e-mosty September 2018 Vessels and Equipment Used for Bridge Construction | Page 71

VESSELS FOR SUPERSTRUCTURE
Fatih Zeybek
Introduction
The suspended deck is an orthotropic stiffened steel box
girder, 4.75m deep and 30.1m wide with cantilevered
2.9m wide inspection walkways on each side, suspended
by the hanger ropes spaced at 25m. The suspended deck
has three traffic lanes in each direction.
The tower is steel construction reaching over 251m
above sea level and was constructed using floating cranes
for the lower part and a self-climbing crane for the upper
part. Cable erection then followed.
Various equipment, temporary steel structures and
elements were used during erection works.
ERECTION OF TOWER STEEL WORK
The tower steel work erection was performed by a
Turkish fabricator Çimtaş under the EPC Contractor’s
supervision (IHI-ITOCHU JV).
The tower block sections and tower panels were
fabricated at the Çimtaş factory in the town of Gemlik
town 60 km southwest of bridge site.
The following activities were completed for erection of
each tower:
Tower Panel Fabrication; 400 panels were fabricated to
build the towers.
During an average month, approximatey 33 panels were
fabricated but at peak production approximately 50
panels were fabricated.
Tower Block assembly; The 11 blocks that make up the
lower part of each tower were welded assemblies,
erected in a box shape. The upper 11 blocks were
assembled using temporary bolts.
Trial Assembly; Four continuous blocks were trial
assembled in a horizontal position with reaction control
to checking geometry. Approximately 6 trial assemblies
per month were performed in a typical month, and 9
were performed during the peak month.
Erection (Tower); For both lower and upper box erection,
temporary bolting of longitudinal ribs without completion
of welding of primary outer skin plates could be used to
expedite erection. Typically approx. 20 blocks per month
were erected and 26 were erected in the peak month.
.
Figures 1-3 : Marine Transportation of Tower
Blocks Using GMK-1 Self propelled Barge
3/2018