OVERHEAD PROTECTIVE STRUCTURE

The present invention relates to a temporary overhead protective structure (OPS) that provides safety to the public. More particularly, though not exclusively, the invention relates to a temporary structure that provides overhead protection for pedestrians from falling objects while walking on a footpath that adjoins a construction site, a demolition site, or adjoining a building or other structure that may require maintenance work.

Background of the Invention

Temporary overhead protective structures are commonly found in a city environment where many pedestrians require access to footpaths. There are various methods currently being used for erecting overhead temporary protective structures. The traditional types in Australia include the use of scaffolding, modular steel structures, timber structures, site- specific structural steel structures with timber decking; all with a protective deck above ground level to separate the construction site from the public space.

Usually part of the overhead protective structure capacity may be used to support construction materials and portable amenity buildings. Where there are separate amenity buildings loaded onto the deck, there are two decks or floors, that is, the amenity building floor and the supporting safety deck or floor.

Currently the workers in the amenity buildings are not usually given the same level of overhead protection from falling objects as pedestrians at footpath level. The current amenities are usually prefabricated buildings with only a thin corrugated metal roof with the walls of lightweight metal or timber framing.

Time is critical to build or erect the overhead protective structures and to then connect amenities. Some systems require a significant amount of special fabrication or many parts are to be connected at night during limited time periods to avoid traffic and when the least number of pedestrians are present. The amenity-prefabricated buildings are usually

delivered on another similar separate occasion and lifted into position after the overhead protective structure has been inspected and certified by an engineer. Final connection for amenities and use is usually days or even weeks after the initial overhead protective structure is initially erected.

The present invention seeks to provide an alternative temporary overhead protective structure that overcomes or substantially ameliorates at least one of the above disadvantages.

Summary of the Invention

In accordance with one aspect the present invention provides an overhead protective structure for providing protection to pedestrians located on a walkway adjacent a construction site, the overhead protective structure including: a modular structural element including a base surface, side wall portions and a roof element, a plurality of support members that supports the modular structural element above the walkway at a height which allows pedestrians to pass underneath the modular structural element, and, a fence element located along the side of the walkway adjacent the construction site.

In one form, the modular structural element is in the form of a shipping container. In another form the structure includes support members located on the side of the walkway adjacent the construction site and support members located on the other side of the walkway wherein the fence element is coupled to the support members located on the side adjacent the construction site. In a preferred form the support members are adjustable in height such that the support members can support the modular structural element at a level horizontal height even when the walkway surface or other ground surface is not level.

In one form the support members include a male coupling element adapted to cooperate

with an existing female coupling element located on the base surface of the shipping container. In a preferred form, the male coupling element engages the female coupling element of the shipping container by placing the male coupling member in the corresponding female coupling member and rotating the male coupling member which thereby engages within a flange located within the female coupling member.

According to another form, the structure further includes one or more brace members that are coupled at one end to the base of the modular structural element and coupled at the other end part way down the one or more support members.

According to a further form, more than one overhead protective structure is joined together in a modular fashion whereby the modular structural members include open end portions that form a continuous corridor suspended above the walkway. In a preferred form, at least one overhead protective structure that includes a modular structural member including one open end portion and one closed end portion thereby closing the continuous corridor at one end.

According to another form, the modular structural member includes amenities within its side wall portions. In a preferred form the amenities are located in the modular structural member before the structural member forms part of the overhead protective structure.

In one form, the overhead protective structure further includes a suspended and/or cantilevered walkway located at substantially the same level as the base surface of the modular structural member, the suspended walkway extending on either the construction site side, and/or the walkway side of the modular structural member and running in the same direction as the walkway.

According to another aspect the present invention provides a method of erecting an overhead protective structure for providing protection to pedestrians located on a walkway adjacent the construction site, the method including the following steps: suspending a modular structural member including a base surface, side wall

portions and a roof element above the walkway; securing the modular structural member onto a plurality of support members that maintain the modular structural member suspended above the walkway; and, securing a fence element to the support members along the side of the walkway adjacent the construction site.

Brief Description of the Figures

The present invention will become better understood from the following detailed description of a preferred but non-limiting embodiments thereof, described in connection with the accompanying figures, wherein:

Figure 1 is a part side elevation of an embodiment of the present invention; Figure 2 is an end view of an embodiment of the present invention; Figure 3 is a cross section of an embodiment of the present invention;

Figure 4 is a close up cross sectional view of the bottom corner of one element of an embodiment of the present invention;

Figure 5 is a plan view of the site fence element fixed to an embodiment of the present invention; Figure 6 is a plan view of the site fence element fixed to an embodiment of the present invention; and,

Figure 7 an alternate method of fixing the cantilever walkway to an embodiment of the present invention.

Detailed Description of the Invention and Preferred Embodiment

By means of the present invention there is provided an alternative overhead protective structure that has significant advantages over what has been typically used to date. In particular, and according to one embodiment, the overhead protective structure of the present invention makes use of existing shipping containers and their significant structural properties to provide the basis of the overhead protective structure. As the shipping

containers have a known structural integrity, it is possible to pre install any amenities within the containers prior to the overhead structure being delivered to a prospective building site and thereby avoid the need for a site inspection by structural engineers necessary when constructing typical overhead structures. This factor significantly reduces the amount of time required before work can effectively start on a construction site.

In addition in a preferred embodiment of the present invention the support members includes a male coupling component in the form of an egg shaped head on top of the support. This egg shaped head is a corresponding shape to a locking component typically used on trucks conveying shipping containers for cargo purposes, and therefore provides use of the pre-existing corresponding female coupling component on the shipping container within the assembly of the overhead protective structure. The shaft usually swivels in a mounting at four corner of a truck. When the container is lowered, the male components are turned like a key 90 degrees to lock into the female housing at each corner of container. The male components are often connected together with a tight cable all round so the locking is done all round while standing at one point.

In the embodiment of the present invention the male coupling component of the support member is welded on to the top of the support member. Therefore in order to lock the support member in coupling arrangement with the female component located on the shipping container, the male component is inserted therein and rotated 90 degrees into locking configuration.

The structure of the modular structural member can be fully fitted-out with worker amenities prior to delivery on site to be erected as part of the overhead protective structure. The amenities may include toilets, showers, first aid room, site office, worker lunchroom, meeting room, etc. Some elements may be open decks and not be enclosed so that construction materials can be loaded and stored on an open deck above the overhead protective structure protecting.

A preferred form of the present invention will now be described by way of example with

reference to figures 1 to 7, wherein: Figure 1 is a part side-elevation of the temporary overhead protective structure in accordance with one embodiment of the present invention.

Item 1 included in the figures is a pavement, footpath, walkway or similar firm ground support for the structure. In the present embodiment the footpath or walkway is adjoining a demolition, construction or building maintenance site (not shown).

Item 2 referred to in the figures is a modular structural unit which in this embodiment is a shipping container. There are several shipping containers that make up the structure depicted in figure 1, and each of these may be optionally internally fitted out with site amenities. In accordance with a preferred form, some of the shipping containers do not include end walls such that the containers joined end on end form a continuous corridor.

Item 3 is a support member in the form of an extendible post that may be twist-locked into standard locking points of said item 2. Item 3 may be bolt fixed to item 6 when delivered to site. Item 3 and usually item 5 are ideally equally spaced on the site side and may be clustered kerb side to provide more open appearance. The adjustable nature of the support members provides that the overhead protective structure may still be erected and provide a level overhead structure even if the walkway or footpath is uneven. Where the footpath or walkway, item 1, is sloping such as on an incline or hill, it may be necessary to step adjoining shipping containers, item 2, as depicted in Figure 1, thus providing a step within the continuous corridor between two adjacent shipping containers, item 2.

The height of the support members, item 3 or 5, is sufficient such that the shipping containers are elevated to a height above the walkway or footpath, item 1, such that pedestrians can comfortably walk underneath the shipping containers, item 2. In a preferred form, the height of the support members is at least 2.0 meters and preferably at least 2.4 meters.

Item 4 is a connection item that usually facilitates the twist-lock motion of item 3 to lock on to item 2. Typically though not necessarily, this fixing method is an adaptation of a

standard shipping container locking-device.

Item 5 is a further support member in the form of an extra extendible post that is usually provided with an angle cleat that is fixed on site to the bottom edge of the shipping container, item 2. These are often used so the structure can be designed to allow for any one post to be removed and the structure still remains stable under reduced design loads.

Item 6 is a brace member in the form of a commonly known knee brace structure and may be attached to increase lateral load capacity of the overhead protection structure by bolt fixing to the underside floor of the shipping container, item 2. Item 6 is knee-bracing that is usually in the form of a steel angle that is delivered to site bolt fixed to item 3 and may be item 5, then bolted to item 2.

Item 7 is a coupler usually in the form of a profiled steel strap, a backing plate and bolts for clamping adjoining posts together, locking the system together even if the decks of the adjoining shipping containers, item 2, are stepped as shown in figure 1. The coupler, item 7 provides additional rigidity to the overall structure. Item 8 is a counterweight, sometimes used to stabilize the structure from overturning under wind and other forces that may act on the overhead protection structure.

Referring specifically to Figure 2 there is shown an end view of said system showing knee- bracing between the support members, item 3, and the underside of the shipping container item 2 in an orthogonal direction.

Referring specifically to figure 3 there is shown a cross section through the middle of the shipping container item 2 and between support members 3 showing an attached cantilevered walkway. Item 9 is a set of beams that support the walkway which in this embodiment are attached to the underside of item 2. Item 10 is a handrail that is site attached to item 9.

Referring now specifically to figure 4, there is shown a close up cross sectional view of the

bottom corner of said shipping container, item 2, at completion of erection (not including view of cantilevered walkway). The components of the fence element, item 15 and item 16, in the form of a site fence are shown below the corner of item 2.

Referring to Figure 5 there is shown a plan view of the site fence preferred fixing method to said item 3 and item 5 prior to locking thereon. Figure 6 is a plan view of the site fence preferred fixing method to item 3 and item 5 after locking on, usually by tightening a bolt. Item 1 1 shown in these figures is an angle on each side of post, item 3 or 5, each with a welded end cleat for a bolted connection to item 13. Item 11 may be a short length at each item 14 fixing-point or an angle may extend down to ground to provide added support for fence during site installation. Item 12 is a bolt that allows rotation of fence girt fixing mechanism and clamps the site fence to items 3 and 5 when tightened. Item 13 is a double angle that is single bolted to said end cleats. The single bolt allows item 13 to rotate to align with item 14 so item 14 does not need to be level or perpendicular to items 3 and 5. Item 14 is usually a z-purlin, also known as a girt, that may be overlapped for site adjustment of length. Self-tapping screws may be used to fix sections together at splice. Item 15 is a panel that is usually structural plywood and is usually fixed to item 14 using self tapping screws. Item 16 is similar to item 15, except on opposite side of item 3 and item 5, near top of same. Item 17 is a pressed metal sheet, profiled to close off gap between items 15 and 16, sloped to avoid rubbish accumulation and screw fixed to above said items.

Item 18 is a handrail located on the roof of the shipping container, item 2, which may be used to confine falling objects and to be a safety barrier for workers.

Referring to figure 7 there is depicted an alternate method of fixing the cantilever walkway to the safety structure, referred to as a "strutted deck" wherein item 19 is a knee-brace that supports the walkway and exerts lateral forces on to item 3 and item 5 which are usually equally spaced adjoining the site. Item 20 is a tie member usually locked into the shipping container locking device at item 3 and a similar manufactured connection at midspan of item 2.

In accordance with another embodiment of the present invention, a method of erecting the overhead protective structure is described as follows:

After the shipping container delivery arrives on site, the cantilever walkway beams with or without the decking may be attached prior to lifting each container into position. When the container is lifted into position, it is held in suspension until all posts supporting the unit are twist-locked or cleat-bolted into position. This is followed by post knee-bracing being fixed and the posts extended to reach ground level. Once the container is supported on posts, the optional cantilever walkway and optional site fence is completed.

One of the elements of the system is the use of shipping containers which are widespread, robust and can be rapidly fixed into position. The shipping containers can be fitted-out with amenities, critical for workers and at the same time provide protection to the public on the footpath below.

The present invention saves on the amount of specialised component parts and fabrication required for an overhead protective structure for public on the footpath. A separate deck is now not normally required in locations where amenities are provided. In these areas only the posts and knee-bracing (or a portal frame) require fabrication as well as the optional cantilevered walkway, the optional site fence and other component parts to make the system more versatile.

With previous forms of overhead protective structure, there is an initial separate delivery of the overhead protective structure. The structure was then inspected and certified by an engineer before approval is granted from the local authority to deliver amenity buildings and for loading onto the deck.

Advantageously in a preferred form of the present invention the amenities are housed within the modular structural units with known structural integrity. This allows the connection of services to occur at almost same time as the structural assembly of the overhead protective structure. Accordingly, the present invention should reduce the

number of truck deliveries and / or delivery times compared to existing methods to complete the safety structure and install amenities. Therefore this should lead to faster completion of the required protective structure, delivering 'days earlier' occupation and use of site office, first aid room and amenities by workers.

In addition, the old method of unsightly exposed amenity buildings can now no longer be seen above the traditional Im high handrail or a preferred aspect of the present invention. For prestigious projects, optional advertising banners may be easily fixed to the side of the 2.4m high shipping container sides. Alternately the more robust corrugated facade finish of the container sides can be clad with structural plywood or steel plate to provide a more aesthetic finish to the overhead protective structure.

One method of stacking modified shipping containers one above the other on the ground creates difficulties: double truck delivery; unnecessary footpath ramps that restrict disabled access; trip hazard for side entry to the protection zone; no easy solution to make units level on a sloping footpath (often in both directions); the floor of the shipping container potentially blocks access-lids to essential utility services under footpath; blocks access for concrete pump-lines that require crossing the footpath, etc.

Currently overhead protection is provided only to pedestrians at footpath level, but the same protection is not usually extended to the workers in the amenity buildings. The shipping containers and associated robust elements of the present invention are able to provide improved overhead protection to workers in the elevated amenities located within the modular structural elements of the present invention. The system has independently adjustable support members in the form of posts for uneven ground and can be stepped for sites adjoining steep road gradients.

In further preferred features of the present invention modified elements can provide open decks for storage of construction materials, or made with reduced deck-width to accommodate trees, light poles, etc. A set of handrails can relatively easily be fitted to roof of container to confine falling objects bouncing off roof of amenities, not usually

currently provided.

In further preferred forms, the modular structural elements in the form of shipping containers that are now supported on posts eliminate problems created by merely stacking shipping containers placed directly on the ground because: there is less number of truck deliveries required; this eliminates the problems of required ramps; this eliminates the problems of levelling the containers when on the usual sloping footpaths, often sloping in two directions; this eliminates the problem of blocked access lids to utility services.

Finally, it can be understood that the inventive concept in any of its aspects can be incorporated in many different constructions so that generality of the preceding description is not superseded by the particularity of the attached drawings. Various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or ambit of the present invention.