DEVELOPMENT OF TFIE METHOD FOR MAINTENANCE OF WATER ROUTE FRONT OF DISCHARGE GATE LINES ON ARIAKE SEA COAST

有明海岸排泄闸门线前水路维护TFIE方法的开发

• 批准号: 13660246
• 负责人: KATO Osamu
• 金额: $ 1.98万
• 依托单位: SAGA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13660246/
• 关键词: Ariake clay; dead weight consolidation; water route; water content; critical erosional rate; jet theory; flash water; screw; 干潟排水; フラッシュ; 限界流速; 排水樋門

Concerning to maintain the water route in front of discharge gate setting at land reclamation, the effective methods are said to remove the mud deposit by flash water, and/or erode by the screw of the fishing boat. Thus, to obtain the basic aspects for developing the water route maintenance system, the field survey for the mechanism of the mud accumulation was carried out, then the experiments were attempted to analyze following items, 1) the erosional and depositional behaviors of fine sediments, 2) the change of critical erosion rate of mud according to dead weight consolidation and 3) the characteristics of the erosional rate by a screw of boatIn the bottom area of Ariake bay, Nanaura tidal land in Saga prefecture, the deposition rate of mud at water route region was measured as about 5cm/day, when the water was not discharged from the gate.The experiment using Ariake clay with sea water in the annular rotating channel elucidated the change of water contents, the cohesion and the critical erosional rate of the clay during 72hr after the dead weight consolidation occurring. In addition, the vertical distribution of water contents ratio was also revealed in mud area. In this experiment, the progress of consolidation by passing time was obviously shown as the change of water content ratio at 10cm depth from the bottom level; 900% at the beginning time subsequently turning to 540% and 300% after 6hr and 72hr, respectively.The flow characteristics caused by rotating of a screw were accountable with the Jet theory, and revealed its action against the bottom. As the axis velocity of flow was decayed with distance from screw -1 powers, the flow rate on the bottom was widen according to Gaussian distribution.The results obtained in this experiment were new and believed to contribute to develop the water route maintenance system.

对于填海造地中排放闸门设置前水路的维护，有效的方法是通过闪水去除泥浆沉积物，和/或通过渔船螺旋侵蚀。因此，为了获得开发水路维护系统的基本知识，对泥浆堆积机制进行了实地调查，然后通过实验分析以下项目：1）细沉积物的侵蚀和沉积行为，2）泥浆临界侵蚀速率随自重固结的变化以及3）船螺旋侵蚀速率特征七浦有明湾底部 在佐贺县的潮汐地，在没有从闸门放水的情况下，测得水路区域的泥浆沉积速率约为5厘米/天。在环形旋转通道中使用有明粘土与海水进行的实验，阐明了自重固结发生后72小时内粘土的含水量、粘聚力和临界侵蚀速率的变化。此外，泥区还揭示了含水率的垂直分布。本次试验中，随着时间的推移，固结的进展明显地表现为距底部10cm深度处含水率的变化；开始时为 900%，随后在 6 小时和 72 小时后分别变为 540% 和 300%。螺杆旋转引起的流动特性符合射流理论，并揭示了其对底部的作用。由于轴流速度随着距螺杆-1次方的距离而衰减，底部流速按照高斯分布变宽。本实验获得的结果是新的，相信有助于开发水路维护系统。