Design of rubble mound river structures from a view point of hydrospheric environment

用碎石丘构筑河道构筑物，可以营造对自然友好的环境。预计碎石丘的湍流将促进通气，孔隙可能为水生生物提供生存空间。基于在2000和2001财政年度的科学研究资助计划中建立的科学背景，我们将研究活动扩展到更多不同的工程主题。我们调查的河流结构有腹沟、护岸工程、粗糙坡道、人工水池、鱼梯。除了结构的水力特性外，该项目还研究了结构周围的生态系统。为了考察这些结构对水力和生态系统的影响，进行了实地测量。针对每种结构进行了各种类型的实验室实验。测量了结构周围的流动和湍流特性，并建立了模拟流场的数值模型。在大多数情况下，数值模型的再现性能令人满意，这将成为进行结构设计的有力工程工具。研究成果已经发表，并计划在期刊和会议论文集上发表。

River structures constructed with rubble mound may create environment being friendly to nature. It is expected that aeration would be promoted by turbulence in the rubble mound and pore may provide living space for aquatic lives. Based on the scientific background established during the last program from the Grant in Aid for Scientific Research in the fiscal 2000 and 2001, we extended our research activities to more various engineering topics. The river structures we investigated are groin, shore protection works, rough ramps, artificial pools, fish ladders. In addition to hydraulic properties of the structures, ecological systems around the structures were examined in this program. A field measurement was carried out in order to examine effects of the structures on hydraulic and ecological systems. Various types of laboratory experiment were carried out with respect to each structure. Flow and turbulence properties around the structures were measured and numerical models were developed for reproducing the flow field. In most cases, reproduction performance of the numerical model was satisfactory which will be a powerful engineering tool for making design of the structures. Research achievements have been published and are scheduled to be published in journals and conference proceedings.