Multistorey car park


A multistorey car park or parking garage, also called a multistorey, parking building, parking structure, parkade, parking ramp, parking deck, or indoor parking, is a building designed for car, motorcycle, and bicycle parking in which parking takes place on more than one floor or level. The first known multistorey facility was built in London in 1901 and the first underground parking was built in Barcelona in 1904. The term multistorey is almost never used in the United States, because almost all parking structures have multiple parking levels. Parking structures may be heated if they are enclosed.
Design of parking structures can add considerable cost for planning new developments, with costs in the United States around $28,000 per space and $56,000 per space for underground, and can be required by cities in parking mandates for new buildings. Some cities such as London have abolished previously enacted minimum parking requirements. Minimum parking requirements are a hallmark of zoning and planning codes for municipalities in the US..

History

The earliest known multi-storey car park was opened in May 1901 by City & Suburban Electric Carriage Company at 6 Denman Street, central London. The location had space for 100 vehicles over seven floors, totalling. The same company opened a second location in 1902 for 230 vehicles. The company specialized in the sale, storage, valeting, and on-demand delivery of electric vehicles that could travel about and had a top speed of.
The earliest known parking garage in the United States was built in 1918 for the Hotel La Salle at 215 West Washington Street in the West Loop area of downtown Chicago, Illinois. It was designed by Holabird and Roche. The Hotel La Salle was demolished in 1976, but the parking structure remained because it had been designated as preliminary landmark status and the structure was several blocks from the hotel. It was demolished in 2005 after failing to receive landmark status from the city of Chicago. A 49-storey apartment tower, 215 West, has taken its place, also featuring a parking garage. When the Capital Garage in Washington, D.C. was built in 1927, it was reportedly the largest parking structure of its kind in the country. It was imploded in 1974.

Design

The movement of vehicles between floors can take place by means of:
  • interior inclined parking ramps and express ramps without parking – common
  • interior circular or helical express ramps
  • exterior ramps – which may take the form of a circular or helical ramp
  • vehicle lifts – the least common
  • automated robot systems – combination of ramp and elevator
Where the car park is built on sloping land, it may be split-level or have sloped parking.
Many parking structures are independent buildings dedicated exclusively to that use. The design loads for car parks are often less than the office building they serve, leading to long floor spans of that permit cars to park in rows without supporting columns in between . Podium parking below high-rise and mid-rise buildings are often short-span clear between columns, since office/residential/retail floors above require more support . Columns in short -span structures obstruct row based parking spaces and will be less efficient than long-span designs; parking efficiency is measured in cars per level square footage . Common structural systems in the United States for long-span structures are prestressed concrete double-tee floor systems, post-tensioned cast-in-place concrete floor systems or short-span podium parking with post-tensioned slabs and drop panels
In recent times, parking structures built to serve residential and some business properties have been built as part of a larger building, often underground as part of the basement, such as the parking lot at the Atlantic Station redevelopment in Atlanta. This saves land for other uses, is cheaper and more practical in most cases than a separate structure, and is hidden from view. It protects customers and their cars from weather such as rain, snow, or hot summer sunshine that raises a vehicle's interior temperature to extremely high levels. Underground parking of only two levels was considered an innovative concept in 1964, when developer Louis Lesser developed a two-level underground parking structure under six 10-storey high-rise residential halls at California State University, Los Angeles, which lacked space for horizontal expansion in the university. The simple two-level parking structure was considered unusual enough in 1964 that a separate newspaper section entitled "Parking Underground" described the parking lot as an innovative "concept" and as "subterranean spaces". In Toronto, a 2,400 space underground parking structure below Nathan Phillips Square is one of the world's largest.
Parking which serve shopping centers can be built adjacent to the center for easier access at each floor between shops and parking. One example is Mall of America in Bloomington, Minnesota, USA, which has two large parking lots attached to the building, at the eastern and western ends. A common position for parking within shopping centers in the UK is on the roof, around the various utility systems, enabling customers to take lifts straight down into the center. Examples of such are The Oracle in Reading and Festival Place in Basingstoke. Parking garages without mixed use can provide excellent uses for the Roof area: The Grove Parking Garage is the site for movies on its 8th level roof, The Grand Prix of Long Beach, California can be viewed from the Roof level of The Aquarium of the Pacific Parking Garage and The Pike Parking Garage were built with a thickened post-tensioned roof slab to accommodate crowds of people.
These parking structures often have low ceiling clearances, typically and for accessible parking, which restrict access by full-size vans and other large vehicles. On 15 December 2013, a man was killed during a robbery in the parking garage at The Mall at Short Hills in Millburn, New Jersey. The paramedics responding to the shooting were delayed because their ambulance was too large to enter the structure.
In the United States, costs for parking garages are estimated to cost between $25,000 per space, with underground parking costing around $35,000 per space.

Structural integrity

Parking structures are subjected to the heavy and shifting loads of moving vehicles, and must bear the associated physical stresses. Expansion joints are used between sections not only for thermal expansion but to accommodate the flexing of the structure's sections due to vehicle traffic. Parking structures are generally not subject to building inspections after being checked for their initial occupancy permit. Seismic retrofits can be applied where earthquakes are an issue.
Some parking structures have partly collapsed, either during construction or years later. In July 2009 a fourth-floor section failed at the Centergy building in midtown Atlanta, pancaking down and destroying more than 30 vehicles but injuring no-one. In December 2007, a car crashed into the wall of the deck at the SouthPark Mall in Charlotte, North Carolina, weakening it and causing a small collapse which destroyed two cars below. On the same day, one under construction in Jacksonville, Florida collapsed as concrete was being poured on the sixth floor.
In November 2008, the sudden collapse of the middle level of a deck in Montreal was preceded by warning signs some weeks before, including cracks and water leaks.
In June 2012, the Algo Centre Mall's rooftop parking deck collapsed into the building, crashing through the upper level lottery kiosk adjacent to the food court and escalators to the ground floor below, killing two people.
In October 2012 four people were killed and nine more injured when a parking structure under construction at a campus of Miami-Dade College in Florida collapsed, purportedly due to an unfinished column.
The Surfside condominium's main building's collapse that killed ninety-eight people was likely caused by the failure of the long-term degradation of reinforced concrete structural support in the basement-level parking garage.

Precast parking structures

As multi-storey car parks have become more common since the middle of the twentieth century, many constructions of such structures have been using precast concrete to reduce the construction time. The design involves putting parking structure parts together. The parts of precast concrete include multi-storey structural wall panels, interior and exterior columns, structural floors, girders, wall panels, stairs, and slabs. The precast concrete parts are transported using flatbed semi-trailers to the sites. The structural floor modules may need to be laid tilted during the transportation in order to cover as large floor area as possible while they can be easily transported on the roadways. The modules are lifted using precast concrete lifting anchor systems at the sites for assembly. Decorations may include using of covers to close the holes in the precast concrete that contains the lifting anchors, and installing facades to the exterior of the structures.
In modern construction of the precast modules, there are other features to improve the strength of the structure. An example is to use prestressed strands on post-tensioned concrete for the construction of the shear walls. Another example is the use of carbon-fiber-reinforced polymer to replace steel wire mesh to lighten the load and yield more corrosion resistance especially for the cold-climate areas which use salt for melting snow.

Architectural value

These structures are not usually known for their architectural value. As Architectural Record has noted, "In the Pantheon of Building Types, the parking garage lurks somewhere in the vicinity of prisons and toll plazas." The New York Times has labelled parking structures as "the grim afterthought of American design".
A handful of structures have received considerable praise for their design, including