Cedarhurst, Maryland (1970) 



i-0.3m 



Finished Grade 



Interlocking Concrete Blocks 



El. I.2in 



El. 0.9 m i 



Tongue-ond-6roove Joint 



Concrete __- 



Originol Beocti Profile 



Stone Toe Protection 



Crustied Stone 



Geotextile Filter 



El. -0.6m 



Goivonized Rods C?i 5m on center Through Tinfiber Liner 



Figure 6-12. Interlocking concrete-block revetment. 



The stability of an Interlocking concrete block depends largely on the 

 type of mechanical interlock. It is impossible to analyze block stability 

 under specified wave action based on the weight alone. However, prototype 

 tests at the U.S. Army Engineer Waterways Experiment Station Coastal Engineer- 

 ing Research Center (CERC), on blocks having shiplap joints and tongue-and- 

 groove joints indicate that the stability of tongue-and-groove blocks is much 

 greater than the shiplap blocks (Hall, 1967). An installation of the tongue- 

 and-groove interlock block is shown in Figure 6-12. 



2 . Selection of Structural Type . 



Major considerations for selection of a structural type are as follows: 

 foundation conditions, exposure to wave action, availability of materials, 

 both initial costs and repair costs, and past performance. 



6-13 



