CURRENT OBJECTS
Olympic Stadium Outer Column 89
Sample repair of a damaged support head
client
Berlin Senate Department for Urban Development
building description
The support to be processed is located in the listed Olympic Stadium in Berlin. It is an external support of the outer arcade covered with natural stone. The stadium was built from 1934 to 1936, received a partial stadium roof in the VIP area in 1973-74 and was completely rebuilt and modernized from 2000 to 2004, taking into account monument protection. 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 pillar head 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.
Coarse transverse cracks were currently found in the upper block of natural stone on the outer support in axis 89. The natural stones on the pillar head were immediately secured and the planning for the repair initiated.
As part of the building material investigations and a static calculation verification, it was determined that the support head was not supported unconstrainedly by the ring beam (as was also determined in 2006), which in turn led to the above-mentioned crack pattern. The constraint that occurs at the head of the support cannot therefore be held out permanently without damage using the needling principle from planning 2006.
For this reason, the bearing has to be renewed and the support head has to be dismantled and rebuilt in order to professionally implement the bearing principle from the original specification from 2000 to 2004.
A sample repair should first be carried out on the most conspicuous support, axis 89. Subsequently, further supports with comparable but smaller crack formation should also be processed if necessary after the sample repair. These support heads are shown schematically in the enclosed documents.