Deep foundations and excavations in urban environments require extensive monitoring to ensure their stability and to verify that nearby structures are not adversely affected. Typical excavation and/or foundation-related projects may require instrumentation for the walls (slurry walls and tiebacks), bracing (cross-lot struts), and/or the underlying ground or adjacent structures and utilities. Many major cities throughout the world including New York, Boston, Kuala Lumpur and Berlin have used GEOKON instruments in these situations.
The development of the Daimler Benz project around the Potsdamer Platz, in the center of Berlin, required excavations to 18 m over several areas of about 20,000 m² each. A high water table and deep sandy soils required complex excavation procedures, including diaphragm walls and concrete slabs held by tension piles.
At each of three locations, Temperature Sensors, Concrete Embedment Strain Gages and Stressmeters were installed by divers into the concrete slab. Additionally at each location, surface mounted Strain Gages were welded onto piles that were driven from a raft through the water into the ground and grouted. The bundle of instrument cables led to a battery operated Datalogger with radio data transmission. The datalogger was fixed to a buoy floating above the array, and the data transmitted by radio to a computer, for on-line visualization.
GEOKON welcomes Case History contributions. If you have a project you would like to be considered for inclusion in our Case History section, please submit details along with 2 or 3 suitable images to the GEOKON Web Manager.