jetties as a core and building a new structure over them. The south jetty had the 

 following reconstruction design (USAED, Los Angeles 1988): 



Ocean-side slope 



1V:2H 



Channel-side slope 



1V:2H 



Shape (cross sectional) 



Trapezoidal 



Height, station 44+00 to 67+00 



+4.5 m (+14.8 ft) 



Height, station 67+00 to 91+00 



+5.2 m (+17.2 ft) 



Height, station 91+00 to end 



+5.8 m (+19 ft) 



Three classes of rock were used for the reconstruction, and the material was 

 placed according to specifications established by the Corps. Class I stones con- 

 sisted of armor stone weighing from 9,070 to 18,140 kg (10 to 20 tons). These 

 stones were used exclusively for armoring the ocean-side slope of the outer 732 m 

 (2,400 ft) of jetty. Class II stones, weighing from 450 to 9,070 kg (0.5 to 10 tons) 

 each, made up the majority of the south jetty reconstruction, the larger of these 

 stones being used for armoring the structure slopes shoreward of the Class I stones. 

 Class IQ stones, weighing from 1 .4 to 227 kg (3 to 500 lb), were used for core mate- 

 rial as well as to level off the cap of the existing structure in preparation for the 

 placement of a concrete cap that was 0.6 m (2 ft) thick and 6. 1 m (20 ft) wide. 

 Embedded within the cap were wooden ties used for the placement of rails for a 

 crane and rail cars. 



The head of the south jetty, which had been subjected to some of the most severe 

 damage, was reinforced with a concrete monolith that was 9.1 m (30 ft) wide and 

 4.3 m (14 ft) deep (Figure 2). The 861,825-kg (950-ton) monolith was placed in 

 the center of the head and armor stones up to 1 8,140 kg (20 tons) were laid up adja- 

 cent to the monolith. The el of the head was raised to +7.3 m (+24 ft) and the voids 

 between the armor stones were filled with stones of not less than 227 kg (500 lb) in 

 weight. 



The north jetty was reconstructed after completion of work on the south struc- 

 ture. The original structure was used as the core for the restoration, with the 

 completed cross section being trapezoidal with a concrete cap. Also, a concrete 

 monolith, weighing 952,540 kg (1,050 tons), was poured in the center of the head of 

 the north jetty. The range of stone size within each class varied slightly from what 



Chapter 1 Introduction 



