Orientation about the project
The project included the execution of a new casting shaft for Norsk
Hydro, Upper Årdal. The construction which has a circular shape,
has an internal diameter of 9 meters and a length of 27
meters under the floor in the existing hall. It was required that
there was to be full operation in the hall during the entire construction period,
which meant very little space for construction equipment. A crane
who constantly passed over the workplace also asked very much
strict safety requirements. The shaft is also placed all the way in
to a heavily loaded foundation at a depth of 2.2 meters below
floor level. The requirement for tremors/vibrations and sentences was 0.
Basic conditions
Glacifluvial delta masses with similar frictional masses.
Groundwater level approx. 5 meters below floor level.
Problem statement
The casting shaft is the country’s deepest, and is circular with a
internal net total height of 25 metres. The requirement for
the pile construction was to be a permanent one
unreinforced and dense concrete construction which was designed so that
there should be no stretch marks or unacceptable areas
shear forces. The construction is also influenced by large exteriors
earth and water pressure.
The construction project had a very high degree of difficulty and
therefore set very strict requirements for quality and execution.
The construction belongs to safety class 3 and associated
high requirements for control of calculations and execution.
Solution
The construction project was solved using the J-2 method with
the following arguments for choosing the method:.
the method was feasible in the relevant cases
masses and high water pressure – that you could
maintain full production in the foundry premises
during the entire construction period
any kind of phrases, shakes or
vibrations
work processes that would otherwise be involved
conventional methods
by other solutions
Norsk Hydro ASA, Årdal
Metallverk
