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Patent Searching and Data


Title:
COLUMN SHOE
Document Type and Number:
WIPO Patent Application WO/2007/074212
Kind Code:
A1
Abstract:
The invention relates to a column shoe for fastening reinforced concrete col- umns to a base. The column shoe comprises a bottom plate (1) provided with a bolt hole (2) and a side plate (3) fastened to the bottom plate for providing a bolt casing, main bonds (4) for fastening the column shoe and the reinforced concrete column to one another, and a back bond (5) for transmitting a lower horizontal force of a horizontal force couple, produced by eccentric positions of the main bonds and the bolt at the bolt hole (2), to concrete. The back bond (5) is arranged to comprise a flexible cable loop (6).

Inventors:
KINNUNEN, Jorma (Pengertie 22, Lahti, FI-15230, FI)
Application Number:
FI2006/050568
Publication Date:
July 05, 2007
Filing Date:
December 20, 2006
Export Citation:
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Assignee:
PEIKKO FINLAND OY (Vipusenkatu 20, Lahti, FI-15100, FI)
KINNUNEN, Jorma (Pengertie 22, Lahti, FI-15230, FI)
International Classes:
E02D5/52; E02D5/22; E04B1/21
Domestic Patent References:
WO2003074821A1
Foreign References:
DE19514685A1
US20050102924A1
EP0952265A2
Other References:
See also references of EP 1966445A1
Attorney, Agent or Firm:
KOLSTER OY AB (Iso Roobertinkatu 23, P.O. Box 148, Helsinki, FI-00121, FI)
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Claims:
CLAIMS

1. A column shoe for fastening reinforced concrete columns to a base, the column shoe comprising a bottom plate (1) provided with a bolt hole (2) and a side plate (3) fastened to the bottom plate for providing a bolt casing, main bonds (4) for fastening the column shoe and the reinforced concrete column to one another, and a back bond (5) for transmitting a lower horizontal force of a horizontal force couple, produced by eccentric positions of the main bonds and the bolt at the bolt hole (2), to concrete, characterized in that the back bond (5) is arranged to comprise a flexible cable loop (6).

2. A column shoe as claimed in claim 1, characterized in that the flexible cable loop (6) is arranged to be anchored to the column.

3. A column shoe as claimed in claim 1, characterized in that the flexible cable loop (6) is arranged to be anchored to another column shoe or other column shoes.

4. A column shoe as claimed in claim 1 or 2, characterized in that both ends of the flexible cable loop (6) are fastened to the column shoe.

5. A column shoe as claimed in claim 1 or 3, characterized in that a connecting element (7) is fastened to the column shoe and that the flexible cable loop (6) is arranged to grip the connecting element.

6. A column shoe as claimed in claim 1, characterized in that the flexible cable loop (6) is arranged to surround the lower flange (1) of the column shoe.

7. A column shoe as claimed in claim 1 or 3, characterized in that the flexible cable loop (6) is arranged to pass through at least one opening (9, 10, 12) in the side plate (3).

8. A column shoe as claimed in claim 7, characterized in that the flexible cable loop (6) is arranged to pass through two openings (9) provided in the side plate (3) and arranged at a distance from one another.

9. A column shoe as claimed in claim 7, characterized in that both ends of the flexible cable loop (6) are arranged to pass through the same opening (10) and that the ends are joined together by a locking element (11), which is arranged to prevent the ends from moving through the opening (10).

10. A column shoe as claimed in claim 5, characterized in that the connecting element (7) is arranged at the surface of the side plate (3)

that is on the side of the bolt hole (2) and that the flexible cable loop (6) is arranged to pass over the side plate (3) to the fastening element (7).

11. A column shoe as claimed in claim 7, characterized in that the flexible cable loop (6) is arranged to pass over the side plate (3) and through an opening (12) in the lower part of the side plate (3).

Description:

COLUMN SHOE

[0001] The invention relates to a column shoe for fastening reinforced concrete columns to a base, the column shoe comprising a bottom plate provided with a bolt hole and a side plate fastened to the bottom plate for providing a bolt casing, main bonds for fastening the column shoe and the reinforced concrete column to one another, and a back bond for transmitting a lower horizontal force of a horizontal force couple, produced by eccentric positions of the main bonds and the bolt at the bolt hole, to concrete.

[0002] Column shoes are used at the lower end of reinforced concrete columns at the corners and on the sides for fastening the column to bolts in the foundations or the rest of the base structure. By using column shoes, the column may be left unsupported during installation. The column shoes join the column with the base structure by means of the bolts.

[0003] A bolt joint mainly transmits vertical forces in the direction of the bolt. Due to the structure of the column shoes, the force to be transmitted from the column to the bolts is not transmitted in the same line but it must be transmitted horizontally to the side in the region of the bolt casing. The force from the column and the bolt are thus positioned eccentrically to one another, which means that the main bonds of the column shoe and the bolt extending from the base structure are positioned eccentrically to one another. In the shoe structure this causes a bending moment, which is transmitted as a horizontal force couple to the column.

[0004] As compression force is transmitted to the bolts, the bending moment caused by the eccentricity tends to push the lower part of the column shoe from the corner of the column towards the middle. Accordingly, the upper part of the side plate of the column shoe tends to move towards the middle of the column. When pulling force is transmitted to the bolts, the bending moment caused by the eccentricity tends to push the lower part of the column shoe towards the middle of the column and the upper part of the column shoe out of the column.

[0005] The upper force of the horizontal force couple is in the upper part of the side plates of the column shoe, and it is transmitted as compression to the concrete when the bolts are under compression or as pulling of a web reinforcement around the column shoes when the bolts are under pulling. The lower force of the horizontal force couple is on the same plane as the bottom plate of the column shoe. In modern column shoes that are on the market, this

horizontal force is transmitted by back bonds, such as a bent ribbed reinforcing bar or an upset bar fastened to the inner corner of the lower edge of the column shoe, when the bolts are under compression or as compression to the concrete when the bolts are under pulling.

[0006] Examples of the above-mentioned prior art solutions include column shoes described in Finnish Patent 95164 and Swedish Patent 511606.

[0007] The above-mentioned known solutions are cumbersome in practice, because they restrict the fitting of column shoes into a column with small side measures. A problem is that the back bonds bang against one another in the middle of the column. In this case, the back bonds are usually detached and the lower horizontal force is transmitted by fastening the column shoes to a common bottom plate or fastening the column shoes to one another in some other way. Furthermore, a problem of column shoes is that it has not been possible to manufacture column shoes before the side measures of the column, to which the column shoes will be fastened, have been found out. Thus, column shoes intended for columns of different sizes must have been manufactured separately. The automation of the manufacture has not been profitable, because the side measures of the columns differ from one another. Thus, the costs have increased and delivery times have become longer. The column shoes connected to one another take up more space during storage and transportation and are also quite heavy, which makes the handling more difficult. Also, individual column shoes on a stiff back bond take up a lot of space during packing and reduce the cost efficiency. As a whole, the handling costs increase due to the above reasons.

[0008] It is an object of the invention to provide a column shoe, by which the prior art disadvantages can be eliminated. This is achieved by a column shoe of the invention. The column shoe of the invention is characterized in that the back bond is arranged to comprise a flexible cable loop.

[0009] The invention provides the advantage that back bonds composed of flexible cable loops are easily interlocked when placed in a small column. Thus, the column shoes may be manufactured to be similar, regardless of the side measures of the column. It is possible to manufacture column shoes to the storage in advance, which makes the automation of the manufacture profitable. The storage and handling of the column shoes also become easier, as they do not need to be bundled. This increases cost-efficiency and makes delivery times shorter. The invention also provides the advantage that

the invention may be implemented in a very flexible manner. For example, the cable loop may be fastened to the column shoe either during the manufacture of the column shoe or at a prefabricated reinforced concrete factory when column shoes are mounted in a mould.

[0010] The invention will now be described in greater detail by means of examples shown in the attached drawing, in which

Figure 1 shows a top view of the principle of a structure, in which four column shoes according to an embodiment of the invention are arranged at an end of the column,

Figure 2 shows a perspective view of the structure of Figure 1 , Figure 3 shows a top view of the principle of a structure, in which four column shoes according to a second embodiment of the invention are arranged at an end of the column,

Figure 4 shows a perspective view of the structure of Figure 3, Figure 5 shows a top view of the principle of a structure, in which four column shoes according to a third embodiment of the invention are arranged at an end of the column,

Figure 6 shows a perspective view of the structure of Figure 5, Figure 7 shows a top view of the principle of a structure, in which four column shoes according to a fourth embodiment of the invention are arranged at an end of the column,

Figure 8 shows a perspective view of the structure of Figure 7, Figure 9 shows a top view of the principle of a structure, in which four column shoes according to a fifth embodiment of the invention are arranged at an end of the column,

Figure 10 shows a perspective view of the structure of Figure 9, Figure 11 shows a top view of the principle of a structure, in which four column shoes according to a sixth embodiment of the invention are arranged at an end of the column,

Figure 12 shows a perspective view of the structure of Figure 11 , Figure 13 shows a top view of the principle of a structure, in which four column shoes according to a seventh embodiment of the invention are arranged at an end of the column, and

Figure 14 shows a perspective view of the structure of Figure 13. [0011] Figures 1 and 2 show the principle of a first embodiment of the invention. The reference numeral 1 refers to a bottom plate provided with a

bolt hole 2. A side plate fastened to the bottom plate is marked with the reference numeral 3. The side plate 3 and the bottom plate constitute a bolt casing. In the example of the figures, the side plate 3 is provided with main bonds 4 for fastening a column shoe and a reinforced concrete column to one another.

[0012] As shown above, a horizontal force couple, which must be taken into account in the structure, is produced due to the eccentric positions of the main bonds and the bolt at the bolt hole 2. A back bond 5 is used for transmitting the lower horizontal force of the above-mentioned horizontal force couple to the concrete.

[0013] Figures 1 and 2 show a position, in which the column shoes are located at an end of the column. The column itself is not illustrated in the figures. The column shoes are mounted in their places during the manufacture of the column, i.e. they are brought to their places in the mould before the concrete casting. As a result of the casting and hardening of the concrete, the column shoes are an integral part of the column in such a manner that the column may be fixed to the bolts on the base by arranging the bolts in the holes in the bottom plate of the column shoe and driving nuts in the bolts.

[0014] The above facts represent background art entirely obvious to a person skilled in the art, wherefore they will not be explained in greater detail here. In this context, a reference is made, for example, to publications Fl 95164 and SE 511606 cited above as prior art.

[0015] The essential idea of the invention is that the back bond 5 is arranged to comprise a flexible cable loop 6. The above-mentioned flexible cable loop transmits the lower horizontal force of the column shoe either by being anchored to the column directly or by connecting to other shoes, as shown in the following examples. In the example of Figures 1 and 2, the flexible cable loops are anchored directly to the column. In the example of Figures 1 and 2, both ends of the flexible cable loop 6 are fastened to the column shoe. The fastening may be implemented, for instance, by providing the side plate 3 with slot parts 8, in which the ends of the cable loop 6 are arranged, as shown in Figures 1 and 2.

[0016] Figures 3 and 4 show a second embodiment of the column shoe of the invention. The same reference numerals are used in Figures 3 and 4 to refer to corresponding parts as in Figures 1 and 2.

[0017] In the embodiment of Figures 3 and 4, a connecting element 7 is fastened to the column shoe and the flexible cable loop 6 is arranged to

grip the connecting element. In the embodiment of Figures 3 and 4, the connecting element 7 consists of a flange part fastened to the column shoe. The flange part includes a hole, through which the flexible cable loop 6 is arranged to pass. In the example of Figures 3 and 4, the cable loop 6 is arranged to grip the connecting elements 7 of all four column shoes, which means that the column shoes are connected to one another by means of the flexible cable loop 6. However, it is obvious that the embodiment of Figures 3 and 4 may also be applied in such a manner that each column shoe has its own flexible cable loop 6, which is anchored directly to the column.

[0018] Figures 5 and 6 show a third example of the column shoe of the invention. The same reference numerals are used in Figures 5 and 6 to refer to corresponding parts as in the examples of Figures 1 and 2 as well as 3 and 4.

[0019] In the embodiment of Figures 5 and 6, the flexible cable loop 6 is arranged to surround the lower flange 1 of the column shoe. In the example of Figures 5 and 6, the flexible cable loops 6 are arranged to be anchored directly to the column. The flexible cable loops are formed by arranging the cable to pass around the lower flange 1 and by joining the free ends of the cable together.

[0020] The invention is not, however, restricted to the example of Figures 5 and 6 in any way, but it is perfectly possible that this embodiment is also applied in such a manner that the lower horizontal forces of the column shoes are transmitted by means of the flexible cable loops by connecting to other shoes, i.e. by fastening the column shoes to one another by means of the flexible cable loops 6.

[0021] Figures 7 and 8 show an embodiment of the invention, wherein the flexible cable loop 6 is arranged to pass through openings 9 in the side plate 3. The openings 9 are arranged at a distance from one another. The openings 9 may be formed, for instance, by providing the lower edge of the side plate 3 with a groove or slot, through which the cable loop 6 can easily be mounted in its place before the side plate is fastened to the lower flange 1. The lower edge of the groove or slot is closed as the side plate 3 is fastened to the lower flange 1 , as shown in Figure 8. The openings may naturally be formed in some other way, such as by drilling or cutting a suitable opening in the side plate, etc.

[0022] Figure 8 also shows bolts, which are arranged to pass

through the bolt holes 2. In the example of Figures 7 and 8, the flexible cable loops 6 are arranged to pass around the bolts.

[0023] The number of openings in the side plate 3 is not restricted to two in any way, but the number of openings may vary. Figures 9 and 10 show an embodiment, in which both ends of the flexible cable loop 6 are arranged to pass through the same opening 10. In this embodiment, the ends of the flexible cable loop 6 are joined together by a locking element 11 , which is arranged to prevent the ends from moving through the opening 10.

[0024] Figures 11 and 12 show an example of the invention, wherein a connecting element 7 fastened to the side plate is used. Compared to the example of Figures 3 and 4, the connecting element is in this embodiment fastened to the other side of the side plate 3. In the example of Figures

11 and 12, the connecting element 7 is arranged at the surface of the side plate 3 that is on the side of the bolt hole 2 and the flexible cable loop 6 is arranged to pass over the side plate 3 to the fastening element 7.

[0025] Figures 13 and 14 show an embodiment, in which the flexible cable loop 6 is arranged to pass over the side plate 3 and through an opening

12 in the lower part of the side plate 3.

[0026] The above examples of the invention are not intended to restrict the invention in any way, but the invention may be freely modified within the scope of the claims. Thus, it is obvious that the column shoe of the invention or the details thereof need not be exactly similar to those shown in the figures, but other solutions are feasible as well. The shape of the column shoe and the number of bonds, for instance, may naturally be varied according to each situation, the embodiments shown in the figures may also be applied in such a manner that the flexible cable loop is anchored to another column shoe or other column shoes by means of a cable loop of another column shoe, for instance, etc.