ICE AND MARINE STRUCTURES: PT. 1, THE MAGNITUDE OF ICE FORCES INVOLVED IN DESIGN

Outlines the problems connected with the effects of ice on marine structures as encountered in Cook Inlet, and cites four examples to demonstrate the solutions to some of the problems. Lateral forces on offshore oil drilling platforms may reach 15 million lb at elevations varying with the tide, ranging 35 feet or more. The structural simplicity of the monopod for use in depths of 100 feet or less is the best design to date. A shoreside dock located where ice moves generally parallel to the beach and in only one direction, uses "ice breakers", or tubes, at a 40 degrees angle to the horizontal, bracing out from the vertical tubes, to produce bending failure of the ice sheets. Close spacing of the structural elements is precluded in such cases, to prevent ice bridging from tube to tube. The dock at Anchorage is in a protected location and deep water, where predominant ice forces are vertical. Closely spaced piling provides for formation of a contiguous ice mass which may be thawed free due to heat condition along the length of the piling, and then float up and down with the tide. The only recent failure of a major structure due to ice loads was an extension to this dock: the piles were too widely spaced so that ice masses were separate about each and bent some single piles. When ice masses thawed free in the spring the entire weight of the mass at low tide was supported by the steel lateral bracing pile. Failures occurred when racking of the ice mass broke the concrete piling free of the relatively light cap, both elastic and permanent bending occurred in the bracing pile, and the cap was fractured due to joint rotation between the bracing pile and the cap.

  • Corporate Authors:

    Gulf Publishing Company

    Box 2608
    Houston, TX  USA  77001
  • Authors:
    • Peyton, H R
  • Publication Date: 1968

Media Info

  • Pagination: p. 40-44
  • Serial:
    • Ocean Industry
    • Volume: 3
    • Issue Number: 3
    • Publisher: Gulf Publishing Company

Subject/Index Terms

Filing Info

  • Accession Number: 00037570
  • Record Type: Publication
  • Source Agency: Arctic Institute of North America
  • Files: TRIS
  • Created Date: Nov 10 1973 12:00AM