Method for Constructing Water Barriers and Coastal Protection

Abstract

The invention relates to a method for constructing a water barrier. In the method a core of quarry run is arranged on the underwater bottom and provided with a protective layer of stones or concrete blocks, with the proviso that, at least at the position of the water barrier, the underwater bottom is raised using bottom material. The method is particularly suitable for constructing a water barrier for relatively deep water.

1 . Method for constructing a water barrier, wherein a core of quarry run is arranged on the underwater bottom and is provided with a protective layer of stones or concrete blocks, with the proviso that, at least at the position of the water barrier, the underwater bottom is raised using bottom material. 
     
     
         2 . Method as claimed in  claim 1 , characterized in that the underwater bottom is raised with bottom material prior to the core being arranged. 
     
     
         3 . Method as claimed in  claim 1  or  2 , characterized in that the underwater bottom is raised to a height such that the average water depth at the position of the water barrier decreases by 20 to 80%. 
     
     
         4 . Method as claimed in any of the foregoing claims, characterized in that the underwater bottom is raised to a water depth which does not exceed 50% of the closure depth. 
     
     
         5 . Method as claimed in  claim 4 , characterized in that the underwater bottom is raised to a water depth which does not exceed the closure depth. 
     
     
         6 . Method as claimed in any of the foregoing claims, characterized in that the underwater bottom is raised to a level such that the volume of material required for core and protective layer decreases by 20 to 80% relative to a water barrier with non-raised underwater bottom. 
     
     
         7 . Method as claimed in any of the foregoing claims, characterized in that the raised underwater bottom is compacted at least at the position of the water barrier. 
     
     
         8 . Method as claimed in  claim 7 , characterized in that the raised underwater bottom is compacted to a saturated density lying between 1.6 ton/m 3  and 2.3 ton/m 3 . 
     
     
         9 . Method as claimed in any of the foregoing claims, characterized in that a filter layer is arranged between the raised underwater bottom and the core. 
     
     
         10 . Method as claimed in any of the foregoing claims, characterized in that the underwater bottom is raised gradually from the natural level thereof up to a position in the vicinity of the water barrier, whereby the raising has an inclination. 
     
     
         11 . Method as claimed in  claim 10 , characterized in that the height of the raising increases at a substantially constant inclination in the direction of the water barrier. 
     
     
         12 . Method as claimed in  claim 11 , characterized in that the angle of inclination to the horizontal direction lies between 1:2 and 1:20, more preferably between 1:5 and 1:15, and most preferably between 1:7 and 1:10. 
     
     
         13 . Method as claimed in any of the  claims 1 - 9 , characterized in that the underwater bottom is raised gradually from the natural level thereof up to a position in the vicinity of the water barrier, whereby the raising has an average inclination and wherein this average inclination comprises one or more substantially horizontal parts. 
     
     
         14 . Method as claimed in any of the  claims 10 - 13 , characterized in that the inclination is provided with a plurality of water barriers which lie substantially in line with the water barrier. 
     
     
         15 . Method as claimed in  claim 14 , characterized in that the crests of the multiple water barriers lie at increasing height, but do not exceed the crest height of the water barrier.