Betontechnik für die Stelen des Holocaust‐Mahnmals in Berlin

Summary The 2711 concrete stelae of the Holocaust Memorial erected in the centre of Berlin, have to satisfy high requirements with respect to their appearance and durability. Therefore the invitation to tender provided for a reinforced structural concrete having a minimum compressive strength of 40 MPa and a maximum acceptable crack width of 0.1 mm at the surface of the stelae. Comprehensive analyses on the actions upon the stelae showed that the requirements may be fulfilled significantly more reliable, if no reinforcement is used and if undesired crack formations are restricted only by appropriate concrete technological measures. As a result a dark coloured high‐performance concrete having self‐compacting properties has been developed and used.     

Verbundbauten für das neue Berlin

Composite structures for the new Berlin. Since the reunion of Germany Berlin is rising up to a site with a high intensity of building. Places, which were forgotten until the wall was torn down, changed to first class sites. They got excellent new buildings and modifications of historic buildings. Due to the Berlin concept of Critical Reconstruction in most cases it is not visible, if there are great constructions behind the facade. For this reason the following examples will focus on the composite constructions behind the facades.     

Online‐Monitoring des Temperaturzwangs für ein Trogbauwerk am Hauptbahnhof Berlin infolge Kopplung des Trogs mit der Unterwasserbetonsohle

Online‐monitoring of thermal restraint for a trough structure at the main station Berlin caused by the coupling of the trough and underwater concrete slab. At the main station of Berlin the North–South and East–West main railway lines intersect. The N‐S lines are located at the lowest level of station. They run on both sides of the station in tunnels. The trough structure N begins at the northern end of tunnel and guides the N‐S lines to ground level. The structural design of trough proved to be complex. The high ground water pressure required the coupling of the trough slab with the underwater concrete slab being back‐anchored by injection piles. These piles had to be extended into the trough slab and anchored there. For the coupling of the slabs several structural alternatives were investigated, in order to study their effects on the restraint of the trough slab due to temperature and shrinkage. Studies showed that the temperature load requirements of existing specifications in‐adequately reflect the representative winter situation of Berlin. Realistic temperature values were derived on basis of meteorological and thermal analyses. For the assessment of the efficacy of shear bond between the underwater concrete slab and trough slab, on‐site tests were performed. Expert opinions formulated the necessary design values. In view of the complex structural model of trough and of various assumptions, the owner DB decided the online monitoring for a representative trough. Monitoring is being performed by the MPA Braunschweig. Measurements commenced in July 2003 with the casting of the trough slab and will continue well into the service stage of structure. This report deals with the measuring techniques and with the results prior to the on‐set of railway traffic. All assumptions relevant to the thermal restraint could be verified by the measurements.     

Museumsinsel Berlin – Geotechnische Untersuchungen für die Grundinstandsetzung und Ergänzung des Pergamonmuseums

Museum Island in Berlin – Geotechnical investigations for the overhauling and completion of the Pergamon Museum. Overhauling the Pergamon Museum on the Museum Island in Berlin is a particularly complex task concerning geotechnics. On the one hand the substratum and ground water conditions in the area concerned are very inhomogeneous and on the other hand the Pergamon Museum and its neighbouring museums are especially valuable buildings worthy of protection. The initial target of the geotechnical investigation programme was to further safeguard the substratum and ground water conditions. Here systematic investigation of the substratum was carried out based on old historical drillings in order to enable the use of innovative special civil and underground engineering procedures. Furthermore it was necessary to investigate the foundation situation of the existing buildings. The planning objective is the technical and cost‐effectively optimized choice of the required geotechnical measures for the intended overhaul and refurbishment of the Pergamon Museum.     

Anpassungsfaktoren für das Lastmodell 1 des DIN‐Fachberichtes 101 für gewichtsbeschränkt beschilderte Straßenbrücken

Correction Factors for the Load Model 1 according to the DIN‐Fachbericht 101 for Weight constricted signposted Road Bridges Since 2003 the DIN‐Fachbericht 101 is the normative basis for the design loads of bridges in Germany. In contrast to the previous code of practice, the DIN 1072, the DIN‐Fachbericht does not include details about bridges, which will be signed with traffic weight limitations. This paper describes the development of reduction factors for the Load Model 1 in the DIN‐Fachbericht and presents the new calculated factors. Therefore the DIN‐Fachbericht Load Model 1 has been extended for the application of traffic weight limitations signed bridges.