 
| ||||||||||
Excavating for the Tokamak Complex  The Tokamak Complex Seismic Isolation Pit: 130 metres long, 90 metres wide and 17 metres deep. Photo: F4E The Tokamak Complex will be nestled into the Seismic Isolation Pit—a 17-metre-deep, 90 x 130 metre hollow in the ITER platform excavated to house the concrete basemat and 493 seismic pads that will protect the buildings and the equipment from ground motion in the case of a seismic event. The three buildings of the Tokamak Complex will share a single foundation: having a monolithic structure avoids the relative displacement of process pipes crossing the buildings. The excavation works to remove 210,000 cubic metres of soil and rock for the Seismic Isolation Pit began in August 2010. After excavating down to 17 metres, engineers conducted sample drilling and radar surveys to establish a detailed map of the underlying bedrock. Several small voids ("karsts") were detected and explored, widened, and filled with concrete. Engineers used survey data to verify the assumptions used for Tokamak Complex design, before the establishment of the final structural design. The final excavation phase for the Seismic Isolation Pit involved milling the rock in order to achieve a perfectly flat surface on which to lay a "blinding" layer of concrete. Construction of the Seismic Pit basemat began in August 2010. Click here to view a video of the excavation.
|
||||||||||
| Comments & questions should be addressed to webmaster@iter.org. © 2012, ITER Organization | ||||||||||
