Yangtze River Tunnel – A Project Of E&C ... - Roof & Facade

Image Courtesy:Bentley Systems Inc
TECHNOLOGY & COMMUNICATIONS
structure (13.65 meters by 150 meters by
132.65 meters). The substructure includes
twin circular piers on a large-diameter
deep caisson double D-shaped well foundation.
The bridge’s superstructure is conceived
as a trussed arch that follows the
bending moment profile. The two planes
of the truss are placed 12.1 meters apart
to provide two broad-gauge railway lines
at the bottom level of the superstructure.
The truss planes are connected together
through cross girders and lateral
bracings at the top, bottom and middle
levels.
Efficiency of 3D Analysis
The superstructure weighs 6,000 tons
and contains more than 11,000 members.
RITES used Bentley’s STAAD.Pro and
MXRAIL to create a 3D beam model of
the superstructure and design of the
alignment, respectively. RITES used the
3D models to analyse the effects of various
loads, with the entire design and
analysis carried out in accordance with
prevailing code provisions.
In the preliminary design stage, the
truss arch design was optimised so that
stress flows in a controlled manner. The
graphical output of STAAD.Pro helped
perform this task effectively. The solution
also helped engineers calculate secondary
stresses, eliminating the need to prestress
the members.
The input/output graphics of
STAAD.Pro proved immensely helpful
during this process. For example, the effects
of rigid and semi-rigid joints were
analysed for stress relief to the bottom
floor system. The bracing system and
joints were modelled using user-defined
support commands to study the effects
of rigid connection.
Stringer to cross-girder connections
must be flexible in order to minimise inbuilt
and longitudinal stresses. As a result,
stringers were released for longitudinal
forces at one end to minimise the
effect of longitudinal movement and
maximise flexibility.
Engineers also used customisable
report-generation tools of STAAD.Pro
to generate final submissions, which
were proof-checked and submitted to
the client well within the time scheduled.
It is claimed that use of
STAAD.Pro will save man-months in
design time. Through optimising the
design, the firm would cut steel requirement
for the superstructure by 15
percent alone, or about 1,000 tons.
The New Jubilee Bridge is currently
under construction, with an estimated
cost of $30 million and is expected to be
commissioned by 2010. ICA
PROJECT CREDITS:
Consultancy, Design & Supervision:
RITES Ltd
Client: Indian Railways
Software: Bentley Systems Inc.
●From page 10
studies and design, taking into account
development in the built-up area around
the approaches and the river hydraulics.
Eastern Railways requested that the
profile of the New Jubilee Bridge’s superstructure
coexist with the existing
bridge, which will be declared a historical
landmark. Used for the first time on
an Indian railway, the RITES design incorporates
a 415.6-meter three-span railway
bridge with a continuous super-
RITES designed a new railway bridge in harmony with the Replaced Victorian-era bridge
Volume 2 Issue 7 2008 ICA 11