Plan 2B 



Plan 2B was identical to plan 2A except the toe reinforcement was con- 

 structed using a board anchored to the floor to represent a toe trench 1.5 m high 

 with vertical sides (Figure 15). The breakwater armor was rebuilt and the 

 packing density for the 11-tonne Core-Locs was 0.63. To expedite the study, all 

 3.7-m waves and the 13-sec, 5.2-m condition were omitted for this test series. 

 From previous experiments with plans which included a restrained toe, the 

 omitted wave conditions caused no or only minor damage to the breakwater. No 

 units were displaced during this series (Photos A34 through A36). Plan 2B was 

 rebuilt with the same packing density and the experiment was repeated. One 

 Core-Loc was displaced off the head midway through 19-sec, 6.7-m waves, but 

 the structure remained stable throughout the rest of the wave condition. 



Plan 2C 



The breakwater was rebuilt entirely of 11-tonne Core-Locs (0 =0.63), but the 

 board used to simulate a toe trench was removed between Profile 4 to a location 

 70 m from the elbow (Figure 16, Photos A37 through A39). Model concrete 

 blocks were placed in this area to simulate 6.1-m-long, 2.5-m-wide, 1.2-m-high 

 cargo containers filled with concrete. The containers had an approximate 

 prototype weight of 42.4 tonnes using a concrete specific gravity of 2.3 in the 

 prototype. The containers were placed 1 m apart along the toe and 11-tonne 

 Core-Locs were placed against the containers. 



The structure was subjected to all waves listed in Table 3. The containers 

 began to displace during 13-sec, 3.0-m waves and movement of containers 

 increased as wave height increased. However, the containers provided some 

 sheltering and prevented unraveling of the Core-Loc toe up to 3.7-m waves for 

 all three periods. Waves higher than 3.7 m for all periods displaced the con- 

 tainers out of the section and moved them southward along the toe and around 

 the elbow to the head (Photos A40 through A42). After the containers were dis- 

 placed from the original section, toe units in the area were displaced and upslope 

 units slipped, causing significant exposure of the underlayer stone between 

 Profiles 4 and 5 (Photo A40). 



Plan 2D 



Plan 2D was identical to Plan 2C except the cargo containers were placed end 

 to end along the Core-Loc toe (Figure 16, Photos A43 and A44). The armor 

 layer was rebuilt with a packing density of 0.62. Results were similar to experi- 

 ments with Plan 2C; the containers began to displace during 13-sec, 3.0-m waves 

 and movement continued with higher waves. Eventually, all containers were 

 displaced from their original position and moved southward along the break- 

 water. Without toe protection, Core-Loc toe units were displaced and upslope 



22 Chapter 3 Results 



