structure would be situated (Figures 1-4) . Unless otherwise mentioned, all 

 wave heights H and water depths d s defined herein are those measured at 

 the sea-side toe of the test sections. 



Test Sections 



9. All rubble-mound test sections were constructed to reproduce as 

 closely as possible typical results of full-scale construction. The core 

 material was dumped and compacted to simulate natural consolidation that would 

 occur during construction due to wave action. Underlayer stone was dumped and 

 smoothed to grade. Primary armor units- -in this case either stone, dolosse, 

 or tribars- -were added to the structure one at a time. The one -layer tribar 

 armor was constructed using uniform placement. (All vertical tribar legs were 

 placed normal to structure slope.) Except for the dolos toe where the first 

 two rows were specially placed to accomplish maximum interlocking, the stone 

 and dolos armor layers were constructed using random placement. (Random 

 placement means that the units were randomly selected from a stock pile and 

 were placed without any special orientation or interlocking with one another.) 

 Berm armor stones, with weights equal to or greater than one-quarter the 

 weight of the primary armor stone needed for stability, were added using 

 random placement. Berm stones with smaller weights were dumped and smoothed 

 to grade. Toe buttressing stones were placed after the tribar armor and with 

 a conscious effort of maximizing contact between the buttressing stone and the 

 bottom row of tribars. 



2-D toe berm stone tests 



10. Eight toe berm armor stone plans were tested. All cross sections 

 tested were conventional three-layered stone structures designed for one-sided 

 breaking wave attack with no solid water overtopping (SPM 1984) . Plan details 

 for model test sections are shown in Figure 5. Side and sea-side views of a 

 typical test section are shown in Photos 2 and 3. 



2-D buttressing stone tests 



11. In conjunction with the REMR research work unit "Use of Dissimilar 

 Armor for Repair and Rehabilitation of Rubble-Mound Coastal Structures," 

 limited tests were conducted of toe buttressing stone fronting one- layer, 

 uniformly placed tribar overlays on IV on 1 . 5H slopes (Carver and Wright 1988) 

 (Figure 6 and Photos 4 and 5) . This type of structure exists on a section of 



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