid beds, an increase of interparticle friction angle causes flow resistance to increase. On the other hand, in debris flows over erodible beds, the inverse tendency appears.The influence of sediment size on flow of sediment-water mixture were investigated experimentally and theoretically. An experiment was employed with different sizes of sand, in the region from debris flows to the flows including a clear-water larger. The data obtained by flume tests were compared with the numerical simulated profiles of velocity, and sediment concentration. The calculated results agreed well with the flume data. The sediment transport rate became small when the sediment size was large, and became large when the sediment size was small for both large or small bed shear stress.Methods to predict the reference concentration and reference level of suspended flows were proposed using Egashira et al.'s constitutive relationships and taking the vertical distribution of the Reynolds' stress into account According to this method, the reference concentration was small when the sediment size was small. The calculated results were fitted with previous experimental data obtained by many researchers.

这项研究试图对以下主题进行统一处理：流动水溶剂混合物的组成关系，沉积物浓度和流速从碎屑流到流量的流速度的剖面，并以床上的载荷为单位，以及“透明”的水掠水量来计算悬浮悬浮液的参考浓度。在这项研究中，Egashira等人提出的构成关系。包括一些物理参数：沉积物尺寸，粒子摩擦角和沉积物的特定重量等。在实验和理论上研究了颗粒摩擦角对碎屑流的影响。获得以下结果：在刚性床上的碎屑流中，颗粒摩擦角的增加会导致流动阻力增加。另一方面，在可侵蚀的床上碎屑流中，出现了反向趋势。沉积物尺寸对沉积物水混合物流动的影响进行了实验和理论上研究。从碎屑流到包括透明水的碎屑，采用了不同尺寸的沙子的实验。将通过水槽测试获得的数据与速度的数值模拟曲线和沉积物浓度进行了比较。计算出的结果与Flume数据很好地吻合。当沉积物尺寸较大时，沉积物的传输速率变小，并且当沉积物尺寸小时，对于大或小床剪切应力时。用于预测使用Egashira等人的组成型关系的参考浓度和悬浮水平的参考浓度和参考水平，并根据此方法的参考浓度很小，而雷诺（Reynolds）的垂直分布很小。计算出的结果与许多研究人员获得的先前实验数据拟合。

项目成果

江頭進治: "流砂および流砂を伴う流れの力学(3.掃流砂の力学)" 混相流. 11・4. 388-393 (1997)

Shinji Egashira：“流沙动力学和涉及流沙的流动（3.底土力学）”多相流11・4（1997）。

江頭進治: "土石流の流動機構と氾濫・堆積域の解析-基礎理論からハザードマップまで-"1999年度(第35回)水工学に関する夏期研修会講義集. A-6-1-A-6-18 (1999)

Shinji Egashira：“泥石流机制和洪水/沉积区域的分析 - 从基础理论到灾害图”1999年（第35届）水利工程夏季研讨会讲座集A-6-1-A-6 -18（1999年）。 ）

Egashira, S.: "Mechanics of sediment transport and sediment laden flows (2.Sediment gravity flow)"Japanese Journal of Multiphase Flow. Vol.11 No.3. 258-262 (1997)

Egashira, S.：“沉积物输送和沉积物负载流的力学（2.沉积物重力流）”日本多相流杂志。

Egashira, S.: "The 1996 Gamahara debris flow hazard mitigation"Journal of The Japan Society of Civil Engineering. 83. 49-54 (1998)

Egashira, S.：“1996 年伽马原泥石流灾害缓解”日本土木工程学会杂志。

江頭進治: "流砂および流砂を伴う流れの力学(3.掃流砂の力学)"混掃流. 11・4. 388-393 (1997)

Shinji Egashira：“流沙和流沙的动力学（3.床荷载力学）”11・4 388-393（1997）。