115
EUROPA
The large Vierendeel truss
A Vierendeel structure, spanning 27.30 m,
skims over the railway tunnel and supports
the floors located behind the truss, as well as
the four other trusses, A, B, C, D, installed in
the existing building in the ADC phase (demo-
litions and precautionary measures). Due to
the major loads and spans, this structure gets
distorted as the construction progresses. This
delicate situation requires great precision as
to the cambers, with respect to their lengths
and jacks. The concrete wall located next to
truss C further complicates matters; as its
rigidity in fact increases as it nears comple-
tion, hence attracting increasing stress due
to its function as a beam with high depth/
span ratio.
Dr
philippe samyn
, engineer
GLASS ELLIPSES
