28 July 2005
Where rail access is planned for either crane or railroad, a separate approach is
not necessary. However, consider a separate walkway. Consider approach
slope limit for crane or railroad.
At the intersection of approach and piers and wharves, provide fillets or
additional deck area at corners to allow for ease in executing turns. Where a
one-lane approach roadway is provided as the only access, provide the pier or
wharf with sufficient turnaround space on the facility so that outgoing vehicles do
not have to back out along the approach.
On all approaches, provide safety barriers adequate for the type of traffic using
the facility (pedestrian, vehicular, and/or rail). However, safety barriers should
not be provided in areas where mission operations, such as ship or small craft
berthing, are performed. Rail only approaches do not normally require safety
barriers. Provide traffic barriers between pedestrian and traffic lanes. Traffic and
pedestrian barrier design must conform to AASHTO Guide Specifications for
Bridge Railings and AASHTO Bridge Guide and Manual Interim Specifications.
The three major structural types for piers and wharves are open, solid, and
floating. Open type piers and wharves are pile supported platform structures that
allow water to flow underneath. Figure 2-7 illustrates the open type. Solid type
uses a retaining structure such as anchored sheet pile walls or quaywalls, behind
which a fill is placed to form the working surface. Solid type will prevent stream
flow underneath. Figure 2-7 illustrates the solid structural type. Floating type is a
pontoon structure that is anchored to the seabed through spud piles or mooring
lines and connected to the shore by bridges or ramps. A floating double deck
pier is shown in Figure 2-8. This pier is currently under development by NFESC,
types can be either single or double level.
Selection of Type.
Numerous factors influence the selection of one structural type over the other.
Evaluate each of these factors against the construction and operating costs of
the facility before a final decision is made on the structural type. Place greater
emphasis on selecting the type that will withstand: unexpected berthing/mooring
forces, adverse meteorological and hydrological conditions, and the corrosive
effects of a harsh marine environment such that it will require little or no