Destruction Mechanism and Design of Rubble Mound Structures by Irregular Waves

Statistical Investigations on Dike Failure

“…As for the ascertain of the statistical reliability of generated waves and related discussions, readers are referred to Ryu(1984) or Sawaragi et al(1985). Fig.2 shows the occurrence probability of run-length of higher waves j( j = l,2,3, , oo ) for the present data, reported field data and predicted results by the well-known stochastic process.…”

“…where 8 is the slope of the structures, H the wave height, L 0 the deep sea wave length, and subscript max the maximum wave. As for the detail discussions of the run, readers are referred to Sawaragi et al(1985).…”

“…, «>) denote the k-th wave height of group formed waves in a wave trian, P is the density of sea water and g is the acceleration of gravity. From the author's another study results on the relations among the mean run-sum, the mean run-length and the spectrum peakedness parameter Qp , we can estimate the E sum by the following equation (Sawaragi et al(1985)). (1976,1978) and Ahrens(1975Ahrens( ,1981 pointed out the wave period effects on the stability as a important factor in design.…”

“…The effects of irregularity on the stability of rubble monnd structures were pointed out by Johnson et al (1978) and Sawaragi et al(1984 and1985) as an important external force index that should be considered in the design.…”

“…of construction of lower crown-height in the design of coastal structures with an optimal design concept. Considering those irregularity effects on the stability and the reduction of wave reflection and run-up, Sawaragi et al(1985) and Ryu et al (1986) developed the design formula introducing the irregular wave force index such as the mean run-sum, but still the formula has a problem that the design rubble weight must be calculated by every design formula for every slope. In this paper, the characteristics on the reduction of wave reflection and wave run-up, and stability increasing functions by the change of the slope shape are studied through model tests, and new design formulas are developed for the uniform slopes that can apply an universal formula to every slope and for the optimal composite slope considered wave control and stability increasing functions.…”