Car Park Structural Design Concepts

CAR PARK DESIGN Introduction The multi-storey car park is a unique style of building; one in which all elements of the structure are normally exposed to the public. The information presented here gives examples of good practical design, that enable the structure to blend with all environments whilst utilising the inherent versatility, elegance and economy of a steel frame. Fundamental design information is given to illustrate how steel, with its ability to accommodate long clear spans and minimise column sizes, can create aesthetically pleasing, secure, user-friendly car parks. This guidance is intended to assist the designer with the preparation of budget schemes, without the need for complex calculations at the outset. It does not however, relieve the designer of his responsibility for providing full design data for the built structure. Further guidance is available from the Advisory Services of British Steel. Attributes of good car park design. Easy Entry and Egress to Car Park and Stalls Uncomplicated and Logical Traffic flow Unimpeded Movement Light and Airy Low Maintenance Safe and Secure Advantages of steel construction Ideal for Long Spans Lightweight Robust Fire Resistant Easily Maintained Vandal Resistant Minimalist Economic

Outline design The dimensions of large, standard and small size cars are well established and form the basis of the dimensions required for stalls, aisles and ramps. The minimum dimensions are based on the standard car, and the bin size on the parking angle and stall width. This is shown in table 1.

Parking Angle

m

Stall width Parallel to Aisle m

o

2.3 2.4 2.5

3.25 3.39 3.54

3.60

13.85 13.71 13.57

60o

2.3 2.4 2.5

2.66 2.77 2.89

4.20

14.93 14.83 14.73

o

2.3 2.4 2.5

2.38 2.49 2.60

4.98

15.34 15.39 15.45

90o

2.3 2.4 2.5

2.30 2.40 2.50

6.00

15.50

45

75

Stall Width

Aisle Width

Bin Width

m

m

Table 1. Effect of varying parking angle on parking bin requirements. Dynamic efficiency The dynamic efficiency of a car park depends on the ease with which entry, egress and parking can be achieved. The general principle should be that cars cover as many stalls as possible on entry and as few as possible on exit. The layout of the exits and the size of the reservoir capacity are other major factors when considering dynamic efficiency. Flow patterns There are broadly two flow patterns used in modern car park construction: one way and two-way flow. These can be combined with either 90o or angled parking.

Figure 1. One way flow, angled parking

One way flow systems, if used with angled parking, provide a very good solution to the parking problem. They ensure easier entry and exit to stalls and allow significant flow capacities to be achieved with the self enforcing flow pattern. Difficulties can arise when the intended flow is ignored therefore good signage is required.

Circulation Design  Keep it simple. What looks like a clever solution could be a nightmare for the user.  Minimise the workload on the driver and avoid confusion as to where to go and what to do. This is solved partly by signs but mainly by good design.  Cover as many stalls as possible on the entry route.  Pass as few stalls as possible on the way out.  Separate inward traffic from outward traffic if possible, without causing additional complications.  Circulate to the right if possible so that the driver is on the inside of the turn.

Ramp width and slope The widths of the ramps should be no less than 3.65m for a single ramp and 7.0m for a double ramp. It is recommended that ramp widths are kept in line with stall widths for example with single flow traffic, the ramp would be two stall widths wide and for two way traffic flow, three stall widths wide. The slope of the ramp is dependent on the clear headroom and the structural zone. The shallower and wider the ramp, the better it will meet the needs of users. However less steep ramps are longer. The split-level system, shown in figure 3, offers a method of reducing ramp length, whilst keeping the gradient within reasonable limits by staggering the parking levels by half a storey height.

Car park layout There are many layouts used for multi-storey car parks, each having specific advantages to the user and operator. The layouts indicated are those most commonly used in the UK. All are eminently suited to a steelframed solution, which will be competitive on price and provide excellent performance.

Figure 3 - Split level layout Split level layouts (Figure 3) have good dynamic flow rates and excellent structural efficiency. They can be used with one-way and two-way circulation patterns and a variety of ramp arrangements to achieve the desired performance. This is probably the most popular layout in the U.K. for car parks with row capacities greater than 24 cars. Entry and exit traffic are separated and the flow pattern is simple and uncomplicated. When built in steel, with column free spans, this layout will give the best combination of economy and operating efficiency.

Figure 4 - Flat deck layout Flat deck layouts (Figure 4) are becoming increasingly popular for their simplicity of construction, clean lines and ease of use. They are particularly suitable in situations where the floor levels have to be matched to another building. This layout is less efficient than the split-level arrangement but can have comparable dynamic capacity for infrequent users. However the larger search paths can be frustrating for frequent users where the "parking ramp" may be more acceptable. The layout illustrated (Figure 4) would be used for smaller car parks where the dynamic capacity is not critical. Two-way flow is used with external rapid entry and exit ramps

Figure 5 - Parking ramp Parking ramps (Figure 5) may be used with great success where frequent users are the prevalent customers, for example, a large office. Their main advantage is that the user must pass all stalls on entry to the car park, resulting in a rapid search path and less frustration. Users can be disadvantaged when exiting the car park unless an express exit is provided. The parking ramp shown is a single ramp with two-way flow. It offers ease of use combined with efficient usage of space. External ramps may be added if rapid exit from the park is required. In this case a one way system would be preferred.

Figure 2. Two way flow, 90o parking Two-way flow systems are more familiar to the user and if properly designed can achieve a higher flow rate than one way systems. They require marginally more space and are therefore less structurally efficient than one way systems. Two-way systems are best used with 90o parking as their use with angled parking can cause confusion to the driver.

Structural Form The structural design of a car park will usually determine its quality as a user-friendly structure. The structural form should provide: Ease of entry and egress to and from stalls so that users can gain rapid entry and exit without the risk of damage to vehicle or person. Few obstructions to movement. The driver should be guided through the park without encountering severe obstructions such as columns in the drive path and badly parked cars caused by inefficient design or layout. A light and airy environment. The environment the car park provides will often determine how profitable it is. A light and airy environment should be one of the major goals of the car park designer. Steel is ideally placed to provide this type of environment because of its lightweight nature and long span capabilities. This can be further enhanced if open web sections are chosen. See the cellular beam case study. A safe and secure environment. Today, personal security is high on the list of priorities for any building; car parks are no exception and due to their public nature, they must be safe for users and their vehicles. A building with minimal internal structure will help to enhance the feeling of security by making the area as open as possible with few barriers to sight lines. The light and airy environment made possible with steel will help to enhance the feeling of security required of these buildings. Foundations The design loading for car parks is given in BS6399, which specifies an imposed loading of 2.5 kN/m 2 for the parking areas and ramps. The loading on foundations is greatly influenced by the material chosen for the frame. Steel is the lightest practical construction material and will often allow the use of simple foundations where other, heavier materials will not. The type of foundation required is often the deciding factor on whether a project is viable. Steel is often the only viable construction material for multi-storey car parks. Column Positions The desirable attributes indicated above will only be completely fulfilled if there are no internal columns (Figure 6). If steel is chosen as the frame material, a clear span solution can be used for the majority of car

parks. However there may be occasions, for example where the car park is beneath another form of structure with a different span arrangement, where internal columns must be used (Figure 7). Increasing the width of the stalls should compensate for this situation. (Table 2)

Figure 6. No internal columns to impede traffic flow

Figure 7. Alternative positions of columns impede traffic flow

No of cars between columns

Equivalent dimensions for clear span

Column centres

2

1800 x 2+ 600 x 3+300

= 5.7m

4.8m

3

1800 x 3 + 600 x 4+300

= 8.1m

7.2m

4

1800 x 4+ 600 x 5+300

=10.7m

9.6m

Table 2. Effect of internal columns on overall width It is generally preferable to arrange longitudinal column and beam spacing to coincide with parking stall widths; the equivalent of one, two or three stall widths is the most commonly used. Using a single width has the advantage of visually separating the stalls for the driver, but it is not suitable when using internal columns. With column spacing up to two stall widths, it is not generally necessary to use secondary beams. Above this, additional secondary beams may be necessary to avoid propping of the floor during construction, to limit depth of construction and ensure economy of design. Floor & Frame solutions There are many structural framing arrangements that are particularly suitable for steel framed construction using universal beams or open web beams. Steel is particularly well placed to offer the optimum solution that fulfils all of the desirable attributes previously indicated. A variety of floor systems can be used in multi-storey car park construction. The ultimate choice will depend upon many factors, such as height restrictions and structural layout. Four of the most common types of floor construction used in steel-framed car parks are shown (Figures 8 - 11). All the systems illustrated are composite types, where the steel beam and floor act together to enhance the load carrying capacity of the beam. There is, however no reason, apart from structural efficiency, why all the floors cannot be used non-compositely, where the steel beam acts independently of the floor slab.

Figure 8. Composite beam with PCC hollow core slab Figure 8 shows hollow core pre-cast units used compositely with the steel beam. To achieve the composite action, the cores of the pre-cast units must be broken out and filled with in-situ concrete for the effective width of the slab. Additional transverse reinforcement may also be required. A concrete topping would normally be used to give adequate resistance to moisture penetration and to tie the pre-cast units together to form a monolithic floor slab. The system has the advantage that wider spacing of main beams can be achieved because of the precast unit's spanning capabilities. Speed of construction will be improved over a solid slab, leading to greater cost savings on the scheme. In the non-composite version of this system the cores of the pre-cast units do not require to be broken out, this leads to faster construction times at the expense of greater steel weight.

Figure 9. Composite beam and metal deck The metal deck solution, shown in Figure 9, has been used for a number of car parks, where the metal deck was used as permanent formwork. Speed of erection is improved and less cranage is required than for the other systems described. The maximum unpropped span of these types of decks is around 3.5m (consult manufacturer's literature for exact details), therefore the spacing of the main beams cannot be greater than one stall width unless secondary beams are used. Improvements in deck rolling technology and British Steel's Colourcoat system may offer a solution which is both rapid to construct and cost effective.

Figure 10. Composite beam with composite PCC slab and topping Figure 10 shows a composite beam with composite pre-cast concrete slab and topping. The pre-cast slab in this case is solid and usually only 75 mm to 100 mm thick. This spans between beams, the maximum span being around 5m, allowing main beams to be spaced at two stall widths, without propping of the slab during construction. Composite construction is achieved with shear connectors welded to the top flange of the steel beam. Transverse reinforcement will be required and additional bars may also be required at the stud location to act as bottom reinforcement.

Figure 11. 'Montex' pre-cast slab system A variation on the pre-cast slab design is the 'Montex' system illustrated in Figure 11 which is a proprietary design using special slabs with hooped bars emerging from the ends of the units which tie the system together, illlustrated in figure 11. The void is filled with in-situ concrete, then covered with a strip waterproof membrane. Vehicle Safety Barriers All car parks should be fitted with adequate vehicle safety barriers to prevent accidental damage to the structure and restrain out of control vehicles. Edge barriers in particular should be adequate to restrain vehicles and be of a height and design which will safeguard small children. BS 6180: 1995. "A code of practice for barriers in and about buildings" may be of assistance. Deflection Where clear span construction and high strength steels are used for the main beams, deflection may govern the design. These beams may therefore be pre-cambered to compensate for dead load deflection. An additional pre-camber may also be introduced to compensate for some of the live load deflection (usually up to 1/3). This has the advantage that the beams have a slight upward bow, which avoids the optical illusion of a heavily deflected beam when it is level.

Pre-cambered cellular beams as used at the Buttercrane Centre car park, N Ireland. Stability The stability and robustness of a structure is a vital structural design consideration. Multi-storey car parks pose a particular problem because they contain few internal walls. This is especially true of demountable structures. There are various methods to ensure structural stability against horizontal forces, two of the most common options are outlined below. a. Braced structure. Suitable bays or cores are placed around the building to provide stability in two orthogonal directions. Bracing may take the form of cross members or eccentric type bracing. In car parks, the eccentric bracing can be used across the structure because it allows relatively unimpeded

circulation throughout the floor area. An example of a braced car park structure is shown in the case studies. b. Unbraced structure. In this case the frame is designed as 'rigid'. Moments are transferred from beams into columns via moment connections and stability is gained from the stiffness and continuity of the connections. Haunches may be required in the plane of the beams of car parks because of the long spans used in clear span construction. For shorter spans, haunches may not be required, providing that sufficient moment capacity in the connection can be gained within the depth of the beam.

Cross bracing as used at the Genesis car park, World Cargo Centre, Heathrow. A combination of these methods may be used. For example, use a rigid frame across the structure and brace longitudinally at the outside edge of the building. With all methods of achieving stability, it is important to remember the construction stage of the building as well as the completed structure, providing stability for both conditions. The floor slab in most cases is designed to carry the horizontal forces to the braced parts of the structure. Until this plate has gained sufficient strength it may be necessary to provide plan bracing, which can be temporary if the floor is capable, when cured, of transferring the horizontal forces to the bracing system

Fire Resistance of Steel Framed Car Parks Steel-framed car parks have been rigorously fire tested in a number of countries (Table 3). These tests demonstrate that most unprotected steel in open sided steel-framed car parks has sufficient inherent resistance to withstand the effects of any fires that are likely to occur. Table 3 lists the maximum temperatures reached in open sided car park tests in four countries. These can be compared with the characteristic failure temperatures for beams carrying insulating floor slabs and columns of 620 oC and 550oC respectively. Open sided car parks are defined in Approved Document B to the Building Regulations 1991 for England & Wales as having open ventilation of at least 5% of the floor area at each level, at least half of which should be in opposing walls. The fire resistance requirements for open sided car parks in the United Kingdom and Ireland are outlined in Table 4. The dominant period is 15 minutes. Most Universal Beams and Columns will achieve 15 minutes fire resistance without added protection although a small number of sections at the lower end of the range, for example the 152x152x23UC and 127x76x13UB, will do so only when less than fully loaded. In general, where a section does not have 15 minutes inherent fire resistance, it is usually more efficient to increase the section size than to fire protect.

Full scale fire tests

Maximum measured steel temperature

Country

Beam

Column

UK

275oC

360oC

Japan

245oC

242oC

USA

226oC

-

Australia

340oC

320oC

Table 3. Fire tests in various countries

Requirements from regulations

England & Wales

Scotland

Northern Ireland

Republic of Ireland

Height of top floor

Up to 30 metres

Over 30 metres

15 minutes * +

60 minutes

15 minutes

15 minutes

15 minutes * +

Not permitted

15 minutes *

Not permitted

* Increased to 60 minutes for compartment walls separating buildings + Increased to 30 minutes for elements protecting a means of escape

Table 4. Fire resistance requirements for open sided car parks

Durability A car park should be designed to give the best possible return on investment and should therefore be maintenance free as far as possible. Car parks, by their very nature exist in environments that are far from ideal. The air is often contaminated with fumes from car engines. The surfaces of the structure may be sprayed with water, which in winter can be contaminated by de-icing salts and other highly corrosive elements. It is therefore necessary to consider

the design and protection of components within the car park, which are likely to be in close contact with these contaminants. The major elements are the steel frame and the concrete floor slab. The Steel Frame. Steel is the durable framing material. It will, if protected correctly, give a trouble free life with minimal refurbishment. In most cases all that is required is a repaint at the first maintenance period, which can be 20 years or more, depending on the initial protection specified. Three suggested treatments are given in table 5. A galvanised protection system and a paint protection system are given for a period to first maintenance of 15 to 20 years together with an alternative paint system for 20 - 30 years. Table 5. Corrosion Protection Systems (Extracted from 'A Corrosion Protection Guide for Steelwork', See references)

Car Parks

System Number

B12

E6

E9

Anticipated durability of the coating system in years (notes 1& 2)

15-20

15-20

25

Nearest Equivalent (BS 5493)

SB1

SL2

SK4

Blast Clean to Sa 21/2

Blast Clean to Sa 21/2

Surface Preparatio n (BS7079: Part A1)

Shop Applie d Coatings (note 5)

Hot dip galvanize to EN ISO 1461 or BS729

85 m

(note 3)

Site Applie

Coatings

None (note4)

Zinc rich epoxy primer

High build epoxy MIO

High build epoxy MIO

40 m

100 m

100

Zinc rich epoxy primer

1 or 2 coats high build epoxy MIO

High solid aliphatic polyurethane

40 m

200 m

80 m

d

Approximate Cost in £/m2 (note 6)

m

8.25

9.75

finish

12.75

Notes 1. Coating system durability given in the table is based on practical experience. It is the expected life, in years, before first major maintenance. This is taken as degradation level Ri3 from ISO 4628 Part 3 (1% of surface area rusted). It should be noted that this does not imply a guarantee of life expectancy. In coastal areas, coating life expectation may be reduced by around 30%. 2. The durability of galvanised steelwork is derived from the figures in EN ISO 14713. 3. Galvanising should be carried out to Standard EN ISO 1461. 4. Where painting of galvanised steelwork is required for aesthetic or other reasons, suitable systems from ISO 12944 may be used. 5. The thickness values given for primers are the total thickness used and may include a prefabrication primer. 6. Costs given here are for guidance only. There will be considerable variation that may typically be +/50% for a variety of reasons. Quotations should be obtained before making the final selection of the protective treatment. The indicative costs given are for 1995. They include estimates for material and labour, but exclude taxes. The average surface area/tonne is assumed to be 25m 2/tonne. 7. At the time of publication, March 1998, some of the ISO standards referred to had been finalised but not published.

Concrete floors The concrete within a car park is particularly susceptible to deterioration if it is not properly specified. A grade 50 concrete should be used wherever possible. Pre-cast units are generally more durable than in-situ concrete due to factory controlled production conditions. It is recommended therefore, that one of the precast systems outlined above with a limited amount of structural topping should be used. If a metal deck solution is chosen, a suitable protection system to avoid corrosion of the deck should be used. It is recommended that British Steel be consulted at an early stage if this solution is to be adopted. Waterproofing Car parks are outdoor structures, which require treatment against the effects of an external climate. The conditions under which the structure is likely to serve can be very onerous, especially where aggressive snow and ice clearing methods are adopted. It is therefore recommended that at least the top deck of the car park is waterproofed with a traditional bituminous membrane or liquid applied seamless coating. The other floors may generally be left untreated. With all floors it is necessary to provide adequate falls and drainage to prevent the build up of water on the slabs. There is a growing trend to use a lightweight roof over the top parking deck. This gives added protection to the top floor of the car park and allows users to park in all weathers with full protection. The aesthetic appeal of a car park can be significantly enhanced by this method enabling the park to blend in with the urban

environment. The long term benefits of reduced maintenance can far outweigh the initial cost of this approach. The car parks at Aylesbury and Guildford typify this method of construction.

Aylesbury Car Park

Guildford Car Park.

Weybridge Car Park Before Refurbishment.

Weybridge Car Park Refurbished Interior

Weybridge Car Park After Refurbishment.

Refurbishment One of steel's major advantages is the ease with which it can be refurbished and adapted. Car parks in steel are no different in this respect. Where examples can be found they have been refurbished with minimal expense and great success as at the recently refurbished Waitrose car park at Weybridge.

Aesthetic Design Steel car park structures have been designed to accept all types of external cladding. Early examples include teak fins, as used at Truro(not shown) and purpose made panels as at Swindon(not Shown). Recent trends are Brickwork as at Aylesbury, Buttercrane, Guildford and Tallaght; Metal cladding as at Heathrow and Poole; and open sided as at Stockley Park. There are also various steel cladding systems ranging from the simple sheet to sophisticated composite panels. All are compatible with the steel frame. Brick cladding of steel frames is well proven for offices, car parks and many other structures. Steel's inherent accuracy is a positive advantage when attaching brickwork support systems. The cladding may be designed to be load bearing as well as aesthetic. In particular crash barriers have been designed as an integral part of the cladding system. These may be load resistant (stiff) or energy absorbing (flexible). The steel frame provides an excellent interface for connection of either type.

Buttercrane Car Park

Tallaght Car Park.

Genesis Centre Car Park, Heathrow.

Car Park at Poole, Dorset

Car Park at Stockley Park, Heathrow.

Commercial viability The cost per space for an average-sized (250-space) multi-storey car park is in the region of £2800 - £3500 (1997 figures) inclusive of framework, floors, barriers, foundations and cladding.

The cost of a steel frame in real terms has decreased appreciably over the last few years through greater efficiency in both the steel manufacturing and fabrication industries. The shorter construction period made possible through the use of a steel frame and consequently the earlier return on investment increases the commercial viability. The elimination of fire protection costs has had a major influence in making a steel framed car park one of the most competitive options available. The case studies shown below demonstrate the flexibility and cost effectiveness of steel frames used to produce car parking solutions, which are both economically viable and aesthetically pleasing.

The Future Demountable Car Parks The exponential upward trend in the use of cars in the UK is resulting in the need to provide a greater number of car parks. Large companies and institutions especially, have a growing need for parking facilities. This need may be met in many cases by the use of demountable structures, to give an eminently flexible solution to the parking problem. Steel is considered the only practical solution that can be constructed as demountable. The car park at Luton is an example of a car park which could be demountable with some minor modifications.

Car Park at Luton, (Client: Coultee Electronics Ltd, Design and Build: Bourne Steel Ltd) Underground Car Parks Steel sheet piles are ideal for producing an efficient, cost effective and quick retaining structure for underground car parks and deep basement car parks. Floors can be designed to act as struts for the finished structure which can be utilised in the "Top Down" construction method (Figure 12)

This combined with the ability of a steel sheet pile retaining wall to accept vertical bearing loads make this form of construction particularly effective for car parks beneath new buildings.

Figure 12. Procedure for top down construction of basements

References J D Hill, D C Shenton, A J Jarrold "Multi-storey Car Parks" British Steel General Steels, Redcar. UK July 1989. I D Bennetts, D J Proe, R r Lewins, I R Thomas "Open-deck Car Park Fire Tests". BHP Melbourne Research Laboratories. August 1985. I D Bennetts, D J Proe, R R Lewins, IR Thomas "Fire and Unprotected Steel In Closed Car Parks". BHP Melbourne Research Laboratories 1988. "The Scranton Fire Test" American Iron and Steel Institute Brochure. Dr B R Kirby "Reassessment of the fire resistance requirements of tall, multi-storey open sided steel framed car parking structures". British Steel Swinden Technology Centre ECCS technical note 75 "Fire Safety in Open Car Parks" Modern Fire Engineering 1993 IISI "Fire Engineering Design for Steel Structures": State of the art 1993. Eurofer "Steel and Fire Safety: A Global Approach" 1990. "Design Recommendations For Multi-Storey and Underground Car Parks" (second edition): Institute of Structural Engineers 1984. "Architecture and construction in steel" Blanc, McEvoy, Plank: E & FN Spon & Steel Construction Institute 1992. BS 5950 Structural use of steelwork in building. BS 6180 : 1995. A code of practice for barriers in and about buildings. BS 6399:Part 1:1996 Code of practice for dead and imposed loads. A Corrosion Protection Guide for Steelwork in Building Interiors and Perimeter Walls. British Steel SP & CS 1996.

FDR Multi-Storey Car Park, Basildon, Essex

External Elevations

Interior

Barriers and roof extension

Details of car park Car Park

Multi-storey car park for First Data Resources, Basildon, Essex

Area (suspended)

9000 m2

No of floors

4 including ground floor

No of parking spaces (including ground floor)

517

Steel Tonnage

500T

Construction Period

17 weeks total

Date completed

October 1996

Design

Bourne Steel’s Montex slab on Clear

span steel frame.

Façade

Insulated cladding, mesh panels, architectural bracing.

Total construction costs

£1,490,000

Total cost per space

£2,882

Total cost per m2

£165

Type of Contract

Design and Build

Client

First Data Resources

Architect

Bourne Parking Ltd

Engineer

Bourne Parking Ltd

Contractor/Fabricator

Bourne Parking Ltd

Brief The client’s brief for this car park was to produce a modern car park with around 500 spaces to service the nearby offices of the client. It was to be constructed as quickly as possible to minimise the cost of renting temporary car parking during construction. The car park was to be constructed to a minimum budget.

Attributes The car park was designed as a flat deck with two-way flow giving easy access to the parking stalls. An external ramp system was used to give rapid entry and exit to and from the car park. Clear span construction was chosen for the car park. The16m spans give areas for parking which are clear of all structural obstructions. The use of clear span construction and open sides to the car park give a light and airy environment in which to park. Low energy lighting has been installed to enhance the internal environment.

The steel in the car park is galvanised to give a long life to first maintenance and the pre-cast concrete floor deck is resistant to the ingress of water and corrosive salts. High grade concrete is used as the infill between the slabs, this is then covered with a waterproof membrane to ensure watertightness. The top deck of the car park is covered with a mastic asphalt layer to give added resistance to the upper deck. The clear span construction helps to provide a safer environment in which to park, this is aided by good lighting.

Special features Construction program of 17 weeks from start to finish. Cost of construction less than £3000 per space Future proof. Two additional floors have been allowed for in the design of the structure and foundations within the cost.

Buttercrane Multi-storey Car Park, Newry, Co Down.

External Elevation

Interior

Interior

Steel frame during construction

Details of car park Car Park

Multi-storey car park for Buttercrane centre Ltd

Area (suspended)

12,300 m2

No of floors

5 including ground floor

No of parking spaces (including ground floor)

606

Steel Tonnage

500T

End elevation of steel frame during construction

Construction Period

30 weeks total

Date completed

November 1997

Design

Pre-cast concrete slab (75mm thick) with insitu topping on clear span steel frame using composite cellular beams and universal columns.

Façade

Facing Brickwork

Construction costs (Frame, floors, barriers only)

£2,445,000

Cost per Space

£4,035

Cost per m2

£171

Type of Contract

JCT 80 – Negotiated contract

Client

Buttercrane Centre Ltd

Architect

WDR & RT Taggart

Engineer

WDR & RT Taggart

Contractor

O’Hare & McGovern

Fabricator

Ballykine (Structural Engineers) Ltd.

Cellular Beams Supply

Westok Structural Services Ltd.

Managing Agents

Lambert Smith Hampton

Brief The client’s brief for this project included a 4,400m 2 extension to the retail area of an existing shopping centre plus the provision of approximately 600 car parking spaces. The car parking areas were to be bright and welcoming to the shoppers whilst keeping within tight budget costs.

Attributes Nine levels of parking on split deck construction. Clear span construction using compositely designed, cambered cellular floor beams. High specification paint-work and good quality lighting provide a bright and comfortable environment. Top decks are overcoated with an elastomeric waterproof membrane which is colour coded to indicate the parking areas. The structure and foundations were designed and constructed to allow for an additional two levels of car parking in the future.

Special features A 225mm pre-camber in the cellular beams was used for natural water shedding. This was provided at no additional cost.

The Genesis multi-storey car park, World Cargo Centre, Heathrow

Details of car park Car Park

The Genesis multi-storey car park, World Cargo Centre, Heathrow

Area (suspended)

19,100m2

No of floors

5 including the ground floor

No of parking spaces (including ground floor)

1000

Steel Tonnage

728

Construction Period

39 weeks

Date completed

March 1997

Design

Steel frames at 7.2m centres, 150 deep hollow core units with 75mm structural topping.

Façade

Aluminium cladding

Total construction costs

£3,900,000

Total cost per space

£3900

Total cost per m2

£163

Type of Contract

Design and build

Client

BAA plc

Architect

HGP Architects

Engineer/Fabricator

Bison Structures Ltd

Management Contractor

MACE

Brief The brief was to design a 1000-space multi-storey car park for staff at Heathrow’s World Cargo Centre to suit the site constraints. The car park was to incorporate a small retail area at ground floor and meet the requirements of a gold standard award. It was to be durable, fit for purpose and give value for money.

Attributes 5 levels of open single deck parking minimum clear headroom of 2400mm Galvanised protection system Waterproof membrane to top floor and first floor retail area Steel vehicle impact barrier system.

Special features The construction process was radically re-engineered to reduce cost and time and to develop what was to become known as the "World Class Construction Process". Efficiency and economy in the use of structural steelwork by standardisation, modularization and a simple design approach resulted from the innovative design and construction processes.

Stockley Park Car Park, Heathrow

External Elevation

Side Elevation

View on upper level

Details of car park

Car Park

New car park at Stockley Park business park near Heathrow airport.

Area (suspended)

3100m2

No of floors

1 additional floor (suspended)

No of parking spaces (including ground floor)

178

Construction Period

16 weeks

Date completed

December 1995

Design

Steel portal frames of tapered I section plate girders with tubular legs and tie rods. The deck comprises pre-cast concrete and glass panels.

Façade

Open

Total construction costs

£1,200,000

Total cost per space

£6,742

Total cost per m2

£380

Type of Contract

Traditional

Client

BP Properties

Architect & Landscape Architect

Broadway Malyan

Engineer

Ove Arup & Partners

Main Contractor

Try Construction

Fabricator

Dyer (Structural Steelwork) Ltd

Brief Stockley Park is an intensively developed business park containing a mixture of buildings and surface parking. 170 additional car-parking spaces were required. The design and construction program was very short and the surrounding environment dictated a structure of high aesthetic and constructional quality.

Attributes High architectural quality. Pre-fabrication allowed very rapid design and construction phase (26 weeks from concept to completion). Piled foundations were used because of the difficult ground conditions. Open design improves the safety of the environment, enhanced by metal halide lighting and improved around observation. Narrow columns save floor space and allow very tight stall widths to be used. Slim pre-cast and glass floor reduced the height and access ramp length.

Special features Clear span construction allowed the car park to be built without losing ground floor parking. Very tight spacing of bays at 2.2m Marine styling.

Tallaght Multi-storey Car Park

External Elevation

End Elevation

Front Elevation

Details of car park

Car Park

Tallaght multi-storey car park, Dublin

Area (suspended)

22,000m2

No of floors

6 including the ground floor

No of parking spaces (including ground floor)

900

Steel Tonnage

955T

Construction Period

26 weeks

Date completed

November 1996

Design

Beam and column construction braced to stair towers and lift shafts. Pre-cast floors and screed designed to act compositely with the steel beams.

Façade

Facing brickwork to blend with existing exterior elevations.

Total construction costs

?3,960,000

Interior

Total cost per space

?4,400

Total cost per m2

?180

Type of Contract

Design and Build

Client

Phase II Partnership

Design, Fabrication and Erection of Structural Steelwork

Severfield-Reeve Structures Ltd

Consulting Engineer

Spain Courtney Doyle

Management Contractor

John Paul Construction

Brief Due to rapid expansion of the square in the shopping centre at Tallaght, Dublin, extra car parking spaces were required to be developed in conjunction with the extension to the existing centre. (Previous car parking was surface only). The brickwork to the external envelope of the extension was required to blend in with the existing exterior elevations.