Calibration of overtopping roughness factors for concrete armor units in non-breaking conditions using the CLASH database

Abstract

Elsevier Molines, J.; Medina Folgado, JR. (2015). Calibration of overtopping roughness factors for concrete armor units in non-breaking conditions using the CLASH database. Coastal Engineering. 96:62-70.

Explicit Wave-Overtopping Formula for Mound Breakwaters with Crown Walls Using CLASH Neural Network–Derived Data

“…(2)-type overtopping estimator. Molines and Medina (2015) analyzed different overtopping estimators for CMBW and found that the CLASH NN estimator had a far superior performance compared to Eqs. (2) to (4) and Eq.…”

“…Two sets of data corresponding to CMBW were considered from the CLASH database For perpendicular wave attack (β=0 o ), the data filter applied was the same as that detailed by Molines and Medina (2015): β=0 o ; cotαd=cotαu=cotα; 1.19 ≤cotα ≤ 4; B=0; tanαb=0; hb=0; CF (Complexity Factor)=1; RF (Reliability Factor)≤2; non-breaking conditions and Q>10 -6 .…”

“…This is the most common typology for mound breakwaters, especially when concrete armor units are used. Molines and Medina (2015) compared different overtopping estimators and found that the CLASH NN performed better in comparison to other estimators; however, it is a "black-box" which does not clarify how overtopping is affected by specific explanatory variables. This paper describes a methodology to build-up a new and explicit overtopping formula which can provide predictions for CMBW in non-breaking conditions.…”

“…Fig. 3 illustrates the performance of the CLASH NN estimator with the roughness factor given by Molines and Medina (2015) for the ranges of applications given by Table 1. The low rMSE=8.1%…”

“…where a1 = -1.6 and b1 = -2.6. The roughness factor was taken initially as the best fitted value for the CLASH NN model given by Molines and Medina (2015), so for the final estimator Q6, the γf was then derived specifically following their methodology.…”