CURRENT OBJECTS
Olympic Stadium external supports
Repair of damaged supports
client
Olympiastadion Berlin GmbH
building description
The supports to be processed are located in the listed Olympic Stadium in Berlin. These are various external supports of the outer arcade, which are clad with natural stones. The stadium was built between 1934 and 1936, received a partial stadium roof in the VIP area in 1973-74 and was completely rebuilt and modernized between 2000 and 2004, taking monument protection into account. During this time, today's membrane roof with a new surrounding reinforced concrete ring was created.
During this conversion until 2004, a new static system with a massive ring beam as ballast beam was created for the roof. This resulted in new constraint points due to the construction, which could not be accommodated without damage over the existing decades of effective expansion joint system. For this reason, new intermediate plain bearings were designed on individual outer supports. This system has been tested and approved by the building authorities.
In 2006, however, after the very cold winter of 2005/06, transverse cracks caused by deformation were found in the shell limestone cladding of individual supports. During an in-depth investigation, it was determined that the planned bearing design on the support head was not carried out professionally.
To secure and compensate, the head of the support was needled (see: Gastmeyer, Knöfel, Nolte, Bautechnik, Vol. 85 (4), 2008, pp 294-299, attached to the building application). These security measures proved effective until 2018. During a visual inspection, crack patterns comparable to those in 2006 were identified.
The renovation of the sample support axis 89 was completed in 2023. As a result of this renovation, further supports with comparable crack formations are now being repaired in two construction phases BA 1 and BA 2. Control, coordination of those involved in the planning such as structural engineers, geologists, monument protection and the other specialist planners involved in the implementation of the measure. Furthermore taking over the technical site management with the preparation of the tender, participation in the award and construction supervision of the renovation measure, in connection with the coordination of the events by specification of the operator.
renovation concept
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A maximum of the upper 4 natural stone layers are renovated.
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Crack repair using the injection method of all cracks up to the first 4 layers of natural stone from the top.
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Replacement and renewal of all natural stone crossings. After setting, press the crossings with injection mortar or synthetic resin (the cavity) using a previously used injection hose.
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Replacement and renewal with natural stone of all mortar repair sites. (Like previously described)
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After the cracks have been injected, stainless steel anchors are placed through the cracks to needle the damaged area and injected with K-resin. In addition, a separate plan about the needling from the structural engineer.
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Anchoring with stainless steel anchors (in the direction of axis A) through the entire column after completion of the repairs listed above. According to the current status, the anchoring is carried out without prestressing the anchors. The structural engineer rechecks the need for and attachment of anchor plates.
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Monitoring of the support using sensors (two sensors per support head. One in the front and one in the rear head area) for monitoring for a period of approx. 10 years. Involvement of an office for measurement technology.