Wave Control Functions and Design Principles of Composite Slope Rubble Mound Structures

Statistical Investigations on Dike Failure

“…The reduction of reflection coefficient and run-up are very important for a calm sea and a low crest height respectively. Ryu and Sawaragi (1986) discussed the wave control functions according to the change of relative depth and width of the berm of composite slope.…”

“…If the optimum composite slope is selected, the reflection coefficient decreases more than 50%, the run-up height decreases about 10%, and the run-down height decreases about 20-50% comparing the results for the uniform slopes. As for the detail discussion of the reduction mechanisms, readers are referred to Ryu and Sawaragi(1986).…”

“…To estimate the design weight of a rubble unit, Eq. (13) and (14) can be transformed as: For the uniform s lated by the only a design advantage comparing the au and only a design formula irregularity effects of oc into the design formula un composite slope, however, composite slopes, only can ) and Eq. (18) reflect the allowable percentage uping effects on the rubble stability using a run-sum as an index of the irregular wave lopes, the design rubble weight can be calcuformula of Eq.…”

“…It is desirable to use a berm type composite slope at the initial design stage for the ease of construction, and is important in a optimal design concept with allowable failure ratio. Ryu(1984) and Ryu et al(1986) stressed the reflected wave problems for a calm sea and the reduction of run-up correspond to the necessity 1) Assistant Professor, Department of Ocean Engineering, National Fisheries University of Pusan, Pusan, 608 Korea. 2) Professor, Department of Civil Engineering, Osaka University, Osaka, Japan.…”

“…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.…”