CONTAINER
This invention relates to a container. In particular, this invention relates to a container of the type used to accommodate trees and other large plants in public places. Such containers are commonly known as planters.
Trees and other large plants can provide an attractive background to a landscape. This is particularly the case in urban environments where the landscape can otherwise appear rather monotonous and dull. In such environments, trees are commonly accommodated in containers. Containers allow for the trees to be conveniently sited close to buildings without any major preparation work being required. Containers also allow for trees to be grown to off-site, for example at a" tree nursery, and only positioned in the intended environment, for example at the entrance to an office building, once semi- mature.
According to the invention, there is provided an impact resistant container for trees or other large plants, the container comprising: side walls fabricated from a plurality of layers of steel beams, the beams having a rectangular open cross- section; and a rigid base member arranged within the side walls, wherein at least one of the side walls comprises a deformation initiating means for initiating deformation of the steel beams in an impact.
The invention recognises that containers of the type used for accommodating trees can be adapted to form effective barriers to protect against attacks on buildings from motorised vehicles, for example by terrorists. With such containers strategically placed outside a building, the building can be protected by ensuring that any impact from a motorised vehicle is absorbed by the containers.
The invention provides a container having a side walls and a base member arranged within the side walls. At least one of the side walls is provided with a deformation initiating means, for example, the side wall facing away from a
building. When a vehicle is driven at speed at the container positioned in front of the building, the side wall is intended to collapse, and thereby absorb a substantial amount of the impact energy of the collision. In this way, the container and/or the vehicle are prevented from being projected into the building.
The container is also intended to immobilise the vehicle before it can reach the building. Specifically, the axles of the vehicle may be immobilised, for example by the rigid base member of the container.
In preferred embodiments, a side wall thickness provided by an upper layer of the beams is greater than a side wall thickness provided by lower layers of the beams. Such an arrangement provides a structure which may collapse in a controlled and predictable way.
If the beams have a non-square cross-section, then the lower layers of beams may be arranged with the side wall thickness being provided by the smaller dimension of the beam cross-section. The upper layer beams are then simply rotated by 90 degrees to provide a greater wall thickness.
The upper layer of the beams may be inwardly extending, so as to provide a flat outer surface to the side walls.
The deformation initiating means may comprise any combination of suitable features, such as cuts, serrations, holes, depressions and material weaknesses formed in the beams. The deformation initiating means is preferably provided in the upper layer of the beams, and is preferably formed in an inwardly facing portion.
In embodiments, the cross-section of the beams may have a length in the range 50mm to 150mm, more preferably 75mm to 125mm and most preferably 90mm to 110mm. The cross-section may have a width in the range 150mm to 300mm, more preferably 175mm to 250mm and most preferably 190mm to
220mm. The wall thickness of the beams may be in the range 3mm to 10mm, more preferably 3mm to 7mm and most preferably about 5mm.
The steel beams are preferably welded together at discrete locations, rather than along their entire lengths. For example, the beams may be "stitch welded".
The side walls may together define a rectangle in plan view, so as to provide a rectangular container. Ends of the beams of adjacent sidewalls may be overlapped. By overlapping the steel beams in this way, at least one beam in each side wall is supported from behind by the ends of beams in adjacent side walls.
The side walls may have a height in the range 600mm to 1200mm, and the base member may have a height in the range 300mm to 500mm.
The base member preferably comprises a block of concrete. The block of concrete provides a bottom for the container and adds mass to the container. The block of concrete may comprise concrete reinforced with steel mesh.
The base member may have a number of apertures through its fabric for anchoring the container to the ground. The apertures are for use in anchoring the container to the ground, thereby reducing its tendency to act as a projectile when impacted.
At least one of the apertures may be angled towards a side wall. In a preferred embodiment, apertures nearest a side wall facing a building to be protected are angled towards the building at their lower end, while apertures nearest a side wall facing away from the building will not be angled. Intermediate apertures may be provided at intermediate angles.
The base member may further comprise a number of brackets for attaching the base member to the side walls.
The container may be clad in a decorative sheet material, .such as stainless steel. The container may contain a planting compost or the like, with trees or other large plants arranged therein.
The invention also provides an arrangement comprising the container described above, positioned on the ground. The arrangement further comprises a number of bars anchoring the container to the ground, the bars extending through respective ones of the apertures in the base member and received in corresponding holes in the ground. Threaded nuts may be used for urging the container against the ground.
The arrangement may comprise a cement, for example an epoxy resin, for bonding the bars into the apertures and holes through which they extend/are received.
The invention will now be described, purely by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a plan view of a container according to the invention; Figure 2 is a cross sectional view of the container shown in Figure 1 ; and
Figure 3 is a partially cut away front view of the container shown in Figure 1.
Figures 1 to 3 show a container according to the invention. The Figures are intended for the purpose of explaining the invention and are not drawn to scale. Moreover, the Figures omit some features for the sake of clarity, which features will be apparent to those skilled in the art.
Referring to Figures 1 to 3, the container 1 according to the invention comprises side walls 3 and a base member 5 arranged within the side walls 3.
Four side walls 3 are provided, which together define a square shape for the container 1. The side walls are each 2200mm long (outside measurement) and 900mm high.
The side walls 3 are fabricated from galvanised steel beams having a rectangular open cross-section, as shown in Figure 2. The length of the beam cross-section is 200mm and the width of the beam cross section is 100mm. The wall thickness of the beams is 5mm.
As shown in Figure 2, the side walls 3 are fabricated with four lower layers 7 of the beams stacked on their minor surfaces. An upper layer 9 of the beams is stacked on top of the lower layers 7. The beams of the upper layer 9 are stacked on their major surfaces. The upper layer 9 of the beams is arranged to be inwardly extending, so that the outer surface of the side walls is substantially flat. The total height of the sidewalls is 900mm.
One of the beams forming the upper layer 9 has a number of serrations 11 formed on the inwardly extending portion thereof, as shown in Figure 1. The serrations are formed perpendicular to the beam axis. The serrations effectively weaken the beam and act as a deformation initiating means in the event of an impact.
As shown in Figure 3, beams of adjacent layers overlap each other at the ends of the side walls 3. The overlapping of the beams is alternated through the layers.
Adjacent beams of the side walls 3 are welded together at discrete locations. In particular, the beams are welded together at their ends and also intermittently along their entire length.
The base member 5 is in the form of a concrete insert that provides a bottom wall of the container 1. The base member 5 is 400 mm high and encapsulates
brackets (not shown) that are welded to the interior of the side walls 3. The concrete of the base member 5 is reinforced with a steel reinforcement mesh.
The base member 5 has nine of apertures 13 formed therein for anchoring the container 1 to the ground. An aperture 13 closest to the side wall 3 having the serrations 11 is formed perpendicular to the plane of the base member 5. An aperture 13 furthest from the side wall 3 having the serrations 11 is formed with its lower end angled away from the side wall 3 having the serrations 11. Intermediately located apertures are formed at intermediate angles.
The outside surface of the side walls 3 is clad in stainless steel sheet material 15 having a thickness of 0.9mm. The sheet material 15 is intended to primarily serve an aesthetic purpose. At the top and bottom of the container 1 , the sheet material 15 is folded back horizontally to mask the underlying structure of the container 1.
In use, the container 1 is permanently anchored to the ground by nine threaded steel bars of 25mm diameter. The threaded bars are set into the apertures 13 in the base member 5 and the ground using an epoxy resin. The bars penetrate the ground to a depth of 150mm. The concrete insert 9 is secured by tightening nuts onto the threaded bars.
The container 1 is arranged with the side wall 3 having the serrations 11 facing away from a building to be protected.
A semi-mature tree (approximate height 9m) is then lifted and inserted into the container 1. In Figure 1 , the base of the tree is represented by circle 17.
The container 1 provides an attractive background for an environment, while at the same time serving as an impact resistant barrier adapted to immobilise motorised vehicles that are driven at the container 1.
Testing has shown that the above described container is particularly effective as an impact resistant barrier. In particular, the heavy base member 5 immobilises the front axle of a motorised vehicle, while the side walls, and in particular the upper layer 9 of the beams, deform to absorb the energy of the impact.
In an impact, the threaded bars in the apertures 13 that are perpendicular to a plane of the base member 5 prevent the container from lifting off the ground, while the threaded bars in the angled apertures 13 restrict movement of the container 1 towards a protected building.
A specific example of a container according to the invention has been described. Various modifications within the scope of the invention will be apparent the those skilled in the art.
For example, the tree may be inserted in the container before the sheet material is applied, so as to preserve the aesthetic finish of the sheet material.
Although a square container has been described, the container may be of any shape depending on practical requirements.
In the above described example, the container is anchored to the ground by nine threaded steel bars. However, any number of bars may be used to anchor the container, although there are preferably at least four such bars. ' Other methods of anchoring may also be appropriate.
In the above described example, a side wall has a deformation initiating means in the form of serrations cut into a beam. However, other forms of deformation initiating means are suitable, such as holes cut into the beam and depressions formed in a surface of the beam. The above described deformation initiating means is intended to initiate bending of the beam when loaded from the side. However, other deformation initiating means may, for example, initiate buckling of the beam when loaded at its ends.