Analytical Design Method for Relatively Closed Block Revetments

Abstract

A semianalytical, semiempirical method is developed to compute the loads on and the strength of a placed block revetment under perpendicular wave attack. The method consists of an empirical computation of the external wave loads on the revetment and an analytical method to calculate the internal hydraulic loads in the sublayers of the slope protection structure. Together, the internal and the external loads determine the resulting pressure differences across the top layer. The strength of the top layer is treated as the sum of the weight of the block revetment and a number of additional strength factors: the friction between adjacent blocks, the inertia of a block when it becomes unstable, and the pressure drop underneath an unstable, ejecting block. These additional strength factors are quantified analytically and are verified separately by means of extensive experimental model testing on a prototype scale. The method as a whole is verified by means of large‐scale model tests in a large wave flume, where the external and internal pressures are measured and the resulting block motions are registered. The preliminary results of these verification tests are presented briefly.