AU2015100194A4 - Perimeter Screens - Google Patents

Abstract

Abstract A method of constructing a multiple level building comprising, attaching a screen to a perimeter of the building such that a framework of the screen spans at least a 5 portion of the perimeter of a storey of the building to which a facade element is to be attached to the building; and attaching the facade element to the portion of the building perimeter over which the framework of the screen spans. - J~RUCTLRE EC0C 12 -- ----N- --- x x ------ ----------- PRDOTO ES&?EE-P rETAz CCtNCRETE C 81 CLU$MS N %flV r ~E z 3T A = I ' 15 ~o~ 1320 1 0,FAAE TLLTION1 Q Fr'gM3 CS ER .T-0c'IT CYCIE OMEI$2E T-&JT SEW~ENrF / 16 Figure 1

Description

-1 Perimeter Screens Technical Field The present invention relates to a perimeter screen used in the construction of a 5 multiple level building and to a method of constructing a multiple storey building. Background During the construction of multiple storey buildings such as apartment of office towers, safety barriers are generally required to protect people and equipment on the ground and neighbouring buildings from items accidentally falling from the building. .o Safety barriers are generally used on any buildings larger than two storeys, but they are particularly important and are generally used for buildings 10 storeys or higher an are critical for very high buildings (for example over 40 storeys). Such buildings can be exposed to high winds and thus have an increased risk of items falling off the building during construction. .s Some types of safety barriers are located near the base of the building (such as on the ground floor or higher if required) and act as a "protection deck" to occupants or the public below by 'catching' items that may potentially fall off the building. Such barriers include protection gantries which extend generally horizontally away from the building and protection fans which generally comprise screens that are 1o positioned at an angle from the horizontal. One drawback with these types of safety barriers is that they may be required to extend over a very large area in order to provide adequate safety. For example, if a neighbouring building is particularly sensitive to falling items, a gantry may need to be erected across the entire area of that building. A further problem is the inherent risk that, particularly in high wind s conditions and on very high buildings, falling items may be blown beyond these types of 'catching' or protection decks. Another type of safety barrier for use during the construction of a building is a perimeter screen that is attached to the perimeter of the building to prevent items falling from the building by essentially enveloping the building. However, a problem 30 with previously used perimeter screens is that they provide only limited access to the external perimeter of the building and must be anchored to the building. This has restricted the ability to use the screens through the entire construction process. An additional difficulty with using perimeter screens is that during construction of a multiple storey building, different phases of the construction are carried out 35 simultaneously on different storeys. Accordingly, the perimeter screens have to be regularly moved to allow construction of the structure to progress upwards and to provide access to the perimeter of the building where required, in particular when installing the building facade. Because of these factors, perimeter screens have only been provided over a small section of the building (generally for structural works) -2 and have not fully ameliorated the need to also provide gantries, fans or other types of catching barrier screens. It would therefore be desirable to provide an improved safety barrier for use in the construction of a multiple storey building and/or an improved method for constructing 5 a multiple storey building. Summary The present invention, provides a method of constructing a multiple level building comprising: attaching a screen to a perimeter of the building such that a framework of the .0 screen spans at least a portion of the perimeter of a storey of the building to which a facade element is to be attached to the building; and attaching the facade element to the portion of the building perimeter over which the framework of the screen spans. In an embodiment, the framework spans at least a portion of the perimeter of a .s storey of a structural zone of the building on which the structure of that storey is being built and wherein the method comprises building the structure of each storey in the structural zone over which the framework of the screen spans. In an embodiment, the method further comprises moving the screen up the building at least one storey after attaching the facade element to the perimeter of the 1o building. In an embodiment, at least one guide is provided to guide the movement of the screen up the building. In an embodiment, attaching the screen to the building comprises using an engagement member that is attached to the building to engage the framework of the 25 screen and wherein the engagement member also provides the at least one guide for moving the scree up the building. In an embodiment, attaching the facade element to the perimeter of the building comprises moving the facade element from inside to outside of the perimeter of the building and into a space between the perimeter of the building and the framework of 30 the screen. In an embodiment, moving the facade element comprises moving the facade element from lying in a substantially horizontal plane inside the perimeter of the building to lying in a substantially vertical plane in the space between the perimeter of the building and the framework of the screen. 35 The present invention also provides a screen attached to a portion of the perimeter of a multiple storey building during construction of the building, the screen -3 comprising a framework spaced from the perimeter of the building and arranged to span at least a portion of the perimeter of a storey of the building to which a facade of the building is to be attached to the building. In an embodiment, the framework vertically spans the perimeter of at least a portion 5 of a storey of a structural zone in the building on which the structure of that storey is being built. In an embodiment, the screen also comprises a deck extending between the lower end of the framework and the building perimeter. In an embodiment, the deck comprises at least one resilient member that engages a .o facade that has been attached to the building. In an embodiment, each resilient member comprises a flap or a roller. In an embodiment, the framework is spaced a sufficient distance from the perimeter of the building to enable a facade element to be moved from inside to outside the perimeter of the building and into the space between the framework and the .s perimeter of the building. The present invention also provides a screen configured to be attached to a portion of the perimeter of a multiple storey building during construction of the building, the screen comprising a framework configured to be spaced from the perimeter of the building and arranged to span at least a portion of the perimeter of a storey of the 1o building to which a facade is to be attached to the building and a deck configured to extend between the lower end of the framework and the building perimeter, wherein the deck comprises at least one resilient member configured to engage a facade that has been attached to the building. Brief Description of the Drawings 25 Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings: Figure 1 is a schematic end view of part of a multiple storey building under construction and with a perimeter screen according to an embodiment of the present invention attached to the building; 30 Figures 2A - 2C are a sequence of schematic end views of part of a multiple storey building being constructed using a method according to an embodiment of the present invention; Figure 3 is a partial end view of a perimeter screen according to another embodiment of the present invention attached to a building under construction; and 35 Figure 4 is front view of the perimeter screen of Figure 1 with a mesh of the screen shown in partial sections.

-4 Detailed Description of Embodiments Referring firstly to Figure 1, a part of a multiple storey building 10 under construction is shown. A partial view of a number of storeys of the building are shown. Although these are marked level 12 (L12) through to level 20 (L20) this is only indicative and 5 the storeys could be any relevant levels of a multiple storey building. The upper section of the building 10 as illustrated in Figure 1 constitutes a structural zone 11 in which the structure of each respective storey in the zone is being built. Each storey in the structural zone is typically at a different stage of construction. The uppermost storey (marked as level 20) is having its concrete floor slab poured and .0 may therefore be referred to as the "wet deck". The storeys under this uppermost storey in the structural zone 11 are undergoing various other stages of structural work including curing of the concrete floor slab, stripping, roughing in of services (eg. water, electricity, gas), setting out and other work to prepare the storey for fitting out later in the construction process. As shown in Figure 1, supports 12 (commonly .s referred to as "backprops") are provided between the floors 13 of each of the storeys in the structural zone 11 in particular to support the floor slabs whilst they are hardening. Although Figure 1 shows four storeys (levels 17 - 20) as part of the structural zone 11, the structural zone could comprise more or less storeys depending on the construction process. o Below the structural zone 11, the building 10 comprises a facade zone 15 in which a facade of the building is being attached to the building's external perimeter. The facade comprises facade elements 16 that are attached to the building 10, typically to the floors 13 such that each facade element extends vertically between adjacent floors. The facade elements 16 may be any suitable panels, sheets or windows that s can be used to form the facade or outer skin of the building. Embodiments of the present disclosure are particular suitable for in attaching elements of a curtain wall facade. A curtain wall facade provides an external wall to the building 10 that is non structural but keeps the weather (eg. rain, wind) out and the building occupants in. On the uppermost storey of the facade zone, a crane in the form of a crawler crane 30 20 is provided for lifting, positioning and holding the facade elements 16 in place to enable them to be attached to the building 10. The crane 20 lifts the facade elements 16 off a trolley 21 located on the storey on which the facade element is being installed. The positioning of a facade element for attachment to the building on the lowest level of the facade zone is shown in dashed lines (with respect to level 14 35 of the building). Although Figure 1 shows three storeys (levels 14 - 16) as part of the facade zone 12, the facade zone could comprise more or less storeys depending on the construction process. Below the facade zone 12, the building 10 comprises a fit out zone 25 in which each storey having had its facade attached is now fitted out.

-5 During construction of the building 10, once sufficient storeys have been constructed, the steps of building the structure of each storey, attaching the facade and fitting out occur simultaneously in the different zones, 11, 15, 25 but sequentially on each storey. As a result, the zones move up the building as the building is 5 gradually constructed, as illustrated in Figure 2. To provide protection against items falling from the building 10 during construction, a perimeter screen 30 is attached to the building 10. The perimeter screen may wrap around the building or extend horizontally across one or several external walls of the building or across only a portion of one external wall of the building. The screen 30 .o comprises a framework 31 that is spaced from the perimeter of the building 10 and spans a portion of the perimeter of the building 10 including vertically spanning a portion of the perimeter of the structural zone 11 and the facade zone 15. Because the screen's framework 31 spans the facade zone and the structural zone the screen provides a safety barrier against any items falling from the building 10. .s Advantageously, this reduces and potentially eliminates the need to have any catching type safety barriers such as gantry screens and fans. The screen 30 is particularly advantageous when used in the construction of very tall buildings where high winds increase the risk of items being blow a large distance of the building and beyond where catching type safety barriers could be feasibly positioned. It is not 0 necessary for the screen's framework to span the fit out zone 25 below the facade zone because the building in the fit out zone 25 is enclosed by the attached facade. Accordingly, the risk of items falling from the fit out zone of the building is minimal. The screen 30 could be split into two screen portions, separately spanning the structural zone and the facade zone. However, a further advantage of having a s single unitary screen spanning both zones is that the screen can be easily moved up the building as construction progresses as a single unit and without the difficulty of having to attach and detach two screens with one immediately above the other. The framework 31 is spaced sufficiently from the perimeter of the building to enable a facade element 16 to be lifted from a storey in the facade zone 15 and pulled 30 outside of the perimeter of the building and then placed into position where it is to be attached to the building. The Applicant has designed the screen 30 and developed the methods of construction described herein so that this action occurs without the facade element heavily contacting the framework of the screen, and preferably without contacting the framework of the screen at all. In particular embodiments, the 35 spacing between the framework 31 and the outer edge of the floor slabs 13 is 800 900mm, preferably about 850mm. The framework 31 is about 200mm wide. The framework 31 is fastened to the building 10 by an anchor in the form of a needle 32 fastened to one of the floor slabs 13. Although Figure 1 shows the needle 32 fastened to the floor slab of the bottom storey of the structural zone 11 40 (corresponding to level 17), the needle 32 could be fastened to any of the other floor -6 slabs. A number of props 33 and ties 34 also extend from the framework 31 and are engaged to different floor slabs 13 of the building 10 to restrict the framework from pivoting about the needle 32. Each of the props 33 pivot about a shoulder joint connection to the framework 31 to enable the props to be manoeuvrable so that they 5 can be quickly and easily moved out of a work area. The ties 34 are attached to vertical projection (not shown) from one of the floor slabs 13. As shown in Figure 4, the framework 31 comprises vertical members 35 to which are mounted a plurality of horizontally extending panels 36. Each of the panels 36 have brace members 37 for rigidity. The needle 32 connects to the framework 31 by .o engagement members in the form of clamps that respectively engage the vertical members 35. Steel mesh 38 (shown only in partial sections in Figure 4) is also attached to each of the panels to provide a barrier for items falling from the building 10. Cloth may also be provided over the steel mesh to protect construction workers from the sun and weather. .s Referring again to Figure 1, the screen 30 comprises a plurality of decks extending from the framework 31 towards the building 10. An upper protection deck 40 is provided in a mid section of the framework 31 and is configured to separate the structural zone 11 from the facade zone 15 by engaging with the floor slab of the lowest level in the structural zone. The upper protection deck 40 thus limits items 0 falling from the structural zone to the facade zone, protecting both the workers below as well as the facade elements attached or being attached to the building. In a variation, rather than a crawler crane, the crane may be in the form of a gantry crane 120 that is mounted to the underneath of the upper protection deck 40. As such, the crane forms part of the perimeter screen 30. This variation is shown in s Figure 3. The gantry crane 120 is configured to move horizontally along the underneath of the upper protection deck 40. A lower protection deck 41 extends from the lower end of the framework 31 towards the building 10. The lower protection deck 41 engages the facade elements 16 that are already attached to the building 10 below the facade zone 15. In doing so, the 30 lower protection deck 41 closes off the facade zone and thus limits items falling from the facade zone of the building 10. Figure 3 shows the lower protection deck 41 in greater detail. The deck 41 comprises a main body 42 and a resilient member in the form of a flap 43 that extends from the body 42 to engage the facade elements 16 attached to the building. The flap 43 is formed of a plastic or other suitably resilient 35 material that does not mark the facade elements even though the flap is engagement with the facade elements. The flap thus protects the finish of the facade elements 16. In a variation to the flap, the lower protection deck is provide with rollers at an end of the deck body which engage the facade elements 16 attached to the building. The 40 rollers may be formed, for example, from neoprene.

-7 The screen 30 is also provided with a plurality of working decks 45, each working deck aligned with a respective floor slab 13. The working decks 45 extend from the framework 31 towards their respective floor slab and provide a surface for workers to stand on to conduct construction work outside the perimeter of the building 10. Each 5 working deck 45 may be split into two portions that are connected by a hinge to enable the portions to fold on each other, as shown in Figure 3. This allows for access between storeys for example to move items between the storeys. The protection decks 40, 41 may be similarly split into two hinged portions. In Figure 3, the screen 30 is shown having a working deck 45 in the facade zone 15. .0 However, in other embodiments, as shown for example in Figure 1, there are no working decks in the facade zone to provide greater clearway between the framework 31 of the screen and the perimeter of the building 10 for moving the facade elements. In the embodiment shown in Figure 1, working decks 45 are provided only in the structural zone 11. .5 Referring now to Figures 2A - 2C, use of the screen 30 in a method of constructing a multiple storey building is illustrated. In Figure 2A, the screen 30 is attached to the building such that it's framework 31 spans three storeys of the building in the facade zone 15 (corresponding to levels 13 - 15 in Figure 2A) and four storeys of the building in the structural zone 11 (corresponding to levels 16 - 19). 1o With the screen 30 attached as shown in Figure 2A, a facade element 16 is attached to the lowest storey of the facade zone over which the framework spans. This is achieved by attaching a cable from the crawler crane 20 (or the gantry crane 120) to a facade element 16 that has been placed on the trolley 21 in a generally horizontal alignment. The cable is then wound up by the crane to pull the facade element and 5 the trolley carrying the facade element to the edge of the floor slab 13. A stop is provided to prevent the trolley travelling past the end of the floor slab 13. Once the trolley has reached the stop, the crane 20 is operated to lift the facade element 16 off the trolley and out past the perimeter of the building 10, taking the leading edge 50 of the facade element past the floor slab of the above storey. This action involves 30 moving, for example by swinging, the facade element from lying in substantially horizontal plane on the trolley into a substantially vertical plane, parallel to the perimeter of the building and to the framework 31 of the screen. This occurs without the facade element heavily contacting the framework 31, preferably with no contact. Once the facade element is in a vertical alignment in the space between the 35 framework 31 of the screen 30 and the perimeter of the building, the facade element is pulled back towards the building and located in its attachment position, before being attached to the building in an appropriate manner. This process is repeated along the horizontal length of the lowest storey in the facade zone. Simultaneously, the required structural work is carried out on the storeys in the structural zone 11. 40 This includes pouring the floor slab for the uppermost storey of the structural zone (level 19 in Figure 2A).

-8 Once the facade on the lowest storey of the facade zone is completed, the screen 30 is moved up one storey to its configuration as shown in Figure 2B. This corresponds to both the facade zone and the structural zone of the building also moving up the building one storey. Moving the screen 30 up one storey involves lifting the screen 5 vertically using a lifting apparatus such as a tower crane or a hydraulic jacking system. The clamps of the needle 32 that engage the vertical members 35 of the screen's framework 31 act as guides for the vertical lifting of the screen 30. The needle 32, however, remains attached to the floor slab 13. Prior to lifting, the clamps are loosened to enable the vertical members 35 of the framework to slide through .0 them. When the screen 30 has been lifted to its new height, the clamps of the same needle 32 may be retightened to anchor the screen to the building (as shown in Figure 2B. Alternatively, a further needle may be positioned on a higher storey of the building and is engaged to the screen to anchor the screen to the building after the screen has been raised (as shown in Figure 2C). Because the framework 31 .s spans several storeys, a further needle at a higher storey need only be used to anchor the building every second time the screen 30 is raised one storey If a crawler crane 20 is used to lift the facade elements into position, the crane may also be moved up one storey when the screen 30 is raised one storey or may be moved two storeys every second time the screen is raised one storey. This is o because the framework 31 of the screen spans a facade zone of three storeys. Once the screen 30 has been repositioned as shown in Figure 2B, the attachment of facade elements to the building and the structural work recommences as described previously. Once the facade on the lowest storey of the facade zone is completed again, the screen 30 is moved up another storey to its configuration as shown in s Figure 2C. This process continues as the building is constructed. In the claims which follow and in the preceding disclosure, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the 30 presence or addition of further features in various embodiments of the present disclosure. From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the 35 present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Claims (5)

1. A method of constructing a multiple level building comprising: attaching a screen to a perimeter of the building such that a framework of the screen spans at least a portion of the perimeter of a storey of the building to which a 5 facade element is to be attached to the building; and attaching the facade element to the portion of the building perimeter over which the framework of the screen spans.

2. A method as claimed in claim 1, wherein the framework spans at least a portion of the perimeter of a storey of a structural zone of the building on which the .o structure of that storey is being built and wherein the method comprises building the structure of each storey in the structural zone over which the framework of the screen spans.

3. A method as claimed in claims 1 or 2, wherein attaching the facade element to the perimeter of the building comprises moving the facade element from inside to .s outside of the perimeter of the building and into a space between the perimeter of the building and the framework of the screen.

4. A screen attached to a portion of the perimeter of a multiple storey building during construction of the building, the screen comprising a framework spaced from the perimeter of the building and arranged to span at least a portion of the perimeter 1o of a storey of the building to which a facade of the building is to be attached to the building.

5. A screen configured to be attached to a portion of the perimeter of a multiple storey building during construction of the building, the screen comprising a framework configured to be spaced from the perimeter of the building and arranged 25 to span at least a portion of the perimeter of a storey of the building to which a facade is to be attached to the building and a deck configured to extend between the lower end of the framework and the building perimeter, wherein the deck comprises at least one resilient member configured to engage a facade that has been attached to the building.