Armer instability 



Armor Breakage 



.sz_ 



IX 



Foundation setUement 



Figure 1.1. Breakwater failure modes 



complex and difficult to quantify for the wide range and many permutations of the many 

 variables involved. The variability is dependent on the stochastic nature of both the 

 armor boundary conditions and loading. Boundary conditions are the points of contact 

 underneath and between the armor stones. The boundary conditions are uncertain 

 because of the irregular stone shape and stone placement. The geotechnical 

 characteristics of the foundation are also often uncertain. The loading of engineering 

 interest is primarily due to incident storm waves that vary with storm intensity and 

 storm location. The impact of the waves varies with water level and local bathymetry. 

 The local water level varies with tide and storm surge. Waves can dislodge armor units 

 by uplifting, rolling, or sliding individual units or by causing en masse movement of the 

 entire armor layer. Armor units can be dislodged from the upslope layer without 

 jeopardizing the integrity of the armor layer. But if enough armor units move and the 



