Title: 'PRECISION STRUCTURAL SYSTEM'
BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION
THIS INVENTION relates to improvements in structural systems for skeletal structures, such as towers and bridges, and in structural frameworks for buildings, and includes improvements in manufacturing, assembly and erection techniques, and construction sequences which result in significant savings in time and cost for a large range of structures and building types. 2- PRIOR ART
A thorough investigation of structural systems and construction methods prior to drafting of this patent has revealed the existing state of the art as follows:
(a) Many buildings and structures are designed and constructed as "one off" projects, where the benefits of productions runs and the economies of scale are sacrificed. This results in added expense and time delays.
(b) Structurally the various components of both traditional and modular systems depend too heavily on each other, eg. footings and floors support walls which in turn support the roof. This dependency reduced flexibility of designs and increases costs.
(c) "System built" and "kit built" buildings still require the use of very significant amounts of skilled trade work, which has a major effect on building costs, particularly in remote areas.
(d) The use of prefabricated steel trusses in buildings for roof and wall components has over recent years become popular, however there remains much room for improvements in joint design and a simple site assembled systemised truss, suitable for easy transport
is yet to be produced.
(e) Where prefabricated steel trusses are used in buildings they are of two types i.e. welded or bolted, each with its own advantages and disadvantages, however they both use rigid joint designs, which means inefficiencies in member sizing because of induced bending moments, and they both require specialist installation, particularly larger bolted trusses where friction grip bolting in gusset plate joints is used. None of these trusses use simple single pin connections for pivotal joints.
(f) In many cases the roof designs for buildings, because they are not considered as independent structures, tend to become "add hoc", using support locations determined by building layouts, without much concern for the efficiency of the roof structure itself. In most cases too many supports are used which makes future renovations both difficult and expensive.
(g) The construction of roofs is almost without exception carried out in its final elevated position.
This means working at heights and the necessary and expensive safety precautions are added to the cost of construction, as well as crane costs for larger roof components. (h) Construction methods usually employ a sequence of construction where the roof is erected towards the middle or near the end of the construction period, which means that the period before the roof erection is subject to time delays because of rain, snow, wind, harsh sunlight etc.
(i) The systems are too complex to allow easy disassembly and relocation particularly by unskilled people. (j) All systems are still too expensive. SUMMARY OF THE INVENTION
With all of the above in mind the preferred objects of this invention are as follows:
(a) To provide a precision structural system, easily understood by all sections of the building industry, including architects, engineers, tradesman and end users, which is capable of offering significant cost and construction time savings in a wide range of building and structure types.
(b) To provide a modular building construction system, in which the structural dependency of various separable parts of the building is reduced to an absolute minimum, such that each separable part, including the roof, floor, walls and furniture, all have the benefit of economies in design and/or construction methods, and in particular where the walls are non- load bearing and relocatable for increased functionality to suit changing needs.
(c) To provide a modular building construction system, designed to be easily understood and assembled by unskilled labour, which will reduce construction costs particularly in remote areas.
(d) To provide a modular building construction system, which incorporates simple, easily transported, site assembled steel trusses and frames as the basic structural components of the system, where the trusses are easily fabricated from standard steel sections, and three dimensional frames are assembled by fixing together intersecting trusses in different planes.
(e) To provide a modular building construction system, incorporating significant improvements in structural design of the basic trusses in the system, by using simple single pin joints to replace welded or multiple bolt joints, where the geometry of the trusses using these single pins is such that length fabrication tolerances of the components is not critical for correct
load sharing in the truss.
(f) To provide a modular building construction system, in which the roof is designed as an independent, stand alone structure, where an absolute minimum number of column supports can be used because of a very efficient form of frame construction, using intersecting trusses, which enhances the functionality of the total structure and substantially reduces the cost of renovations, and where the space inside the roof frame may be used as living area.
(g) To provide a modular building construction system, in which the roof or floor system is constructed at or near ground level, including the installation of all roof sheeting, ceiling, facias, gutters, gable ends, vents, insulation and services, and then lifted and fixed in its final location on a minimum number of support columns, which are also used to support temporary lifting equipment, where this method of construction is safer and more cost effective than elevated construction.
(h) To provide a modular building construction system, incorporating a construction sequence where the roof is constructed first in the sequence, thereby allowing all other work to be carried out under cover, which reduces total construction time and reduces "on site" trade dependant operations e.g. services can be run in the roof space at the same time as a concrete floor slab is poured, (i) To provide a modular building construction system which allows easy unskilled disassembly for relocation, reassembly and erection, using another set of support columns at a different location. (j ) To provide a precision structural system which will significantly reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS
To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which:
FIGS. 1 to 71 illustrate planar truss geometry and joints of the invention;
FIGS. 72 to 78 illustrate three-dimensional frame geometries and joints of the invention; and
FIGS. 79 to 105 illustrate building structures, in accordance with the invention and their possible uses, and also show various construction sequences.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is an isometric view of a planar truss comprising channel chords 101 to 110 which form the perimeter of the rectangular truss. Channel posts 111 to 113 further sub-divide the enclosed area of the truss into unstable four sided polygons, in this case rectangles. Channel braces 114 to 117 further sub¬ divide these unstable shapes, into stable four sided polygons.
It can be seen that each member connects to another member at a separate location via a pin or bolt
(not shown) inserted through aligned holes 118 in the members, where one pin or bolt secures one member to only one other member.
In FIG. 1 it can be seen that all members are channel sections and the action of the pin or bolt is to clamp the outside faces of the channel webs together into co-planar abutment; whilst still allowing angular adjustment between members by rotation about the pin or bolt axis which is perpendicular to the plane of the members and the truss. The clamping means incorporated in the pin to hold the members in co-planar abutment is preferably a thread on each end of the pin with a nut screwed onto each end, where washers of sufficient
thickness ensure that the walls of the holes in the members bear on the unthreaded section of the pin or bolt.
Also from FIG. 1 the pins or bolts are preferably circular in section about their longitudinal axis for insertion into circular holes in the members where the ratio of the hole diameter to pin diameter is less than 1.007.
From FIG. 1 it can also be seen that at lest two members and up to five members are discontinuous in a restricted or limited area called a node, e.g. two members 101 and 110 join at a single pin node, three members 109, 110 and 114 form a two pin node, four members 101, 102, 111 and 114 form a three pin node and five members 102, 103, 112, 115 and 116 form a four pin node. Preferably the hole openings for the pins in each member are on the longitudinal axis of the member.
From FIG. 1 an assembly sequence termed progressive stabilization can be explained to demonstrate that the length of members between hole centres is not critical for non forced assembly to occur, and that the term "precision" structural system refers to the hole to pin tolerance ratio of less than 1.007 which prevents excessive deformation under live load or load reversal. Firstly an assembly from the left hand end members 101, 109, 110 and 111 are joined using four pins to form a rectangle. This rectangle is then pushed into a parallelogram shape until the holes in members 101 and 109 exactly match the centre to centre hole distance in member 114. This progressive stabilization procedure is then repeated by adding members 102, 108 and 112 to form another rectangle and stabilizing that rectangle by pushing it into a parallelogram and adding brace 115. This procedure is repeated until the total truss is assembled. Note also
that the pin connections are only required to work in shear to prevent excessive deformation of the loaded truss because of the close hole to pin tolerance and the perpendicular loads of the member walls on the pin face. Normally in a truss of this type deformation of the truss would be limited by using friction grip bolts to secure one member to another and holes oversized by one or two millimetre from the pin instead of 0.1 mm to 0.2 mm in this truss. In the above description loading and deformation of the truss is based on vertical supports under members 110 and 105 and vertical loads at the tops of members 111, 112 and 113 producing vertical displacement of the truss members.
Stabilization of the truss is also due in part to the continuous and rigid nature of the ends of some members progressing from one four sided polygon into adjacent four sided polygons, e.g. one end of member 102 has three holes in it and the integral nature of the member 102 and the end section 102A and 102B between these ends holes, acts in conjunction with the truss geometry to progress stabilization from the polygon boarded by members 101, 102, 115, 108, 109 and 111 to the polygon boarded by members 102A, 112, 108 and 115, and it can be also seen that these rigid end sections allow member joints within the length of any side of the four sided polygon without destabilizing the truss, e.g. member 102 joins member 103 within the length of the top side of this polygon where the polygon 102B, 103A, 116, 107, 108 and 112 remains stable in part because of the continuously rigid end sections 102B and 103A and in part because of the truss geometry. It can also be seen that the sections 102B and 103A need not be in line and this polygon 102B, 103A, 116, 107, 108 and 112 could be considered a six sided polygon. FIG. 1A shows the use of nesting Z section
chords and channel posts and braces, whilst FIG. IB shows the use of nesting channel chords and channel braces and posts for use in the truss of FIG. 1. Of course any type of section could be used for any members, provided co-planar face abutment between members is possible, including angles, tees and hollow sections.
From FIGS 1, 1A and IB it can be envisaged that a range of truss shapes could be assembled using variations in lengths and angles between members, including triangles, bowstring, arch, etc.
FIGS. 2 to 4 show various other truss geometries where the chords are not in alignment to form the perimeter and the posts and braces have more than one hole at each end, however, in all cases only two members are joined at any one pin.
FIGS. 2 to 4 can also be assembled by progressive stabilization.
FIGS. 5 and 6 show diagrammatic layouts of planar trusses, where the node locations shown in large circles 501, 502 and 601 have both a two member joint with one pin and a three member joint with only one pin at the node. The smaller circles at the node with no line through it represents the three member, one pin node and the smaller circle with the line through it the two member, one pin node.
FIG. 7 shows an exploded isometric view of node 501 or 601 using angle chords 701 and 702 and angle braces 703. FIG. 8 is an isometric view of nodes 501 or
601 using Z section 801 and 802 for chords and channel sections 803 for braces.
It can also be seen from FIGS. 5 to 8 that both braces could be fixed at one point to the chord and the chords joined separately in which case bending is
eliminated from the members.
FIGS. 9 and 10 show diagrammatic layouts of planar trusses where all members at a node 901 or 1001 are joined by one pin only which eliminates bending in all members.
FIG. 11 shows an exploded isometric view of a four member, one pin node 901 or 1001 in FIGS. 9 or 10, using angle chords 1101 and angle braces 1102. This detail also shows that the pin 1103 has clamping threads 1104 on its ends and nuts 1105. The chords have holes 1106 and the braces have holes 1107 and the joint is assembled along the axis 1108. The chords have longitudinal axes 1109 and the braces have longitudinal axes 1110 which intersect the assembly axis 1108. FIG. 12 shows nesting Z section chords and channel braces at a four member, one pin node as in FIGS. 9 or 10. The pin and clamping action nuts in FIG. 11 is typical for all FIGS, from 1 to 12.
In FIGS. 1 to 4, a single pin secures only two members at a single pin or multiple pin nodes; in FIGS. 5 to 8, at least one pin secures more than two members at a single pin or multiple pin node; in FIGS. 9 to 12, a single pin fixes all members at a node.
FIG. 13 is an exploded isometric view of a four member, one pin node using channel chords 1301 and channel braces 1302 assembled along an axis 1303, where the ends of members have been cut on a mitre to allow co-planar face abutment of the webs without interference by the flanges. FIG. 14 is an exploded isometric view of a four member, one pin joint, where channel chords 1401 and channel braces 1402 are assembled along an axis 1404 and the need to remove any part of members is eliminated by using packing pieces 1403. FIG. 15 introduces the concept of a member
with more than one planar face. In this case a post 1501 has aligned holes 1502 in opposite parallel faces. In this case single pins pass through the post 1501 to secure two channel chords 1503 or one or two channel braces 1504.
FIG. 16 is similar to FIG. 15 except that two sets of chords are used to provide opposite torsion loads in the post 1601 induced by the chords 1602 and 1603 and braces 1604. FIG. 17 shows a roll formed or pressed section which has three vertical planar faces with aligned holes for co-planar abutment to other members.
FIG. 18 shows a roll formed or pressed section which has four vertical planar faces with aligned holes for co-planar adjustment with other members.
FIG. 19 shows an exploded isometric view of a roll formed or pressed member 1901 with four vertical faces, an aligned square hollow section chord 1902, a square hollow section post 1903, and square hollow section braces 1904, where the square hollow section members fit neatly inside the flanges of the member 1901 for co-planar abutment of both opposite faces of each square hollow section member.
FIG. 20 shows a four member, one pin joint using a square hollow section chord 2001 sleeved or telescopically engaged within a larger square hollow section chord 2002 where two channel braces 2003 are also attached along the pin axis 2004.
FIG. 21 shows a four member, three pin joint where a square hollow section 2101 sleeves inside a channel 2102 and joins at one pin, and a square or rectangular hollow section post 2103 and brace 2104 each join inside the chord 2102 at separate pin locations.
FIG. 22 shows a means of extending the planar face of the channel chord 2201 for abutment with channel
chord 2202 by using a flat plate 2203 rigidly fixed with two pins to channel 2201 where channel braces 2204 also join to form a four member, two pin node.
FIG. 23 shows a means of extending both opposite walls of square hollow section chord 2301, using short length channels 2302 rigidly fixed to 2301 using two pins. Aligned holes in the channel extension of the square hollow section chord join to another chord 2303 and braces 2304. FIG. 24 shows a single pin joint where four members can all achieve two co-planar abutments with other members by removing parts of the top and bottom faces of chords 2401, 2402 and brace 2403 such that the remaining side walls act as member extension of the co- planar square hollow section walls.
FIGS. 22 to 24 show various means of achieving singular and multiple face co-planar abutment using extended member walls.
FIGS. 25 and 26 show diagrammatic layouts of truss geometries using five member, four pin nodes and four member, three pin nodes, where FIGS. 27 and 28 show details of these joints.
FIG. 27 is a detail of node 2501 in FIG. 25 or node 2601 in FIG. 26 where member 2502 or 2602 is a double channel member 2701 in FIG. 27 and where aligned holes in the double channel chord 2701 join separately to holes in the square hollow section chord, post and braces.
FIG. 28 is similar to FIG. 27 except it is an exploded view of nodes 2503 or 2603 , in reverse attitude, of a four member, three pin node, where one member is actually two channel chords 2801 with square hollow section chord 2602, and braces 2803 joining at separate pins. Also shown in FIG. 28 is the bolt or pin 2804, clamping nut 2805 and an internal sleeve spacer
2806 fitted inside the square hollow section chord 2802.
FIGS. 29 to 34 show various other node geometries with varying numbers of members, member types and pins, where at least one member has been replaced by two transversely separated members.
FIG. 29 shows the use of chords as double members in a three pin joint.
FIG. 30 shows the use of braces as double members in a three pin joint. FIG. 31 shows the use of posts as double members in a three pin joint.
FIG. 32 shows the use of chords as double members in a two pin joint; and
FIG. 33 the use of chords as double members in a one pin joint.
From FIGS. 29 to 33 it can be seen that any chord, post or brace member can be replaced with two transversely separated members, using various member types and node types. FIG. 34 shows the use of double square hollow section chords 3401 used with square hollow section chord 3402, post 3403 and brace 3404. FIG. 34 also shows the use of hand holes 3405 and 3406 in a slot 3407 shown dashed to give access to the pin or bolt clamping means.
FIGS. 35 to 39 show various methods of stiffening or strengthening single or double members.
FIG. 35 shows a single channel member 3501 with a stiffening plate 3502 fixed to its flanges by four bolts or screws 3503.
FIG. 36 shows a double channel member 3601 stiffened by a plate 3602 fixed to the member flanges with two bolts or screws 3603 for each member.
FIG. 37 shows a plan view of a double channel member 3701 fixed at each end by a single pin 3702 to a
square hollow section member 3703 where a long pin or bolt 3704 spans between holes in the centre of each member of the double channel member, such that the threaded length on the pin 3704 enables the channel members 3701 to be forced apart and held in a stressed bent mode by nuts and locking nuts 3705. This action sets the mode or direction of lateral buckling failure of each channel and increases the axial compressive capacity of the double channel member. FIG. 38 is similar to FIG. 37 except the central pin, nuts and locking nuts force the double channel members into co-planar abutment at the centre and also sets the mode or direction of lateral buckling failure, with an increase in compressive capacity. FIG. 39 again is a plan view of a double channel member as in FIGS. 37 and 38 with a central pin. In this case the central pin is able to exert a pre- stress force in the cables or straps 3901 which are also attached to the channel, square hollow section pin join, such that the stress induced by the outwards movement of the nuts 3902 on the pin thread provides a beneficial stress and/or lateral movement restraint to the double channel member.
FIGS. 40 and 41 show truss geometries where additional nodes are contained within the central area of the truss, where these nodes are put at or near the perimeter of the truss as in conventional Howe, Pratt, Fink and Warren type trusses and where all σf th nodes and members may be any type as previously described. Note in FIGS. 40 and 41 the members do not cross one or the other.
FIGS. 42 to 45 show various truss geometries where one member can pass by, or between another member.
FIGS. 42 and 43 show single pin truss geometries where one member passing by or between other
members is illustrated by a semi-circle in the length of one member, as distinct from smaller circles at its ends.
FIG. 44 shows a truss geometry where alternate square or rectangular hollow section braces 4401 pass between alternate double channel members 4402 forming trusses which are known by those skilled in the art as indeterminant trusses.
FIG. 45 shows a two pin node geometry for a truss where rectangular hollow section braces 4501 pass by each other by virtue of their transverse separation at their ends at the nodes, allowed by the rectangular hollow section brace 4501 being half the width of the square hollow section chord 4503. Holes and/or slotted holes 4502 allow a sliding or fixed connection between braces at or near their centres, which will assist in reducing the effective buckling length of the brace in compression as the brace in tension will support or partly restrain it from lateral deflection. FIG. 46 shows a pin or bolt connection means between two channel member 4601. FIG. 46 is a sectional elevation which also shows a pin or bolt 4602 which has an enlarged head 4603, one threaded end 4604, a washer 4605 and a nut 4606. It can be seen from FIG. 46 that the body of the pin 4602 is shown as a tapered body where the tightening of nut 4606 would cause the outer face of the pin to bear on the face of the hole in the" left- hand" channel which would result in a precise bolt to hole fit. Obviously a cylindrical shanked bolt with a standard forged head could also be used. The action of the pin or bolt in FIG. 46 is to clamp the co-planar faces of members together with a force that is commensurate with restraint against wall lateral deformation whilst still allowing rotation of one member
in relation to the others in the plane of the truss. The pin or bolt is required to function only in shear and not in tension.
FIG. 47 is similar to FIG. 46 except it is a sectional elevation where two single pins or bolts are used in members, e.g. square hollow section 4701 with more than one planar face. The type of connection provided in FIGS. 46 and 47 is called a restrained joint because the walls of the tube or channel are restrained from lateral deformation.
FIG. 48 is a sectional elevation of separate pinned connections holding or joining a square hollow section member to outside plates or member faces. On the left hand side a short bolt 4801 is inserted from outside through the plate or member 4802, the square hollow section wall 4803, an oversized washer 4804 and into a nut 4805, where the washer and nut may be integral and may be fastened to the inside wall of the tube. On the right hand side the bolt 4806 is positioned from inside the tube, through a washer 4807, the tube wall 4808, a plate or member 4809, another washer 4810 and a nut 4811. In assembly of the trusses the captive nut arrangement on the left hand side of FIG. 48 is easiest, however, the right hand side is easiest to fabricate. Holding the head of the nut 4806 can be difficult, inside the tube and one solution to this is to use a special bolt as in FIG. 49 or special washer as in FIG. 50.
In FIG. 49 a fabricated bolt consists of a rod or pin 4901 with a thread 4902 inserted through a flat strap 4903 and fixed with welds 4904. The flat strap would bear on the inside top or bottom face of the tube and prevent the pin 4901 rotating when a nut (not shown) was turned onto the thread 4902. Similarly in FIG. 50 a short channel section
washer 5001 would hold the head of a standard bolt captive and also bear on the top or bottom inside face of the tube to prevent rotation of the externally threaded nut. FIG. 51 is a sectional elevation of a square hollow section member 5101, with other channel members 5102 and a single pin 5103 being used for the pivotal connection to both the channel members. Nuts 5104 secure both joints, however the joints are not restrained, in that the square hollow section wall can deform inwards under load. These two joints can be restrained as in FIG. 52 which is similar to FIG. 51 except that a sleeve or extended washer 5201 positioned over or around the pin and inside the tube prevents inwards wall deformation.
FIGS. 53 to 55 are diagrammatic truss layouts showing where either single or double members are wide enough to have their holes for joining of other members, not on this longitudinal axis where preferably some of the holes are on an axis perpendicular to the longitudinal axis. FIG. 53 shows wide chords, FIG. 54 wide posts and FIG. 55 wide braces.
FIG. 56 shows an exploded wide post joint similar to that in FIG. 54 where the posts are double wide channels 5601 and the chords square hollow sections 5602, and braces square hollow sections 5603.
FIGS. 57 to 58 show various means of using members which have had their normal straight e-longate shape changed or bent so that one type of member is continued to become part of another member.
FIG. 57 is a diagrammatic layout where posts have been realigned to become part of the chords at these ends. Similarly FIG. 58 is a double member channel brace realigned to become part of the perimeter chords.
FIGS. 59 to 63 show the use of separate plates rigidly attached to various member ends to provide the means for attaching other members.
FIG. 59 shows two plates 5901 rigidly welded to square hollow section post 5902 where square hollow section chords 5903 and brace 5904 are attached via a long pin or two short pins to aligned holes in the plates.
FIG. 60 is a diagrammatic representation of a truss, where posts have plates fixed to their top and bottom ends and chords and braces attach to the plates at separate jointing points.
FIG. 61 is an isometric view of a square hollow section truss, where plates 6101 are rigidly bolted using two bolts to the post 6102 and chords 6103 and braces 6104 attach to aligned holes in the plates.
FIG. 62 is an end elevation of FIG. 61 where it is shown that the plates 6101 may be stiffened or strengthened by forming an angle along the top edge of the plate to better resist plate deformation when transferring chord loads across the plates.
FIG. 63 is an exploded isometric view of a node where the plates are short channels rigidly fixed using two bolts to the rectangular hollow section post. FIGS. 64 to 66 show various means of developing bending moment forces to resist or oppose bending moments generated by working loads being applied to members and nodes.
In FIG. 64 the vertical arrows between the node points, represent loads applied to the chords from snow weight or wind loads, applied via purlins, joists, etc. The effect of these non-nodal loads is to produce a bending moment in these chords which must be combined with the axial load in the chord to determine a member size to resist these combined loads. However if the
member were curved, as shown in the left hand side of FIG. 64, or bent as shown in the right hand side, the offsetting of the axis of the member from the axis between pivot holes provides an opposite bending moment, generated by the axial loads. This means a reduced sized member can be used to resist the combined loads.
In FIG. 65 the same effect is achieved by simply offsetting the holes in the member away from its longitudinal axis. FIG. 66 is similar to FIG. 65 except that a greater offset distance can be achieved by increasing the member depth, by a suitable means e.g. plates in the vicinity of the pivot holes.
FIGS. 67 to 71 shows how some members in the trusses previously described could be members capable of carrying tension loads only e.g. steel rods or cables carry negligible compression loads.
In FIG. 67 the right hand side of the truss uses tension only members AB, CD, DF and BE, where if the truss were supported only at its end points G and N, and vertical downwards loads were applied at the nodes, A, D, and E, only members CD and BE would be loaded in tension and members AB and DF would be required to develop compression loads, which they could not, so that they would remain or become redundant. Conversely members AB and DF would carry tension under upwards loads at nodes C, B, F or A, D, E and members CD and BE would be redundant. All chord members in FIG. 67 are- required to carry both compression and tension as are post members AC, DB, and EF on the right hand side. On the left hand side all brace members AH, HI, IJ, JK, KL and LM are required to carry both tension and compression, however if the loading conditions on the truss are such that load reversal never takes place and the vertical loads at nodes M, K and I are always
trusses previously described could be members capable of carrying tension loads only e.g. steel rods or cables carry negligible compression loads.
In FIG. 67 the right hand side of the truss uses tension only members AB, CD, DF and BE, where if the truss were supported only at its end points G and N, and vertical downwards loads were applied at the nodes, A, D, and E, only members CD and BE would be loaded in tension and members AB and DF would be required to develop compression loads, which they could not, so that they would remain or become redundant. Conversely members AB and DF would carry tension under upwards loads at nodes C, B, F or A, D, E and members CD and BE would be redundant. All chord members in FIG. 67 are required to carry both compression and tension as are post members AC, DB, and EF on the right hand side. On the left hand side all brace members AH, HI, IJ, JK, KL and LM are required to carry both tension and compression, however if the loading conditions on the truss are such that load reversal never takes place and the vertical loads at nodes M, K and I are always downwards, then members AH, IJ and KL would always be in tension and could therefore be a tension only rod or cable. Connection of tension only rods or cables to a single planar face could be by using a plate 6801 fixed to the rod 6802 where a hole 6803 is part of the node connection, as in FIG. 68. FIG. 69 shows a U bracket connection means to connect tension only members to two co-planar faces as in a square a hollow node, where the bracket 6901 connects to the rod via a hole 6902 and nut 6903 screwed on to rod thread 6904 and holes 6905 connect to the node pin or pins.
FIGS. 70 and 71 show two different truss arrangements using the U bracket as shown in FIG. 69 to connect the tension only member to the node, and where
this bracket also allows length adjustment of the tension only rod by virtue of the thread 6904 and nut 6903 in FIG. 69. It can also be seen in FIGS. 70 and 71 that the top chords need no longer be discontinuous at the nodes as the tension only length adjustment will allow non forced assembly.
Referring again now to FIG. 67 it can be seen that the bracket connectors as in FIGS. 68 and 69 when used in the right hand side of the truss, in conjunction with pivotal connections between the posts and chords, will allow rotation or angular adjustment between all members i.e. chord AD and braces AB and CD, post AC to braces CD and AB and chords AD and CB. It can also be envisaged that under some circumstances that the length of compression/tension members may need to be adjustable and this can be achieved by any suitable means provided it is accompanied by rotational adjustment between all members as previously described.
FIGS. 72 to 74 show how trusses previously described can be joined or intersected to form a three dimensional frame, by using members common to more than one truss.
FIG. 72 is a diagrammatic layout of a truss showing how chords, posts or braces can be extended beyond the node to provide a connection means for trusses in another plane. The node 7201 in FIG. 71 shows a post extended to form another point of connection and the node 7202 shows a connection point within the post length. FIG. 73 shows a three dimensional frame node where a common square hollow section post 7301 provide the connection means for double channel chords 7302 and a square hollow section chord 7303 and brace 7304 for a truss node in one direction and the connection means for double channel chords 7305 and a square hollow section
chord 7306 and brace 7307 for a truss node in a second plane perpendicular to the first.
FIG. 74 is similar to FIG. 73 except angle members are used and a common angle post 7401 provides the connection pivot holes for truss nodes in two directions.
FIGS. 75 to 78 show means of attaching plates to members which are common to two or more trusses in different planes. In FIG. 75 two plates 7501 are rigidly attached to the bottom of common post 7502, where the plates have attached fin plates in a second direction which allows square hollow section chords 7503 and braces 7504 to connect to the common post at the same level. FIG. 76 shows four separate plates 7601 rigidly attached with two bolts to the common post 7602 and square hollow section chord 7603 and brace 7604 joining the two higher level plates whilst chord 7605 and brace 7606 join the lower level plates. FIGS. 77 and 78 show two other means where chords and braces from different planes directions can join the common post at the same level. In FIG. 77 two flat plates 7701 pass through two channel plates 7702 and may or may not be attached to each other. In FIG. 78 two smaller plates 7801 pass through two larger plates 7802.
FIGS. 79 to 105 now show how the planar trusses and three dimensional frames described in FIGS. 1 to 78 are used to construct structures and building frames, where the methods of obtaining the objects of significant time and cost savings claimed by this invention are show to be both novel and practical.
FIG. 79 shows a method of using two parallel chord trusses 7901 joined to at least two triangular trusses 7902 to provide a building framework, preferably for a roof, where purlins 7903 are connected to the top chords of the triangular trusses, at 90° to them, and where profiled metal roof sheeting 7904 or tiles are fixed to the purlins to span the distance between the purlins. The roof structure can be assembled at ground level and then lifted and attached to support columns 7905.
From FIG. 79 it can be seen that any vertical loads from say wind or snow applied to the roof sheeting will be transferred by the purlins first to the triangular trusses, which transfer their loads to the two parallel chord trusses, which in turn transfer their loads to ground level via the support columns. Any horizontal loads are resisted by the diaphragm action of the roof sheeting or any other form of horizontal bracing fixed between the trusses, which is transferred to the support columns and back to ground level. The columns are preferably designed as free standing cantilevers, so that no bracing is needed below the level of the bottom chords of the trusses.
From FIG. 79 it can also be seen that the frame assembly concept is quite different from the more usual and more logical portal frame layout. If the frame layout as shown in FIG. 79 were of an industrial shed 40 metres long (longitudinal truss 7201 length) and 20 metres wide (lateral truss 7202 width) it would be normal and seemingly more logical to support each lateral truss 7902 by a column at its ends and eliminate the longitudinal trusses. This would mean the trusses span 20 metres instead of 40 and purlins would span 8 metres between trusses 7902. On the face of it this certainly seems the logical structural layout, however,
it has been found by completing many analysis that the structural framework in FIG. 79 is more cost efficient provided the length of the structure is not more than 2.5 times the width.
The reasons for this are as follows:
1. The lateral trusses are much more efficient when supported at their 1/4 span or at calculated positions such that the cantilever section acts to reduce member loads and, therefore, member sizes.
2. There are only four columns compared to ten in the portal frame system where the savings in 1. and 2. above are more than enough to cover the cost of the two longitudinal trusses, especially when on ground assembly is included.
It is obvious from FIG. 79 that all frame members have not been included to achieve total stability, eg. lateral bracing of the longitudinal trusses has not been shown.
This may be achieved by using a longitudinal wind truss or the diaphragm action of the roof sheeting. As an indication of practical sizes for this four column structure, it has been found that additional longitudinal trusses are desirable when the width of the lateral trusses is over 50 metres and that the limit of practicality for the length of the longitudinal trusses is 80 metres. On the lower end of the scale, a house size of 7 or 8 metres wide by 10 to 16 metres long is very suited to this particular geometry. Obviously, then a vast number of types of buildings are suited to this frame geometry and the support columns being limited to four offers enormous unhindered free space in buildings up to 4000 square metres or one acre in size. FIG. 80 shows how the roof structure is
constructed to be independent of the floor, walls and furniture, and how services may be carried inside the column supports for reticulation from the roof space to the rooms below. In FIG. 80, the columns 8001 support the roof structure 8002, where this cross sectional elevation in FIG. 80 can also be related to FIG. 79 and column service ducts 8003 are run inside the columns. Also shown in FIG. 80 is the ground floor slab 8004 which, it can be seen, is totally independent from the column and roof structure. Also shown are three different types of wall panels 8005, 8006 and 8007, where wall panel 8005 is secured in place by having pins or protruding rods extending from it which are inserted into holes in the ceiling and into holes in the floor slab. Wall panel 8006 is fixed to the ceiling and floor using channel sections where the panel may be inserted from a side position into the channels or the top channel may be deeper than the bottom channel which allows the panel to be positioned with an upwards and drop motion, which will still provide a slip joint at the ceiling level, or alternatively two angle skirting board sections may secure the panel at floor level. Wall panel 8007 is different in principle to the other two panels, in that it is hung from the roof structure and has a slip joint arrangement at the floor level. Also shown in FIG. 80 is a mobile cupboard 8008 which can also be used as a wall. A system of drains. 8.QQ9.is__ shown below the floor slab with risers 8010 extending to floor level, however, it should also be noted that underground drains can be eliminated by using small macerator pumps and small discharge lines, located above floor level, which can be supplied and installed as a total wall, fixture and discharge pump unit, prefabricated in a factory situation. Now that the independent nature of the roof,
floor, walls and the furniture has been shown with the aid of FIG. 80, it is necessary to return to FIG. 79 to explain the construction sequence, where it can be seen that the floor columns are outside the plan area of the total roof and that the roof can be completed at or near ground level including all sheeting, gutters, fascias, vents, insulation, linings, gable ends, skylights, services and attic room construction, prior to lifting and fixing to the support columns. From FIG. 79, it can be seen that it is preferred to support the roof on only four columns, one at each end of the parallel chord trusses, and also it can be seen that having erected the roof as the first phase of the construction sequence, other work such as floor, slab, walls and services can be carried out with the roof protecting from sun, rain, snow, etc. which will significantly reduce construction times.
From FIGS. 79 and 80, it can also be seen that not only is the system suitable for concurrent factory fabrication of walls, but also suits the factory fabrication of total rooms, particularly wet area rooms which could be delivered onto the site and slid sideways into place between the ceiling and floor, and it can also be seen that these prefabricated walls and/or rooms not immediately apparent from FIGS. 79 and 80 is that economies in design are available because of the independent nature of the roof, floor and walls, ie. the floor does not support the walls which are in turn required to support the roof. FIG. 81 shows how different roof styles can be produced using different shaped trusses. In FIG. 81, two longitudinal roof trusses 8101 are intersected by five lateral trusses 8102, 8103, 8104, 8105 and 8106. Lateral trusses 8102 and 8106 are similar and in
conjunction with the triangular ends of the longitudinal trusses 8101 and the purlins from the basis of dutch gable ends. Trusses 8103 and 8105 are similar, with their bottom chords running through to a triangular gable truss 8107. It will be readily seen by persons experienced in roof framing that the illustrated frame in FIG. 81 provides the basic members for hip and gable forms, valleys, dutch gables, mansards and dormer windows. FIG. 81 also shows the use of floor trusses 8018 supporting floor joists 8109. The roof trusses 8101 and floor trusses 8108 are supported by free standing cantilever columns 8110. Typical dimensions for FIG. 81 when used as a house structure would be 6 to 8 metres laterally between columns and 6 to 10 metres longitudinally between columns.
FIGS. 82 and 87 show the sequence of erection of the structure where the roof 8201 is assembled on the ground between the columns 8202, which are free standing cantilever extensions of bored piers 8203. In FIG. 83, the roof is raised and fixed in its final location and in FIG. 84, the first floor/ceiling unit is assembled and raised as in FIG. 85.
In FIG. 86, the second floor/ceiling unit is assembled and raised as shown in FIG. 87.
FIG. 88 shows how the roof structure 8801 can be used to suspend floors in multi storey buildings. FIG. 88 is a sectional elevation where columns 8802 are fixed to footings 8803 and the roof structure 8801 is assembled at ground level and then lifted to its final location and fixed to the columns. Preferably, at least four columns 8802 are used to give stability. As the roof structure 8801 is lifted, it can be temporarily
stopped to assemble and fix the floors 8804 to it by means of suspension cables 8805. Similarly, a floor/ceiling structure 8806 can be assembled at ground level and raised to its final location, pausing to support ground level assembled floors 8804 as it is elevated. The depth of floor units 8806 may vary from 0.5 metres to 3 metres. Where the depth is larger, the floor could be used to contain air conditioning or lift machinery where the structure members would not interfere with living areas. Any type of walls 8807 as shown in FIG. 80 can be installed after the roof and floors are erected.
In FIG. 88, the lower floor is shown left open or used for car parking. Suspension of the floor units 8804 in this manner, particularly if the floor units are light weight, eg. light weight precast concrete, will significantly reduce the cost of multi level construction.
FIG. 89 shows details of a building using a roof structure 8901 supported on only one central column 8902 and one footing 8903. As in FIG. 88, light weight floors 8904 are suspended by cables or rods 8905, and as described for FIG. 88, can be assembled at ground level and elevated by staged lifting of the roof. Walls 8906 can be fitted between the roof structure 8901 and floor 8904 or between floors 8904 and these walls 8906 could conceal the cables or rods 8905. Alternative wall panels 8907 can be fixed to the ends or edges of floors 8904. Additional cables or rods 8808 between the lower floor and ground level can be connected to extra tie down footings 8909.
From FIG. 89, it can also be seen that a collar or bearing 8910 fixed to the column 8902 will
allow the assembled roof structure 8901, floors 8904, cables 8905 and walls 8906 and 8907 to rotate about the axis of the column 8902, provided cable 8908 is disconnected. Access stairs 8911 can be attached to the rotating floors or be spiral stairs around column 8902. Service ducts 8912 may be stationery inside the column 8902 or service ducts 8913 may be flexibly coiled around the column 8902 and inside a protective jacket 8914.
FIG. 90 shows further details of the one pole house in FIG. 89. In FIG. 90, which is an isometric drawing of the framework of the roof frame members is a pyramidal shape.
In FIG. 90, the column 9001 is a circular hollow section and roof frame members are square hollow sections 9002 and angles 9003. A rotating collar or sleeve 9003, also shown in FIG. 91, rotates around the column 9001. A fixed sleeve or collar 9005 has a bearing interface 9006 with the rotating sleeve 9004. Suspension rods or cables 9007 support floor framing members 9008. Threaded extensions of the rods 9009 allow for extra lower floors to be added. Diagonal bracing rods 9010 stabilise the structure horizontally and lightweight floor panels 9011 are supported by the floor framing members 9008. Wall panels 9012 can be fixed to roof members 9003 and floor members 9008. As explained in FIG. 89, all roof members are assembled at ground level and are lifted in stages such that floors can also be assembled at ground level and lifted by raising the roof structure. FIGS. 92 to 96 show various means of forming box trusses by using common members. In FIG. 92, square hollow section posts 9201 have an angled plate 9202 attached to each end. One section of the angled plate 9202 is coplanar with the walls of common chord 9203 and
another section coplanar with tension rods 9204. Assembly of the posts and chords in a loose fashion using pins or bolts, allows the rods to be tensioned to form a three plane box truss. FIGS. 93, 94, 95 and 96 show details of tower construction using joints, trusses and frames as previously described. FIG. 93 is an elevation of an erected tower showing a jacking platform 9301 in heavy line, which is firmly fixed to the pad and pier foundations 9302. The jacking platform in this case is a triangular box truss formed using a 3, 2 or 1 pin joint system. The tower 9303 is then assembled at ground level, outside the plan area of the jacking platform, in pieces one bay deep in the trusses. When the jacks 9404 have raised the assembled tower, the tower is temporarily fixed to the jacking platform over a depth of at least two bays, the jacks are lowered and another lower section is added to the base of the tower at ground level, the temporary fixing released and the tower jacked up one more bay in height. The process is repeated until the tower reaches full height. Of course, the member sizes can be increased towards the base of the tower and the bay depth decreased for added strength. Preferably, the jacking tower is left in place for added strength at the base.
FIGS. 94, 95 and 96 show alternative plan layouts of the triangular box truss shown., in. FIG.., 93. In FIG. 94, external legs 9401 are fixed to posts and braces 9403 using 3, 2 or 1 pin joint arrangements. The posts and braces 9403 may be angle channels or box sections. The legs 9401 are assembled in lengths equal to one bay depth in the elevation FIG. 94, so that the 3, 2 or 1 pin, non-critical assembly geometry is maintained. Additional vertical legs 9402 and posts or braces 9404 can be assembled inside the main structure
to reduce the effective spanning length of the posts and braces 9403.
FIG. 95 shows the use of internal legs 9505 and an alternative method of using struts 9506 to reduce the effective length of the posts and braces.
FIG. 96 shows various double leg arrangements which are suited to square or rectangular hollow section posts and braces. The double legs 9507 are a combined internal and external leg which will be inherently strong. The double legs 9608 result in post and brace length savings, and the double legs 9609 are a variation on 9607. The difference between the concepts in this tower construction and one of the basis of claiming novelty over other towers with specially shaped legs is in the concept of progressive stabilization, non- critical assembly geometry in each of the trusses forming each side of the box truss, including the single pin joints with their tolerance requirement for their receiving holes. Of course, square or other polygon shapes can be used to construct the tower instead of the triangular box type illustrated.
FIGS. 97, 98 and 99 show details of bridge construction using the concepts previously described. FIG. 97 shows a fixed launching platform 9701 in heavy line, which is fixed through footings to the ground. The bridge structure 9702 being either a triangular or rectangular box truss as shown in section in FIGS. 98 and 99, respectively, is assembled to the left of the launching platform and jacked horizontally through it. The joints used to assemble the bridge structure itself will be either 3, 2 or 1 pin, using separate sections for the chords for each truss bay as per the tower construction in FIGS. 93, 94, 95 and 96. The bridge structure also has its novelty in the single pin concept, pin to hole tolerance and progressive
stabilized, non-critical assembly geometry. Typical dimensions for the elevation in FIG. 97 might be A - 10 metres, B - 10 metres, and C - 50 to 100 metres. Typical dimensions for FIG. 98 being a two lane plus pedestrian bridge could be D and E - 6 metres, F and H- 3 metres and G - 7 metres. Typical dimensions for FIG. 99 could be J - 9 metres, K - 6 metres, L - 7 metres and M - 2 metres.
FIG. 100 shows a structural framework for a high rise or multi-storey building. Trusses 10001 which are all similar geometry for a building square in plan, are jointed together at common members which also act as the four support columns. The trusses 10001 are typically 2.8 to 3.2 deep, being full wall or storey height. Typical length of each truss without additional column support could be 16 to 20 metres.
Smaller trusses 10002 and 10003 are used to frame the roof and additional wind bracing 10004 is also required. The type of construction shown in FIG. 100 is sometimes referred to as a staggered truss construction, which in this particular case results in two sides of each storey being completely open. The floor loads at each level are carried by being attached to the top chords of two opposite trusses below that level and to the bottom chords of two opposite trusses above that level. The novelty in this type of building framework again is in the use of single pins in the trusses, hole tolerance requirements for the pins and non-critical assembly geometry. FIG. 101 shows another method of constructing a framework for a high rise or multi-storied building. The framework is similar to that shown in FIG. 100 in that is has staggered trusses, however, in this case, the trusses are set in from the perimeter of the building such that the end part of each truss is
cantilevered beyond the support truss below. There are five floors in this drawing, each of which has two trusses, ie. 1st floor has trusses 10101, 2nd floor
/ trusses 10102, 3rd floor trusses 10103, 4th floor trusses 10104, 5th floor trusses 10105 and triangular roof trusses 10106. Additional framing members for the roof 10107 are shown and roof sheeting 10108. Perimeter support beams 10109 for the floors and walls are supported at the ends of the trusses, eg. the perimeter beams for level three have floor deck units 10111 supported by the perimeter beam 10109, which is in turn supported by the top of truss 10102 and the bottom of truss 10103. The wall units 10110 are individual prefabricated panels which are supported vertically and laterally at their base by the perimeter beams 10109 and laterally only, at their tops by the perimeter beam. The floor deck units 10111 are also supported by the top chords of the trusses immediately below them as well as the perimeter beams. The setting in of the staggered trusses away from the perimeter face has effectively resulted in the major building columns being formed by the connection of the vertical posts of the staggered trusses in the same plan location, ie. typically in the drawing at 10112. Also, if the ends of the trusses are set in a relatively small amount from the outside face of the perimeter beam, then the wall panels will all have locations uninterrupted by column supports, which in conventional high rise can lead to extensive additional cost due to non-standard detailing. Additionally, the wall panels remain separated vertically by the perimeter beams in the overall building facade and separated horizontally between panels by conventional waterproof joints. This concept of having removable wall panels at each floor level overcomes problems of thermal expansion in building
facades where continuous vertical mullions are used. Additional prop supports 10113 may also be used.
FIG. 102 is an isometric view of a bridge to tower skeletal structure, where square hollow section chords 101, posts 102 and 103, braces 104 and 105, and plates 106 and 107 form a square or rectangular box truss. In FIG. 102, the chords 101 are common to the four planar trusses, with posts 102 and braces 104 connected to plates 106 to form the vertical trusses. Posts 103, braces 105 and plates 107 form the horizontal trusses.
FIG. 103 is an enlarged joint showing the post 102 rigidly fixed with two pins to plates 106 and chords 101 pivotally connected to plates 106 and plates 107 are rigidly fixed to chords 101 using two pins and pivotally fixed to posts 103 and brace 105.
FIGS. 104 and 105 are isometric views of a preferred roof structure using square or rectangular hollow section and joints as per FIG. 76. In FIG. 104, two parallel chords trusses 10401 and two end gable trusses 10402 form the perimeter of the roof. Additional gable trusses 10403 and additional parallel chord trusses 10404 are shown. Purlins 10405 span between trusses and fly bracing 10406 provides lateral restraint for the gable truss bottom chords. It can be seen that if the perimeter trusses 10401 and 10402 and the gable trusses 10403 are non-adjustable, then the additional parallel chord trusses 10404 will need to be adjustable for unstrained assembly between trusses 10403. This can be achieved by using tension only adjustable length braces 10407. Additional bracing of trusses and fixing of roof sheeting may be by any convenient means.