Learning  Objective:  Identify  types of waterfront structures and their uses. 1-16. In which of the following ways are a breakwater and a jetty both (a)  similar  and  (b)  different? 1. (a) Both are used to direct the current flow in a channel (b) a breakwater is an alongshore   structure 2. (a) Both are alongshore structures  used  to  break the action of waves (b) a jetty has a paved top for  vehicular  traffic 3. (a) Both are offshore structures  used  to  break  the action of waves (b) a jetty directs the current flow along the line of a channel 4. (a)  Both  are  harbor-shelter structures (b)  a  breakwater  extends  out from  the  shoreline 1-17. To establish a definite shoreline and  maintain  it  against  wave erosion,  what  type  of  structure should  the  engineer  design? 1. Seawall 2. Breakwater 3. Jetty 4. Groin 1-18. To  allow  ships  to  lie  alongside for  loading  and  unloading,  what type of structure should be used? 1. Wharfage 2. Offshore 3. Stable  shoreline 4. Mole 1-19. In  which  of  the  following conditions can a concrete cap structure  be  used  on  a  breakwater or jetty? 1. Deep-water  site  only 2. Extra-high  tide  range  only 3. Deep-water  site  or  extra-high tide range 4. Shallow-water site 1-20. How are the individual units of a precast cap structure for a breakwater (a) taken to and (b) placed in their proper location? 1. (a) Floated (b) sunk 2. (a) Carried (b) driven 3. (a) Craned (b) dropped 4. (a) Barged (b) unloaded 1-21. In which of the following uays are a seawall and a bulkhead both 1-22. (a) 1. 2. 3. 4. similar and (b) different? (a) Both protect a shoreline against  erosion (b) a bulkhead is supported by its own weight (a) Both protect a shoreline against  erosion (b) a bulkhead is relatively thin and usually consists of steel  sheet  piles (a) Both are relatively thin and   self-contained (b)  bulkheads  are  normally cast-in-place   concrete structures (a) Both are relatively thick and   self-contained (b) a bulkhead can be constructed using wooden sheet piles To allow ships to come alongside, bulkheads are fitted with 1. wales and anchors 2. piles  and  quays 3. timber caps and batter fenders 4. mooring cleats and dolphins 3