WO2008135634A1

WO2008135634A1 - Steel frame and method for raising the same

Info

Publication number: WO2008135634A1
Application number: PCT/FI2008/050237
Authority: WO
Inventors: Marko Moisio
Original assignee: Rautaruukki Oyj
Current assignee: Rautaruukki Oyj
Priority date: 2007-05-03
Filing date: 2008-04-30
Publication date: 2008-11-13
Anticipated expiration: 2009-11-03
Also published as: FI20075312A7; RU2459911C2; RU2009144784A; FI20075312A0; FI20075312L; EP2142717A1; EP2142717A4

Abstract

A steel frame of a building comprising at least horizontal beams (3) and vertical pillars (1, 2), in which a support surface is formed to at least one end of one pillar (1) and a mating surface is formed to at least the end of another pillar (2) so that the support surface and mating surface can be arranged one inside the other, thus forming a sleeve construction. In the method vertical pillars (1, 2) are erected and at least (1, 2) are arranged as extensions of each other by means of sleeve connection.

Description

Steel frame and method for raising the same

The present invention relates to a steel frame of a building the frame comprising at least horizontal beams and vertical pillars.

The invention also relates to a method of erecting a steel frame.

The steel frame of buildings is a structure mainly consisting of vertical support pillars and horizontal load-bearing beams. Additionally, trellis structures having various kinds of diagonal braces, triangular structures and the like, are used. The trellis structures are often prefabricated into installation modules in the workshop. The dimensioning and structure of the frame are planned individually for each case. The frame can, for example, be a part of the load-bearing frame structure of the building and act as connector structure with, for example, concrete structures. The frame can also act as a stand-alone load-bearing structure. The advantages of a steel frame are, among others, quick assembly, precisely dimensioned parts due to which they can easily be attached to each other and a good load-bearing capacity in relation to the dimensions and weight of the frame. The flexibility of designing a steel frame is exemplified in thin and low structures and the easiness of connections. A steel frame makes it possible to achieve a good dimensional precision for e.g. parts related to the facade.

At a construction site, the steel frames are transported and handled with the same lifting and transport apparatuses as the other component parts, i.e. either fixed cranes or movable vehicle cranes. Both of these lift the load with a hook or other carrying means suspended by wires and the load hangs freely from the ends of the wires. During such lifting the load can freely swing sideways and the pillars or beams must be guided precisely onto their places by hand. Thus, installing the parts requires in addition to the crane driver at least one installer for guiding the beam or pillar and for performing the necessary fastening. The most common ways of fastening structures are welding and various bolt connections. The frame is assembled one floor at a time and the crane is used for moving the pillars and beams into their correct places. Screw fastenings can be lightly installed in their places and the welded connections can also be preinstalled for final fastening welding and the bolts are tightened and the final welding is made in their time after the parts are lifted in place. However, regardless of the phase in which the final fastening is performed, the installation work of the frame requires a lot of labour because the pillars and frames must be guided into their places by hand. The accuracy of a wire-operated crane moving a freely hanging load is not sufficient for positioning parts without manual labour. Especially with bolt connections the bolt holes must be exactly aligned in order to be able to make the connection. Weld seams do require a good installation accuracy as well for forming a correct groove that can be reliably welded. To achieve a sufficient installation accuracy frame installers position the parts of the frame in place and manufacture the connection. Often the pillar or beam must also be supported during manufacturing of the connection or at least in the beginning thereof so that the part is not allowed to move out of alignment. The support is provided with the site lifting apparatuses, the capacity of which must be used for a long time. When, for example, the construction site crane is in use, the supplies and machinery needed by other jobs cannot be moved. Thus the erecting of the frame can require a dedicated crane or it can slow down the site schedule.

The aim of the present invention is to provide a novel kind of steel frame, easier to erect than previous frame structure.

The invention is based on the idea that a support surface is formed on the end of at least one pillar and a mating surface on the opposite end of a pillar so that the support surface and the mating surface can be located nested one inside the other, thus forming a sleeve structure.

Preferably at least one of the nested surfaces includes a chamfering for making aligning the ends of the pillars easier.

According to one embodiment the ends of the pillars are provided with positioning means by means of which the pillars formed as extensions of each other can be positioned in the direction of their longitudinal axis. According to one preferred embodiment the pillar is tubular and the chamfering is a cone arranged in the end of the pillar and the first positioning means is a flange, whereby their mating surfaces at the other end of the pillar are the inner hole of the pillar and the edge of the end of the pillar.

According to one preferred embodiment the pillars comprise positioning and suspension means for at least transverse beams.

According to one preferred embodiment at least one end of the pillar comprises locking means for gripping another pillar.

The features described above and other inventive features in the disclosure and claims can be realized either directly working on the ends of the pillars or using separate fastening means.

Preferably the locking means are a collar tightened around the end of the pillar.

The invention is defined in more detail in the claims.

Considerable advantages are achieved by means of applications of the invention.

The invention allows a faster and less labour-intensive assembly of the frame than with previous installation methods. The erecting of the frame can to large degree be automatized by using the apparatus described by the applicant in a parallel application for handling the pillars. The apparatus is used for taking the pillars into their places and positioning them by means of a grabber. The grabber can comprise a welding apparatus for attaching the pillar or means for rotating the pillar, whereby a threaded connection can be used in the ends of the pillar. Many other connection methods can also be used for assembling the structure. When using a grabber apparatus the erecting of the frame and making the connections can be almost totally automatized, if desired. Another possible connection method is, for example, shrink fit connection, in which the end of the outer pillar is heated so that it can be arranged around the end of the inner pillar. Thus the outer pillar is rigidly attached to the inner pillar as it cools down. The heating can easily be carried out by means of, for example, a gas-operated flame ring or an induction heater attached on the grabber. This installation method can even be faster than automatic welding. All in all the invention makes it possible reliably erect the frame without bolt connections, the installation and tightening of which is time- consuming and requires a lot of labour.

In order to increase fire resistance and load capacity the pillars can be filled with concrete or fire resistant material.

In the following, the invention is examined by means of examples and by reference to the appended drawings.

Figure 1 illustrates one pillar connection method according to the invention.

Figure 2 illustrates another connection method according to the invention.

Figure 3 illustrates one pillar connection structure method according to the invention.

Figure 4 illustrates one pillar connection structure method according to the invention.

Figure 5 illustrates one pillar connection structure method according to the invention.

Figure 6 illustrates an assembled frame structure.

Figure 7 is a schematic diagram of assembly of a frame according to the invention by means of a frame erecting apparatus comprising a grabber.

In the embodiments of figures 1 and 2 the pillars 1 and 2 are straight pillars made of steel tubing. Rectangular hollow beams having a lower flange are used as beams 3. The connection is made via a sleeve 4, 5 formed between pillars 1 and 2. In this case the sleeve comprises a support part going inside the first pillar - lower pillar 1 - that is preferably conical, a transverse flange 5 supported by the upper end of the lower pillar 1 and an installation cone 4 in the shape of a truncated cone to be inserted inside the pillar tube of the second pillar - upper pillar 2. The support part inserted into the lower pillar 1 and the installation cone 4 inserted into the upper pillar 2 preferably have similar form, but as such their form can be freely selected and the forms can differ from each other, as long as the functional requirements presented below are fulfilled. In the construction method shown in figures 1 and 2 the extension point of beams 3 is arranged at the connection point between pillars 1, 2. The advantage of this arrangement is that the connections of both beams and pillars are made in the same installation point, whereby there is no need to move the machines and tools when making, for example, a weld connection. The upper and lower flanges 6, 7 of the beams to be connected are provided with semi-circular cuts 8 corresponding to the outer diameter of the upper pillar 2.

The structure of figure 2 differs from that of figure 1 so that there at least the part of the installation cone 4 on the side of the flange 4 comprises a cylindrical support surface 9. This support surface 9 can be supported by the inner part of the upper pillar 2 or the cuts 8 in the beams 3 in the connection point. If the support surface 9 is dimensioned so as to be supported by the cuts 8 of the beam 3, the upper part of the support surface 9 at the connection point of the cone 4 is provided with an edge 10 on which the upper pillar 2 can be placed. If the beam 3 is supported directly by the support surface 9, the advantage is that the beam 3 is better supported during installation, but on the other hand, the support for the upper pillar 2 is weaker. If the upper pillar 2 is located over the support surface 9 and is supported by flange 5, the assembled structure will be stronger.

Figure 3 illustrates a sleeve solution in which the diameters of the pillars must be similar. In this example the lower pillar 1 has a smaller diameter and the diameter of the upper pillar is larger. The connection sleeve is a cup located over the lower pillar comprising a cylindrical body part 11, a sleeve 5 forming a collar connected on one edge thereof, a cone part 12 connected to the opposite end of the body part and a cover 13 closing the sleeve cup. The inner surface of the body part 11 is dimensioned to fit around the outer surface of the lower pillar 1 and its outer surface corresponds to the inner diameter of the upper pillar. The end of the lower pillar 1 is provided with a bevel 14 supported by the lower surface of the cone part 12. The upper end of the lower pillar 1 is supported by the inner surface of the cover 13 of the sleeve cup. Thus the cone part 12 and the cover 13 position the sleeve cup onto the end of the lower pillar 1. Beam 3 or beams are arranged on flange 5 and they are installed around the outer surface of the upper pillar.

The above-mentioned structure can be turned around so that the places of the lower pillar 1 and the upper pillar are reversed. Thus, only the beam or beams 3 are located on the other side of the flange 5. Because the lower pillar 1 has a larger load, this structure is more preferred because in it the pillar having the larger diameter and the larger load capacity is located lower.

Figure 4 illustrates a simpler embodiment than the previous ones. In this embodiment the pillar structure comprises nested pillar tubes 1, 2 of which the thinner one 2 is provided with a flange 5 by means of, e.g. welding, at a distance from the end of the pillar. The end of the same pillar 1 is provided with a bevel 15. The pillars are installed in this position, the upper pillar 2 is located over the lower pillar 1, supported by the flange 5. The bevel 15 makes it easier to arrange the lower end of the upper pillar 2 onto the end of the lower pillar. In order to provide a strong connection the outer and inner diameters of the tubes must closely fit each other, especially when using a shrink fit connection. The beam 3 is installed over the flange 5 so that it is supported by the outer surface of the upper pillar. This connection method can be reversed as well, whereby the beam 3 is located on the other side of the flange 5 and it is supported by the surface of the thinner pillar 1. The alternative of figure 5 is different from this one in that there the beam 3 is located on the flange 5 and against the surface of the thinner pillar 1. The larger pillar 2 is located on the beam 3, the inside of the box structure of the beam 3 being provided with a support flange 16 for transferring the load exerted on the upper surface of the beam to the flange 5. Figure 5 illustrates an assembled structure according to the invention. There the connection points of the beams 17 are located offset from the connection points of the pillars, whereby a hole is formed in the box structure of the beams at the place of the pillars. The advantage of this solution is a reasonable stability already when the beams are only placed on the pillars and there is no need for separate support.

The assembly method of all the above-mentioned connection method is relatively similar. The beams and pillars are prepared either at the factory or at the construction site at the latest by making into the beams round holes or curved cuts for the pillars. The holes or cuts are made to suit the diameters of the pillars. For box-section beams it is preferable to have vertical webs intact on the side of the pillars. With I-beams the web can be left intact and the grooves needed for the web can be cut into the ends of the pillars. If sleeves according to figures 1 , 2 or 3 are used, the sleeves are placed to the ends of the pillars, preferably to the ends of the lower pillars, whereby the beams can be placed on their flanges. Most preferably the parts are manufactured at the machine shop, whereby it is possible to use correct machining tools for manufacturing the parts and the parts are ready for installation at the construction site. Firstly, the first lower pillars 1 are installed on the foundation. If sleeves 4, 5 or 11-13 are used, they are placed on top of the pillars if that has already not been done. Next, the beams 3 are lifted on flanges 5, subsequent to which the next pillars 2, i.e. upper pillars, can be installed.

Welding is an advantageous way of making the connections of the structure. Welding machines are used on construction sites and welding is the most preferred connection method for connecting beams to pillars. The beams and pillars themselves can be fastened to each other by other means as well. One preferred method is shrink fit connection, in which the larger tube, in this case the end of the pillar, is heated, whereby its diameter increases. The heated end of the pillar is taken over the head of the smaller pillar and the pillars are pushed one inside the other. When the heated tube cools, it shrinks tightly over the smaller tube. Various flame or induction heaters are inexpensively available and they are easy to use. A shrink fit connection is immediately load-bearing, so no flange 5 is necessarily needed for positioning the height position of pillars in the case of e.g. figures 4 and 5, but the upper pillar can be pushed accurately on place and then wait a while for it to cool, subsequent to which the installation is complete. It is, however, advantageous to use a flange just for easing positioning, but in case there is no flange, the beams must be suspended during the whole of the fastening process. Shrink-fit connection is also suitable for fastening the sleeves. A shrink-fit connection can require shortening the ends of beams to an accurate length, but not necessarily. Forming a threaded connection between the ends of the beams is also possible, but making such to the ends of the pillars is currently expensive. An interference fit, in which parts accurately fitting each other are pressed into contact with each other, can also be used for connections. In an interference fit the inner diameter is slightly larger than the outer diameter, whereby a necessary connection force is provided. The connection can be made by forming a groove in the end of the pillar and by fitting a tightenable collar around the end of the pillar or by providing tightening lugs along the edges of the groove, by means of which the end of the pillar is fastened to a separate sleeve or to the end of another pillar. The possibility of using such a fastening method depends on the beam structure. All seam points can, if necessary, be ensured with weld seams.

The frame structure according to the invention is very suitable for erecting with the apparatus described below. Therein at least the pillars are moved to place with an erecting apparatus comprising a rigid boom system and a grabber. This apparatus allows moving the pillars straight to their places and due to the bevels made to the structure no separate guiding is needed in the installation target. The grabber can be provided with flame or induction heater, welding apparatuses or other tools necessary for the installation.

The apparatus illustrated in figure 7 comprises a conventional known tractor 17 and a transfer beam system 18 attached thereto. The end of the beam system 18 is provided with a grabber 19 for gripping the pillars 1, 2. The boom system 18 is to transfer the grabber 19 in a three-dimensional environment to a certain point and this function can be carried out by means of many kinds of boom systems. The grabber is to, naturally, first to try and grip the pillar 1, 2 (in the figure) or a beam. On the other hand it is to position the end of the pillar at exactly the correct place by means of rotation movements about the horizontal and vertical plane of the grabber. The grabber also makes sure that the position of the pillar or the beam is correct, hi the example of figure 7 the pillars 1, 2 are positioned vertically and the beams 3 are positioned horizontally. Construction regulations for steel structures include tolerances for, e.g. the largest permissible inclination of the pillars. In order to control this it is preferable to provide the grabber with sensors by means of which the inclination can be controlled and the pillars can be installed vertically.

With the above-described apparatuses a steel frame is erected as follows.

The grabber 19 of the erection apparatus picks the pillar 2 by gripping it near the lower end thereof, i.e. the end located lower when installed in the frame. The pillar is turned to a vertical position by movements of the boom system 18 and the grabber 19 and it is moved to its installation point, in this case to the upper end of the already erected pillar 1. The new pillar 2 is turned into a vertical position and moved to the sleeve 4, 5 of the end of the erected pillar and lowered so as to be supported by the pillar. In this example the upper ends of the pillars are provided with installation sleeves, so the lower end of a new pillar 2, guided by the cone 4, is easily located on top of the erected pillar. The lower end of the cone is provided with a flange 5 onto which the lower end of the new pillar 2 is lowered and on which the beam 3 also rests. The beam 3 is provided with a cut for the ends 1, 2 of the pillars. When the pillar is positioned in its correct place, it can be fastened. Any suitable connection can be used for fastening, but if the grabber 19 is provided with an automatic welding apparatus, welding is a very preferable connection method. Thereby the connection will be ready at one go. The frame can be erected by first installing the first line of pillars and then positioning cross-beams on it, subsequent to which another line of pillars and the next beams are installed. On the other hand, the beams can be installed with a site crane as well by manually guiding them, whereby it is possible to simultaneously install new pillars and immediately thereafter beams on the formed installation places.

The erecting apparatus and a method of erecting the frame is disclosed in a co-pending application of the applicant. The frame according to the invention can also be erected by means of other kinds of lifting arrangement. The shape of the pillars can be other than round, such as rectangular, square or a polygon. In such a case the other features of the invention must naturally be arranged to fit this shape.

Claims

We claim:

1. A steel frame of a building comprising at least horizontal beams (3) and vertical pillars (1, 2), characterized in that a support surface is formed to at least one end of one pillar (1) and a mating surface is formed to at least the end of another pillar (2) so that the support surface and mating surface can be arranged one inside the other, thus forming a sleeve construction.

2. A steel frame according to claim 1, characterized in that at least one of the surfaces to be nested comprises a chamfering (15) for making the aligning of the ends of the pillars easier.

3. A steel frame according to any of the previous claims, characterized in that positioning means (5) are formed to the ends of the pillars (1, 2) by means of which the pillars (1, 2) to be arranged as extensions of each other can be positioned in the direction of their longitudinal axis.

4. A steel frame according to any of claims 1-3, characterized in that the pillars are tubular and the chamfering is a cone (4, 12, 15) arranged in the end of the pillar (1) and the first positioning means is a flange (5), whereby their mating surfaces at the end of the second pillar (2) are the inside hole and the edge of the end of the pillar.

5. A steel frame according to any of claims 1-4, characterized in that the pillars (1, 2) are provided with positioning and supporting means (5) for at least the transverse beams (3).

6. A steel frame according to any of claims 1-6, characterized in that at least one end of one pillar is provided with locking means for gripping another pillar.

7. A steel frame according to any of previous claims, characterized by cuts (8) made to the horizontal beams (3) made so as to conform to the outer surface of the pillars (1, 2).

8. A steel frame according to claim 7, characterized in that the cuts are round holes made into the beams (3).

9. A steel frame according to claim 7, characterized in that the cuts are semi-circular cuts (8) holes made to the ends of the beams (3).

10. A method of erecting a steel frame of a building, the frame comprising at least horizontal beams (17) and vertical pillars (4, 14), in which method vertical pillars (1, 2) are erected and horizontal beams (3) are arranged supported by them, characterized in that at least two vertical pillars (1, 2) are arranged as extensions of each other by means of a sleeve connection.

11. A method according to claims 10, characterized in that shrink-fit connection is used in at least one sleeve connection.

12. A method according to any of claims 10-11, characterized in that the beams (3) are supported by the pillars (1, 2) by means of flanges (5) arranged on the pillars and cuts corresponding to the shape of the outer surface of the pillars (1, 2) formed into the beams.

13. A method according to any of claims 10-12, characterized in that at least one of the pillars (1, 2) of the frame is taken into place by means of a rigid boom system (18) by moving it with a grabber (19) fastened to the boom system (18) and rotated into the correct installation position by rotating the gripping means of the grabber (19) about at least two axes of rotation.

14. A sleeve for connecting a frame pillar (1) to the next frame pillar (2), the sleeve comprising at least one means (11, 12) for connecting to the end of the first frame pillar (1) and second means (11) for connecting to the second frame pillar, characterized in that the sleeve comprises at least one flange (5) on which at least one horizontal beam (3) can be installed.

15. A sleeve according to claim 14, characterized in that the at least one means (11-13) for connecting to the end of the pillar 81) comprise a cup-like structure.

16. A sleeve according to claim 14, characterized in that the at least one means (4, 9, 10) for connecting to the end of the pillar (2) comprises a cylindrical surface (9) and a conical surface (4) that can be arranged inside the pillar (9).