Abstract:
The invention is related to a floatable structure as a rigid unit for carrying loads and especially to such a structure which is composed of floatable single bodies being connected by longitudinal connecting members provided with cavities.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of pending International patent application PCT/EP2006/009105 filed on Sep. 19, 2006 which designates the United States and claims priority from German patent application 10 2005 046 794.6 filed on Sep. 29, 2005, the content of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a floatable structure as a rigid unit for carrying loads and especially to such a structure which is composed of floatable single bodies being connected with longitudinal connecting members showing cavities. 
         [0003]    Floatable structures according to the invention can be used for a plurality of applications, e.g. loads like roads, buildings, commercial facilities, gardens, terraces and objects being hung under the structures like containers for liquids, pipes and walkable premises under water for watching sea animals can be carried. 
       BACKGROUND OF THE INVENTION 
       [0004]    In the prior art, a floating base is known as a rigid platform from DE 202 07 585. That invention has the object to develop a force-fitted connection of concrete floating bodies with styrofoam inlet or other floating base elements with the goal to manufacture floating bases as a rigid carrying platform for carrying loads of different amount. That purpose is solved by ferroconcrete floating bodies with styrofoam inlets which are on site force-fittedly combined in the water by means of concrete beams being in existing cut-outs of the catwalks being chosen depending on structural analysis, so that loads of different magnitude can be transferred to the floating base. 
         [0005]    A disadvantage of such a known floating base is that a longitudinal base exhibits either a relatively low wrap resistance or its manufacture is associated with relatively high material costs. Furthermore, it is disadvantageous that the construction of known bases is not suitable to approximate arbitrary forms, especially rounded forms. 
       SUMMARY OF THE INVENTION 
       [0006]    Accordingly, it is the object of the present invention to provide an improved floatable structure as a rigid unit which especially needs less material. 
         [0007]    This object is solved by provision of a floatable structure as a rigid unit for carrying loads comprising a plurality of floatable single bodies, wherein the floatable single bodies are provided with one or more longitudinal cut-outs, respectively, in which one or more longitudinal connecting members are inserted to connect at least two of the floatable single bodies with each other, and wherein the longitudinal connecting members show cavities. 
         [0008]    According to the invention, a floatable structure as a rigid unit is composed of a plurality of floatable single bodies, wherein the floatable single bodies are provided with one or more longitudinal cut-outs, respectively. These cut-outs are preferably provided in the same direction in which the structure extends the widest. Longitudinal connecting members which at least connect two of the floatable single bodies are inserted into the cut-outs. 
         [0009]    In order to attain a high wrap resistance of the floatable structure with as little material use as possible, the connecting members according to the present invention show proper profiles such as a box profile or a hollow triangular profile or a comb-like profile. Preferably, a box profile of ferroconcrete can be used as connecting member. Such a box profile does not only allow for saving of material and thus reduces cost, but it also leads to a weight reduction. Low weight is of particular great importance for floatable structures. For further optimization, additional cross beams can be provided in the interior of the profile. 
         [0010]    Besides the saving of weight, the cavities of the connecting members of the present invention offer the possibility to fill the same with floatable materials like styrofoam. As interior lining, non-corrosive material like synthetic material can also be used as upwelling body provided inside. Thus, a box profile of synthetic material can be inserted which is optionally closed at its ends, whereby a waterproof space is created which can accommodate further equipment. This prevents that larger amounts of water can accumulate inside the connecting members in case of leakiness of the outer walls. The same holds also for the floatable single bodies. 
         [0011]    The cavities of the connecting members can also be used for accommodating supply members such as pipes or wires. Together with openings in the upper side of the box profiles, houses and other facilities on the floatable structure can be supplied in this way. 
         [0012]    When working with ferroconcrete, a reinforcement covering for corrosion protection is used which is above 1.5 cm and usually in the range of 2 cm to 5 cm. When choosing the proper reinforcement covering, in addition to standard parameters, also the water composition is to be taken into account for floatable structures. For floatable structures, usually a covering of 4.5 cm or more is used. According to the invention, for the connecting members, carbon fiber or glass fiber material can be used. For textile-reinforced concrete, there is no danger of corrosion in contrast to ferroconcrete. Additionally, by this, a substantially smaller reinforcement covering can be used. This leads to more lightweight constructions and more efficient material use. 
         [0013]    For a particularly high wrap resistance of the floatable structure, several, especially four, connecting members running parallel to each other can be used. The exact arrangement respectively alignment of the cut-outs in which the connecting members are inserted, depends on the geometry and the requirements for the floatable structure. Also constructions are imaginable in which the connecting members are not running parallel to each other. If a plurality of connecting members is used, those can consist of different materials and/or show different profiles/dimensions according to the requirements for the floatable structure. 
         [0014]    Preferably, the connecting members extend over the total length of the structure, whereby the structural unity of the rigid unit is secured in a preferable manner. 
         [0015]    The walls of the floatable single bodies can contain carbon fiber or glass fiber material as the connecting members. In order to reduce reinforcement covering with respect to a ferroconcrete, textile reinforced concrete can also be used here, whereby a weight reduction is achieved. 
         [0016]    In order to build a floatable structure having a curved or irregular perimeter, floatable single bodies are used according to the invention, which show in top view a form which corresponds substantially to the form of an equilateral triangle. The floatable single body has preferably the form of an even prism with the footprint of an equilateral triangle. When the element swims, its upper surface is parallel to the water surface. This is of essential importance for a floatable structure. Would e.g. a non-equilateral triangle be used without taking special provisions with respect to the weight balancing, as a consequence, the upper surface of the floatable single body would not be parallel to the water surface. 
         [0017]    An additional advantage of an equilateral triangle lies in the fact that larger formations can be composed of them without generation of clearances. Thus, arbitrary perimeters can easily be approximated by floatable structures. Nevertheless, designated areas can also be left free to e.g. keep space free for obstacles or building elements like pillars. 
         [0018]    According to the invention, the floatable single bodies feature walls of a ferroconcrete or carbon fiber or glass fiber, especially textile reinforced concrete. Profiled walls can be used, which show profiles as described above. The cavities of the profiles can be filled with styrofoam. Preferably, a unified cover layer will be applied over a plurality of single bodies, which is an advantage for rigid connection of the single bodies. A sealing bottom plate protects the interior of the single bodies from water and damage, however, it is not strictly required. Preferably, the interior of the single body is filled with styrofoam or a different floatable material. 
         [0019]    For stabilization, floating single elements can be anchored with one or more holder means to the ground of the water, especially by anchored nylon cables, which are e.g. pre-tensioned with 15 kN. Hereby, vibrations of the structure caused e.g. by waves can efficiently be reduced when choosing the holding positions appropriately. For this purpose, it is particularly appropriate for longitudinal structures that the holder means are attached in a central area of the structure and that they are transverse outwardly wired, respectively. Nylon wires offer the advantage with respect to usual chains that they cannot corrode. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a spatial view of a floatable structure according to the invention. 
           [0021]      FIG. 2  is a cross-sectional view of a connecting member of  FIG. 1 . 
           [0022]      FIG. 3  is a top view of a floatable structure according to a second embodiment of the invention. 
           [0023]      FIG. 4  is a cross-sectional view parallel to the upper surface of the floatable single body of  FIG. 3 . 
           [0024]      FIG. 5  is a cross-sectional view along the line I-I of  FIG. 1  with holder means. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]      FIG. 1  is a spatial view of a floatable structure showing the floatable single bodies  2  and the connecting members  1 . A plurality of floatable single bodies  2  is provided with cut-outs which are aligned perpendicular to its longer extent and parallel to the water surface. The cut-outs are arranged so that the connecting members  1  can be inserted into them, which then provide for a rigid connection of the single bodies  2 . For reduction of wrapping in the floatable structure, preferably more than two, namely for example four connecting elements  1  are used as shown here. Those extend preferably over the total length of the structure. 
         [0026]      FIG. 2  is a cross-sectional view of a connecting member  1  of  FIG. 1  which shows a box profile  3 . The box profile  3  is preferably manufactured of ferroconcrete. First, a U-form is made in the cut-outs of the single bodies  2 . The upper plate of the box profile  3  is made later on, which allows to insert styrofoam  4  into the inner space of the box profile without any problem. 
         [0027]      FIG. 3  is a top view of a floatable structure according to a second embodiment of the invention which is composed of a plurality of floatable single bodies  5 . The floatable single bodies  5  exhibit the form of an even prism with a footprint of an equilateral triangle, respectively. An example is shown how a desired perimeter with cut-outs can be obtained by combining multiple single bodies  5 . When building a larger structure, a comb-like structure develops as can be seen in  FIG. 3 , wherein such a structure distributes emerging forces especially well and thus provides for a high bearing strength and capacity of the floatable structure. 
         [0028]      FIG. 4  is a cross-sectional view parallel to the upper side of a floatable single body  5  of  FIG. 3 . The floatable single body  5  has the footprint of an equilateral triangle. When it swims, its upper surface is parallel to the water surface. This is of essential importance for a floatable structure. Would e.g. a non-equilateral triangle be used and no special provisions with respect to weight distribution be made, as a consequence, the upper surface of the floatable single body would not be parallel to the water surface. 
         [0029]    The wall  5  of the floatable single body  5  is alternatively of ferroconcrete or carbon fiber or glass fiber, especially of textile reinforced concrete. Profiled walls  6  can be used showing profiles as described above for the connecting members  1 . The cavities of the profiles can be filled with styrofoam. The interior of the single bodies  5  is filled with styrofoam or a different floatable material  7 , whereby the accumulation of water in the interior of the floatable single body  5  is prevented. 
         [0030]      FIG. 5  is a cross-sectional view along the line I-I of  FIG. 1  illustrating the use of holder means  8 ,  9 . The holder means  8 ,  9  can efficiently reduce vibrations of the structure resulting e.g. from waves, when the anchoring positions are chosen properly. For this purpose, it is appropriate especially for longitudinal structures that the holder means are attached in a central area of the structure and that they are transverse outwardly wires, respectively. The holder means  8 ,  9  consist of an anchor or anchoring means  9  and a cable  8 , especially a nylon cable. Depending on the application, this cable  8  is pre-tensioned e.g. with 15 kN to reduce the movements of the structure. 
         [0031]    Alternatively to the bracing described here, the floatable structures can also be anchored by means of chains or post holders. Depending on the needs, the anchoring chains are provided with rider weights.