Breaking wave force distributions and design criteria for slender piles Conference Paper uri icon

abstract

  • Copyright 1989, Offshore Technology Conference Laboratory scale water waves broke on a plane sloping beach in the presence of a slender pile instrumented at one thin section with a specially developed force measuring device. The instrumented pile slice measured the wave force when waves broke in front, directly on, and immediately behind the pile. Time series of measured force were taken and averaged for a number of repetitive, wave breaking events. These were all for the measurement sect ion at one particular vertical elevation. Dummy sections of the pile on each side of the measurement section produced a uniform diameter, vertical pile in the presence of breaking waves. These test were then repeated after repositioning the vertical elevation of the measurement section. In this way, the vertical structure of the breaking/broken wave force distribution could be assembled for a particular type of wave breaking event near, on, or after the pile. The measured results were normalized following the suggested parameters of Kjeldsen et al. (1985) and are compared with measurements made in the ocean basin at Trondheim, Norway. These were in deep water using focused, freak breaking waves on a specially instrumented pile with twenty-six adjacent force measuring sections. In this way, the force di stri but i on for each breaki ng event could be measured directly. Both series of measurements give similar force distribution within breaking/broken waves.. The total integrated force and overturning ¬∑moments exceed those found in nonbreaking waves of a similar steepness by a factor of 2 or more.

author list (cited authors)

  • Basco, D. R., & Niedzwecki, J. M.

publication date

  • January 1989