3 Results 



Introduction 



Three-dimensional stability experiments were conducted for nine configura- 

 tions at a model scale of 1:48.4. The configurations consisted of two basic 

 breakwater plans. Plan 1 and Plan 2 differed in that Plan 1 consisted of 8- and 

 11 -tonne Core-Locs and a crest elevation of +5 m CD at the head section, 

 whereas Plan 2 was armored entirely with 11-tonne Core-Locs and had a head 

 section elevation of +8 m CD. Four toe protection schemes were studied using 

 the Plan 1 configuration, and five toe configurations were used with Plan 2. 



Planl 



Plan 1, the initial plan (Figure 10, Photos Al through A3), consisted of 

 6.25-tonne tetrapods from the shoreward end of the breakwater to Profile 4; 

 8-tonne Core-Locs from Profile 4 to a point between Profiles 6 and 7 (a total 

 reach of approximately 92 m); and 11-tonne Core-Locs on the remainder of the 

 seaward trunk, around the head and terminating at the quay wall on the leeward 

 side of the structure. For this plan, packing densities of the 8- and 11-tonne 

 Core-Loc reaches were 0.55 and 0.59, respectively. The crest elevation of the 

 head section was +5 m CD. Plan 1 was subjected to "shakedown" waves 

 (13 sec, 3 m) to settle and nestle the armor units. During the wave series, apron 

 material was displaced between Profiles 4 and 9, and Core-Locs were displaced 

 at the toe near Profile 4 (Photos A4 through A6). The structure was subjected to 

 3.7-m waves for 13- and 16-sec periods, which caused additional toe unit 

 displacement at Profile 4 and at the elbow near Profile 8. 



Plan 1A 



Plan 1A was the same as Plan 1 except a toe buttress was constructed of stone 

 of identical weight as the underlayer stone (0.75 to 1.8 tonne) and placed 

 between Profile 4 and the terminus of the quay wall near Profile 10 (Photos A7 

 through A9). The buttress was placed two stones high and three stones wide 



1 4 Chapter 3 Results 



