@article{oai:kitami-it.repo.nii.ac.jp:02000010, author = {矢野, 雅昭 and YANO, Masaaki and 渡邊, 康玄 and Watanabe, Yasuhau and 井上, 卓也 and INOUE, Takuya and 山口, 里実 and YAMAGUCHI, Satomi and 新目, 竜一 and SHINME, Ryuichi}, issue = {4}, journal = {土木学会論文集B1(水工学)}, month = {}, note = {過去に著者らが確認した覆礫厚が薄く(砂州波高の半分の厚さ),固定床が平滑な条件での露岩部の伸長現象をより詳細に把握するため,水理実験を行った.通水時間を著者らによる既往研究よりも長くしたケースでは,著者らによる既往研究と同様に,水路中・上流側で砂州前縁部の露岩部が伸長し,下流側においては短縮することを確認した.さらにその後の通水では,水路上流端で新たに発生した砂州の前縁部の露岩部が伸長し,直下流部の伸長していた露岩部(砂州)が短縮した.このことから,覆礫厚が薄く,固定床上が平滑な条件での露岩部(砂州)の挙動の特徴として,露岩部(砂州)の延長が安定しないことが明らかとなった.また,水路底板に粗度付したケースでは,水路底板が平滑なケースと比べ,露岩部の伸長が低減されたが,交互砂州状に発生した露岩部の総延長は変わらず,露出率の低減は少なかった., To understand more detailed phenomena from our previous study on bedrock exposer expansion under condition that bedrock is smooth and alluvial cover thickness is about half of bar height, flume experiments were conducted. In the case that bedrock was smooth and flow was maintained for longer hours than our previous study, the result showed that bedrock exposures along bar front were expanded to downstream on mid and upper side of flume and bedrock exposers along bar front were reduced on lower side of flume. This phenomenon was also confirmed by our previous study. Thereafter, new bars were developed on the upper end of flume and this new bars development caused exposing bedrock along bar front and these new bedrock exposers expanded to downstream. As this new bedrock exposer expanded to downstream side, expanded bedrock exposers on the immediate downstream of new bedrock exposers reduced. Thereby, as characteristics of bar wave lengths under condition that alluvial thickness is thin and bedrock is smooth, bar wave length is not stable. In another case that bedrock was as rough as alluvial cover materials, the results showed that bedrock expansion was reduced in comparison of the previous case. However, bedrock exposer rates were not notably different because total length of alternate bar is almost same between each case.}, pages = {I_841--I_846}, title = {覆礫厚が薄い条件における露岩部の拡大特性に関する実験的研究}, volume = {73}, year = {2017}, yomi = {ワタナベ, ヤスハル and ヤマグチ, サトミ} }