monolithic units separated by construction and expansion joints. Unless these joints are 

 made and spaced properly, cracking, bulging, or separation of units may occur. Adequate 

 imbedment of reinforcing steel in all concrete construction is vital to the prevention of 

 spaUing. Here again, proper design and control of construction procedures are necessary to 

 prevent failures (Fig. 55). 



? 





I In 



,-4J- 



Figure 55. Spalled face of concrete wall due to inadequate rebar imbedment. 



If necessary to cross the basin perimeter to gain access to the berthing area, provision 

 must be made for a pier landing. When a landing is directly on a perimeter wall or top of the 

 slope, adequate structural detailing for each landing must be incorporated in the perimeter 

 structure. Because this landing usually places an extra load on the wall or top of the slope, 

 additional engineering analysis is required to ensure: (a) the adequacy of this perimeter 

 structure to receive the load, and (b) the capability of the substrata to support it. The load 

 may require extra bearing piles under a wall or a special load-distributing seat or abutment 

 at the top of a slope. Whatever the requirement, it should be considered and be planned as 

 an integral part of the perimeter treatment and not deferred to a later phase of the design 

 effort. 



AU bulkhead walls and perimeter slopes steeper than about 1 on 1.5 should be protected 

 by handrails if the adjacent water is more than about 2 feet deep or if at low water level the 



104 



