PROTECTION OF OFFSHORE STRUCTURES AGAINST UNDERSCOUR

The results of several investigations of underscour, which can significantly alter the soil-structure foundation system and subsequently, endanger offshore structures, are summarized in this paper. Reproduction at model scale of an unusual pattern of scour signified by a general lowering of the sea bed under and around the whole structure, and as observed by divers, has led to improved understanding of the phenomenon. Theoretical studies predicting this type of erosion, which contrasts with the usual bridge-pier type, are cited. Conclusions based on these investigations indicate that the flow through the permeable seabed from high pressure zones under wave crests to low pressure zones under the troughs assists the local velocity in rapidly eroding the seabed and that the use of reverse filters will minimize or prevent this erosion. The author states that model tests, special severe erosion studies, and experience with offshore installations show how effective and economical protection can be obtained.

• Supplemental Notes:
  • Presented at the 1970 Second Annual Offshore Technology Conference.
• Corporate Authors:

  American Society of Civil Engineers

  345 East 47th Street
  New York, NY  United States  10017-2398
• Authors:
  • Posey, C J
• Publication Date: 1971-7

Media Info

• Features: References;
• Pagination: p. 1011-16
• Serial:
  • Journal of the Hydraulics Division
  • Volume: 97
  • Issue Number: HY7
  • Publisher: American Society of Civil Engineers

Subject/Index Terms

• TRT Terms: Erosion; Offshore structures; Scour; Support piles
• Old TRIS Terms: Erosion damage
• Subject Areas: Bridges and other structures; Marine Transportation; Terminals and Facilities;

Filing Info

• Accession Number: 00057138
• Record Type: Publication
• Source Agency: Texas A&M University, College Station
• Report/Paper Numbers: Paper #8230 Proceeding
• Files: TRIS
• Created Date: Aug 16 1974 12:00AM