氾濫流に建つ直方体構造物の抗力と揚圧力:－河川自然流を用いた水理研究 その２－ [in Japanese] DRAG AND UPLIFT OF A CUBOID STRUCTURE STANDING IN INUNDATION FLOW:－Hydraulic study in natural river flow Part 2－ [in Japanese]
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Field experiment on hydrodynamic forces exerted on a free-standing box-shaped structure partially submerged in inundation flow was conducted by using a metal frame setup on a natural riverbed wherein Froude number <i>F<sub>r</sub></i> ranged from 0.45 to 1.80. In result, following features were observed. Drag coefficient <i>C<sub>D</sub></i> is significantly affected by both the Froude number and the blockage ratio in subcritical flows in the manner that higher <i>C<sub>D</sub></i> is induced by smaller <i>F<sub>r</sub></i> as well as larger blockage, resulting in <i>C<sub>D</sub></i> varying from 0.6 to 2.1. However, their effects are negligible in supercritical flows, resulting in nearly constant <i>C<sub>D</sub></i> of 1.2±0.2, which may be attributed to reattachment of the separated flows on the side walls of the structure. Uplift coefficient <i>C<sub>upl</sub></i> is predominantly governed by <i>F<sub>r</sub></i> in a way of power law. With the elevation of <i>F<sub>r</sub></i>, the action point of uplift force shifts gradually to the upstream edge of the base of the structure, which develops a larger overturning moment.
- Journal of Structural and Construction Engineering (Transactions of AIJ)
Journal of Structural and Construction Engineering (Transactions of AIJ) 81(720), 219-227, 2016
Architectural Institute of Japan