Sandwich base structure for off-shore wind turbines

Abstract

The invention relates to a base structure ( 1 ) for an off-shore wind power installation having at least a plurality of, in particular three, bases piles ( 2, 3,, 4 ), and a support structure ( 5 ) connecting the upper ends of the base piles ( 2, 3, 4 ) for the pylon of the wind power installation. Furthermore each base pile ( 2, 3, 4 ) has a wall comprising a plurality of layers ( 19, 20, 21 ) of differing material substantially over its entire length, wherein the wall is formed from at least one surface portion, having an inner layer ( 19 ) and an outer layer ( 20 ) and wherein a core material is arranged between the inner layer ( 19 ) and the outer layer ( 20 ) as an intermediate layer ( 21 ).

1 . A base structure ( 1 ) for an off-shore wind power installation having at least a plurality of, in particular three, bases pile ( 2 ,  3 ,  4 ), and a support structure ( 5 ) connecting the upper ends of the base piles ( 2 ,  3 ,  4 ) for the pylon of the wind power installation,
 characterised in that each base pile ( 2 ,  3 ,  4 ) has a wall comprising a plurality of layers ( 19 ,  20 ,  21 ) of differing material substantially over its entire length, wherein the wall is formed from at least one surface portion having an inner layer ( 19 ) and an outer layer ( 20 ) and wherein a core material is arranged between the inner layer ( 19 ) and the outer layer ( 20 ) as an intermediate layer ( 21 ).   
     
     
         2 . A base structure as set forth in  claim 1  characterised in that the inner layer ( 19 ) is in the form of an inner tube and the outer tube ( 20 ) is in the form of an outer tube extending at a spacing relative to the inner tube ( 19 ). 
     
     
         3 . A base structure as set forth in  claim 2  characterised in that the core material is concrete, 
     
     
         4 . A base structure as set forth in  claim 2  or  claim 3  characterised in that the core material is strengthened with reinforcement ( 131 ,  132 ). 
     
     
         5 . A base structure as set forth in one of the preceding claims characterised in that the base piles ( 2 ,  3 ,  4 ) are of an axial length such that at an installation location they extend from the seabed ( 10 ) to above a surface of water ( 14 ). 
     
     
         6 . A base structure as set forth in one of the preceding claims characterised in that the base pile ( 2 ,  3 ,  4 ) is of a diameter in a range of between 2500 mm and 3500 mm and is preferably about 300 mm, the inner layer ( 19 ) and/or the outer layer ( 10 ) are of a wall thickness in a range of between 12 mm and 20 mm and the thickness of the core material is preferably in a range of between 60 mm and 120 mm. 
     
     
         7 . A base structure as set forth in one of  claims 1  through  6  characterised in that at least one further partial region having a plurality of layers, namely an inner layer ( 117 ), an outer layer ( 119 ) and an intermediate layer ( 121 ) is in the form of at least one tube portion ( 6 ′) of a bar ( 6 ,  7 ,  8 ) of the lattice-like support structure ( 5 ) which is composed of a plurality of bars. 
     
     
         8 . A base structure as set forth in  claim 7  characterised in that the inner layer ( 117 ) is in the form of an inner tube and the outer layer ( 119 ) is in the form of an outer tube ( 119 ) extending at a spacing relative to the inner tube ( 117 ), between which is provided the intermediate layer ( 121 ), in particular of concrete. 
     
     
         9 . A base structure as set forth in one of the preceding claims characterised in that arranged at at least one and preferably two axial ends of a base pile ( 2 ,  3 ,  4 ) and/or a bar ( 6 ,  7 ,  8 ) is a sandwich connection ( 50 ,  250 ,  350 ) which connects the inner layer ( 19 ,  117 ) and the outer layer ( 20 ,  119 ) and which in the axial direction forms a prolongation of the base pile ( 2 ,  3 ,  4 ) and/or the bar ( 6 ,  7 ,  8 ) in the form of a connecting tube, 
     
     
         10 . A base structure as set forth in  claim 9  characterised in that the sandwich connection ( 50 ,  250 ,  350 ) has a ring flange ( 52 ,  252 ,  352 ) which is substantially conical in cross-section, wherein the ring flange is connected at one end to the inner layer ( 19 ,  117 ) and the outer layer ( 20 ,  119 ) and at the other end to a connecting tube ( 51 ,  251 ,  351 ). 
     
     
         11 . A base structure as set forth in  claim 10  characterised in that the ring flange ( 52 ,  252 ,  352 ) has openings ( 71 ) for receiving reinforcing bars ( 33 ,  233 ). 
     
     
         12 . A base structure as set forth in one of  claims 9  through  11  characterised by at least one connecting body having two or more connecting tubes for connection, in particular welding, to connecting tubes or sandwich connections ( 50 ,  250 ,  350 ) of a respective base pile ( 2 ,  3 ,  4 ) and at least one bar ( 6 ,  7 ,  8 ) of the support structure ( 5 ). 
     
     
         13 . A base structure as set forth in  claim 12  characterised in that the connecting body is formed from pre-assembled tube portions. 
     
     
         14 . A base structure as set forth in one of  claims 7  through  13  characterised in that at at least one of its end regions each tube portion ( 6 ′) is provided with a bulkhead ( 23 ,  24 ) which sealingly closes at least its free cross-section. 
     
     
         15 . A base structure as set forth in one of the preceding claims characterised in that each tube portion ( 6 ′) has at its end at least one annular connecting flange extending in a plane oriented perpendicularly to the center line of the tube portion ( 6 ′).