AU706721B2

AU706721B2 - Building frame fastening arrangement

Info

Publication number: AU706721B2
Application number: AU68139/96A
Authority: AU
Inventors: Cam Seccombe
Original assignee: BHP Steel JLA Pty Ltd
Current assignee: BHP Steel JLA Pty Ltd
Priority date: 1995-10-11
Filing date: 1996-10-11
Publication date: 1999-06-24
Anticipated expiration: 2016-10-11
Also published as: AU6813996A

Description

P:\OPBR\GCP5917.CAP 8/10/96 -2- BUILDING FRAME FASTENING

ARRANGEMENT

This invention relates to a fastening arrangement in a building frame. An important application of the invention is to the holding down of wall studs in a building frame to base components such as channel-section structural base plates on a concrete slab.

Various approaches have been adopted for holding down the wall studs of steel-framed buildings to the base or bottom plates. In a typical steel-frame construction, the base plate is a steel channel which is normally fastened onto a concrete slab by means of spaced threaded 10 studs cast into the slab. The wall studs, which may for example be dovetail studs, are typically .of a width to seat firmly in the channel of the base plate. Known fastening arrangements include direct attachment at the flanges of the base plate, e.g. by rivetting or clinching, the fixing of right angle brackets to the floor of the base plate, and the use of side plates to tie the wall stud sides to the base plate flanges. In cyclone prone areas, where much higher lift-off 15 forces are experienced, higher failure loads are necessary to ensure that the wall studs are held down and thus a combination of conventional fastening options is usually employed. This is particularly so where it is desired to avoid the use of additional tie down rods for the roof trusses and where the hold down stability of the roof frame is entirely dependent upon the wall studs. It will be appreciated, however, that a combination of the aforementioned fastenings is 20 time consuming and generally untidy.

It is accordingly an object of the invention to provide an improved fastening arrangement in a building frame which may be applied to the holding down of wall studs onto channel-section base plates.

According to the present invention there is provided a building frame comprising: a channel; an elongate structural member, one end of which is received within the channel; a strap which extends about the channel and adjacent to opposed first and second side faces of said structural member; and P:\OPER\Ga'M5917.CAP /10,96 -3fixing means for fixing the strap to said first and second side faces and to said channel.

The invention also provides a method of fixing an elongate structural member to a channel comprising the steps of: locating one end of the structural member within the channel; wrapping a strap about the channel such that one end thereof overlies a first die face of the member, an intermediate port overlies the channel and another end thereof overlies a second side face of the member; and fixing the strap of said first and second side faces and to said channel.

In a typical embodiment the channel frame component is a channel-section structural steel plate serving e.g. as a base plate or top plate of the frame. This plate may be part of a base frame or itself secured to a base frame, or may be fastened to an underlying slab.

15 The other elongate frame component may typically be a wall stud, preferably a steel stud such as a tubular or dovetail stud.

Preferably the fixing means comprises, for each of the four locations, a plurality of welds, rivets or clinches, the number being dependent upon the desired failure load of the 20 fastening arrangement. For a typical single or double storey building frame construction a "°'satisfactory arrangement has entailed three clinches per side of the attachment of the strap to the channel frame component and to the elongate frame component, and four clinches per side for fixing the strap to the latter outside the channel.

The strap is preferably of a gauge in the range 0.5 to 1.5 mm but would typically be in the range 0.8 to 1.2 mm. It is emphasised, however, that the dimensions of the strap would be dependent upon other variables including the dimensions of the frame components and the desired strength of the connection. The strap's width may be in the range 20 to 40 mm but a convenient width is about 25 to 35 mm.

P\OPER\GCP\5917.CAP 810/96 -4- In an embodiment where the channel frame component is fastened by means such as bolts onto an underlying slab, such fixing means is preferably provided in the vicinity of the fastening arrangement, for example, within 100 mm or so.

The invention will now be further described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a fragmentary side elevation of a portion of a steel house frame illustrating an embodiment of fastening arrangement in accordance with the invention; and Figure 2 is a cross-sectional end view on the line 2-2 in Figure 1.

The drawings illustrate a typical inverted T intersection in a steel house frame which includes channel-section structural base plates 12 and dovetail wall studs 14. Each plate 12 is preferably formed from galvanised steel sheet and has a corrugated web 3 and upstanding side legs 5 and 7. The wall studs 14 are also preferably formed from galvanised steel sheet, 15 are received in the channel and extend substantially vertically normally thereto, their width being matched so as to engage the inner faces of the legs 5 and 7 of the channel. Base plates 12 are fastened down onto an underlying concrete slab 16 by spaced threaded studs 18 S* "extending upwardly from and cast into slab 16. The fixings include relatively large diameter washers 20 which rest on the crests of the corrugated web 3, nuts 22 being provided to 20 complete the fixings.

The arrangement by which wall stud 14 is fastened to base plate 12 includes an elongate steel strap 25 which is wrapped about the outside of plate 12 and extends adjacent opposite side face portions 26 and 27 of wall stud 14. This strap 25 is fixed to both plate 12 and stud 14 by multiple clinches 30. More particularly, both lower portions of the upwardly extending arms of the strap 25 are fixed to legs 5 and 7 and the side face portions 26 and 27 of the stud 14 within the channel by applying clinches on each side, these clinches integrating the materials of the three components. The upper portions of the strap 25 above the channel 12 are similarly clinched to side face portions 26 and 27 of wall studs 14.

P:\OFER\GaS917.CAP 8/10/96 It will be noted from Figure 1 that each wall stud 14 is disposed relatively close to an upstanding threaded fixing stud 18, bearing in mind that wall studs 14 would typically be at about 600 mm intervals. As illustrated, the spacing between the axis of threaded stud 18, and the front edge of wall stud 14 is about 45 mm, but a spacing in the range 10 to 75 mm is preferred. The straps preferably extend above the legs of the plate 12 by a distance which is approximately equal to the height of the legs, but this depends upon the number of fastening points required.

It will be appreciated that the illustrated fastening arrangement is especially simple and 10 effective. It comprises a single steel strap which is easily arranged about plate 12. The fixings, being all on the outside and not in the channel, can be rapidly applied with any suitable clinching tool. The straps 25 can be cut to length on site and wrapped about the plates 22 and "studs 14.

15 Initial testing has demonstrated a high failure load the illustrated configuration in the region of 30 kN, indicating a safe loading in the vicinity of 12 kN. This is more than satisfactory for use as a hold down in frames for buildings in cyclone-prone areas.

oooThose skilled in the art will appreciate that the invention described herein is susceptible 20 to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

Throughout this specification unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

P:\OPER\G( S917.CAP 8/10/96 -6- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A building frame comprising: a channel; an elongate structural member, one end of which is received within the channel; a strap which extends about the channel and adjacent to opposed first and second side faces of said structural member; and fixing means for fixing the strap to said first and second side faces and to said channel.

10 2. A building frame as claimed in claim 1 wherein the fixing means also fixes said one *end of the structural member to said channel.

3. A building frame as claimed in claim 1 or 2 wherein the channel is generally C-shaped .and includes a web and first and second legs and wherein said first and second side faces of the structural member engage said first and second legs.

4. A building frame as claimed in claim 1, 2 or 3 wherein the channel comprises a base plate which is fixed to a floor structure and said structural member comprises a wall stud.

S

20 5. A building frame as claimed in claim 4 wherein there are a plurality of said wall studs fixed to the base plate at spaced locations.

6. A building frame as claimed in claim 5 wherein the floor structure comprises a concrete slab and the base plate is bolted to the slab at points closely adjacent to said studs.

7. A building frame as claimed in any one of claims 3 to 6 wherein the strap extends above upper edges of the legs by a distance at least as great as the height of the legs.

8. A building frame as claimed in any one of the preceding claims wherein the strap is 0 f LVIIe d 11 lr sheelLt imetal having a thickness in the range 0.5 to 1.5 mm; a width in the range

Claims

9. A method of fixing an elongate structural member to a channel comprising the steps of: locating one end of the structural member within the channel; wrapping a strap about the channel such that one end thereof overlies a first side face of the member, an intermediate port overlies the channel and another end thereof overlies a second side face of the member; and fixing the strap of said first and second side faces and to said channel. a
10. A method as claimed in claim 10 wherein said fixing includes the step of simultaneously fixing said one end of the structural member to said channel.
11. A method as claimed in claim 10 or 11 wherein the structural member and channel 15 form part of a building frame as defined in any one of claims 1 to 9. 20 DATED this 11th day of October, 1996 BHP STEEL (JLA) PTY. LTD. By its Patent Attorneys DAVIES COLLISON CAVE P:\OPER\GCPM5917.CAP 8/1096 ABSTRACT A building frame comprising: a channel; an elongate structural member, one end of which is received within the channel; S: 10 a strap which extends about the channel and adjacent to opposed first and second side faces of the structural member; and fixing means for fixing the strap to the first and second side faces and to the channel. ooo* *o