Summaries
The project HISTOS, a hydro-meteo
information system for the Oosterschelde
Within the organization preparing the building
of the storm-surge barrier, a separate project
has been set up, known as HISTOS.
This organization also works in aid of the
construction of the compartment dams.
The principal tasks of HISTOS are: the
preparation of statements regarding the
working conditions of the storm-surge barrier,
the study of the water-movement in the
Oosterscheldebasin, specially in behalf of the
environmental control, and the surveillance of
the barrier when finished.
The office of the Delta Service, located in
Zierikzee, has been designated as the central
post for the information system. Provisions
have been made within the project for
a close collaboration with the K.N.M.I. (Royal
Netherlands Meteorological Institute).
Results of tests made with caissons on Neeltje
Jans
While investigating the stability of the barrier
usage was made of among other things, large
scale models on the construction island of
Neeltje Jans. At the same time general research
study was done into the phenomenon of the
softening of the sea-bed and into the accuracy
of the current calculation technics. From the
outcome of these tests it became clear that the
prognosis regarding the stability of the barrier
proves to be much more favourable than earlier
anticipated.
Other parts of the test are still subject to
scientific discussion. It appeared, however, that
a construction without a solidified sea-bed and
without a sill would collapse even sooner than
earlier calculations predicted.
The design of the gates for the storm-surge
barrier in the Oosterschelde
The gates for the barrier have to meet certain
hydraulic conditions and technical demands.
The water-levels and wave-heights that they will
have to retain are summed up in this paper. The
height of the gates has been so selected that the
probability of being exceeded equals that of the
other primary dams in Zeeland, viz.: 2.5 x 10"4 a
year.
This contribution equally provides a multitude
of details concerning the sheeting, the bearing
systems, the suspension, the sliding planes and
the grooves of the gates.
The operating mechanism must be relied upon to
function optimally, thus reducing the chance of
failure to 2 x 10-3 a year.
The set-up the organization and the blending
into the landscape of the barrier and the
compartment dams.
Apart from their retaining function the barrier
and compartment dams also have recreational,
appreciative, traffic and ecological functions. All
these functions are supposed to find also
expression in the design and the make-up of the
works now, or in any case can be incorporated
at a later date. In this connection a number of
project groups, purposely set up to this end,
have made suggestions regarding the
longitudinal and cross sections, the outlay of
the roads, the beautification of both the dams
and the sluice island in the Oesterdam. A
description is given of some of the appraisals
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