c. Shore-Connected Structures . 



(1) Breakwaters, Jetties and Groins . Breakwaters, jetties and 

 goins could be made in the same manner as offshore structures using bitumi- 

 nous concrete or preplaced aggregate methods. 



(2) Seawalls . 



(a) Bituminous Concrete . In addition to the types of uses 

 described for offshore structures, bituminous concrete products and sealers 

 may be required to make impermeable membranes, where required. 



(b) Preplaced Concrete . Preplaced concrete techniques can be 

 used for mass concrete seawalls. Forms for the vertical or specially 

 contoured faces would be required. Otherwise, the placement methods would 

 be as described for offshore structures except that a tremie may not be 

 necessary for layers placed above the waterline. For good void filling, a 

 vibrator would be used to ensure that the concrete grout flows into all the 

 voids and fills the form. 



(c) Portland Cement Grout . Portland cement grout would be 

 used to fill synthetic mesh bags and tubes used to form seawall units. 



(3) Revetments . 



(a) Bituminous Concrete . Bituminous concrete is used to bind 

 stone blankets together to form a stable mass or can be used by itself as 

 slope protection, as shown in Figure 43. 



(b) Portland Cement Grout . Portland cement grout may be used 

 to bind stones in a blanket together to form a stable but brittle mass. It 

 can also be pumped into weak soils to firm them for foundations or can be 

 used to fill voids in earth layers to obtain foundation continuity. 



(c) Soil Cement . Soil cement techniques may be used where the 

 slope is composed of the right type of soil and the exposure is not subject 

 to severe wave action. It has the advantage of not requiring aggregate 

 materials to be hauled to the site. 



(4) Piers and Wharves. 



[a) Bituminous Concrete . Bituminous concrete wearing surfaces 

 are sometimes used to provide an economical surface to be sacrificed to the 

 wear of ordinary use. Replacement or refurbishment is easily and cheaply 

 done and the underlying structure remains undisturbed. 



(b) Preplaced Aggregate Concrete . Preplaced aggregate con- 

 crete has been used along the perimeter of landfills to act as a combination 

 seawall, retaining wall, and wharf structure. Such structures are usually 

 topped with a large reinforced concrete wall that supports the fender system 

 and forms the "face of wharf." 



203 



