NEW DESIGN PRINCIPLES FOR RUBBLE MOUND STRUCTURES

Per Bruun, Ali Riza Gunbak

Abstract


This paper describes the effect of wave period on the stability of rubble mound breakwaters. Introductorily wave run-up and run-down on smooth slopes and on rubble mounds were measured, and breaker types were observed and recorded for different incoming wave and slope characteristics. The surf similarity parameter, 5 = , 9° = /-~ • ~^r ' T was found practical for /H/L0 / 2TT /H description of breaker type, run-up and run-down on both smooth and permeable slopes. Pressure measurements along the smooth slopes and in the core of a rubble mound were undertaken with two different core materials. It was shown that the most dangerous condition for the stability of rubble mounds occurs at the so-called "resonance condition". Resonance refers to the situation that occurs when run-down is in a low position and collapsing- plunging wave breaking takes place simultaneously and repeatedly at or close to that location. This corresponds to a range of E, values in between 2 and 3. Photographic instrumentation was introduced and tested to quantify the initial damage on a rubble mound. This paper is a 1/3 abstact of a thesis for the Dr. Eng. degree by Ali Riza Giinbak.

Keywords


design principles; rubble mound; coastal structure

Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.