US20100281796A1 - Structural member and a stepped structure - Google Patents
Structural member and a stepped structure Download PDFInfo
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- US20100281796A1 US20100281796A1 US12/746,023 US74602308A US2010281796A1 US 20100281796 A1 US20100281796 A1 US 20100281796A1 US 74602308 A US74602308 A US 74602308A US 2010281796 A1 US2010281796 A1 US 2010281796A1
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- structural member
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B15/08—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B15/06—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of natural rubber or synthetic rubber
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form
- B32B3/02—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by features of form at particular places, e.g. in edge regions
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form
- B32B3/02—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by features of form at particular places, e.g. in edge regions
- B32B3/08—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by features of form at particular places, e.g. in edge regions characterised by added members at particular parts
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
- E04F11/00—Stairways, ramps, or like structures; Balustrades; Handrails
- E04F11/02—Stairways; Layouts thereof
- E04F11/022—Stairways; Layouts thereof characterised by the supporting structure
- E04F11/035—Stairways consisting of a plurality of assembled modular parts without further support
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
- E04F11/00—Stairways, ramps, or like structures; Balustrades; Handrails
- E04F11/02—Stairways; Layouts thereof
- E04F11/104—Treads
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
- E04F11/00—Stairways, ramps, or like structures; Balustrades; Handrails
- E04F11/02—Stairways; Layouts thereof
- E04F11/104—Treads
- E04F11/1045—Treads composed of several layers, e.g. sandwich panels
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
- E04H3/00—Buildings or groups of buildings for public or similar purposes; Institutions, e.g. infirmaries or prisons
- E04H3/10—Buildings or groups of buildings for public or similar purposes; Institutions, e.g. infirmaries or prisons for meetings, entertainments, or sports
- E04H3/12—Tribunes, grandstands or terraces for spectators
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2311/00—Metals, their alloys or their compounds
- B32B2311/24—Aluminium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2311/00—Metals, their alloys or their compounds
- B32B2311/30—Iron, e.g. steel
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2375/00—Polyureas; Polyurethanes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2419/00—Buildings or parts thereof
Abstract
A structural member (1) comprising: a run portion (2) formed by a sandwich structure having first (10) and second (20) plates and a core of a plastics or polymer material between and bonded to said metal plates so as to transfer shear forces therebetween; and a rise portion (3) formed by a metal member/said rise portion being fixed to said run portion and with a first longitudinal end portion (41) of said metal member being inserted between said metal plates.
Description
- The present invention relates to a structural member, particularly a structural member for use as part of a stepped structure such as a stepped riser, perhaps a seating riser e.g. for a sports stadium or other entertainment venue. A stepped structure can be formed from a plurality of the structural members.
- To increase the revenue from sporting and other events, it is desirable to maximize the number of spectators that can be accommodated in a sports stadium or other venue. To do this it is necessary to provide additional tiers of seats, often resulting in structures in which a significant portion of the upper bowl seating cantilevers over other parts of the structure. Accordingly, the weight of risers supporting such seating should be minimized to reduce the size and cost of the supporting structure. To reduce transient and resonating vibrations associated with sporting and entertainment events the risers must be stiff, have sufficient mass, or be constructed with materials having good clamping characteristics. Existing designs of seating risers are made of prestressed or precast concrete or steel. Known riser sections are generally constructed from concrete as it allows for long clear spans between rakers (typically 12,200 mm) with reasonable vibration control since concrete has a damping coefficient of 0.2, good fire resistance and relatively low maintenance cost. The major disadvantage of concrete construction is that the riser section is heavy, e.g. about 10T for a two tier riser, with self weight (deadload) equal to the design superimposed live load due to use and occupancy. It is therefore necessary to provide heavier, stronger, stiffer and more costly superstructure and foundations to support the riser sections, especially for large cantilever seating sections.
- To minimise self weight, and hence reduce the cost of the superstructure and foundations, the riser sections may be constructed with folded steel plates that are supported by intermediate rakers and a secondary steel framework. Typically the maximum span for this type of construction is approximately 6100 mm and the self weight about 40% of an equivalent concrete structure. However, steel risers are more susceptible to sound and vibration problems, having a damping coefficient of 0.1, and have additional costs associated with the fabrication and erection of the intermediate rakers and secondary steel framework.
- Structural sandwich plate members are described in U.S. Pat. No. 5,778,813 and U.S. Pat. No. 6,050,208, which documents are hereby incorporated by reference, and comprise outer metal, e.g. steel, plates bonded together with an intermediate elastomer core, e.g. of unfoamed polyurethane. These sandwich plate systems (often referred to as SPS structures) may be used in many forms of construction to replace stiffened steel plates, formed steel plates, reinforced concrete or composite steel-concrete structures and greatly simplify the resultant structures, improving strength and structural performance (e.g. stiffness, damping characteristics) while saving weight. Further developments of these structural sandwich plate members are described in WO 01/32414, also incorporated hereby by reference. As described therein, foam forms or inserts may be incorporated in the core layer to reduce weight and transverse metal shear plates may be added to improve stiffness.
- According to the teachings of WO 01/32414 the foam forms can be either hollow or solid. Hollow forms generate a greater weight reduction and are therefore advantageous. The forms described in that document are not confined to being made of light weight foam material and can also be make of other materials such as wood or steel boxes, plastic extruded shapes and hollow plastic spheres.
- GB 2,368,041 discloses a stepped riser comprising a sandwich structure having upper and lower metal plates and an intermediate layer of plastics or polymer materials bonded to the metal plates so as to transfer shear forces therebetween i.e. a SPS structure. The plates are pre bent into the desired stepped riser shape and welded together and then the intermediate layer is injected into the stepped riser shaped cavity between the two plates. The sandwich structure plates used in forming the stepped riser have increased stiffness as compared to steel plates of comparable thickness and avoid or reduce the need to provide stiffening elements. This results in a considerably simpler structure with fewer welds leading to both simplified manufacture and a reduction in the area vulnerable to fatigue or corrosion. However, the structure into which the elastomer is injected is bulky and complicated to assemble.
- One aim of the present invention is to provide an improved structural member.
- The present invention provides a structural member comprising:
- a run portion formed by a sandwich structure having first and second plates and a core of a plastics or polymer material between and bonded to said metal plates so as to transfer shear forces therebetween; and a rise portion formed by a metal member, said rise portion being fixed to said run portion and with a first portion of said metal member being inserted between said metal plates.
- In this way the number of welds needed to manufacture a stepped riser with the sandwich plate system (SPS) is kept low and assembly is relatively easy. This not only reduces the cost of welding but also eliminates a potentially fatigue prone detail. Also, the present design thereby avoids greater potential for welding distortion. Furthermore, the structural element is relatively easily transportable and a plurality of structural elements can be stacked. Fixing together and fixing to a frame work is also simplified.
- The materials, dimensions and general properties of the sheets of metal and core of polymer or plastics material of the invention may be chosen as desired for the particular use to which the stepped riser is to be put and in general may be as described in U.S. Pat. No. 5,778,813 and U.S. Pat. No. 6,050,208. Steel or stainless steel is commonly used in thicknesses of 0.5 to 20 mm and aluminium may be used where light weight is desirable. Similarly, the plastics or polymer core is preferably compact (i.e. not foamed) and may be any suitable material, for example an elastomer such as polyurethane, as described in U.S. Pat. No. 5,778,813 and U.S. Pat. No. 6,050,208. Lightweight forms or inserts may also be included as described in WO 01/32414. The first sheet of metal may be painted or have a different surface treatment applied to improve traction.
- A stepped structure according to the present invention can be designed to meet relevant serviceability criteria and construction constraints related to vibration and deflection control, and plate handling. The resulting structure is light, stiff and, with the plastics or polymer material's inherent dampening characteristics, provides improved structural and vibration response performance over risers built with stiffened steel plates and rolled sections (secondary steel work) or those built with prestressed concrete.
- The present invention will be described further below with reference to the following description of an exemplary embodiment and the accompanying schematic drawings, in which:
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FIG. 1 is a perspective view of a structural element according to a first embodiment of the present invention; -
FIGS. 2 a and b are transverse cross-sectional views of a riser portion of the first embodiment of the present invention; -
FIG. 3 is a transverse cross-sectional view of a stepped structure according to the first embodiment of the present invention; -
FIG. 4 is a transverse cross-sectional view of a stepped structure according to a second embodiment of the present invention; -
FIG. 5 is a transverse cross-sectional view of a further stepped structure according to the second embodiment of the present invention; -
FIG. 6 is a transverse cross-sectional view of a further stepped structure according to the second embodiment of the present invention; -
FIG. 7 is a transverse cross-sectional view of a further stepped structure according to a third embodiment; and -
FIGS. 8 a and b are transverse cross-sectional views showing details of the third embodiment. -
FIG. 1 shows a perspective view of astructural member 1 according to the present invention. Thestructural member 1 can be used for forming astepped structure 100, for example a seating riser for use in a theatre or sports stadium etc. - Typically a section of seating has a width of between 10 and 15 metres and is supported at each end by raker beams which can cantilever over other parts of the stadium. Seats are then placed on run
portions 2 of the stepped structure. Therun portions 2 are generally horizontal and steps between therun portions 2 are formed byrise portions 3 which are generally vertical. The stepped structure can be assembled on site or can be pre-assembled partially or completely. - As can be seen from
FIG. 1 in the structural element the step portion 2 (which is elongate in the longitudinal direction) is made of afirst layer 10 and asecond layer 20. The first andsecond layers plates - The thickness of the first and
second layers - Between the first and
second layers core 30 of plastics or polymer material, preferably a compact thermosetting material such as polyurethane elastomer, so as to form a structural plate member (SPS) which acts as therun portion 2 or the tread of the structural member. Thecore 30 is formed of a material which transfers shear forces between the first andsecond layers second layers layers layers - For low load applications, such as staircase risers, where the typical use and occupancy loads are of the order of 1.4 kPa to 7.2 kPa, the bond strength may be lower, e.g. approximately 0.5 MPa. By virtue of the
core layer 30, the structural sandwich plate member has a strength and load bearing capacity of a stiffened steel plate having a substantially greater plate thickness and significant additional stiffening. - To manufacture the structural member, the inner surfaces of
layers - The core material is preferably injected into a cavity and then allowed to cure in the cavity. In order to manufacture the
structural member 1 in this way, a cavity is formed between thelayers longitudinal edges 21 of the structural plate member (as is described below) andtransverse edges 22 of the structural plate member (for example by welding a face plate between the first andsecond layers 10, 20). Thus, a core cavity is formed between the first andsecond layers layers second layers - Although not shown, spacers, light weight forms, shear plates and other inserts may be positioned in the core cavity before the first and second layers, 10, 20 are fixed in place. Spacers are advantageous because they ensure that the spacing of the sections, and hence the core thickness, is uniform across the riser. Furthermore, other low density bulking materials may be used in the core material such as micro spheres and these help in keeping the weight of the structural member low. Detailing, such as seat and safety rail mounts may be welded or otherwise fixed onto the structural member as desired before injection or after curing of the core. In the latter case however, care must be taken to avoid damage to the core.
- As mentioned above, the
longitudinal edges 21 of the core cavity are sealed by firstlongitudinal end portions 41 ofrise portions 3. Therise portions 3 are formed by a metal member. Put another way, thelongitudinal end portion 41 of therise portion 3 is inserted between the first andsecond layers rise portion 3 is in contact with, on a first side, thefirst layer 10 and on the second side, thesecond layer 20. Preferably therise portion 3 is directly welded to the first andsecond layers longitudinal end portion 41 of therise portion 3 and thefirst layer 10 and/or thesecond layer 20. However, it is particularly convenient to use thelongitudinal end portion 41 of therise portion 3 to block the longitudinal gap between the first andsecond layers - As can be seen in
FIG. 1 , therise portion 3 is made of an L-shaped element such that, in use, thelongitudinal end portion 41 extends substantially horizontally so that it can be inserted between the first andsecond layers rise portion 3 also comprises avertical portion 42 which forms the vertical component of the L-shape and, in use, can be used (as is illustrated inFIG. 3 and as will be described below) vertically to separateconsecutive run portions 2. - As can be seen in
FIG. 1 each structural member preferably comprises two rise portions 3 (which are elongate in the longitudinal direction), one inserted between the first andsecond layers longitudinal edge 21 and thesecond rise portion 3 inserted between the first andsecond layers longitudinal edge 21 which second longitudinal edge is on an opposite side of therun portion 2 to the first longitudinal edge. - As is illustrated in
FIG. 1 , the first and second rise portions are so orientated that thefirst rise portion 3 extends beyond an outer plane of the second layer 20 (preferably it is perpendicular to the outer plane of the second layer). Theother rise portion 3 extends beyond the outer plane of thefirst layer 10 and again the part protruding protrudes in a generally perpendicular direction to the plane of the outer surface of thefirst layer 10. Thus, the tworise portions 3 extend in opposite directions from each other. - Preferably the
rise portions 3 are formed of rolled metal (e.g. steel or aluminium). However, therise portions 3 may be formed of non-metallic materials (though they are preferably steel) and also may be formed by other methods, such as bending a sheet of metal. However, preferably the rise portion is a rolled metal member and this can be particularly beneficial because certain features can be incorporated. These will be described with reference toFIG. 2 which is a detailed transverse cross-sectional view of arise portion 3. - As can be seen from
FIG. 2 a, therise portion 3 is generally L-shaped with the base of the L forming, at its end, the firstlongitudinal end portion 41. Preferably thelongitudinal end portion 41 is thicker (preferably about 20 mm) than thevertical portion 42 of therise portion 3 which need only be about 8 mm wide to provide enough strength to act as a riser. - Preferably the outer corner of the L-shape, where the base and the vertical part of the L-shape meet, has a radius of about 10 mm. This is because, in use, that radius will be exposed and sharp edges are to be avoided, if possible.
- As can be seen, the base portion of the L at the first
longitudinal end portion 41 comprises astep 45 on its inner surface. Preferably thestep 45 is made as deep as the thickness of the first and/orsecond layer 20, as appropriate. This helps in assembly and the first and/orsecond layer 20 can then be placed into that step 45 (as illustrated inFIG. 3 ) and welded in place. The outer surface of thesecond layer 20 is then substantially flush with the exposed surface of the base of the L-shaped rise portion. A similar step can be used on the outer surface of the base of the L-shaped rise portion (this is not illustrated). -
FIG. 2 b illustrates afurther rise portion 3 on which certain dimensions have been illustrated. Particular note is the 2% slope. That is, the firstlongitudinal end portion 41 is not at exactly 90° to thevertical portion 42. This ensures that therise portions 2 slope outwardly allowing water, for example, to run off them. The below table shows typical dimensions for three types of rise portion. These dimensions are for a hot-rolled rise portion for use withrun portions 2 which comprise first and second layers with a thickness of 4 mm and acore 30 of 20 mm thickness. -
TABLE 1 HOT ROLLED SHAPE SIZE A1 A2 T B C t b Type A 125 126 8 40 20 4 23 Type B 215 216 10 40 20 4 23 Type C 305 306 12 40 20 4 23 - The design of structural member illustrated in
FIG. 1 which is for use in a stepped structure is easy to assemble partly because the number of welds needed to form the structural member is kept low. For example, as can be seen fromFIG. 1 , only four longitudinal welds are needed. These are between the first rise portion and the first layer, between the first rise portion and the second layer, between the second rise portion and the first layer and between the second rise portion and the second layer. As weld details can be prone to fatigue, the low number of welds necessary is a distinct advantage. - Also, only the rise portions need to be shaped and if this is done by rolling, great lengths of the rise portions can be easily manufactured. Thus, the amount of metal working/tooling needed is reduced. Preferably the length of rise and run portions are substantially equal so that no transverse joins are necessary.
- Furthermore,
structural members 1 such as those illustrated inFIG. 1 can be assembled off site and, as illustrated inFIG. 3 can then be put together to form a steppedstructure 100 on site. This has particular advantages including (but not limited to) quality control in the production of the laminate of the first and second layers and the core material because this can be done off site at a location specifically designed for that purpose. The stepped structure can then be assembled (without requiring welding) through the use of threaded fastenings (though of course welding, if carefully controlled, can be used, if so desired). -
FIG. 3 shows a plurality ofstructural members 1 connected together to form a steppedstructure 100. Neighbouringstructural members 1 are preferably connected together using a plurality of threadedfastenings 110 such as (countersunk) bolts spaced along therise portion 3 in the longitudinal direction. The threadedfastening 110 passes through thevertical portions 42 ofrise portions 3 of adjacentstructural members 1. Preferably those riseportions 3 are connected to each other adjacent respective second longitudinal end portions. The second longitudinal end portions are at an opposite end of therise portion 3 to the firstlongitudinal end portion 41. - The rise portions which are connected together extend in opposite directions (i.e. in use one extends upwards and the other extends downwards) so that a stepped structure is formed.
- A
plate member 60 is provided as a support member for supporting thestructural member 1 and to which the plurality ofstructural members 1 are attached. Threadedfastenings 70 are used to connect theplate member 60 to the structural members. As can be seen fromFIG. 3 a convenient location for the threadedfastenings 70 is through theplate member 60 and into the base part of therise portion 3. Of course other methods of attaching the structural members to theplate member 60 can be used but this method avoids welding and is therefore preferred.Rockwool 130 or similar can be placed on theplate member 60 between the plate member and thestructural members 1 to provide thermal and/or acoustic insulation. Theplate member 60 can then be attached to raker beams (in the form of I beams) and appropriate framing can be designed to carry the whole structure. The raker beams lie in the transverse direction parallel to theplate 60 and can be longitudinally spaced as appropriate, preferably between 10 and 15 metres apart. - It is important to control the dynamic mechanical frequency of stepped risers because of the likelihood of people moving on the risers in unison. A typical, target design frequency of 7.5 Hz exists for an unloaded structure which will reduce to about 6 Hz when the structure is loaded.
- The present invention provides a further additional
vertical support 80 for changing the mechanical dynamic performance of a stepped riser. This member can influence the dynamic mechanical frequency of the stepped riser. -
FIG. 3 shows the further additionalvertical support 80 which extends between theplate member 60 and at least some of thestructural members 1. The additionalvertical support 80 extends in the longitudinal direction and is connected to the correspondingstructural member 1 approximately at a position at which therun portion 1 is furthest from theplate member 60 or where it is attached to therise portion 3. Of course the additionalvertical support 80 is not actually vertical and may be off set by a few tens of degrees from the vertical position. The additional vertical support plate provides the correct dynamic performance of the structural member (for example during movement of humans on the structural member, perhaps movement in unison). - The second embodiment is the same as the first embodiment except as described below. Variations on the second embodiment are illustrated in
FIGS. 4-6 . As can be seen, a portion of therise member 3 is bent over (for example to form a part which projects out of the general plane of the riser 3) and this bent part is inserted between the first andsecond layers rise portion 3 to be made of a metal member, for example a sheet, which is thinner than in the first embodiment. The bend may be roll formed, preferably hot roll formed. - In fact a longitudinal end of the
rise portion 3 is bent back on itself through 180° to form a U shape in cross-section. Thatlongitudinal end portion 41 is then bent through a further 90° to give therise portion 3 an overall L shape with the base of the L being formed by the bent back firstlongitudinal end portion 41. It may be necessary to make a weld between the bent back end and the main vertical part of therise portion 3 in order to prevent water or other undesirable fluids from entering the hollow cavity in the middle of thelongitudinal end portion 41. - A variation of the second embodiment is illustrated in
FIG. 5 . In this embodiment one of the risers also has a portion which is inserted between the first and second layers of thestep portion 2. In thelower rise portion 3 it is a portion intermediate of the longitudinal ends of the metal member which is inserted between the first andsecond layers rise portion 3 is bent in the longitudinal direction by 90°, then at a position lower down the rise portion it is bent again in a longitudinal direction by 90° in the opposite direction to the first bending. A further bend by 90° in the opposition direct to the first bend is made followed by a final bend in the original direction by 90°. - The portions to be inserted between the first and second layers of the step portion can be selected from both types illustrated in
FIGS. 4 and 5 and may be mixed. -
FIG. 6 illustrates a further variation. The embodiment ofFIG. 6 is the same as that ofFIG. 5 except that acorrugation 50 is formed in a vertical part of theriser 3. This corrugation has a C shape in cross-section and is formed in the same way as the portion inserted between the first andsecond layers FIG. 5 . Thecorrugation 50 helps with the stiffness of therise portion 3. Furthermore, thelower rise portion 3 of the pair ofrise portions 3 illustrated inFIG. 6 can have its second end (which is opposite the first longitudinal end) abutting the underside of thecorrugation 50. In this way an interlock is formed and part of the load is taken by thecorrugation 50 rather than by the fastening means holding the tworise portions 3 together. - The third embodiment is the same as the second embodiment except as described below. The third embodiment is described with reference to
FIG. 7 . - In the third embodiment a portion of the
rise member 3 is bent back on itself over the top of the end of therise member 3. This bent part is inserted between the first andsecond layers rise portion 3 which is in contact with the inner surfaces of the first andsecond layers 20. As with the second embodiment, this allows therise portion 3 to be made of a metal member, for example a sheet, which is thinner than in the first embodiment. The bend may be roll formed, perhaps cold roll formed. - The bent portion is illustrated in more detail in
FIG. 8 a. As can be seen inFIG. 8 a the bend in the longitudinal end of the rise portion is such that at least a portion of the rise portion is bent through 180°. In this way part of the bend is parallel to thevertical portion 42 of therise portion 3. As can be seen inFIG. 8 a afinal end 45 is bent away from thevertical portion 42. This allows the top end of a different lower rise portion to lie between two parts of the top rise portion. Thefinal end 45 is effective to prevent water, such as rain, from entering the space between the two rise portions. - As illustrated in
FIG. 7 the two rise portions are different and are attached to each other using bolts. Such bolts could for example be huck fastener magna-lok fasteners. - The second riser illustrated in
FIG. 7 is similar to the second riser ofFIG. 6 . That is, the portion which is inserted between the first and second layers of thestep portion 2 is a portion intermediate of the longitudinal ends of the rise portion. - A difference of the
FIG. 7 embodiment over theFIG. 6 embodiment is that the rise portion which has a part between the two layers of the lower step portion is in an outer most position of the two rise portions (rather than an inner most). As a result it is possible for both rise portions to extend down to the supporting member. This is illustrated in detail inFIG. 8 b. - As can be seen in
FIG. 8 b both rise portions extend down to atab 75 of the supporting member, for example, formed byplate member 60 ends. The rise portions can be for example, through bolted onto thetab 75. As can be seen fromFIG. 8 b, theplate member 60 is actually formed of two metal plates and the same fastener which fastens the rise portions to thetab 75 can be used to connect the twoplate members 60 together. - As with the embodiment of
FIG. 3 , insulation and/or fire proofing can be placed on theplate member 60. The insulation may be cafco board, for example with a thickness of 50 mm. - As illustrated in
FIG. 8 b afurther member 90 is positioned between the two plates making up theplate member 60. This provides additional stiffness, should it be necessary. -
FIGS. 8 a and 8 b show in detail the longitudinal welds between the rise and run portions used to attach the run portions to the rise portions. Similar welds can be used in the other embodiments described elsewhere. - The sheets of
metal - The plastics or polymer material should have, once cured, a modulus of elasticity, E, of at least 250 MPa, preferably 275 MPa, at the maximum expected temperature in the environment in which the member is to be used. In civil applications this may be as high as 100° C.
- The ductility of the plastics or polymer material at the lowest operating temperature must be greater than that of the metal layers, which is about 20%. A preferred value for the ductility of the core material at lowest operating temperature is 50%. The thermal coefficient of the core material must also be sufficiently close to that of the steel so that temperature variation across the expected operating range, and during welding, does not cause delamination. The extent by which the thermal coefficients of the two materials can differ will depend in part on the elasticity of the core material but it is believed that the thermal expansion coefficient of the core material may be about 10 times that of the metal layers. The coefficient of thermal expansion may be controlled by the addition of fillers.
- The bond strength between the core and metal layers must be at least 0.5, preferably 6, MPa over the entire operating range. This is preferably achieved by the inherent adhesiveness of the core material to metal but additional bond agents may be provided.
- The core material is preferably a polyurethane elastomer and may essentially comprise a polyol (e.g. polyester or polyether) together with an isocyanate or a diisocyanate, a chain extender and a filler. The filler is provided, as necessary, to reduce the thermal coefficient of the intermediate layer, reduce its cost and otherwise control the physical properties of the elastomer. Further additives, e.g. to alter mechanical properties or other characteristics (e.g. adhesion and water or oil resistance), and fire retardants may also be included.
- Whilst an embodiment of the invention has been described above, it should be appreciated that this is illustrative and not intended to be limitative of the scope of the invention, as defined in the appended claims. In particular, the dimensions given are intended as guides and not to be prescriptive. Also, the present invention has been exemplified by description of a seating riser but it will be appreciated that the present invention is applicable to other forms of stepped structure.
Claims (24)
1. A structural member comprising:
a run portion formed by a sandwich structure having first and second plates and a core of a plastics or polymer material between and bonded to said metal plates so as to transfer shear forces therebetween; and
a rise portion formed by a metal member, said rise portion being fixed to said run portion and with a first portion of said metal member being inserted between said metal plates wherein said first portion has a thickness substantially equal to the separation of said plates such that by being inserted between said metal plates said first portion spans the gap between the plates; and
further comprising a further rise portion, said further rise portion being formed by a further metal member and being fixed to said run portion and with a first portion of said further metal member inserted between said metal plates.
2. (canceled)
3. The structural member of claim 1 , wherein said first portion is formed by a part of said metal member being bent back on itself such that an outer surface of said metal member abuts both an inner surface of said first plate and an inner surface of said second plate.
4. The structural member of claim 1 , wherein said first portion is formed by a part of said metal member being bent back on itself such that an inner surface of said metal member abuts both an inner surface of said first plate and an inner surface of said second plate.
5. The structural member of claim 2 , wherein said part is a longitudinal end.
6. The structural member of claim 1 wherein said first portion is a first longitudinal end portion.
7. The structural member of claim 2 , wherein said part is intermediate longitudinal ends of said metal member.
8. The structural member of claim 1 , wherein said first portion is a portion of said metal member bent to form a shape sized to fit between and be in contact with said metal plates.
9. The structural member of claim 1 , wherein said metal member is a rolled metal member.
10. The structural member of claim 1 , wherein said metal member is generally L-shaped in cross-section in a plane perpendicular to the longitudinal direction.
11. The structural member of claim 9 , wherein said first portion comprises at least a part of the base of the L of the L-shaped cross-section.
12. The structural member of claim 1 , wherein said first portion is inserted between said metal plates along a longitudinal edge of said run portion.
13. (canceled)
14. The structural member of claim 1 , wherein said first portions of respective rise portions are inserted between said metal plates along opposite longitudinal edges of said run portion.
15. The structural member of claim 1 , wherein one of said rise portions projects beyond a plane of an outer surface of one of said metal plates of said run portion and the other of said rise portions projects beyond a plane of an outer surface of the other of said metal plates.
16. The structural member of claim 1 , wherein said rise portion comprises at least one longitudinal corrugation.
17. A stepped structure comprising a plurality of structural members according to claim 1 .
18. The stepped structure of claim 15 , wherein rise portions of adjacent structural members are connected to each other adjacent respective second longitudinal end portions, said second longitudinal end portion being at an opposite end to a first longitudinal end portion.
19. The stepped structure of claim 16 , wherein said connection between rise portions of adjacent structural members is made with a fastening member, preferably a threaded fastening member, preferably a bolt.
20. The stepped structure of claim 15 , further comprising a support member for supporting said structural members.
21. The stepped structure of claim 18 , further comprising at least one further member extending directly between said support member and a run portion, desirably wherein said structural members are fixed to said support member by a threaded fastening member which passes through said support member and into said rise portion.
22. (canceled)
23. The stepped structure of claim 15 , wherein the stepped structure is a tiered seating structure.
24. (canceled)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0723813A GB2455271A (en) | 2007-12-05 | 2007-12-05 | Structural member for a stepped structure |
GB0723813.2 | 2007-12-05 | ||
PCT/GB2008/004040 WO2009071918A2 (en) | 2007-12-05 | 2008-12-05 | Structural member and a stepped structure |
Publications (1)
Publication Number | Publication Date |
---|---|
US20100281796A1 true US20100281796A1 (en) | 2010-11-11 |
Family
ID=38983044
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/746,023 Abandoned US20100281796A1 (en) | 2007-12-05 | 2008-12-05 | Structural member and a stepped structure |
Country Status (12)
Country | Link |
---|---|
US (1) | US20100281796A1 (en) |
EP (1) | EP2231965B1 (en) |
JP (1) | JP2011506799A (en) |
KR (1) | KR20100102141A (en) |
CN (1) | CN101889122A (en) |
AT (1) | ATE510980T1 (en) |
BR (1) | BRPI0820684A2 (en) |
CA (1) | CA2708041A1 (en) |
ES (1) | ES2366991T3 (en) |
GB (1) | GB2455271A (en) |
PL (1) | PL2231965T3 (en) |
WO (1) | WO2009071918A2 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110179729A1 (en) * | 2009-10-07 | 2011-07-28 | Thompson Marianne | Stair tread assembly and method |
US20120040135A1 (en) * | 2008-12-04 | 2012-02-16 | Jon Micheal Werthen | Sandwich Panel, Support Member for Use in a Sandwich Panel and Aircraft Provided with Such a Sandwich Panel |
PL422321A1 (en) * | 2017-07-23 | 2019-01-28 | Ciepliński Wojciech Fullmet | Modular stairs |
USD997386S1 (en) * | 2021-05-26 | 2023-08-29 | Zamma Corporation, Inc. | Stair tread |
USD1004799S1 (en) * | 2021-05-19 | 2023-11-14 | Casey Swier | Auxiliary step platform for ladder |
USD1021147S1 (en) * | 2021-07-07 | 2024-04-02 | Robert Jeffrey YOUNG | Stair tread |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT1403384B1 (en) * | 2010-12-23 | 2013-10-17 | Icun Nuovi Stadi S R L | INNOVATIVE COMPONENT FOR THE CONSTRUCTION OF TRIBUNES FOR SPORTS FACILITIES AND TRIBUNE FOR SPORTS FACILITIES MADE BY MEANS OF THIS INNOVATIVE COMPONENT |
CN102444247A (en) * | 2011-09-13 | 2012-05-09 | 宁波市鄞州千峰机械科技有限公司 | Gentle slope fluctuating stair special for classroom building |
US9631659B2 (en) * | 2013-04-26 | 2017-04-25 | Honda Motor Co., Ltd. | Multi-material joints and methods |
CN103967233B (en) * | 2014-04-13 | 2016-08-24 | 苏州金螳螂建筑装饰股份有限公司 | Steel ladder damping noise reducing structure |
CN105501400B (en) * | 2015-12-18 | 2017-10-24 | 广船国际有限公司 | A kind of residential area manhole ladder |
GB2557214A (en) * | 2016-11-30 | 2018-06-20 | Intelligent Engineering Bahamas Ltd | Composite structural laminate |
CN112360920B (en) * | 2020-11-02 | 2022-07-22 | 福建金鼎建筑发展有限公司 | Buffer damping stair floor and debugging method thereof |
CN112878750A (en) * | 2021-01-06 | 2021-06-01 | 中国建筑第八工程局有限公司 | Continuous bare concrete prefabricated stand plate and construction method thereof |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5014475A (en) * | 1989-12-21 | 1991-05-14 | Anderson Industries, Inc. | Step module for use in constructing stairways |
US5357724A (en) * | 1992-12-21 | 1994-10-25 | Sonoda Factory Co., Ltd. | Stair tread |
US20040010981A1 (en) * | 2000-10-17 | 2004-01-22 | Kennedy Stephen J | Sandwich plate stepped risers |
US6895717B1 (en) * | 2003-06-03 | 2005-05-24 | J.D. Grinstead General Construction Company, Inc. | Component and method for restoring a stairway |
US20060150540A1 (en) * | 2004-12-28 | 2006-07-13 | Intelligent Engineering (Bahamas) Limited | Sandwich plate risers |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6050208A (en) | 1996-11-13 | 2000-04-18 | Fern Investments Limited | Composite structural laminate |
US5778813A (en) | 1996-11-13 | 1998-07-14 | Fern Investments Limited | Composite steel structural plastic sandwich plate systems |
PA8506001A1 (en) | 1999-11-05 | 2002-04-25 | Intelligent Engenieering Baham | CONSTRUCTION OF A STRUCTURAL LAMINATED PLATE COMPOUND |
-
2007
- 2007-12-05 GB GB0723813A patent/GB2455271A/en not_active Withdrawn
-
2008
- 2008-12-05 EP EP08856399A patent/EP2231965B1/en active Active
- 2008-12-05 ES ES08856399T patent/ES2366991T3/en active Active
- 2008-12-05 CA CA2708041A patent/CA2708041A1/en not_active Abandoned
- 2008-12-05 AT AT08856399T patent/ATE510980T1/en not_active IP Right Cessation
- 2008-12-05 KR KR1020107014897A patent/KR20100102141A/en not_active Application Discontinuation
- 2008-12-05 WO PCT/GB2008/004040 patent/WO2009071918A2/en active Application Filing
- 2008-12-05 PL PL08856399T patent/PL2231965T3/en unknown
- 2008-12-05 CN CN2008801192834A patent/CN101889122A/en active Pending
- 2008-12-05 US US12/746,023 patent/US20100281796A1/en not_active Abandoned
- 2008-12-05 BR BRPI0820684-8A patent/BRPI0820684A2/en not_active IP Right Cessation
- 2008-12-05 JP JP2010536532A patent/JP2011506799A/en active Pending
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5014475A (en) * | 1989-12-21 | 1991-05-14 | Anderson Industries, Inc. | Step module for use in constructing stairways |
US5357724A (en) * | 1992-12-21 | 1994-10-25 | Sonoda Factory Co., Ltd. | Stair tread |
US20040010981A1 (en) * | 2000-10-17 | 2004-01-22 | Kennedy Stephen J | Sandwich plate stepped risers |
US6895717B1 (en) * | 2003-06-03 | 2005-05-24 | J.D. Grinstead General Construction Company, Inc. | Component and method for restoring a stairway |
US20050210775A1 (en) * | 2003-06-03 | 2005-09-29 | Grinstead John D | Component and method for restoring a stairway |
US20060150540A1 (en) * | 2004-12-28 | 2006-07-13 | Intelligent Engineering (Bahamas) Limited | Sandwich plate risers |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120040135A1 (en) * | 2008-12-04 | 2012-02-16 | Jon Micheal Werthen | Sandwich Panel, Support Member for Use in a Sandwich Panel and Aircraft Provided with Such a Sandwich Panel |
US20110179729A1 (en) * | 2009-10-07 | 2011-07-28 | Thompson Marianne | Stair tread assembly and method |
US8316594B2 (en) * | 2009-10-07 | 2012-11-27 | Moulure Alexandria Moulding Inc. | Stair tread assembly and method |
PL422321A1 (en) * | 2017-07-23 | 2019-01-28 | Ciepliński Wojciech Fullmet | Modular stairs |
USD1004799S1 (en) * | 2021-05-19 | 2023-11-14 | Casey Swier | Auxiliary step platform for ladder |
USD997386S1 (en) * | 2021-05-26 | 2023-08-29 | Zamma Corporation, Inc. | Stair tread |
USD1021147S1 (en) * | 2021-07-07 | 2024-04-02 | Robert Jeffrey YOUNG | Stair tread |
Also Published As
Publication number | Publication date |
---|---|
BRPI0820684A2 (en) | 2015-06-16 |
WO2009071918A2 (en) | 2009-06-11 |
GB2455271A (en) | 2009-06-10 |
ATE510980T1 (en) | 2011-06-15 |
WO2009071918A3 (en) | 2009-07-23 |
KR20100102141A (en) | 2010-09-20 |
ES2366991T3 (en) | 2011-10-27 |
EP2231965A2 (en) | 2010-09-29 |
EP2231965B1 (en) | 2011-05-25 |
PL2231965T3 (en) | 2011-10-31 |
JP2011506799A (en) | 2011-03-03 |
CN101889122A (en) | 2010-11-17 |
CA2708041A1 (en) | 2009-06-11 |
GB0723813D0 (en) | 2008-01-16 |
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Legal Events
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |