WO2005121464A1

WO2005121464A1 - Disaster area modular building and its building method

Info

Publication number: WO2005121464A1
Application number: PCT/BE2005/000096
Authority: WO
Inventors: Pierre Carbonez; Marc Depauw
Original assignee: Sadef N.V.
Priority date: 2004-06-11
Filing date: 2005-06-13
Publication date: 2005-12-22
Also published as: EP1774109A1; GB0413066D0

Abstract

Modular buildings and building methods are described for use in disaster areas, such as earthquake, tornado or hurricane prone areas. Such buildings have a frame structure comprising columns (3,4) and braced load bearing panels (7), the panels being made up of elongate members, wherein: the braced load bearing panels are joined together into polygonal modules (2) and at least some of the polygonal modules are joined together at extreme corners of the polygonal modules to form nodes (9), panel members joining at the nodes transferring forces from the members substantially centrically to said nodes (9).

Description

DISASTER AREA MODULAR BUILDING AND ITS BUILDING METHOD

The present invention relates to buildings and building methods for use in disaster areas, such as earthquake, tornado or hurricane prone areas.

Technical background The design of earthquake resistant buildings is^' nown - see for example "Seismic Design of Buildings and Bridges", 3^rd edition, Engineering Press, Austin, Texas, USA, 2000, especially chapter 4, or the relevant current edition. Besides earthquakes, wind forces may impose heavy loads on buildings, e.g. hurricanes and tornadoes. For seismic design of steel structures three basic design types have been proposed: concentrically braced frames, eccentrically braced frames, and special moment resisting frames. It is uneconomic to design a building so that it stays within its elastic limit during an earthquake, hence some non-linear energy absorbing capacity by limited damage is allowed. The structure response modification factor R is the ratio of the base shear as developed in an elastic system to the prescribed base shear and is a measure of the ability of the system to absorb energy and sustain cyclic inelastic deformations without collapse. Steel braced frame systems can be used up to an R value of about 5.5 and up to a building height of about 50 m (UBC section 1629.6 and UBC table 16-N). Steel eccentrically braced frame and moment resisting frame systems can be used in more severe situations and for higher building if properly designed.

Summary of the Invention The object of the present invention is to provide modular buildings, building modules and methods of making and constructing the same for concentric braced frame structures. The application of the buildings is preferably at least for an R value of 2, more preferably 3 or above, e.g. 3 up to 5.5. A building method, building module and building frame structure are provided by the present invention which allow the bracing of panels in 2 or 3 directions. Such a building may be provided in earthquake zones for an R value of at least 2, e.g. 3, 4 or up 5.5, and up to 6 floors in height. The structure comprises 2 D panels which are made up of members, e.g. metal members and may be prefabricated. The panels can be joined together into modules either on site or the modules can be prefabricated and the frame structure built on site by joining the modules at their extreme corners. The joins at the corners form nodes of the frame structure. The modules may have any polygonal form in horizontal cross-section, e.g. square, quadratic, triangular or hexagonal. The panels and/or modules may be joined together on site to form a multi-storey building. The panels are joined together so that forces exerted on the nodes are substantially centric. The columns of the frame structure are formed of segments comprising load bearing panel columns which are joined together to form a composite column. The composite columns are formed from panel columns of one floor joined to a composite column formed from panels of other floors. The frame structure formed is a concentric braced frame. Floor slabs can be provided which are constructed at the level of the connections between floors, i.e. the nodes of the frame structure so that horizontal tension or compression forces in the horizontal members of the panels and in the floor are aligned with or concentric with the nodes of the structure. If poured concrete is used to complete the floor slabs, passages between the floors at the nodes can be sealed to prevent flame and fire spread. Braces can be joined at the nodes in a concentric way. The braces may be X or V braces but other braces may be used, e.g. chevron braces. X braces may be use where no openings are required in a panel and V braces when openings such as doors or windows need to be provided in a panel. X braces are joined at the nodes of the building and traverse the panels diagonally. The X and V braces and the connections of these to the frame members remain within the width of the frame members, that is they do not project laterally beyond the width of the panel members. Hence wall panels may be attached to the outside or inside of the frame panels easily. The wall panels may be shear walls to increase building strength. The complete frame structure can be formed by bolting or riveting thus avoiding the problems of welding. The frame structure is preferably made of steel sections of specific types are detailed above. A frame structure and its component panels and modules are claimed as described and substantially as shown in the attached drawings.

Brief Description of the Drawings

Fig. 1 shows an overall view of a braced frame structure according to an embodiment of the present invention.

Fig. 2 shows a detailed view of a braced frame structure according to Fig. 1. Fig. 3 shows a further detailed view of a braced frame structure according to Fig. 1. Fig. 4 shows a detailed view of a node of a frame structure of the kind shown in Fig. 1 in accordance with an embodiment of the present invention. Fig. 5 shows a horizontal cross-section through the node of Fig. 4. Fig. 6 shows a vertical cross-section through a floor slab according to an embodiment of the present invention.

Fig. 7 shows cross-sections a various profiled sections used in the present invention.

Description of the illustrative embodiments The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where the term "comprising" is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. "a" or "an", "the", this includes a plural of that noun unless something else is specifically stated. Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. Fig. 1 shows a modular building braced frame structure 1 which is preferably made of metal, e.g. steel. The structure may include more than one story, e.g. ground level 5 and first floor 6. Such a structure is generally known (without the specific novel and inventive features of the present invention) from the catalogue "Fast track building systems", describing products supplied by Sadef, Belgium. This frame structure 1 does not need to have a primary structure. By primary structure is meant that unitary columns extend from the floor to the top. Instead, each module 2 has load bearing outer columns 3 and can have intermediate columns 4 within it. Intermediate columns 4 need not be load bearing. Module columns 3 from one floor 5 are joined to the module columns 3 of the adjacent floor 6. Thus, the columns of the building are formed by joining together column segments from each module. Each module 2 can be formed of a number of panels 7, e.g. 4 panels, which are joined together at their edges to form a module 2. Panels 7 comprise outer load bearing columns 3, intermediate columns 4, which need not be load bearing, and beams 8. Thus the module columns are formed as a composite of panel columns. The modules 2 do not need to be quadratic frame in horizontal cross-section, for example they can be any suitable shape, e.g. polygonal such as hexagonal or triangular. Also the modules do not need to have the same size at each height or storey of the building. For example, they can taper upwards, e.g. to form a tapering tower structure when stacked one on top of the other. The prefabricated panels 7 may be shipped to site and assembled into modules or the modules may be prefabricated and then shipped to site. As shown in Fig. 2 the panels 7 may include braces. These may be, for example, V- braces 10, or X braces 11 or other types of braces such as chevron braces. It is preferred in accordance with the present invention that the V and X bracings 10, 11 are not attached on the outside or inside of the frame structure 1, but are contained within the width of the members of the frame, e.g. within the width of columns 3, 4 and horizontal beams 8. That is the braces and their fixings do not extend laterally substantially beyond the width of the members of the panels through which they pass or to which they are attached. The advantage is that subsequently wall panels may be attached to the outside or inside of the frame structure easily and there is no requirement to fit such wall panels around protrusions extending from the frame structure 1. The wall panels may be so dimensioned and attached to the frame structure such that they form shear walls to further strengthen the frame structure. The frame structure 1 and the braces 10, 11 preferably form a concentric braced frame structure, e.g. of steel. By concenhic is meant that when the structure is loaded, e.g. by wind or an earthquake, the braces 10, 11 experience mainly tension or compression forces and not significant bending forces or torsional. The braces 10, 11 are joined at nodes 9 of the framed network through gusset means such that longitudinal forces on the nodes 9 applied via the braces 10, 11 pass through the centre of each node 9 (centric loading). Further, the X braces 10 are typically used where there are no openings required in the panels, e.g. no door or window, whereas the V braces are preferably used where an opening such as a door or a window must be provided. The frame structure 1 may be fixed to a foundation layer in accordance with conventional practice, e.g. to a concrete floor slab. An embodiment of the present invention is shown in more detail in Figs. 3-6. It comprises the combination of particular steel sections to provide an optimum design. As shown best in Fig. 4, load bearing edge columns 3 of a number of modules, e.g. from 2-4, are connected together to form a composite column. The panel columns 3 are preferably formed of a profile with a channel section. The channel is provided so that it inner space may accommodate gusset means 16, 17. The channel section is preferably a C or a C plus steel section. Other sections are possible, e.g. a sigma section. For example, two C plus sections from two adjacent modules are bolted or riveted together back-to-back (or "web to web") as shown in Fig. 5 to form a composite column. A further one or two C plus sections of one or two further modules can be riveted or bolted to the composite column to thereby join 3 or 4 modules together as shown in Fig. 5. The cross-sectional forms of various steel sections are shown in Fig. 7 for reference. At a node 9, the horizontal upper beam members 8a of a lower module preferably have a section which provides longitudinal ledges 12 on either side of the beam member 8a. The members 8a are preferably omega sections (see Fig. 7). The outer flanges 12 of the omega profiles provide support and/or fixing ledges for floor/ceiling slabs 20. The centre raised web portion 14 of the omega profile is preferably facing upwards when installed. The floor slabs 20 are not shown in Figs. 1 to 4 but are shown in section in Fig. 6. The lower horizontal beam members 8b of the upper module are preferably of channel section with the open part of the channel facing upwards. The members 8b may be U or C sections with the open part of the U or C facing upwards. The lower horizontal members 8b of the upper module are fixed to the upper horizontal members 8a of the lower module by bolts or rivets 8c through the respective webs. The floor slabs 20 may comprise two layers as shown in Figs. 6a and b in vertical section. The ceiling of the lower module is formed from steel decking 21, e.g. corrugated steel decking and may include suitable service fixings, e.g. for lights and lamps. The steel decking 21 rests on the ledges formed by the outer web flanges 12 of the omega sections and is preferably bolted or riveted thereto. Above the steel decking 21 a floor layer 22 is provided for the upper module. This floor layer 22 is preferably made of reinforced concrete. Preferably the reinforcing bars 23 of the main concrete floor between the panels overlap with, or are looped with, or are joined to the reinforcing bars 24 of an adjacent floor layer by means of reinforcing bars 25, e.g. hoops, loops or stirrups which pass through holes in the upwardly directed flanges of the U or C section of the lower members 8b of the upper module. It will be appreciated that the floor slabs 20 are arranged concentrically with respect to the centre of the node 9 so that they experience mainly compression or tension during building movement and exert these forces at the centre of the node 9. The concrete should preferably be poured to fill up the upwardly facing open U or C profiles of horizontal members 8b right up to the joints of the nodes 9. This seals each floor layer of the building and reduces or prevents the risk of fire penetrating from one floor to another via the load bearing composite columns 3. Returning to Fig. 4, the arrangement of the braces will now be described. Gusset means 16, 17 are provided for attachment of the X braces and V braces, respectively. Each gusset means 16, 17 comprises a left and a right gusset element 16a, 16b; 17a, 17b. Each gusset element 16a, 16b has three mutually perpendicular wall elements. Thus each gusset element forms a box with 3 closed sides and three open sides. Each gusset element 16a, 16b has a bottom plate, one side plate and a back plate. The gusset elements 16a, 16b may be formed from two pieces of angled steel sheet which cooperate together to form the box with three open sides. Each gusset element 17a, 17b has four wall elements. Thus, each gusset element 17a, 17b forms a box with 4 closed sides and two open sides. Each gusset element 17a, 17b has a bottom plate, two parallel side plates and a back plate. The gusset elements 17a, 17b may be formed from two pieces of angled steel sheet which cooperate together to form the box with three open sides. The bottom plate of each gusset element 16a, 16b; 17a, 17b is riveted or bolted to a lower horizontal member 8b. A rear plate of the gusset element is bolted to a column section 3. Two plates of two gusset means 16a, 17a; 16b, 17b may be bolted together through the web of one column 3 and the flange of another - see Fig. 5. The X braces 11 generally only take tension forces and may be formed from a flat steel strip which is fixed between the left and right hand gusset elements 16a, 16b, of one gusset means e.g. by a bolt or bolts or a rivet or rivets. The V braces 10 usually have to withstand compression loads as well as tension loads and are preferably made of a stronger section with a large moment of inertia, e.g. a square, quadratic or round tube, I beam, etc. This may be attached to a piece of steel 18 which is fixed between the mutually facing side plates of two gusset means 17, e.g. by a bolt or bolts or a rivet or rivets. A similar arrangement is provided on the lower side of the node for upwardly rising X and V braces. In this case the gusset means 16, 17 are arranged in the central channel of the omega profile forming member 8 a. Alternative gusset means are included within the scope of the present invention provided the gusset and its fixings to the braces does not extend beyond the width of the members of the frame structure, hi particular the gusset means should transfer load to the frame structure through the nodes 9 without generating a torsional force on the gusset means. Due to the use of two gusset elements and the angle of the brace with respect to the gusset means and the centre of the node as described above, no torsional forces are induced by compression or tension loads on the braces. The X braces 11 preferably pass through the intermediate columns 4, e.g. through slits or holes. The V braces 10 are connected to intermediate columns 4 where these impede the trajectory of the V brace. Alternatively the X braces 10 may also be terminated on each intermediate column 4. A building method, building module and building frame structure have been described above which allow the bracing of panels in 2 or 3 directions. Such a building may be provided in earthquake zones for an R value of at least 2, e.g. 3, 4 or up 5.5, and up to 6 floors in height. The structure comprises 2 D panels which are made up of metal members and may be prefabricated. The panels can be joined together into modules either on site or prefabricated. The places the panels are joined between floors form nodes. The members of the nodes exert forces on the nodes in a centric manner. The modules may be joined together on site to form a multi-storey building. The columns of the building are formed of segments comprising load bearing panel columns which are joined together to form a composite column. The composite columns are formed from panel columns of one floor joined to a composite column formed from panels of other floors. Floor slabs can be provided which are formed at the level of the connections between floors, i.e. the nodes so that horizontal tension or compression forces in the top or bottom horizontal members of the panels and in the floor are concentric with the nodes of the structure. If poured concrete is used to complete the floor slabs, passages between the floors at the nodes can be sealed to prevent flame and fire spread. Braces can be joined at the nodes in a concentric way. The braces may be X or V braces but other braces may be used, e.g. chevron braces. X braces may be use where no openings are required in a panel and V braces when openings such as doors or windows need to be provided. The braces and the connections of these to the frame members remain within the width of the frame members. Hence wall panels may be attached to the outside or inside of the frame panels easily. The wall panels may be shear walls to increase building strength. The complete frame structure can be formed by bolting or riveting thus avoiding the problems of welding. The frame structure is preferably made of steel sections of specific types are detailed above. While the invention has been shown and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes or modifications in form and detail may be made without departing from the scope and spirit of this invention.

Claims

Claims 1. A multi-storey building frame structure comprising columns and braced load bearing panels, the panels being made up of elongate members, wherein: the braced load bearing panels are joined together into polygonal modules and at least some of the polygonal modules are joined together at extreme corners of the polygonal modules to form nodes, panel members joining at the nodes transferring forces from the members substantially centrically to said nodes.

2. The multi-story frame structure according to claim 1 being a concentric braced frame structure

3. The multi-story building frame of claim 1 or 2, wherein the columns of the frame structure are formed of segments which are joined together to form a composite columns, the segments comprising column sections in the braced load bearing panels, and the composite columns being formed from column section of the panels of one floor joined to a composite column formed from column sections of the panels of at least one other floor,

4. The frame structure of claim is suitable for earthquake zones for an R value of at least 2, 3, 4 or up 5.5, and up to 6 floors in height.

5. The frame structure of any previous claim wherein the elongate members are metal members.

6. The frame structure of any previous claim wherein floor slabs are provided which are constructed at the level of connections between floors.

7. The frame structure according to claim 4, wherein the connections are nodes of the frame structure and the floor slabs are provided so that horizontal tension or compression forces in horizontal members of the panels and in the floor slabs are centrically aligned with or concentric with the nodes of the structure.

8. The frame structure according to claim 7, wherein concrete is used to complete the floor slabs, the concrete passing through passages between the floors at the nodes which are sealed to prevent flame and fire spread.

9. The frame structure according to any previous claim wherein braces are joined at the nodes centrically.

10. The frame structure of claim 9, wherein the braces are X, V or chevron braces.

11. The frame structure according to claim 8, wherein the X, V or chevron braces and connections of these to the panel members remain within the width of the frame members.

12. A method of building a multi-storey building frame structure comprising columns and braced load bearing panels, the frame structure being a concentric braced frame structure, the method comprising: joining together braced load bearing panels together into polygonal modules; joining at least some of the polygonal modules together at extreme comers of the polygonal modules to form nodes, and joining panel members at the nodes so that forces in the panel members are transferred substantially centrically to said nodes.

13. Load bearing panels for constructing the frame structure of any of claims 1 to 11.