軟質FRPライニング工法による開水路の粗度係数
| Autor: | Hiromu, OKAZAWA, TAKEUCHI Yasushi, MASHINO Michito, MAKI Tsuneo |
|---|---|
| Jazyk: | japonština |
| Předmět: | |
| Popis: | 老朽化水路の補修に用いる軟質FRPライニング板を実験用開水路に設置し,粗度係数の測定を行った。その結果,補修水路の粗度係数は0.0094であり,新設コンクリート水路に勝る通水機能を有することが明らかになった。また,粗度係数は,流速,径深との関係よりも,動水勾配との相関が最も大きかったことから,勾配の変化に対して粗度係数も変化することが示された。一方,流量の指標であるレイノルズ数と粗度係数の関係を検討したところ,レイノルズ数の増加に伴って粗度係数の変動が大きくなる傾向を示した。以上のことから,粗度係数は,流況や現場の地形要素に影響を受けて変化することから,補修板による水路補修を考える場合,これらの指標をふまえて適切な粗度係数を適用する必要がある。 A flexible fiber-reinforced plastic lining that is used for repairing deteriorated water channel was installed in an experimental water channel to examine the effect of such repair on flow in the channel. Manning's roughness coefficient, which is an indicator of the smoothness of flow, was used in the examination. The measured roughness coefficient of the repaired channel was 0.0094, which is lower than in a newly constructed concrete channel. This shows that the water flow after such a repair is smoother than in a newly constructed concrete channel. The influence of flow velocity, channel depth and hydraulic gradient on the roughness coefficient was examined. Changes in the roughness coefficient were found to correlate most closely with changes in the hydraulic gradient, i.e., channel gradient has the greatest influence on the smoothness of the water flow. The relationship between roughness coefficient and Reynolds number (an index of discharge) was examined. The greater is the Reynolds number, the greater is the dispersion in roughness coefficient for different discharges. This shows that the roughness coefficient is influenced by topography and flow regime at repair sites. When determining the roughness coefficient for a repair site, it is necessary to consider the topography and flow regime. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|