| WO/2008/036934 | PARTIALLY PREFABRICATED MODULAR FOUNDATION SYSTEM |
| WO/2005/015013 | TOWER FOUNDATION, IN PARTICULAR FOR A WIND ENERGY TURBINE |
| WO/2011/034603 | MODULAR FOUNDATION SYSTEM AND METHOD |
TUOMINEN, Kari (Laiturikatu 3 B 34, Lahti, FI-15140, FI)
| CLAIMS 1. An arrangement in connection with foundations of mast-like structures, the foundation comprising a reinforced concrete structure having fastening bolts (3) for anchoring the mast-like structure to the foundation by means of nuts (5) to be screwed to the fastening bolts (3) and positioned above a lower flange (4) of the mast-like structure, characterized by a distance piece assembly to be arranged between the lower flange of the mastlike structure and the foundation, the assembly comprising a sleeve-like threaded part (9) and a counterpart (7) with threads matching the threads of the sleeve-like threaded part (9), whereby the sleeve-like threaded part (9) is arranged around each fastening bolt (3) at a desired height by means of the threads of the sleeve-like threaded part and counterpart, and whereby the distance piece assembly is arranged between the foundation and the lower flange of the mast-like structure by means of an upper nut (5) to be screwed to the fastening bolt. 2. An arrangement according to claim 1, characterized in that the arrangement comprises a plate-like support part (10), one surface of which is a calotte-like surface, whereby the plate-like support part (10) is arranged to be pressed by its calotte-like surface against one end of sleevelike threaded part (9). 3. An arrangement according to claim 1 or 2, characterized in that the sleeve-like threaded part (9) is a sleeve-like female part. 4. An arrangement according to claim 1 or 2, characterized in that the sleeve-like threaded part (9) is a sleeve-like male part. 5. An arrangement according to claim 3, characterized in that through the fastening bolt (3), a washer (6) has been passed which is arranged to be supported against the concrete surface/form structure of the foundation around the fastening bolt (3); onto the washer (6), a male part has been threaded which serves as a counterpart (7) and is pre-tightened in place by means of a fastening nut (8) screwed to the fastening bolt; and the sleevelike threaded part (9) has been screwed to the male part to a desired height. 6. An arrangement according to claim 5, characterized in that the plate-like support part (10) is arranged to be pressed by its calotte-like surface against the upper end of the sleeve-like threaded part (9) and by its other surface against the lower surface of the lower flange (4) of the mast-like structure. 7. An arrangement according to claim 4, characterized in that a sleeve-like threaded part (9) is arranged around the fastening bolt (3) in such a way that it becomes pressed by its lower end against the surface of the foundation and that it is screwed to the female threads of the hole formed in the lower flange of the mast-like structure in such a way that the lower flange (4) becomes positioned at a desired height. 8. An arrangement according to claim 7, characterized in that the plate-like support part (10) is arranged through the fastening bolt (3) on the surface of the foundation in such a way that it is pressed by its one surface against the foundation and that the sleeve-like threaded part (9) is pressed by its lower end against the calotte-like surface of the plate-like support part (10). 9. An arrangement according to claim 7, characterized in that the upper end of the sleeve-like threaded part is provided with a support flange (11 ), against which the upper nut (5) arranged in the fastening bolt (3) is fastened. 10. An arrangement according to claim 4, characterized in that the sleeve-like threaded part (9) is arranged around the fastening bolt (3) and screwed to the female threads of the hole formed in the flange element serving as the counterpart (7) and being a part of the foundation in such a way that the sleeve-like threaded part (9) protrudes from the surface of the foundation in a desired manner. 11. An arrangement according to claim 10, characterized in that a plate-like support part (10) is arranged around the fastening bolt (3) in such a way that it is supported by its calotte-like surface against the upper surface of the sleeve-like threaded part (9) and by its other surface against the lower surface of the lower flange (4) of the mast-like structure. |
[0001 ] The invention relates to an arrangement in connection with foundations of mast-like structures, the foundation comprising a reinforced concrete structure having fastening bolts for anchoring the mast-like structure to the foundation by means of nuts to be screwed to the fastening bolts and positioned above a lower flange of the mast-like structure.
[0002] The invention relates to the context of foundations of mastlike structures, more precisely to structures with which a mast-like structure is connected to the foundation. Mast-like structures include, for example, wind power plants, chimneys, light poles and other dynamically loaded mast-like structures.
[0003] In connection with the foundations of mast-like structures of wind power plants, two common basic solutions have been used. In the first known solution type, the steel part of the tower of a wind power plant is cast in the foundation. In the second known solution, the tower of a wind power plant is installed upon the foundation, and the tensile forces are anchored to the foundation with anchor bolts. The area between the foundation and the tower is soldered with soldering mass by means of which the compression forces are transmitted to the foundation.
[0004] A drawback with the first known basic solution is, for example, that when making a foundation, workmen normally handle smallish reinforcement products with a weight of 100 kg at the most. In construction site conditions, particular further problems arise when it is a steel tower part of 10 000 to 20 000 kg that has to be arranged at the reinforcements. This problem increases the costs accrued from, for example, an increase in the size of the equipment. In addition, the costs are increased because the logistics becomes more difficult as the delivery times of the tower are different from those of the rest of the foundation reinforcement.
[0005] Additional problems are caused because installing a heavy steel tower part is a demanding task as after the casting, the flange remaining on the surface of the concrete pouring must be sufficiently accurately on the horizontal plane. The problem is substantial because the verticality requirements for a tower of 60 to 120 m are particularly strict. The soldering is made when the whole tower has been installed, or the first part of the tower is separately installed and soldered. [0006] A drawback with the second known basic solution mentioned above is, for example, that the whole tower must be installed to be supported merely by bolts at the installing stage. The soldering is not made until after the tower has been installed. In installing, the bolts may be subjected to great forces by the swaying tower. The installing order may also be such that the first part of the tower is installed and soldered and the bolts are pre-tightened, and not until after the soldering has been hardened does it become possible to install the rest of the tower. This means that it takes more time to implement the instalment and that, at the same time, particularly the installing equipment causes additional costs. The concrete of the foundation also creeps, due to which the pre-tightening of the bolts decreases over time. Due to this phenomenon, the pre-tightening must be checked at given intervals, particularly during the year following the concreting. Timewise, creeping is greatest just after the casting, and the creep is affected by the amount of loading. Creeping is a detrimental phenomenon in terms of the pre-tightening of the bolt.
[0007] In dynamically loaded mast-like structures, it is necessary to be able to transmit the prestressing force uniformly from the uppermost nut through the bolt to the anchoring element(s). So far, the solution has typically been tightening of the end flange of a structure directly against the structure. A problem here has been the unevenness of concrete structures, due to which various solutions to ensure the evenness of a concrete surface, such as smoothing second-stage concretes, are used.
[0008] An object of the invention is to provide an arrangement by means of which the drawbacks of the prior art can be eliminated. This has been achieved by means of the arrangement according to the invention. The arrangement according to the invention is characterized by a distance piece assembly to be arranged between the lower flange of the mast-like structure and the foundation, the assembly comprising a sleeve-like threaded part and a counterpart with threads matching the threads of the sleeve-like threaded part, whereby the sleeve-like threaded part is arranged around each fastening bolt at a desired height by means of the threads of the sleeve-like threaded part and counterpart, and whereby the distance piece assembly is arranged between the foundation and the lower flange of the mast-like structure by means of an upper nut to be screwed to the fastening bolt. [0009] An advantage of the arrangement according to the invention is its simplicity and the preferable uniform distribution of forces particularly in dynamic loading situations. A further advantage of the invention is its versatility, since the arrangement according to the invention can be used in all conventional mast-structures in such a way that the adjustability is ensured and, at the same time, the prestressing forces have an even impact all the way from the upper nut to the anchoring element.
[0010] In the following, the invention will be explained in greater detail with reference to the embodiment examples illustrated in the attached drawing, whereby
Figure 1 shows a principled view of a first embodiment of an arrangement according to the invention;
Figures 2 to 5 show a detail of the embodiment according to Figure 1 in larger scale and seen from different directions;
Figure 6 shows a side and principled view of a second embodiment of the arrangement according to the invention;
Figures 7 to 9 show a detail of the embodiment according to Figure 6 in larger scale and seen from different directions;
Figure 10 shows a side and principled view of a third embodiment of the arrangement according to the invention; and
Figures 1 1 to 13 show a detail of the embodiment according to Figure 10 in larger scale and seen from different directions.
[0011] Figures 1 to 5 show a first embodiment of the invention. Reference numeral 1 denotes a mast-like structure or a part of a mast-like structure. Reference numeral 2 shows generally a reinforced concrete structure with fastening bolts 3 by means of which the mast-like structure 1 is fastened to the foundation. The fastening is carried out by means of nuts 5 above a lower flange 4 of the mast-like structure 1 , the nuts being screwed to the fastening bolts 3.
[0012] An essential feature in the invention is that the solution uses a distance piece formed in the following way. In the embodiment according to Figures 1 to 5, after the casting, a washer 6 is passed through the fastening bolt 3 to become positioned against the concrete surface/form structure. Subsequently, a thick male part serving as a counterpart 7 is threaded onto the washer. Finally, a fastening nut 8 is screwed and pre-tightened to the planned force. This pre-tightening force is transmitted as compression through the thick threaded part serving as the counterpart 7 and the washer 6 to the concrete. At the same time, the foundation is prestressed and creeping due to the loads begins to be generated.
[0013] For installing the mast-like structure 1 , i.e. the column tower itself, a tubular threaded part 9 is threaded to the thick male part serving as the counterpart 7 to exactly the right height. This provides the desired height adjustment. In this embodiment, the sleeve-like threaded part 9 is a sleeve-like female part.
[0014] Upon the sleeve-like threaded part 9, a plate-like support part 10 may preferably be mounted in which one surface is a calotte-like surface while the other surface may be, for instance, a planar surface or another suitable surface. The plate-like support part 10 evens out the forces on the lower flange 4 of the wind power tower. Since the flange 4 has deviations due to manufacturing tolerances and deflections, it is important that the forces be evenly distributed because in dynamic loading, point loads are dangerous. In connection with installing the first tower part, the nut 5 above the flange 4 is tightened in place. The nut may also be tightened to an agreed/final pre- tightening value. The plate-like support part 10 is not necessary but the invention may also be applied without the above plate-like support part.
[0015] In the embodiment according to Figure 1 , the plate-like support part 10 is arranged to be pressed by its calotte-like surface against the upper end of the sleeve-like threaded part 9 and by its planar surface against the mast-like structure.
[0016] Figures 2 to 5 show the above-mentioned distance piece in separate views seen from different directions.
[0017] The distance piece may be designed in such a way that no second-stage concrete is made under the tower, in which case the adjustability of the position of the tower is improved, for example owing to subsidence of the ground or for other reasons. Using second-stage concrete is possible and, at the same time, the implementation of the second-stage concrete may be selected technically and in terms of schedule in the best possible way.
[0018] Figures 6 to 9 show a second embodiment of the invention. The same reference numerals as in Figures 1 to 5 are used at corresponding points in Figures 6 to 9.
[0019] In the embodiment of Figures 6 to 9, the plate-like support part 10 is arranged on the surface of the foundation through the fastening bolt 3 in such a way that the part is pressed by its planar surface against the foundation. Further, a sleeve-like threaded part 9 is arranged around the fastening bolt 3 in such a way that it is pressed by its lower end against the calotte-like surface of the support part 10. The sleeve-like threaded part 9 is, in this embodiment, a male part. The sleeve-like threaded part 9 is threaded to the female threads of the hole formed in the lower flange 4 of the mast-like structure serving as the counterpart in this embodiment in such a way that the lower flange 4 becomes positioned at a desired height. This provides the desired height adjustment. Reference numeral 1 1 indicates a support flange arranged at the upper end of the sleeve-like threaded part, the upper nut 5 arranged in the fastening bolt 3 being tightened against this support flange.
[0020] Figures 7 to 9 show the distance piece of this embodiment, seen from different directions.
[0021] Figures 10 to 13 show a third embodiment of the invention. The same reference numerals as in Figures 1 to 9 are used at corresponding points in Figures 10 to 13.
[0022] In the embodiment according to Figures 10 to 13, the sleevelike part 9 is a male part. The sleeve-like threaded part 9 is arranged around the fastening bolt 3 and threaded to the female threads of the hole formed in a flange element 12, which serves as the counterpart of this embodiment and is a part of the foundation, in such a way that the sleeve-like threaded part 9 protrudes in a desired manner from the surface of the foundation, whereby the desired height adjustment is provided. The plate-like support part 10 is arranged around the fastening bolt 3 in such a way that it is supported by its calotte-like surface against the upper end of the sleeve-like threaded part 9 and by its planar surface against the lower surface of the lower flange 4 of the mast-like structure.
[0023] The above embodiments are by no means intended to restrict the invention but the invention may be modified completely freely within the claims. For example, the shaping and the number of various components are not, in any way, restricted to the examples of the figures but different solutions are also feasible.