Construction—South America—Brazil—Bridges
A permanent Solution:
DYNA Grip ® 109 Strand Stay Cables stabilize Capivari Bridge, Brazil
Recently, DSI was awarded a contract to strengthen an existing steel
girder bridge that crosses the Capivari Water Reservoir in southern Brazil.
The bridge forms part of the BR-116 connecting road that leads from
Curitiba, the capital of the federal state of Paraná, further north towards
São Paulo.
The existing bridge was re-built in 2006 after it
collapsed in 2005. Since the bridge was built
on unstable ground, settlements occurred that
caused the bridge pier to sink into the soil by
approximately 40cm so that the bridge was
once again in danger of collapse.
As a permanent solution, the decision was
made to build a reinforced concrete frame
below the existing bridge. This bracing
structure consists of two longitudinal girders,
two transverse girders around the caved
pier, an H-shaped pylon and two concrete
abutments on the opposite side of the river to
anchor the back span stay cables.
The support frame is suspended from 4
approximately 55m long, Type DG-P109
DYNA Grip ® Stay Cables that are anchored
at the pylon. The support structure
accommodates the weight of the existing
bridge so that the damaged pier of the existing
structure could be removed.
The tricky part of this job was to determine
the exact force that had to be applied to the
156
stay cables. The force had to be sufficient to
lift the old bridge deck without overstressing
it. Furthermore, all of the strands in each of
the DYNA Grip ® Stay Cables needed to have
the same stress level. This was achieved by
dividing the stressing process into 5 steps, an
accurate estimation of the existing loads that
had to be lifted and the precise functioning of
the ConTen stressing method developed by
DSI.
In addition to the DYNA Grip ® Stay Cables,
the DSI companies Protendidos DYWIDAG
and DSI Prepron also supplied, installed,
stressed and grouted the 32 and 36mm Ø
DYWIDAG Bar Post-Tensioning Systems
that were used in the pylon and the strand
post-tensioning systems for the transverse
girders of the new structure.
This special application is a milestone and a
first reference for DSI for stay cable systems in
Brazil. Furthermore, DSI Prepron successfully
acted as a subcontractor for stay cable
systems for the first time in this project.
Owner
Agência Nacional de
Transportes Terrestres
(ANTT), Brazil
Operator
Arteris S.A., Brazil
Contractor
Leão Engenharia Ltda., Brazil
Engineering
Enescil, Brazil
DSI Units
Protendidos DYWIDAG Ltda. and
DSI Prepron, both Brazil
Protendidos DYWIDAG &
DSI Prepron Scope
Production, supply, installation,
engineering services, technical
support, supervision
DYWIDAG Products
4 Type DG-P109, 55m long DYNA
Grip ® Stay Cables, 32 and 36mm
Ø DYWIDAG Bar Post-Tensioning
Systems, strand post-tensioning
systems