Table 31 



East Pass Channel Jetties 



East Pass Channel, Florida. SAM 



Date(s) Construction and Rehabilitation History 



1928- In April 1923 the present East Pass Channel, connecting 

 1951 Choctowhatchee Bay with the Gulf of Mexico, came into existence as a 

 result of a severe storm and high tides. In 1930 Congress autho- 

 rized a Federal project to provide a 6- by 100-ft channel through 

 the inlet. In 1951, the project was authorized to provide a 12- by 

 180-f t channel (present project dimensions) . 



1968- Because of continued channel shoaling and hazardous navigation, twin 

 1969 converging jetties were constructed, extending from each shore of 

 the inlet to about the -6 ft mlw contour and spaced 1,000 ft apart 

 at their seaward ends (Figure 53) . Similar in design to Corps 

 jetties at Perdido Pass (built during this time) and Masonboro Inlet 

 (completed in 1966) the west jetty incorporated a concrete sheet- 

 pile weir to allow movement of littoral drift material into the 

 deposition basin. This feature potentially minimizes the effect of 

 the updrift jetty on the beach topography and provides a source of 

 material for beach renourishment on the downdrift side, thus main- 

 taining the net movement of littoral drift material. The 4,850-ft- 

 long west jetty as constructed consisted of 1,200 ft of sand dike at 

 the landward end, followed by 900 ft of rubble mound, followed by 

 1,000 ft of sheet pile, and ending with 1,750 ft of rubble mound (of 

 which the seaward end consisted of 105- and 100-ft transition and 

 head sections, respectively). The 2,270-f t-long east jetty con- 

 sisted of 1,270 ft of sand dike and 1,000 ft of rubble mound. 

 Design cross sections (Figure 54) were the same for both jetties. 

 The sand dike sections had a 50-ft crest width at +10 ft mlw with 

 1V:20H side slopes and were built up with dredged material from the 

 deposition basin. The jetty rubble-mound sections were placed on a 

 2.5-ft-thick bed of 5- to 100-lb blanket material. The jetty trunk 

 sections had a 10-ft crest width at +6 ft mlw, 1V:1.5H side slopes, 

 one layer of 3- to 6-ton cover stone, one layer of 500- to 1,000-lb 

 underlayer stone, and 5- to 100-lb core stone. The 100-f t-long 

 jetty head sections had a 14-ft crest width at +13 ft mlw, 1V:2H 

 side slopes, two layers of 11- to 15-ton cover stone, one layer of 

 1 to 1.5 ton underlayer stone, and 100- to 350-lb core stone. The 

 105-f t-long transition section's geometry varied linearly between 

 the trunk and head sections, with one layer of 4- to 11-ton cover 

 stone, 500- to 3,000-lb underlayer stone, and 100- to 350-lb core 

 stone. The concrete sheet-pile sections, placed to -0.5 ft mlw, 

 were 10 in. thick, 2.5 ft wide, and 10, 14, or 18 ft long. They 

 were reinforced with prestressed steel cable and had tongue-and- 

 groove joints to provide interlocking between sections. In addi- 

 tion, 12- by 12-in. timber wales were bolted along the top of 



(Continued) 



(Sheet 1 of 4) 



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