Mechanisms of the interaction among waves, sediment transport and bed evolution around a marine structure and the integrated analysis

• Project/Area Number: 24760389
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Hydraulic engineering
• Research Institution: Kanazawa University
• Principal Investigator: UMEDA Shinya 金沢大学, 環境デザイン学系, 准教授 (30313688)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2014: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2012: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 海岸工学 / 洗掘 / 砂漣 / 底質輸送 / 波 / 移動限界 / 相互作用 / 海岸構造物 / 渦 / 浮遊砂 / 掃流砂 / 砂連 / 埋戻し / 暴浪

Outline of Final Research Achievements

This study investigates the scour process at a slender monopile during various phases of a storm to give a better understanding of scour and backfilling mechanisms. Laboratory experiments were carried out to simulate the scouring effect at a pile by a storm consisting of a succession of seven phases of irregular waves. A numerical model was developed in order to perform simulations of the process of the scour and backfilling around a pile in waves. The initiation of sediment motion under waves was studied to develop a simple empirical model for determining critical Shields parameter and critical velocity of fine sand. Evolutions of vortex ripples and scour around a pile were simulated to demonstrate the effectiveness of the numerical model and empirical model. It was found that the methods has proved useful in understanding of dynamics of small scale bed form (vortex ripples) and middle scale bed form (pile scour).

Research Products

• [Journal Article] 波による海底砂の移動限界に関する研究 (2014)
  • Author(s): 楳田真也，横山珠実
  • Journal Title: 土木学会論文集B2（海岸工学） Volume: 70
  • NAID: 130004706938
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Human impact on morphology and sediment budget in the Tedori River, Japan (2013)
  • Author(s): M.H. Dang, S.Umeda and M.Yuhi
  • Journal Title: Advances in River Sediment Research Pages: 289-297
  • Peer Reviewed
• [Journal Article] Scour process around monopiles during various phases of sea storms (2013)
  • Author(s): Shinya Umeda
  • Journal Title: Journal of Coastal Research Volume: 65 Pages: 1599-1604
  • Peer Reviewed
• [Presentation] 波による砂漣の発生・発達過程に関する数値解析 (2015)
  • Author(s): 市岡大昌，楳田真也，由比政年
  • Organizer: 土木学会中部支部
  • Place of Presentation: 豊橋技術科学大学
  • Year and Date: 2015-03-06
• [Presentation] 波による海底砂の移動限界に関する研究 (2014)
  • Author(s): 楳田真也，横山珠実
  • Organizer: 土木学会海岸工学講演会
  • Place of Presentation: ウィンクあいち
  • Year and Date: 2014-11-12 – 2014-11-14