Page 35 - TT Magazine Feb-Mar 2019

INFRASTRUCTURE

1800 km away respectively. The average At the Bogibeel project, the HCC team
lead time of procuring these materials is
four months. Procurement plan was made used ‘Most 2D’ automatic nesting
according to minimum order quantity software to generate efficient two-
required for thickness-wise also estimating
future market price trends as the order lot dimensional cutting plans for fabricating
sizes ranges from 3500 MT to 10000 MT. the steel superstructure for the bridge.
Spherical bearings were inspected
at Germany, shipped to China for load The nesting technology was based on
testing and then shipped to Bhopal for the advanced cutting algorithms specifically
refitting of tested bearings and then finally designed to optimise the cutting layouts
shipped to project site. The lead time of
such consignments is six months. Average in shearing. The software generates high-
daily consumption of welding wire was utilisation layouts, significantly reducing
to the tune of 2000kg per day; Grinding
wheels around 5000 per day; Argon + Co2 waste and maximizes productivity.
shielding gas more than 200 cylinders per
day; O2 cylinders around 500 per day and
around 50 BMCG cylinders per day. Besides bridges. These bearings are made of steel
4,50,000 Shear studs were imported from elements coupled with a PTFE surface to
Nelson, USA, (lead time of 3 months), High allow movement and rotations. One side
Strength Friction Grip bolts for around of the internal median plate is machined
7,00,000 quantity were manufactured as a spherical surface to allow tilting
at different sources in India and Diamant movement (rotation) whilst on the other
MM1018FL gap compensation were side, a flat sliding surface is obtained to
imported from Germany (lead time of three allow displacements.
months). Spherical Bearings with four support
The fabrication of various components, system as per European bearing standard
using reinforcement bars and plates, has EN- 1337 have been used in the Bogibeel
become an integral part of infrastructure Bridge. A total of 164 such bearings have
projects. Advanced software is used to been used to construct the bridge. Each
determine the optimum sizes of bars span is supported by four spherical bearings.
and plates before procurement, thereby These bearings had been manufactured by
reducing wastage and volume.
Spherical Bearings

Railways has traditionally used steel
rocker-roller bearings for bridges with
larger spans. For the Bogibeel Bridge, the
initial plan was to use Pot-PTFE bearing
with metallic pins and guide bearings.
However, it was found out that the size of
bearing required for taking the anticipated
load cannot be accommodated in the pier
cap, hence Spherical Bearings have been
used.
Spherical Bearing is designed to carry
combinations of vertical loads, horizontal
loads, longitudinal and transversal
movements & rotations. They are used
in steel and concrete road and railway

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