Ice interaction with a rubble mound breakwater; a case study.

Abstract

The undersigned recommend to the Faculty of Graduate Studies and Research acceptance of the thesis "Ice Interaction With A Rubble Mound Breakwater: A Case Study" submitted by Kevin J. Macintosh, B.Sc., P.Eng. ABSTRACTThis thesis describes a program of field measurements and the analysis of data describing the action of ice on a rubble mound breakwater. In 1984 a rubble mound breakwater was built at North Bay. The design of this structure is unique. The structure consisted entirely of 100 to 450 mm stones, which are many times smaller than the armour stones required to protect a conventional breakwater from wave action under similar conditions. The smaller stones are effective since the voids allow wave action to propagate into the breakwater and dissipate their energy within the structure. Concern was expressed about the formation and action of ice on this breakwater. As no prototype information on analytical procedures was available to assess protection problems, a comprehensive field study was required to determine if problems would occur.The field study, undertaken throughout the winter of 1984-85, included the use of an array of thermocouples installed within the breakwater to record internal temperatures, water column temperature measurements, surveys of the external profile of the berm and surrounding snow and ice conditions, determination of the ice properties surrounding the breakwater using crystallographic techniques, and observations concerning icestructure interaction.Small Craft Harbours, and especially Mr. Dennis Chartrand, for supporting this project financially.Mr. Gord Simpson of PWC North Bay for continuously supplying information on the local weather and ice conditions and for relaying his invaluable knowledge on the history of the ice climatology in the area.Tony Edwards for his donation and preparation of the thermocouple switches.

Prototype Experience With Rubble Mound Breakwaters

“…In addition to the measurements noted above, visual observations were made of the modes of failure of ice on the breakwater and the relationship of water level changes to failure modes. The visual observations of ice-structure interaction were documented using field notes, photography and video recorders, as presented in Macintosh (1985).…”