PARKINGS

The present invention relates to an improved column for realizing prefabricated structures, particularly for realizing modular parkings.

More specifically, the invention concerns a column of the above kind permitting optimizing the realization of prefabricated structures without foundations.

As it is well known, in recent years many solutions have been proposed relating to prefabricated structures employed for the construction of overhead installations, in particular when, in the absence of sufficient space, it is necessary to temporarily or semi-temporarily create a raised floor in a short time.

In particular, solutions related to installation of modular parkings have been studied and implemented.

In the following, the specification will be particularly addressed to the use of the column according to the invention in a modular parking structure, but it is well evident that the same can also be used in modular systems for the construction of prefabricated structures of another type or intended to a different use.

Among the solutions for modular parkings, temporary or semi- permanent modular parkings are known which provide two levels, one on the ground and the other one raised, without the use of conventional foundations.

Each level of such parking provides at least a parking area, or "bin", consisting of the assembly comprising a central traffic flow lane and two lateral stop zones, the latter being arranged opposite each other with respect to the central lane, and delimited by longitudinal sides of the bin (with respect to the longitudinal direction of the lane). Each one of said lateral zones comprises a plurality of parking lots, arranged according to a comb arrangement and at least accessible from said central lane.

Some modular parkings, such as that described in European Patent EP 0364414, provide, in correspondence of the ground level bin, a plurality of pillars or columns arranged either on both longitudinal edges of the bin and on both edges of the lane, one every two parking lots.

It is also provided an assembly of beams, connected to said pillars or columns, forming an adjustable structural grid, in order to support the floor of the upper level.

Said arrangement, although structurally efficient, is not particularly easy for drivers during parking maneuvers, which are partially obstructed by said pillars or columns along the sides of the central lane.

On the other hand, the arrangement described providing a column every two parking lots, allows a transmission to the ground of the upper level loads in a manner well distributed among the pillars or columns. In fact, considering that street surface must be able to support, at a minimum, the load transmitted from a wheel of a heavy vehicle, i.e. about 4 kg/cm ² , usually street load is at least 6 kg/cm ² . Given that, in line of principle, the weight per square meter to be taken into consideration when calculating the structures for modular parkings of the above type (including both own loads own and accidental loads), is equal to about 600 kg/m ² , and since that in the above arrangement each pillar must work for about 25 m ² , the load transmitted to its base (usually a plate of about 3600 cm ² ) is almost equal to 4 kg/cm ² . The load transmitted to the ground by each pillar is therefore compatible with the normal load-bearing capacity of the street surface, which thus does not need, in general, to be reinforced with additional conventional underground foundations.

Another known configuration for modular parkings without conventional foundations is that described in patent EP 1507053. It provides for the presence of pillars or columns for supporting the floor of the upper level, one for each parking lot, only in correspondence of the longitudinal sides of the bin and not along the sides of the lane. The support beams of the floor of the upper level are provided transversely wih respect to the longitudinal direction of the lane and supported on two pillars opposite with respect to the same lane. Such an arrangement, although undoubtedly advantageous for the maneuvering comfort, is instead disadvantageous as far as structure transportation and assembling/disassembling operationsf, because of the excessive size of the modular elements. In fact, the connecting beams between the pillars are very long, generally around 16 meters or more, and therefore difficult to handle during the production, namely during the galvanizing, transportation and yard handling operations of. The yard handling is particularly problematic when operating spaces are reduced, as very often occurs in this type of yards.

The main disadvantage of this solution consists in the fact that it can be used without foundations of conventional type fixed only on the condition to employ a lightweight structure floor for the raised level, e.g. an entirely metallic floor. Indeed, in case a floor of the type described in the above in relation to EP 0364414 is employed (e.g. made up of reinforced concrete or concrete with cooperating corrugated sheet), weighing about 600 kg/m ² , the central pillars between two contiguous bin should bear the load on about a floor surface of 40 m ² (16m x 2.5m), i.e. more than 24,000 kg each one. This equates to transferring on the ground of more than 6.5 kg/cm ² , a value higher than that normally required for road paving.

Despite the need for lightening the structures imposed by the absence of foundations has led engineers to explore any kind of solution using lightweight materials in place of the concrete to construct the floor, decades of use of these modular parking structures have demonstrated that concrete, suitably waterproofed and equipped with a suitable wear layer, remains at present the only material capable of providing performances in line with the expectations and needs of the parking operator, that is, a lifespan that allows not only a temporary use of the structure, but also, if desired, a semi-permanent use of the same.

In fact, the solution providing a steel floor has proved to be suitable only for a short term use (from few weeks to few months), due to the problems connected to excessive noise caused by vehicles passage and to the low resistance to rain water, potentially containing oils, by the metal sheets and the joints between them.

Other problems of the structure described in patent EP 1507053 lies in the fact that it is not possible to provide bracings in the transverse direction of the lane. This involves the creation of a burdensome interlocking between the beam and the pillar in the lane transverse direction, and the consequent presence of a bending moment in the pillar, not compatible with the bayonet and screw joints adopted in order to permit height adjustment and easy dismantling of the structure. Moreover, the beams are not transportable unless an "exceptional" transport is organised, or they should be realised on site by joining the various pieces employing complex joints, which are able to restore the transfer of shear stresses and bending moment on the length of the beam.

In view of the above, it is well evident the advantage of being able to have a solution like the one proposed according to the present invention, which overcomes many of the disadvantages described in the above with reference to the prior art.

In particular, an object of the present invention is that of providing a column for prefabricated structures having such structural features to allow providing, along the lane of a car park without foundations with a single raised level, a single column every three parking lots.

Another object of the present invention is that of providing a column of the above kind having such structural characteristics to allow, in case it is employed according to a traditional layout providing a column every two parking lots, to provide a second raised level, maintaining the absence of foundations.

Another object of the present invention is that of providing a column of the above kind allowing to avoid, or in any case making it not necessary, the provision of the traditional St. Andrew's cross bracing.

It is therefore specific object of the present invention a column for realizing prefabricated structures, in particular for realizing of modular parkings, said column being characterized in that it provides a floor support structure, two ball articulated joints, or hinges, provided on said support structure, two column elements, coupled under stable support conditions, to a respective one of said ball joints, and in such a way to assume a vertical orientation, and at least one bracing structure between said two column elements.

Preferably, according to the invention, said support structure may be comprised of a plate, or of two separate plates, each bearing a respective ball joint.

In particular, said support structure may be supported by the ground, or slightly buried.

Always according to the invention, two, or more bracing structures can be provided between said two column elements, one above the other along the vertical extension direction of said column elements.

Further according to the invention, said at least one bracing structure is adjustable.

Still according to the invention, said column elements can be adjustable in height.

Finally, according to the invention, the distance in the horizontal direction between said column elements may be included between 0,6m and 1 ,5m.

The present invention will be now described, for illustrative but not limitative purposes, according to its preferred embodiments, with particular reference to the figures of the enclosed drawings, wherein:

figure 1 is a schematic side view of a column according to the invention;

figure 2a shows a traditional arrangement columns in a single level prefabricated modular parking without foundations;

figure 2b shows an arrangement of columns according to the invention in a single level prefabricated modular parking without foundations;

figure 2c shows an arrangement of columns according to the invention in a two level prefabricated modular parking without foundations; figure 3a is a schematic side view of a traditional solution of a single level prefabricated modular parking; and

figure 3b is a schematic side view of a solution of a single level prefabricated modular parking according to the invention.

Observing now the figures of the enclosed drawings, and initially in particular figure 1 , there is shown a column according to the invention, generically indicated by the reference number 1 , which includes a pair of suitably stiffened steel plates 2, resting on the support plane (which will not be necessarily a horizontal plane).

Each plate 2 is provided with a ball joint (or hinge) 3, on each one of which it is disposed, according to a stable support condition, a column element 4. Said column element 4 will have a vertical position, and will support the above floor (not shown in Figure 1). Each column element 4 can be adjustable in height, for example by means of an internal screw (not shown) or another suitable system.

It should be however noted that column 1 according to the invention could also provide a single plate 2, on which the two ball joints 3 are provided The single plates, may have a size of 60cm x 60cm, or 70cm x 70cm, or different, but they not necessarily have to have a square shape. Further, they could be buried.

In the embodiment shown in figure 1A bracing structure is provided between the two parallel column elements 4, (at a distance that can range e.g. between 0.6m and 1.5m), , said structure bracing comprising two pairs of diagonal rods 5, suitable for transmitting to the ground the horizontal loads, e.g. due to wind or earthquake, on the whole parking structure.

As it can be observed, in the embodiment of figure 1 , the bracing structure is divided into two bracings, but it is well evident that the column according to the invention can also provide a single bracing, or can provide more than two bracings along the extension in height of the two parallel column elements 4.

The bracing structure may provide adjusting elements 6 for each rod 5. Advantages that are obtained by the column 1 according to the invention are well evident from the simple observation of enclosed figures 2 and 3.

In figure 2a it is shown the arrangement of a prefabricated parking without traditional foundations, providing a center lane C and two lateral stop zones F, each one with a plurality of parking lots.

It is noted that in this case, employing traditional columns, it would be necessary providing a column every two parking lots.

Furthermore, from figure 3a, laterally showing the parking of figure 2a, it is observed that it is necessary providing St. Andrew's cross bracing, with all the drawbacks for the driver described in the introduction of the present specification.

On the contrary, and referring to figures 2b and 3b, a single level prefabricated modular parking, realized by providing columns 1 according to the present invention can.

- provide a single column 1 every three parking lots;

- avoid the provision of St. Andrew's cross bracing (the distance between the two parallel column elements 4, with the relative bracing structure, it is such as to leave sufficient lateral space to open the doors without any hindrance.

In addition, as can be observed from figure 2c, employing columns 1 according to the invention, it is possible, by providing them every two parking lots, realizing a two level prefabricated modular parkings.

The possibility of using the composite column according to the present invention in order to solve the above mentioned technical problems has been developed by careful evaluation of the geometrical characteristics of the space available for placement of a column close the lane, space that can be effectively referred to as "admissible interbin support areas ", [for details, see "Design Recommendations for multistorey and underground car parks "- June 2002 -" The Institution of Structural Enigineers ", London, UK]. The "admissible interbin support zones", in an optimal comfort arrangement, provides a plan distance between the longitudinal side of the bin and the vertical face of the closer column, or distance B, of at least 3.6 m and a distance between the side of the lane and the vertical face of the closer column element, or distance A, of at least 0,46m. The parameter B imposes a minimum distance between the column and the end of the parking lot in order to ensure a smooth opening of the doors of the parked car, parameter A corresponds to inside projection of the column with respect to the lane side, to allow an easy maneuver to the entrance/exit of the car from the parking. The width of the admissible interbin support zone under a maximum comfort condition is equal to 4.8 m (parking lot lenght) - 0,46m - 3,6m = 0,74m.

In a reduced, but still eligible, comfort condition, especially for modular parkings without foundations, the maximum admissible interbin support zones corresponds to a B value of 3.3 m and A value equal to 0 and thus to 1.5 m.

In view of the above it is therefore clear how the elongated plan shape of the admissible interbin support zones is perfectly suitable to the use of a composite column as the one according to the present invention. It should be noted that the internal bracing of the column according to the present invention, with the same horizontal actions applied (wind and/or earthquake) imposes vertical actions according to an opposite sense on "column elements " much larger in absolute value much smaller is interaxis distance between the two column elements.

The reduced distance between column elements, as seen in the above, on the other hand corresponds to a greater comfort situation.

Since the vertical actions must be contained within certain limits, compatibly to the absence of the foundations, it follows that the comfort level obtainable will be inversely proportional to the level of seismic activity and/or wind in the installation area, as well as dependent on the shape and size of the structure.

Similarly, the much the plates below each column element are close together, the lower is the capacity of each plate to effectively distribute the load transmitted to it by the respective column element. Therefore, there is a similar trade-off between the comfort level and the site where the structure is to be installed.

The present invention has been described, for illustrative but not limitative purposes, with particular reference to its preferred embodiments, but it is to be understood that variations and/or changes can be introduced by those skilled in the art, without departing from the relevant scope of protection as defined by the appended claims.