Experimental study on local scour at complex bridge piers under steady currents with bed-form migration

Local scour at pile-supported bridge foundations in coastal and offshore areas are an essential factor to engineering design and evaluation. This study experimentally investigates live-bed local scour at complex bridge piers under the influence of bed-form migration. The results show that the variation of the mean scour depth as a function of flow intensity ratio U/Uc (Uc= threshold velocity for incipient motion) depends on the pile-cap elevation and is significantly different to single piers. Instantaneous bed level, cross-correlation analysis, and power spectra show that bed-forms approaching an exposed pile group may be damped, leading to mean bed level fluctuation that are slightly smaller than the bed-form heights. In contrast, when the pile-cap is completely buried by the original bed but can be exposed during scour, approaching bed-forms tend to keep their individual features and cause larger scour fluctuation at pile-cap's leading edge. The enlargement is due to the concurrence between the enhanced (or weakened) scouring capacity and the decreased (or increased) upstream sediment supply. The scour predictor proposed by previous studies is extended to live-bed range and performs better than existing predictors.

• Record URL:
  https://doi.org/10.1016/j.oceaneng.2021.109329
• Record URL:
  http://www.sciencedirect.com/science/article/pii/S0029801821007460
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00298018
• Supplemental Notes:
  • © 2021 Elsevier Ltd. All rights reserved. Abstract reprinted with permission of Elsevier.
• Authors:
  • Yang, Yifan
  • Melville, Bruce W
  • Macky, Graham H
  • Shamseldin, Asaad Y
• Publication Date: 2021-8-15

Language

• English

Media Info

• Media Type: Web
• Features: Figures; References; Tables;
• Serial:
  • Ocean Engineering
  • Volume: 234
  • Issue Number: 0
  • Publisher: Pergamon
  • ISSN: 0029-8018
  • EISSN: 1873-5258
  • Serial URL: http://www.sciencedirect.com/science/journal/00298018

Subject/Index Terms

• TRT Terms: Bridge piers; Experiments; Ocean currents; Pile caps; Scour
• Subject Areas: Bridges and other structures; Marine Transportation;

Filing Info

• Accession Number: 01777141
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 23 2021 3:25PM