A multi-level parking complex extends over the A8 motorway
Development of a unique assembly concept for the movement of a multi-level parking complex across the A8 motorway for Stuttgart’s Neue Messe exhibition center
Neue Messe Stuttgart
South of Stuttgart, the state capital of Baden-Württemberg, and very close to its international airport, the “Neue Messe” exhibition center was built between 2004 and 2007 on a 60 hectare site. The construction project comprised seven new standard halls 10,000 m² each, a high hall with a floor area of 25,000 m² and a conference center.
In addition, the Neue Messe features an underground parking facility, along with a unique multi-level parking complex, extending over the A8 motorway and covering a total floor space of 125,000 m².
Donges was awarded the contract for the turnkey construction of the multi-level parking complex in a consortium with two Stuttgart-based construction companies. As the technical lead company, Donges was solely responsible for the complete steel construction and shared responsibility for the finishing trades such as wall cladding, building electrical systems and elevators.
The multi-level parking complex
The multi-level parking complex traversing the motorway is the link between the Neue Messe and its environment. The integration into the surrounding landscape was achieved through the greening of the roof and the curved shape of the steel construction. This multi-level parking complex is designed to accommodate 4,000 vehicles and has become the future landmark of the Neue Messe exhibition center.
The fan-shaped design consists of two individual multi-level parking buildings, designated as “North and South Fingers” and connected by a central pedestrian walkway. The fingers traverse the traffic routes, the motorway and the planned ICE route.
Each finger is dimensioned to hold six parking levels. They fit into the curved shape of the trusses, so that their size decreases with each subsequent level. The lowest parking level has a length of 336 m in the south and 264 m in the north. Each finger has a width of 34 m and a maximum height of 22 m. Two counter-rotating circular ramps at the front ends of the building serve the incoming and outgoing traffic.
The stairs and elevators are located in the central area on the inside of the two fingers. The central area forms the main pedestrian walkway for visitors directly to the exhibition plaza and thus to the main entrance.
The frame structure of each finger consists of three parallel truss girders having a clearance of 17.30 m. The trussed girders are up to six levels high and span freely over the motorway and ICE line. The span over the motorway is up to 92 m. The bottom chords are an integral part of the lowest parking level.
The truss girders consist of welded hollow sections with an outer diameter of 600 x 800 mm. These hollow sections are made of metal sheets of different thicknesses. The truss girders rest on four supports, which are also made of welded hollow sections. The external dimensions of these supports are 1500 x 600 mm.
In the transverse direction, the construction of the fingers consists of two multi-level frames. Two different ceiling designs are deployed:
– the lowest level is a composite construction with chambered concrete sections and a concrete slab 18 cm thick.
– The upper levels consist of composite ceiling elements having a height of 8 cm.
In this building, typical structural bridge construction systems such as fixed and loose bearings are combined with high-rise structural engineering designs such as truss frames.
The total tonnage of the steel structure is 13,700 tons and nearly an additional 600 tons are used for required auxiliary assembly structures.
The unique assembly process
Instead of the normal approach of delivering structural parts as small building components, lifting them into place and welding them together via a protective scaffolding of 19,300 m² over the motorway, Donges engineers came up with a worldwide unique assembly concept:
– The gradual movement of pre-assembled truss sections without affecting or blocking motorway traffic.
This concept included the following steps:
– The three complete truss girders of each finger were divided into four sections each.
– During each procedure, three parallel truss girder sections were pre-assembled on the floor, welded together and lifted onto the supports.
– After this step, assembly continued by putting together the beams on the lowest level, along with several beams on the upper levels to stabilize the structure.
– This spatial structure was designed so that it could be moved horizontally on an auxiliary construction of small girders with a stainless steel base. These auxiliary beams were arranged on the supports. PTFE plates were inserted between the stainless steel plates and the bottom chords of the truss girders, which served as moving tracks to enable proper positioning.
– The movable structure was pulled by four strand lifters, of which two were arranged under the central truss and one each under the edge girders. The strand lifters pulled a package of 14 strands attached to the ends of the bottom chords of the truss girders.
The movement was carried out while traffic was running on the A8 motorway.
– Pre-assembly of three truss girder segments was repeated according to this procedure. These truss girder segments were in turn positioned on the supports and welded to the existing truss girders. Using this method, a new increment was completed and moved as described above.
For each finger, five moving operations had to be performed until the steel structure of the parking facility had reached its final position.
For parking garage sections, the final position of which is located directly above the motorway, the concrete ceiling of the lowest level was installed prior to the move. This ceiling provided sufficient protection for motorway traffic and is also an integral part of the final structure.
– The protection of the current traffic was ensured through complete pre-assembly on the ground next to the motorway, through continuous safety inspection for loose parts and through the concrete cover of the first level moved together with the steel construction.
– After completion of the movement processes, all remaining components were installed from the lowest level.
The customer was convinced by the assembly sequence and its safety concept from a technical and economic standpoint. Especially the avoidance of a longer-term motorway closure played a key role.
Bridge-like parking complex above the A8 motorway as part of the overall “Neue Messe Stuttgart” project.
Neue Messe GmbH & Co. KG
70173 Stuttgart, Germany
The parking complex is divided into two ground-level “fingers” extending roughly100 m in a free span above the autobahn and the ICE high-speed rail line. The steel structures consisting of six truss girders as high as the structure, rigid frames and ceiling girders in the transverse direction, were inserted using the “incremental launching method”.
ARGE Parkhaus (Consortium)
Wayss & Freytag Ingenieurbau AG
Donges Stahlbau GmbH
Wulf & Partner Freie Architekten BDA
70188 Stuttgart, Germany
Six-level steel supporting structure
Parking spaces approx. 4,000
Total length 350 m
Width 2 x 35 m
Max. height 20 m
Steel, total 13,500 t
Structural design for fire resistance class F30, fabrication and assembly of the steel support structure including corrosion protection.
Construction period 2004 – 2007
Received the European Steel Design Award in Luxembourg in 2007