3.0 



2.5 



2.0 



1.5 



1.0 



Eq. (7), 5-pct Domoge 

 Eq.(6) 



Eq. (5), Zero Domoge 



1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 



Cotongent of Embonkment Slope, Cot O 



Figure 2. Comparison of stability equations. 



5 10 



Reserve Stobility Porameter 



/w 50 y3 tucot 



•V* 



Figure 3. Reserve stability as a function of the 

 reserve stability parameter. 



Normally the significant wave height should be used as the design wave 

 height for riprap, e.g., in equation (4). The guidance provided in Section 

 7.12 of the SPM should be followed in the selection of the design wave. Re- 

 search underway (1980) at CERC is expected to provide improved guidance on 

 the choice of the design wave for irregular wave attack on riprap. 



