Design and Construction of Pre-Tensioned Sutlej Bridge in Punjab

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be still successfully adopted as expansion/contraction taking
place in pier caps and diaphragms connecting the superstructure
are same. Nevertheless, to avoid the transverse restraint likely
to be caused by thermal effects and wind force, a typical semi
classical bearing arrangement as shown in the layout was
adopted in Sutlej Bridge. As could be seen from the layout,
there were two types of bearings in span and these two types
of bearings might have different plate sizes and bolting
locations, depending upon the forces, rotations and movements.
In the precast construction like Sutlej Bridge, the grooves have
to be left in the beams at the bolting locations and as such the
manufacture of the bearings have to be approved prior to the
precasting of beams. Normally, the approval of bearing
manufacture is a very high lead-time item, which was well
synchronised in this project. At each pier location for a span,
two central bearings were fixed which were guided
longitudinally on the other side, where as two extreme girders
on either side were transversely guided while on other side left
free. This semi classical layout helped in reducing the types of
bearings to suit the precast construction.
HEGGADE, MEHTA & PRAKASH ON
Fig. 15. Bearing configuration for Sutlej bridge
10. LOAD TESTING OF SUPERSTRUCTURE
In line with the contract agreement, one of the spans was
to be validated by load testing to the designed IRC loading,
including impact factor. As shown in the Fig. 16 the IRC loadings
were simulated for the maximum moments in the midspan
including cycle track loadings. All the pedestals were
progressively and simultaneously loaded by progressive
increments of 25 per cent of the test load and the deflections
were recorded at the midspan of all girders and and ¼th
span of the third girder from left side. The maximum load was
sustained for 24 hours; during the period deflection readings
were taken at one-hour interval for the sustained loading. Then
the unloading was simultaneously carried out in 25 per cent
decrements with the readings taken during each decrement.
The deflection readings of unloaded structure continued at
one-hour interval for further 48 hours.
For each stage of loading and unloading, the observations
were made about the likely appearance of cracks, the linearity
of the load deflection curves or any other abnormalities in the