and the general site conditions to narrow the selection of structure 

 possibilities. In the first stages of breakwater design, the environmental 

 design parameters are determined. These include design wave characteristics 

 and site bathymetry. The next step generally is to determine the structure 

 geometry, including profile and cross -sectional layout. Alternative armor 

 unit sizes, shapes, and material characteristics can be judiciously selected 

 to optimize the hydrodynamic stability for the given structure. If CAUs are 

 chosen over stone, then the preliminary dolos design procedure will be 

 initiated. 



Preliminary Dolos Design 



37. Parameterizing the dolos structural response as a maximum 

 principal tensile stress occurring at a critical cross section has the 

 following advantages over other methods. 



a. Allows reduction of the complex stress state within the armor 

 layer matrix to a single stress design distribution. 



b. Allows reduction of several gross structural measurements, 

 such as the two moments and a torque measured in the prototype 

 and in the physical model, to one stress parameter. 



c. Allows scaling of the response to different loadings sepa- 

 rately and allows the combination of the separate response 

 probability distributions. 



d. Allows coupling of hydrodynamic stability with strength design 

 and allows shape optimization and strength enhancement using 

 analytical tools. 



e. Permits comparison of structural response with structural 

 failure criteria. 



f . Expedites the mechanics of the design process using a 

 microcomputer-based program. 



Determining the design principal stress in this manner requires some assump- 

 tions, as discussed below, and can only provide an approximation to the actual 

 stress state (Melby, Rosson, and Tedesco 1990). Yet the probability distri- 

 butions generated from these approximate stresses appear to define the extreme 

 (design) stress states well. The primary disadvantage to using a single 

 stress parameter is that conventional reinforcement analyses for flexure and 

 torsion cannot be done efficiently. Methods for reinforcement analysis are 

 being finalized and will be published in the near future. 



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