Study of the Characteristics of the Flow around a Sequence of Non-Typically Shaped Spur Dikes Installed in a Fluvial Channel

Abstract

本研究では，非典型的な形状の連続型水制周辺の流れの特徴について，3次元流れ解析モデルSSIIMを用いて調査した。流れとせん断応力の分布を示し，水制間の流れにおける水制形状の効果を考察した。T型とI型水制の比較によって，T型水制の設置は水制周辺にせん断力の大きな領域を創り出すだけでなく，主流路側を均一な流れ場にすることが示された。このことは航路維持にとって着目すべき事ことであり，そして淀み領域においても河川生物および動物相のライフサイクルによって適した環境を提供している。

In this study, the features of flow in a sequence of non-typically shaped spur dikes will be examined using a 3-D numerical code, SSIIM. The velocity field and shear stress contour will be presented and the effect of the spaces between the spur dikes on the flow will be discussed. The comparison between the non-typically T-type spur dikes and the straight shape spur dikes showed that by installing the T-type in stream, the distribution of high stress and high energetic zones around the spur dike as well as the main stream is more homogenous. This fact can highlight the capability of T-type spur dikes to provide a better route for navigation, as well as the better stagnation zones which are suitable environment for the life cycle of stream biota and fauna.