AU2017203885B2 - Transfer of racking forces through a truss in a wall plane - Google Patents
Transfer of racking forces through a truss in a wall plane Download PDFInfo
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- AU2017203885B2 AU2017203885B2 AU2017203885A AU2017203885A AU2017203885B2 AU 2017203885 B2 AU2017203885 B2 AU 2017203885B2 AU 2017203885 A AU2017203885 A AU 2017203885A AU 2017203885 A AU2017203885 A AU 2017203885A AU 2017203885 B2 AU2017203885 B2 AU 2017203885B2
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Abstract
ll:\ejl\Interwoven\NRPortbl\DCC\EJL\14707410 l.doc-8/062017 There is disclosed a truss for transferring racking loads in the plane of a wall, the truss including at least one corner which is formed by interconnected ends of an upright chord of 5 the truss and an end web of the truss, the interconnected ends defining a cavity into which an end of a tie-down rod extending through the end of the end member can be received, the cavity being accessible to permit attachment of a fastening element to the rod end to effect a tie-down connection at the comer.
Description
There is disclosed a truss for transferring racking loads in the plane of a wall, the truss including at least one corner which is formed by interconnected ends of an upright chord of 5 the truss and an end web of the truss, the interconnected ends defining a cavity into which an end of a tie-down rod extending through the end of the end member can be received, the cavity being accessible to permit attachment of a fastening element to the rod end to effect a tie-down connection at the comer.
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- 1 TRANSFER OF RACKING FORCES THROUGH A TRUSS IN A WALL PLANE
The content of the complete specification of Australian Patent Application No. 2011205080 as originally filed is incorporated herein by reference.
The present invention relates to improvements in the transfer of racking loads through wall structures. The invention has particular, though not exclusive, application to narrow bracing panels, and especially, though not exclusively, timber trusses.
Commonly, construction of orthogonal, or planar structures like domestic timber framed construction requires a lateral bracing system to ensure stability under the loads to which the structure is likely to be exposed. The forces resisted by the bracing system are caused by a combination of dead, live and wind loads that can be applied in various combinations in various directions.
The bracing system is distributed throughout the structure and properly connected to transfer the applied loads through the structure to the foundations.
The most efficient/cost effective bracing systems transfer the loads in shear through the 20 various planar surfaces.
Each of the planar surfaces forming the bracing system has shear resistance built in by means of either diagonal bracing (commonly metal strap or angle) or some form of sheathing (commonly plywood or hardboard) so that the shear resistance is achieved by 25 diaphragm action. These components are commonly known as bracing units.
The bracing units are designed for different load capacities, which vary depending on the loads applied to the structure and the number of bracing panels sharing the load.
To form an integral system, all bracing units have to be connected together where required to transfer the loads through to the foundation. These connections have also to be \\davics.local\meldfsVedirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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-2conservatively designed to transfer the loads properly.
Common examples of lateral bracing systems are detailed in the Australian Standard for timber framed construction, AS 1684 - 2010.
For both the bracing panels and the connections, increased capacity is reflected by increased cost.
The examples provided in AS 1684-2010 are used in most instances because their details are well understood by the building industry, they make very economical use of materials for their given capacity, they are simple to install on site by commonly used methods, i.e. nails, screws etc., so that comparatively less skill is required on site, they are quick to install, because of their known methods of connection, requiring comparatively less labour on site, and they are easy to inspect for compliance.
The bracing panels have to be distributed throughout the structure, in terms of both position and orientation, to transfer effectively the loads applied to it. A particular length of wall will thus have to transfer a given (or known) amount of racking force.
In past years, most domestic and similar structures would have sufficient unbroken wall length for the bracing recommendations within AS 1684 to be applicable adequately in most, if not all, instances in a given building, the racking resistance required per metre of wall thus being relatively low since numerous bracing units would be able to be included within a given wall. However, the continued market trend is to have more openings and larger openings in more walls within the structures, e.g. for doors, windows, larger connected living areas and adjoining alfresco areas. As bracing panels are precluded from running across the openings, the amount of unbroken wall panel where bracing panels can be located is restricted. Coupled with this, there is also a popular acceptance of large open living areas, which, in turn, results in fewer internal walls to share bracing loads, thus increasing the demand on external walls. In the case of two storeyed structures, the l I:\Interwoven\NRPortbl\DCC\SBT\ 19189676_ 1 .DOC-15/08/2019
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-3 demand is even greater as all of the loads at the upper level need to be transferred through the lower level walls into the foundations.
These high demands cannot be met by narrow sheet bracing units due to their low 5 capacities, in some instances leaving engineers with no option but to specify steel portal frames or the steel version of a wall truss brace (PT Brace) in timber framed structures. Most, if not all, builders are reluctant to use steel components in timber frame structures, which, among other things, are expensive, hence the need for improvements in the racking load transfer capacities in timber wall truss brace applications.
As bracing panels become narrower, the shear strength of the panel becomes less critical, and the resistance to racking deflection or “sway” (by flexural movement) and deflection caused by minute movement in the connection to the foundation becomes more critical, such deflection being exaggerated in the case of narrow (short-length) panels.
Becoming increasingly common are instances of bracing capacity requirements, as a result of the widths of unbroken wall spaces being much less, far exceeding the recommendations of AS 1684.
To be effective, individual narrow wall bracing panels need to be rigid within themselves and to have good shear and moment fixity at their bases (i.e. connection to the foundation).
According to a first aspect of the present invention, there is provided a truss for transferring racking loads in the plane of a wall, the truss including chord members and 25 diagonal and horizontal web members, and having at least one corner which is formed by interconnected ends of an upright chord of the truss and an end web of the truss, the interconnected ends defining a cavity into which an end of a tie-down rod extending through the end of the end web can be received, the cavity being accessible to permit attachment of a fastening element to the rod end to effect a tie-down connection at the 30 comer.
Preferably, an end face of the chord is in abutting engagement with the end web at the \\davics.local\meldfsVedirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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-4comer such that compressive loads in an upright direction are transferrable through the comer. Preferably, the upright chord comprises first and second chord members arranged in side-by-side relation, the end face is defined by the first chord member, and an end of the second chord member is spaced from the end web whereby the cavity is defined 5 between that end and the end web. Preferably, the second chord member is laterally outward of the first chord member.
Preferably, the or each end face directly abuts the end web.
Preferably, the end face is orthogonal to a longitudinal axis of the chord.
Preferably, a hole is formed through the end web at the corner to receive the rod.
Preferably, the cavity opens laterally outwardly.
Preferably, the upright chord and end web are formed from timber. Preferably, the upright chord and web are interconnected by at least one nail plate secured between a front face or rear face of the end web and a front face or rear face, respectively, of the chord. Preferably, the upright chord and web are connected by a pair of nail plates secured 20 between the front faces and the rear faces. Preferably, the nail plates bound the cavity at front and rear positions thereof.
Preferably, the truss comprises a plurality of said comers. In one embodiment of the invention, the truss comprises two said comers, each of which is at a bottom end of the 25 tmss. In another embodiment of the invention, the tmss comprises four said comers, two of which are at a bottom end of the tmss and the other two of which are at a top end of the tmss.
According to a second aspect of the present invention, there is provided a bracing panel 30 comprising a tmss in accordance with the first aspect.
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-5 According to a third aspect of the present invention, there is provided a wall structure including a truss as defined above to which the or each tie-down connection has been effected.
Preferably, an opening is formed on at least one lateral side of the truss. In a preferred embodiment of the invention, an opening is formed on each lateral side of the truss. The opening may be formed through the wall structure or to the/each side thereof.
Disclosed herein is a bracket for forming a tie-down connection between a truss for transferring racking loads in the plane of a wall and a structure above or below the wall, the bracket comprising a flat base member which can be secured against a laterally outer face of an upright chord of the truss adjacent an upper end or lower end, respectively, of the truss and a rod which extends from the base member such that, when the base member is so secured, the rod projects, in general alignment with the chord, beyond the end for fixing to the structure.
Preferably, the base member is configured in the form of a strip.
Preferably, the base member comprises a plate.
Preferably, the base member is configured with holes therethrough for receiving fastening elements to secure the base member to the chord.
The rod may be formed separately from the base and attached thereto. The rod may be 25 attached to an outer face of the base member.
Preferably, the rod is welded to the base member.
Preferably, the rod is configured with exterior formations to be able to be fixedly set into a 30 foundation.
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-6Preferably, the rod is formed with a thread so as to be able to receive a threaded fastening element to fix it to the structure. Preferably, the thread defines said formations.
Also disclosed herein is a wall structure including:
a truss for transferring racking loads in the plane of the wall structure; and at least one bracket as defined above wherein the base member is secured against an upright face of an upright chord of the truss adjacent an upper or lower end thereof and the rod projects beyond the end and is fixed to a structure above or below, respectively, the truss to form a tie-down connection.
Preferably, an opening is formed on at least one lateral side of the truss. Preferably, an opening is formed on each lateral side of the truss. The opening may be formed through the wall structure or to the/each side thereof.
Preferably, the face is a laterally outer face.
Preferably, the wall structure includes a plurality of said brackets. Preferably, the wall structure includes said brackets secured adjacent lower ends of laterally spaced apart upright chords of the truss to form said connections to a structure below the truss at 20 opposite lateral sides of the truss. The structure may comprise, for example, a foundation on which the truss is supported. Alternatively or additionally, the wall structure may include said brackets secured adjacent upper ends of the upright chords of the truss to form said connections to a structure above the truss at opposite lateral sides of the truss. The structure above the truss may comprise a roof structure. In the case where the wall 25 structure comprises said brackets adjacent both lower and upper ends of the truss, the truss can have portal action in the wall structure.
In each of the first, second and third aspects of the invention, the truss is preferably a timber truss, comprising timber chords and webs. Preferably the webs and chords are 30 formed from standard sections of timber, such sections typically being rectangular in cross section. Typical cross sectional dimensions may comprise 35mm x 90mm, 45mm x 90mm \\davics.local\meldfs\redirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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-7and, less commonly, 90 mm x 90 mm.
Preferably, the truss comprises webs and chords which are interconnected by nail plates.
Also, in each of the first, second and third aspects, the truss preferably has a height of between about 2.4 m and about 3.6 m and a width of between about 0.35 m and about
1.2 m. More preferably, the truss has a height of between about 2.7 m and about 3.0 m and a width of between about 0.45 m and about 0.9 m. More preferably, the width of the truss does not exceed about 0.9 m.
In each of the first, second and third aspects, the width of the truss is preferably between about one seventh and about one third of the height of the truss.
The present invention will now be described, by way of non-limiting example only, with 15 reference to the accompanying drawings, in which:
Figures 1A to 1C are schematic front elevation views showing trusses of varying width;
Figure 2 shows detail A in Figure 1 A;
Figure 3A is a schematic front elevation view showing part of a truss according to a preferred embodiment of the invention;
Figure 3B is a view of Section X-X in Figure 3A;
Figures 4A and 4B are schematic front and side elevation views of a bracket which ties down a “wall truss” or bracing truss and
Figure 5 is an elevation view of a trussed portal frame incorporating brackets of the kind shown in Figures 4A and 4B.
The examples and embodiments disclosed herein apply to trusses for transferring racking loads in the plane of a wall, and involve arrangement of tie-down connections close to 30 laterally outer extremities of trusses, at upper and/or lower ends thereof, whereby the lateral spacing between each of those connections and the lateral side of the truss at the \\davics.local\meldfs\redirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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-8same end and opposite to that at which the connection is located is increased, whereby so too is racking load transfer capacity.
Three variants of a truss 1 are illustrated in Figures 1A to 1C and are of similar 5 construction, the trusses 1 having widths W of 750 mm, 600 mm and 450 mm respectively.
Each truss 1 comprises a peripheral frame 11 defined by first 3 and second 5 upright chords and top 7 and bottom 9 web members which extend between upper ends and lower ends respectively of the chords 3, 5. Each truss further comprises an interior web 10 structure 13 arranged within and fixed to the peripheral frame 11.
The chords 3,5 are each formed from two lengths 3A,3B, 5A,5B of timber each having a rectangular cross-section of 90 x 35mm, which are laminated in a plane parallel to the direction in which their longer cross sectional dimension extends, to form a double 15 laminate, though in other examples either or each chord may, for example, comprise only a single length of timber or more than two laminated lengths of timber. The bottom horizontal web 9, in this example, comprises a pair of side-by-side rectangular cross section 90 x 45 mm lengths of timber arranged on edge (i.e. so that their longer cross sectional dimensions extend parallel to a vertical plane), forming a double laminate. The 20 top horizontal web 7, in this example, comprises a single rectangular cross section 35 x 90mm arranged on flat (i.e. so that its longer cross sectional dimension extends perpendicular to the vertical plane). The orientation of the plane of lamination of each laminate member in the truss 1 is not limited to that shown in the illustrations. It may be different for each member and is usually determined by strength, standard material size 25 constraints and wall thickness requirements.
The web structure 13 includes a plurality of diagonal 15 and horizontal 17 web members, each of which extends between and is fixed to the chords 3, 5. Each web member 15/17, in this example, comprises a single length of 90 x 35mm section timber arranged on flat. The 30 truss 1 includes nail plates 30 which secure the webs 7, 9 to the chords 3, 5, the webs in the web structure 13 both to other webs in that structure and to the peripheral frame 11, and \\davics.local\meldfsVedirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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-9the individual timber lengths to each other in each chord. Each truss 1 further comprises nail plates 30 on its rear side (not shown). Those nail plates have the same configuration and layout as the nail plates 30 on the front side of the respective truss 1.
Each truss 1 is dimensioned to extend between a bottom plate 40 and top plate 42 in a wall frame structure. In some instances, either or each end horizontal web may form the respective wall frame top/bottom plate.
In the arrangement shown in each of Figures 1A to 1C, to each side of the truss 1 is an opening through the wall (of which the truss 1 forms a part) defining a space 44, where racking loads within the wall cannot be transferred between the roof structure and foundation. Part of either space may nevertheless be occupied by a structural component, for example a lintel. By way of exemplification, in the arrangement shown in Figure 1A, the laterally outer member 5A in the chord 5 is shorter than the laterally inner member in that chord, such that a cavity, taking the form of a rebate, is defined at the upper end of the chord 5 to receive the end of a lintel 46, whereby a prop stud is defined which supports that end. Also by way of exemplification, the laterally outer member 3A and 3B in each of chords 3 and 5 in the arrangement depicted in Figure IB is configured as a prop stud supporting a respective lintel 46, whereas the chords 3, 5 in the arrangement shown in
Figure 1C are configured as full length studs, in which each member 3A,3B, 5A,5B extends to the top plate 42, with no lintel being supported by either chord.
Each truss 1 is secured against the bottom plate 40 by tie-down rods which are set into the foundation and extend through the bottom plate 40 and web 9. A nut 37 is screwed onto a 25 threaded upper end of each rod 35 and bears down against a respective 50 x 50 mm washer plate 39 received against upper face of web 9.
In each of the arrangements depicted in Figures 1A to 1C, the web structure 13 includes a downwardly convergent or V-shaped pair of first and second diagonal webs 23 and 25.
Diagonal web 23 extends from the junction between first chord 23 and a first end of lowermost horizontal chord 17 to a central position along web 9. Likewise, diagonal \\davics.local\meldfsVedirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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-10web 25 extends from the junction between second chord 5 and a second end of lowermost horizontal web 17 to the central position. Each of webs 23,25 comprises a single length of 90 x 35 timber on flat, though in other examples may, depending on requirements, comprise two or more laminated components. A nail plate 30 secures lower ends of the 5 diagonal webs 23,25 to web 9. Another nail plate 30 secures the upper end of web 23 to the first end of lowermost horizontal web 17, and both these ends to the first chord 3. A further nail plate 30 secures the upper end of web 25 to the second end of lowermost horizontal web 17, and both these ends to the second chord 5, and additionally secures the lower end of the diagonal web immediately above lowermost horizontal web 17 to the 10 second end of that web and to the second chord 5.
Advantageously, owing to the provision of the downwardly convergent pair of webs 23,25, there is no obstruction at either of the lower comers of the space contained within the peripheral frame 11, so that each washer plate 39 can touch the laterally inner face of the 15 respective chord 3/5, whereby there is established, at the lower end of the truss/bracing panel, a relatively large lateral spacing between each tie-down rod and the laterally outer extremity of the truss/bracing panel abutting the bottom plate 40 at the lateral side opposite to that at which the rod is located, that spacing defining the moment arm of the racking load in a respective one of the two, i.e. left-to-right/clockwise and 20 right-to-left/anticlockwise, directions. Accordingly, the racking load capacity of the connections is relatively high in both directions, unlike in the case of a conventional truss, in which a diagonal web member would ordinarily obstruct one of the comers.
Advantageously, the V-shaped profile defined by webs 23,25 helps conceal tie-down 25 connectors within the wall brace, addressing a problem which has been known in the art.
At each of the lower corners of the tmss 1, the nail plates have a width which is substantially the same as that of the respective chord 3/5 and is positioned such that its laterally outermost upright edge is adjacent the laterally outermost face of the respective 30 chord, whereby the laterally inner upright edge of each of those nail plates 30 is spaced sufficiently far from the rod 35 so as not to hinder fitting of the washer plates 39 and \\davics.local\meldfsVedirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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- 11 nuts 37.
A lower corner of a truss Γ according to a preferred embodiment of the invention is shown in Figures 3A to 3B. In the description of this embodiment, the same reference numerals will, where possible/appropriate, be used, as have been used in respect of the truss 1, to refer to corresponding features.
The truss Γ may be substantially identical to truss 1 depicted in any of Figures 1A to 1C, except that each of the lower ends of the chords 3, 5 (only one of which is shown) is 10 formed with a cavity 6 which takes the form of a rebate and opens laterally outwardly, and also frontwards and rearwards, the cavity 6 being formed as the result of the laterally outer timber member 3A,5A in each of the chords 3 and 5 stopping short of the top face of the bottom web 9. The cavity 6 is thus a region of space bounded at upper and lower ends by the face of the lower end of the laterally outermost chord member 3A,5A and the upper 15 face of the web 9 (defined by the upper faces of individual members 9A,9B) respectively, and at a laterally inner side by the laterally outer face of the laterally inner timber member 3B,5B.
In the present embodiment, the upper end of tie rod 35 and nut 37 are received into the 20 respective cavity 6, instead of being received into the space defined within the peripheral frame 11. Each of chords 3,5 is slightly offset such that its laterally outer face is spaced slightly (approximately 6mm) laterally inward of the respective end face of web 9, such that the distance between the end face and the laterally outer face of the inner member 3B is the same as the width of the washer plate 39, whereby the washer plate 39 does not 25 overhang the end of web 9. It will be appreciated that, whilst each end of member 9 thus protrudes slightly beyond the plane in which the laterally outer face of the respective chord 3/5 lies, the width of the bracing unit is maximised within the available space (which is determined or set by architectural requirements). The framework around windows and doors that are fitted into the resultant openings between the bracing panels usually include 30 a 10-20mm gap between their extremities and the envelope of the opening, so as to accommodate building tolerances, i.e. straight, plumb and square. The small protrusion of \\davics.local\meldfs\redirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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- 12the bottom horizontal web is not likely to reduce significantly the fitting adjustment process (e.g. of a window or door frame) on site compared to the more conventional fixing method of fixing by use of an angle bracket.
Owing to the provision of cavities 6, each connection to the foundation 50, via a respective rod 35, can be moved significantly closer to a respective end of web 9, and therefore further from the opposite end of web 9, increasing the moment arm length at the base of the truss Γ and thus the capacity of the connections to transfer racking loads into the foundation 50, whilst continuity between the web 9 and chords 3,5 (via abutment between 10 the lower end of each inner chord member and web member 9) is, advantageously, preserved.
In this embodiment, the web structure 13 inside the peripheral frame 11 may vary. In particular, because the upper end of rod 35, nut 37 and washer plate 39 are, at each lower 15 comer of the truss Γ, laterally outward of the lower corners of the space within the peripheral frame 11, it would not matter if the lowermost part of the web structure 13 were to comprise, instead of the V-shaped pair of webs 23, 25, a single diagonal web, similar to any of webs 15, extending from one chord to the other, a lower end of which would occupy one of the lower corners of the space, consistent with the web structure of a conventional 20 truss.
Shown in Figures 4A and 4B is a bracket 60 for tying down a truss T for transferring racking forces in a wall. The truss T may be any of the trusses 1 shown in Figures 1A to 1C, or may be simply a conventional truss, in which the lowermost part of the internal 25 web structure 13 comprises a diagonal web member 15. The bracket 60 comprises a flat steel plate, which in this version has a thickness of 3mm, the plate defining a cleat 62, which is formed with a plurality of holes 64 therethrough, which receive fasteners, typically screws 66, for securing the cleat 62 against the laterally outer face F of truss chord C. The bracket 60 further comprises a tie-down rod 68, which in this version 30 comprises M12 (Grade 5.8 carbon steel) tie-down anchor, an upper portion of which is received against an outer face of a lower portion of the plate 62 and welded thereto via \\davics.local\meldfs\redirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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- 13 continuous fillet welds 69 to both sides of the line of contact between the rod upper portion and cleat lower portion, the welds 69 each extending substantially the entire length of the rod upper portion.
Advantageously, the bracket substantially removes load eccentricities common to typical tie-down configurations, and is configured such that anchorage is effected as close as possible to the laterally outside face of the wall brace.
The bracket 60 effects connection between at least one, and preferably each, lower corner 10 of the truss T and the foundation, which lies laterally outward of the peripheral frame P, thus, advantageously, increasing the moment arm and therefore the racking force transfer capacity, though lies only slightly proud of the face F so as to have negligible or no impact on the space 44 adjacent the truss T, bearing in mind that the bracket 60 and screw heads can be concealed by the framing of the opening, typically a window or door frame.
The rod 68 is set into the foundation 50 by conventional means, such as by way of epoxy cement, grout or glue.
Within the scope of the invention, the connection types described and illustrated for the 20 embodiment described above can be exploited for establishing fixity between not only the truss base and the foundation but also, alternatively or additionally, the top of the truss and a structure supported upon it. In those embodiments where such fixity is established at both the bottom and top ends of the truss, the truss functions as a portal frame, rather than in a cantilever fashion as is the case in the arrangements shown in Figures 1A to 1C, as 25 described as follows.
An example is shown in Figure 5, which depicts an arrangement in which brackets, exemplarily, are exploited to establish fixity at both the top and bottom of each of two trusses T which support a beam B above space 44. In the structure shown, a respective 30 bracket 60 fixes the laterally inner side of each truss T to the foundation 50 at the truss lower end. Moreover, a respective bracket 60 fixes the laterally inner side of each truss T \\davics.local\meldfsVedirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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- 14to the beam B at an upper end of the truss T. In the illustrated arrangement, configurational constraints preclude brackets 60 from being utilised at the truss laterally outer corners, though in other arrangements, such use may be possible, whereby racking load transfer capacity is, for each truss, increased in not one but both, rotational directions.
In a further example, any of the trusses illustrated in Figures 1A to 1C could be modified such that the web structure 13 incorporates at its upper end a V-shaped web configuration which is substantially the same as that at its lower end and inverted, whereby upper corners of the space within the peripheral frame 11 are freed up, in the same way as the lower comers of that space, to permit top web 7 to be fixed to the structure it supports, in exactly 10 the same manner as the bottom web 9 is fixed to the underlying bottom plate 40 and foundation 50. In yet a further example, the top comers of the truss Γ may be configured in exactly the same manner as the bottom comers (i.e. with cavities 6) whereby the top web 7 can be fixed to the structure it supports, in exactly the same manner as the bottom web 9 is fixed to the underlying foundation 50.
Embodiments of the invention, including in particular that described above with reference to Figures 3A and 3B, offer a number of advantages, including a comparatively high racking load transfer capacity, which is provided by way of prefabricated components. The preferred embodiments, including in particular that described above with reference to 20 Figures 3A and 3B, are simple in construction and in the manner in which they form tiedown connections, and thus can reduce fabrication and installation expense.
Embodiments of the invention, including in particular that described above with reference to Figures 3 A and 3B, serve to increase the moment arm of racking load transfer within a 25 tmss, whereby the inherent strength of a given tie-down connection need not be as great, and provide for reduction in magnitude of movement of a given tie-down connection, and in eccentricity between a chord and tie-down connection adjacent the chord.
Embodiments of the invention, including in particular that described above with reference 30 to Figures 3A and 3B, are particularly suitable for timber wall frames/trusses, for which there is commonly a preference, particularly among carpenters, over steel wall \\davics.local\meldfsVedirected\rnrf\Desktop\draft amended speciflcation.doc-9'04'2019
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- 15 frames/trusses.
Embodiments of the invention, including in particular that described above with reference to Figures 3A and 3B, can also be readily incorporated into a wall structure in which not 5 all of an opening does not occupy the full height of the wall frame, whereby the wall space that remains over the opening can be occupied by a structural component, such as a lintel. Specifically, a narrow bracing panel to which tie-down connections have been effected in accordance with a preferred embodiment of the invention, on either or each the sides of the opening, can resist racking forces by portal action. Given good shear and moment fixity at 10 the connections, these configurations are more efficient and cost effective than individual narrow bracing units.
Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention.
Throughout this specification and the claims which follow, unless the context requires otherwise, the word comprise, and variations such as comprises and comprising, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.
The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of 25 endeavour to which this specification relates.
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Claims (3)
1. A truss for transferring racking loads in the plane of a wall, the truss including chord members and diagonal and horizontal web members, and having at least one corner
5 which is formed by interconnected ends of an upright chord of the truss and an end web of the truss, the interconnected ends defining a cavity into which an end of a tie-down rod extending through the end of the end web can be received, the cavity being accessible to permit attachment of a fastening element to the rod end to effect a tie-down connection at the corner.
2. A truss according to claim 1, wherein an end face of the chord is in abutting engagement with the end web at the corner such that compressive loads in an upright direction are transferrable through the corner.
15 3. A truss according to claim 2, wherein the upright chord comprises first and second ones of said chord members arranged in side-by-side relation, the end face is defined by the first chord member, and an end of the second chord member is spaced from the end web whereby the cavity is defined between that end and the end web.
20 4. A truss according to claim 3, wherein the second chord member is laterally outward of the first chord member.
5. A truss according to claim 2 or 3, wherein the or each end face directly abuts the end web.
6. A truss according to any one of claims 2 to 5, wherein the end face is orthogonal to a longitudinal axis of the chord.
7. A truss according to any one of the preceding claims, wherein a hole is formed 30 through the end web at the comer to receive the rod.
8.
A truss according to any one of the preceding claims, wherein the cavity opens l I:\Interwoven\NRPortbl\DCC\SBT\ 19189676_ 1 .DOC-15/08/2019
2017203885 15 Aug 2019
- 17laterally outwardly.
9. A truss according to any one of the preceding claims, wherein the upright chord and end web are formed from timber.
10. A truss according to any one of the preceding claims, wherein the upright chord and web are interconnected by at least one nail plate secured between a front face or rear face of the end web and a front face or rear face, respectively, of the chord.
10 11. A truss according to claim 10, wherein the upright chord and web are connected by a pair of nail plates secured between the front faces and the rear faces.
12. A truss according to claim 11, wherein the nail plates bound the cavity at front and rear positions thereof.
13. A truss according to any one of the preceding claims, comprising a plurality of said comers.
14. A truss according to claim 13, comprising two said corners, each of which is at a 20 bottom end of the truss.
15. A truss according to claim 13, comprising four said corners, two of which are at a bottom end of the truss and the other two of which are at a top end of the truss.
25 16. A truss according to any one of the preceding claims, being a timber truss, comprising timber chords and webs.
17. A truss according to claim 16, wherein the webs and chords are formed from standard sections of timber.
18. A truss according to claim 17, wherein said sections are rectangular in cross section.
l I:\Interwoven\NRPortbl\DCC\SBT\19189676_I .DOC-15/08/2019
2017203885 15 Aug 2019
19. A truss according to any one of claims 16 to 18, wherein the truss comprises webs and chords which are interconnected by nail plates.
20. A truss according to any one of claims 16 to 19, having a height of between about
5 2.4 m and about 3.6 m and a width of between about 0.35 m and about 1.2 m.
21. A truss according to any one of claims 16 to 19, having a height of between about
2.7 m and about 3.0 m and a width of between about 0.45 m and about 0.9 m.
10 22. A truss according to any one of claims 16 to 21, a width of which does not exceed about 0.9 m.
23. A truss according to any one of claims 16 to 22, a width of which is between about one seventh and about one third of the height of the truss.
24. A truss according to any one of the preceding claims, wherein the web members include a plurality of diagonal web members.
25. A wall structure including a truss according to any one of the preceding claims, to which truss the or each tie-down connection has been effected.
26. A wall structure according to claim 25, wherein an opening is formed on at least one lateral side of the truss.
27. A wall structure according to claim 25, wherein an opening is formed on each 25 lateral side of the truss.
28. A wall structure according to claim 26 or 27, wherein the/each opening is formed through the wall structure or to the/each side thereof.
30 29. A bracing panel comprising a truss according to any one of claims 1 to 24.
l I:\Interwoven\NRPortbl\DCC\SBT\19189676_I .DOC-15/08/2019
2017203885 15 Aug 2019
- 1930. A wall structure according to any one of claims 26 to 28, wherein the opening is a window opening.
31. A wall structure according to any one of claims 26 to 28, wherein the opening is a 5 door opening.
C:\NRPortbl\DCC\MRF\3218397J.DOC-3/]()/2010
1/9
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Fig. 1A
C:\NRPortbl\DCC\MRF\3218397_l. DOC-3/10/2010
2/9
2017203885 08 Jun 2017
PBT 600
Norn, 600 Piinel Length
Bracing Capacity = 7.0 kN
Fig. 1B
C:\NRPortbl\DCC\MRFX32l8397_I.DOC-3/l()/2()|0
3/9
2017203885 08 Jun 2017
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2017203885A AU2017203885B2 (en) | 2010-10-05 | 2017-06-08 | Transfer of racking forces through a truss in a wall plane |
| AU2019202516A AU2019202516B2 (en) | 2010-10-05 | 2019-04-10 | Bracket for forming a tie-down connection between a truss in a wall and a structure above or below the wall |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2010904460A AU2010904460A0 (en) | 2010-10-05 | Transfer of racking forces through a truss in a wall plane | |
| AU2010904460 | 2010-10-05 | ||
| AU2011205080A AU2011205080B2 (en) | 2010-10-05 | 2011-07-29 | Transfer of racking forces through a truss in a wall panel |
| AU2017203885A AU2017203885B2 (en) | 2010-10-05 | 2017-06-08 | Transfer of racking forces through a truss in a wall plane |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2011205080A Division AU2011205080B2 (en) | 2010-10-05 | 2011-07-29 | Transfer of racking forces through a truss in a wall panel |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2019202516A Division AU2019202516B2 (en) | 2010-10-05 | 2019-04-10 | Bracket for forming a tie-down connection between a truss in a wall and a structure above or below the wall |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2017203885A1 AU2017203885A1 (en) | 2017-06-29 |
| AU2017203885B2 true AU2017203885B2 (en) | 2019-09-12 |
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| Application Number | Title | Priority Date | Filing Date |
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| AU2011205080A Active AU2011205080B2 (en) | 2010-10-05 | 2011-07-29 | Transfer of racking forces through a truss in a wall panel |
| AU2017203885A Active AU2017203885B2 (en) | 2010-10-05 | 2017-06-08 | Transfer of racking forces through a truss in a wall plane |
| AU2019202516A Active AU2019202516B2 (en) | 2010-10-05 | 2019-04-10 | Bracket for forming a tie-down connection between a truss in a wall and a structure above or below the wall |
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| AU2011205080A Active AU2011205080B2 (en) | 2010-10-05 | 2011-07-29 | Transfer of racking forces through a truss in a wall panel |
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| Application Number | Title | Priority Date | Filing Date |
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| AU2019202516A Active AU2019202516B2 (en) | 2010-10-05 | 2019-04-10 | Bracket for forming a tie-down connection between a truss in a wall and a structure above or below the wall |
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| AU (3) | AU2011205080B2 (en) |
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| CN113252456B (en) * | 2021-04-12 | 2022-10-04 | 哈尔滨工业大学 | Variable-angle eccentric loading test device for truss structure |
| GB2614268B (en) * | 2021-12-22 | 2024-04-17 | Illinois Tool Works | A timber frame panel |
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|---|---|---|---|---|
| JPH0571301U (en) * | 1992-02-28 | 1993-09-28 | ミサワホーム株式会社 | Structure for mounting square members to the corners of the foundation |
| JPH0573102U (en) * | 1992-03-06 | 1993-10-05 | ミサワホーム株式会社 | Structure for mounting square members to the corners of the foundation |
| US20020046514A1 (en) * | 1999-10-15 | 2002-04-25 | Thomas Leung | Shear wall panel |
| US20030009964A1 (en) * | 2001-06-21 | 2003-01-16 | Shear Force Wall Systems Inc. | Prefabricated shearwall having improved structural characteristics |
| US20060037256A1 (en) * | 2004-08-17 | 2006-02-23 | Pryor Steven E | Shear transfer plate |
| JP2007077611A (en) * | 2005-09-12 | 2007-03-29 | Sumitomo Forestry Co Ltd | Wood member joining structure |
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|---|---|---|---|---|
| US4455795A (en) * | 1981-02-11 | 1984-06-26 | Cole Robert F | Post anchoring device |
| US5501048A (en) * | 1993-09-30 | 1996-03-26 | Nakanishi Construction Company | Structural joint and connector |
| AUPO919997A0 (en) * | 1997-09-15 | 1997-10-09 | Bhp Steel (Jla) Pty Limited | Hold down bracket |
| US6666625B2 (en) * | 1999-08-30 | 2003-12-23 | Scott Anthony Thornton | Retaining wall support posts |
| US7454872B2 (en) * | 2005-03-14 | 2008-11-25 | Concrete Pier System, Llc | Concrete post anchor |
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2011
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- 2019-04-10 AU AU2019202516A patent/AU2019202516B2/en active Active
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0571301U (en) * | 1992-02-28 | 1993-09-28 | ミサワホーム株式会社 | Structure for mounting square members to the corners of the foundation |
| JPH0573102U (en) * | 1992-03-06 | 1993-10-05 | ミサワホーム株式会社 | Structure for mounting square members to the corners of the foundation |
| US20020046514A1 (en) * | 1999-10-15 | 2002-04-25 | Thomas Leung | Shear wall panel |
| US20030009964A1 (en) * | 2001-06-21 | 2003-01-16 | Shear Force Wall Systems Inc. | Prefabricated shearwall having improved structural characteristics |
| US20060037256A1 (en) * | 2004-08-17 | 2006-02-23 | Pryor Steven E | Shear transfer plate |
| JP2007077611A (en) * | 2005-09-12 | 2007-03-29 | Sumitomo Forestry Co Ltd | Wood member joining structure |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2011205080A1 (en) | 2012-04-19 |
| AU2019202516B2 (en) | 2021-07-22 |
| AU2017203885A1 (en) | 2017-06-29 |
| AU2011205080B2 (en) | 2017-03-09 |
| AU2019202516A1 (en) | 2019-05-02 |
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