GB2365883A

GB2365883A - Load-bearing structure

Info

Publication number: GB2365883A
Application number: GB0019630A
Authority: GB
Inventors: Frederick Thomas Alan Coakley; Ian Alick Last Brixey; Gary Andrew Long; Wayne Stephen Perry
Original assignee: M40 TRAINS Ltd; Laing Rail Ltd
Current assignee: M40 TRAINS Ltd; Arriva Trains Holdings Ltd
Priority date: 2000-08-09
Filing date: 2000-08-09
Publication date: 2002-02-27
Also published as: GB0019630D0

Abstract

The structure, primarily for use as a car park, has parallel floor beams 7, for supporting a floor deck 8, which are supported by transfer beams 6 which extend in a direction perpendicular to the floor beams. The transfer beams are supported by columns 30 formed from a main upper portion 3 which is fixed to a lower stub portion 2 that is fixed in the ground.

Description

<Desc/Clms Page number 1> LOAD-BEARING STRUCTURE This invention relates to a load-bearing structure, in particular (not solely) for use in the construction of a car park.

Buildings such as car parks are usually specifically designed for one particular site. They are often multi-storey and have a deck constructed of concrete which is cast on site, producing a permanent structure. There are many ground-level car parks that have a growing need for more parking spaces but have no additional land available.

It would be desirable to be able to provide a structure which may be erected on any suitable site and sized to suit the available space.

The present invention provides a load-bearing structure comprising: (a) beams ("floor beams") for supporting a floor deck, the floor beams extending parallel to one another; (b) beams ("transfer beams") supporting the floor beams, the transfer beams extending parallel to one another and transversely to the floor beams; and (c) columns supporting the transfer beams, each column comprising: (i) an upper part ("main column part"), and (ii) a lower part ("stub column part") which is connected to and supports the main column part, the stub column part being fixed in the ground.

The invention also provides a construction system comprising floor beams, transfer beams, stub column parts, and main column parts, for constructing the load-bearing structure.

The invention also provides a method of constructing the load-bearing structure.

The use of transfer beams allows flexibility in construction of the load-bearing structure on an existing site. Two-part columns permit reuse of the upper part of the structure.

In a preferred embodiment. described in more detail below. the invention provides a modular single-storey car park, utilising prefabricated components. The modular design allows for a variety of layouts and plan sizes to be constructed to suit actual site dimensions using standard components. Manufacture of the components may be carried out off-site. The structure may be erected above an existing ground surface level car park. It allows the erection to be carried out outside the normal operating time period of the existing car park, therefore reducing disturbance and allowing it to continue in operation between each stage of construction. The single-storey car park may be constructed using an upper deck of a size based upon recognised standard dimensions and typical layout of parking space, aisle, and parking space. The structure allows this deck to be located over an existing surface car park even though its layout and dimensions may not follow this convention.

Minimal time on site is require to carry out the construction. The number of columns needed is reduced, allowing one to ensure there are no dark corners, thus achieving a safe environment. It is possible to position the columns so that they are located at the rear of existing parking bays. This removes any intermediate columns that could impede the flow of traffic or risk damage to vehicles or people.

It is possible to construct the load-bearing structure so that it can be easily and quickly dismantled if required.

The invention will now be described further, by way of example only, with reference to the accompanying drawings, in which: Figure I is a partial section through a single-storey car park structure, taken on line I-1 in Figure 10; Figure 2 is a partial section through the structure, taken on line 11-1I in Figure 10; Figure 3 is a view similar to Figure 2. showing columns in different positions; Figure 4 is an enlarged detail of the left-hand portion of Figure 2; Figure 5 is an enlarged detail of the middle portion of Figure 2:

Figure 6 is a side view of a column: Figure 6a is an enlarged detail of the lower end of the column: Figure 7 is an enlarged detail of a connection between upper and lower column parts: Figure 8 is a section through a floor beam. showing its connection to floor deck units: Figure 9 is a section through one edge of the car park structure; and Figure 10 is a schematic partial plan view of the structure, taken above the car park deck level. In the car park structure illustrated, steel floor beams 7 are located at the edge of each standard width car parking bay. Floor deck units 8 are the same width as the car parking bays. They span between the beams 7 and are supported on the top flange. The floor beams 7 are supported by steel transfer beams 6. each of which is supported by columns 30.

Each column 30 comprises several parts. The lower part consists of a circular steel stub column section 2 with a levelling device I. The top part comprises a circular steel main column section 3, which has a circular steel sleeve 4 welded at the bottom. An adjustable screw jack 5 is welded to the top. The screw jack 5 provides additional tolerance in levelling the car park deck and allows for future adjustment should the foundations suffer from differential settlement. The structure may include columns without screw jacks (optionally with a short infill packer piece or with a longer main section 3 and/or a longer stub section 2). As shown in Figure 2, two or more bays can be joined together to form a wider car park. The column centres and span of the floor beams 7 are based on the standard car park upper deck layout of parking bay, aisle, and parking bay: the dimensions are measured from the inside face of a vehicle barrier 12. The maximum design centres are indicated as dimension 9. The adjacent bay shown is a ramp bay: this may van, from the standard column centres to accommodate site-specific dimensions, indicated as dimension 10. The floor beam l I is the same cross-section as the floor beam 7 but its length is based upon dimension 10. The deck slopes towards the outside for drainage (as indicated by arrows in Figure 2).

Figure 3 shows the same section as Figure 2. where the columns 30 have been repositioned to suit an existing car park layout at ground level. There are, of course, limitations on the magnitude of the dimensions.

The detail at the edge of the car park is shown in Figure 4. The vehicle barrier 12 is a proprietary item and can be fixed to the deck units (as shown) or to the floor beam 7 below. The column 30 is centred on the inside edge of the vehicle barrier 12. A pedestrian guard-rail 13 will normally be required to comply with local regulations. It is located at a sufficient distance 14 from the front edge of the vehicle barrier 12 to avoid damage in the event of vehicle impact.

A steel channel 15 is fixed to the end of the floor beams 7. This has several functions: restraint of the deck in the event of a vehicle impact on the barrier 12; structural wind bracing; and serving as a fixing for an external rainwater gutter if provided.

Figure 5 shows a splice detail at an internal column 30. A continuous plate 17 is provided below the deck level, between the end of the beams 7, 11. A packing plate 16 is provided at the bottom of the beams.

The complete column assembly is shown in Figure 6. The bottom section of the column 30 is the stub column part 2 formed from a steel tube; this is set into a pocket in a foundation and is grouted in once levelled and lined through. At the bottom of the stub column part 2 is a threaded bolt I to provide height adjustment; this compensates for minor differences in ground level between adjacent columns and in the tolerance of the foundation level. The stub column part 2 is designed to withstand vehicle impact at parking speed and after installation it is filled with concrete until flush to the top of the tube. The part 2 can vary in length to accommodate significant differences in ground level of the car park; this also caters for the difference in level required to achieve the drainage falls across the deck. The upper part 3 of the column 30 is again formed from a steel tube, but is not designed for vehicle impact (e.g. being of smaller thickness). Welded to the bottom of the part 3 is a steel sleeve 4 in which the lower part 2 fits. At the top of the column assembly is the adjustable screw jack 5 which is welded to the top of the tubular part 3 and allows for re-levelling of the deck should settlement of the structure occur at a later date.

The connection in the column 30 is shown in detail in Figure 7. The stub column part 2 as installed in the foundation pocket is filled with concrete until flush to the top. The sleeve 4 welded to the main column part 3 provides a location fixing to the stub column part 2 below. The part 3 has a curved plate welded to the bottom; this ensures the load is transferred centrally through to the stub column part 2 to avoid eccentricity.

Shown in Figure 8 is the connection of the floor deck units 8 to the beam 7 when precast concrete panels are used for the deck. Channels with welded anchors 19 are cast into the underside of the panel; into these are bolted clamps 20 which fix the panel to the beam 7 without drilling. The joints between all precast panels are sealed with a proprietary sealant 21, which is set below the top surface to avoid damage caused by vehicle movements.

Figure 9 shows a continuous steel channel 15 that is bolted to the end of the floor beams 7 to restrain the deck units 8 in the event of vehicle impact to the crash barrier. The joint between the floor deck and the channel 15 is sealed with a proprietary sealant 22, which is flush with the top surface.

The above-described modular car park can be constructed using a construction system comprising standard components that can be manufactured off-site and erected in a variety of layouts and plan sizes to suit actual site dimensions. The column and transfer beam locations may deviate in location from the standard setting-out dimensions of the deck to suit different site-specific dimensions. A car park can be quickly constructed within an existing car park and outside its normal hours of operation. Preferably the columns 30 are located at the rear of every other parking bay, which identifies the extent of the parking bays. The car park is demountable, so that components can be reused at any other location or locations.

The floor beams may be all of the same standard length or there may be two (or more) standard lengths, as described above. Similarly, the transfer beams are preferably all of the same standard length or two (or more) standard lengths. One standard size or two (or more) standard sizes of floor deck units (panels) may be provided.

There may be one standard length for all the main column parts (or all the stub column parts) or two or more standard lengths, to allow the assembly of columns of different heights using a minimum stock of components.

Various modifications may be made within the scope of the invention. For example, the columns may be of polygonal cross-section. The sleeve may be welded to the stub column part instead of to the main column part. The floor deck may be cast in situ instead of being constructed of floor deck units.

The foundation mentioned above may be a foundation as described in our UK patent application GB0012367.9, filed 22 May 2000, the whole content of which is herein incorporated by reference

Claims

CLAIMS I . A load-bearing structure comprising: (a) floor beams for supporting a floor deck, the floor beams extending parallel to one another; (b) transfer beams supporting the floor beams, the transfer beams extending parallel to one another and transversely to the floor beams; and (c) columns supporting the transfer beams, each column comprising: (i) an upper main column part, and (ii) a lower stub column part which is connected to and supports the main column part, the stub column part being fixed in the ground.
2. A load-bearing structure as claimed in claim 1, in which one of the column parts has a terminal recess in which the other of the column parts fits.
3. A load-bearing structure as claimed in claim 2, in which the terminal recess is defined by a sleeve.
4. A load-bearing structure as claimed in any preceding claim, in which the lower stub column part has a level-adjustment device at its lower end.
5. A load-bearing structure as claimed in any preceding claim, in which there is a height- adjustment device at the junction of at least one of the columns and the associated transfer beam.
6. A load-bearing structure as claimed in claim 5, in which the height-adjustment device comprises a jack.
7. A load-bearing structure as claimed in any preceding claim, in which a plurality of the upper main column parts are of the same height as one another.

<Desc/Clms Page number 8>
8. A load-bearing structure as claimed in any preceding claim, further comprises a floor deck supported by the floor beams.
9. A load-bearing structure as claimed in claim 8, in which the floor deck comprises floor deck units, each supported by at least two of the floor beams.
10. A construction system for constructing a load-bearing structure according to claim 1, comprising: (a) floor beams for supporting a floor deck; (b) transfer beams for supporting the floor beams; (c) stub column parts for fixing in the ground; and (d) main column parts, the lower ends of the main column parts being connectable to the upper ends of corresponding stub column parts to form columns for supporting the transfer beams.
11. A construction system as claimed in claim 10, further comprises floor deck units for mounting on the floor beams.
12. A method of constructing a load-bearing structure according to claim 1, comprising: (a) fixing stub column parts in the ground; (b) connecting a main column part to each stub column part to form a column in which the main column part is supported by the stub column part; (c) mounting transfer beams on the columns, the transfer beams extending parallel to one another; and (d) mounting floor beams on the transfer beams, the floor beams extending parallel to one another and transversely to the transfer beams.
13. A method as claimed in claim 12, further comprising mounting floor deck units on the floor beams.

<Desc/Clms Page number 9>
14. A load-bearing structure substantially as described with reference to the accompanying drawings.
15. A construction system substantially as described with reference to the accompanying drawings.
16. A method of constructing a load-bearing structure, substantially as described with reference to the accompanying drawings.