Basildon Multi Storey Car Park
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Basildon New Town's first multi-storey UDC 624.03 car park by R. F. Burt, CEng, FIStructE, MInstHE Synopsis lt is not the intention to add any improved information to that already written on the subject of multi-storey car park design over the last decade, but to record some of the interesting aspects of the design, both structural and otherwise, relating to Basildon's first multi-storey car park which was opened to the public on 6 November 1972. associated with it are outlined in the hope that those embarking on new designs may find the information of assistance in the preparation of such schemes. Accommodation is provided for 1 112 vehicles and as the structure forms an integral part of the town centre shopping and office complex, its value is enhanced by pedestrian access which links it directly to these amenities. Information relating to the Building Regulations, bearing in mind that this structure is closely integrated with the adjoining shopping development in the town centre, is also given. The choice of structure and certain detailed information Introduction The building, which is five storeys high and measures 131 m x 52 m on plan and rises about 15.25 m above ground level, is of split level design, whereby two adjacent floors are staggered at half-storey level and connected by short ramps at a maximum gradient of 1 in 8. With this arrangement eleven parking levels (including the roof) have been achieved. The floor layout is shown in Fig 1. All cars enter and leave the park from the main road by two entry and four exit lanes. A slip road is provided beyond the exit gates and this permits unimpeded travel beyond the exist barriers and rapid merging with the highway traffic, resulting in less delay at the pay kiosks or coin-operated machines. Because of the large number of cars to be accommodated the car park was divided into an east and west wing, each holding over 550 cars. This was done by installing barriers at all upper floors across the middle of the park in a north/south direction. Identical barriers to those designed as bumper rails were used (Fig 4). To assist traffic circulation these were also painted with black and yellow chevrons and/or bands which have proved very effective. Each barrier was set 0.6 m to 0.9 m apart to permit free pedestrian access. The main left-hand turn into the entrance is located at the east end of the building and the turning circle provided is 16.75 m in diameter, the inner swept path diameter being 9.75 m. Twin lanes are provided and all control equipment is located on islands 11 5 mm high. A useful reservoir of space is available behind the entrance barriers, allowing cars to stand off the highway while awaiting entry to the car park. An electrical device in the farm of a ticket issue delay circuit has also been incorporated into the twin gate operating mechanism at the entrance.Thisensures that the raising of the barrier is delayed while the other barrier is in operation, allowing single vehicle approach on the entry ramp leading to Floor 1 whcre the motorist may proceed either to the east or west wing as previously mentioned. In this, the motorist is assisted by lane markings, parking signs, directional arrows and illuminated signs indicating when a particular wing is full. Recommended car park capacities-observations One of the essential requirements in car park design is to ensure uninterrupted movement of cars to and from the car park so that the minimum of delay and inconvenience is experienced by the motorist. This can best be achieved by limiting the capacity of the car park to 1500 cars on four to five floors, depending upon the site available. In addition, the provision of other car parks in strategic positions in and around a town centre serves to absorb the entry of cars and avoids the possibility of cars queuing to enter. Whether 750 or 1500 are to be accommodated, it is considered prudent to allow for at least two entrance gates and, for every 750 cars leaving the park, two exit gates. This provision has been proved to be adequate. Further sub- division of the car park into smaller units to improve circulation must rest finally with the designer but it has manyadvantages when catering for capacities in excessof 1000. Whilst some designers are in favour of providing even larger carparks to accommodate as many as 3000 to 4000 cars under one roof, it is true to say that many motorists are bewildered by the vastness of those already built and experience difficulty in orientating themselves. It is felt that the designer is under some obligation to the motorist who is seeking to park in the shortest possible time. With the adoption of larger parks, much time can be spent in finding a parking bay via a tedious labyrinth formed by carsparked on either side of a network of aisles provided. It appears, therefore, that by providing a simple layout in conjunction with a smaller car park unit, say 1500 capacity, it will be more readily accepted by the motorist not only from the advantages of speed of entry and parking, but also from the relative ease with which he may locate his car and drive from the park with the minimum of delay. The foregoing presents a case for sub-dividing carparks when the numbers catered for are in excess of 1000. This reasoning was applied to Basildon's first car parkand was found to serve several useful purposes,as outlined: By dividing the plan area into two (east and west wings) by means of barriers, the distance travelled by any car was found to be half a mile to the most remote parking bay on the car park roof; the pedestrian access to stairs and lifts being so arranged as to be within a short walking distance. The dual set of barriers forming the division between the two sections or wings provided a central aisle for pedestrians, allowing them direct access to the walk- ways located at Floors 3, 4 and 5 on the south side, and hence to the shopping facilities in the town centre. The presence of the barriers served to eliminate possible high speeds which would be encouraged by long uninterrupted aisles. Each wing of the car park has been planned so that it may be closed to traffic, thus enabling maintenance work or cleaning operations to be carried out in safety. Associated with this requirement, separate lighting circuits for each floor of each wing were provided. By sub-dividing the park into two wings, each with its exit ramps, an improvement in traffic circulation was obtained which resulted in a more rapid exit for vehicles. The Structural Engineer/November 1975/No. 1 l/Volume 53 47 5
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Car park design presentation
