The weight of overlay stone per linear meter is the product of the weight 

 per square meter times the length of the revetment. For this example, over- 

 lay stone weight per linear meter = 400 x 10.34 = 4,136 kilograms per meter 

 or 1.4 tons per foot. Table 7 shows the results of the overlay computations 

 for each of the four slopes using both blocky quarrystone and rounded boul- 

 ders as overlay stones. Overlay would normally be used to repair a damaged 

 revetment and the reserve stability would be partly a function of the thick- 

 ness and size of the original armor. The overlay layer itself will have 

 little reserve stability as is suggested by comparing the weight of overlay 

 per linear meter in Table 7 with the weight of armor per linear meter in 

 Table 6. 









Table 7 . Overlay stone 



data. 







Slope 



"50 

 kg(lb) 



W 

 kg(lb) 



Blocky quarrystone 



Rounded boulders 



C.F.- 



C 

 kg/m 2 (lb/ft 2 ) 



Armor weight 

 k S /m(lb/ft) 



C.F. 



C 

 kg/m 2 (lb/ft 2 ) 



Armor weight 

 kg/m(lb/ft) 



1 on 1.5 



201 

 (443) 



175 

 (386) 



0.42 



449 

 (92) 



3,098 

 (2,082) 



0.55 



588 

 (120) 



4,057 

 (2,727) 



1 on 2 



173 

 (381) 



151 

 (333) 



0.42 



428 

 (88) 



3,445 

 (2,315) 



0.55 



560. 

 (115) 



4,508 

 (3,030) 



1 on 3 



142 

 (313) 



124 

 (273) 



0.42 



400 

 (82) 



4,136 

 (2,780) 



0.55 



524 

 (107) 



5,418 

 (3,641) 



1 on 5 



109 

 (240) 



95 

 (209) 



0.42 



366 

 (75) 



5,377 

 (3,614) 



0.55 



480 

 (98) 



7,051 

 (4,739) 



*************************************** 



III. SUMMARY AND CONCLUSIONS 



A number of design considerations relating to riprap stability to wave 

 attack and maximum runup elevations are discussed; examples are worked to 

 illustrate techniques. The information presented is primarily the result of 

 laboratory studies. Equally important to the development of a good design 

 are considerations difficult to quantify, such as a careful evaluation of the 

 performance of other revetments near the design site or in similar sites. It 

 is extremely important to utilize the experience of others and when this is 

 coupled with the guidance provided in the literature, many alternative designs 

 can hopefully be reduced to a few good ones. The best design may have to be 

 selected on the basis of model tests. 



29 



