The Model Similitude of Water-Power Type of Debris Flow

• Main Authors: Wen-Ching Yu, 余汶璟
• Other Authors: Shou-Young Chang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/01185862114280805371

碩士 === 國立臺北科技大學 === 環境規劃與管理研究所 === 90 === The purpose of this study is to derive the model similitude of hydraulic failure of debris flow. Two similitude models, ‘governing equation analysis’ and ‘dimensional analysis’, were constructed to explore the insight mechanism of ‘Hydraulic failure’ of debris flow. In addition, the correlation of relevant parameters for the occurrence between the prototype and its model were evaluated. By using experimental data and sensitivity analysis, the significant relevant parameters, C* 、θ、geometric standard deviation and qw/(gD)^0.5, were provided to the transformation of corresponding physical quantities. Because the slope of the debris-flow hazard river ranges is significantly large, the piezometric head in the energy equation should be adjusted. In recent researches, the particle grade similitude can’t transform all sizes of field particles. The equation of ratio of geometric standard deviation was proposed in this study to improve the underestimation of geometric standard deviation. It is found that phi of model can be accordance with phi of prototype when undistorted model was applied. In contrast, the phi of model should be instead of tan(phi of prototype)/ratio of tan(phi) when distorted model was employed. The scale ratios derived by other investigators, Tan and Lian were utilized to set up the similitude between the model and prototype. These scale ratios are physically accepted. Thus, further study on the model similitude is recommended. Each of ‘governing equation analysis’ and ‘dimensional analysis’ has its own theoretical basis. Any of them should be chosen physically to perform the transformation of corresponding physical quantities. The models proposed in this study may not only provide the theoretical basis of model construction, but also bolster up the insufficiency of field data.