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  • Making remote handling less remote

    Over a wet and windy three-day period on the ITER site in November, around 90 representatives of the ITER Organization, the Domestic Agencies of Europe and Japa [...]

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  • The framework for sharing ITER intellectual property

    In signing the ITER Agreement in 2006, the seven ITER Members were agreeing not only to share in the costs of constructing and operating the ITER facility, but [...]

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  • Wendelstein achieves ultra-precise magnetic topology

    A recent article in the online journal Nature Communications confirms that the complex topology of the magnetic field of Wendelstein 7-X—the world's largest ste [...]

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  • The Matrix, rigid and fluid

    A fast-growing array of structures and buildings has been emerging across the ITER worksite platform under the control and supervision of the European Domestic [...]

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  • By road, river and sea

    They travelled by road from the Air Liquide factory near Grenoble, sailed down the Rhône River from Lyon and entered the Mediterranean to the east of Fos-sur-Me [...]

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Of Interest

See archived articles

The Seismic Pit basemat is now complete

An important milestone in the project's schedule: the pouring, on 22 December, of the twenty-first and last concrete slab of the Seismic Pit Basemat. (Click to view larger version...)
An important milestone in the project's schedule: the pouring, on 22 December, of the twenty-first and last concrete slab of the Seismic Pit Basemat.
There is no traditional ceremony attached to the completion of the foundations for a future home as there is one, called a Topping Out, to celebrate the laying of a roof.

Had there been one, ITER, F4E and their contractor GTM could have raised a glass to an important milestone in the project's schedule: the pouring, on 22 December, of the twenty-first and last concrete slab of the Seismic Pit basemat.

Work on this 1.5-metre-thick structure began before dawn on a warm August day six months ago. Since then, some 18,000 m3 of concrete have been poured over a dense array of steel rebar and stirrups—some 3,400 tons of metal in all.

In order to insure close-to-perfect homogeneity of the basemat, each slab had to be poured in one continuous operation lasting no more than an extended workday. Considering that the pumps could deliver an average of 100 m3 of concrete per hour, the 11,500 m2 surface of basemat was broken down into 21 sections, each to be filled successively with 800 m3 of concrete.

In order to ensure ''close to perfect'' homogeneity, each slab had to be poured in one continuous operation lasting no more than an extended workday. (Click to view larger version...)
In order to ensure ''close to perfect'' homogeneity, each slab had to be poured in one continuous operation lasting no more than an extended workday.
This slab-by-slab technique also reduced the forces exerted by concrete "shrinkage" on the steel rebar.

The Seismic Pit basemat was designed to be extremely strong. It supports the anti-seismic pillars and bearings upon which the Tokamak Complex basemat will rest, and will ultimately bear the 360,000 tons of the Tokamak Complex.

A central area of the basemat—approximately 80 m2—was reinforced to bear the weight of the mammoth Central Column Assembly Tool that will operate during the machine assembly phase on the Tokamak Complex basemat. This extra strength was achieved through an increased density of stirrups.

Upon the now-finalized basemat, 159 seismic bearings (out of a total of 493) remain to be installed over the next two months. Twenty percent of the retaining walls have been completed and two parallel operations will commence this spring: a much smaller (5,500 m2) and relatively shallow excavation for the Assembly Building basemat and, prior to rebar reinforcement, horizontal wooden formwork and scaffolding for the next basemat that will be poured: the Tokamak Complex basemat.


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