e-mosty December 2018 e-mosty December 2018 | Page 69

Figure 9: Layout of the bridge
The width of the deck is 30m, as shown in Figure 9,
which consists of sidewalk 3m, arch rib 2m, the
bicycle lane 1.5m, 2-lane carriageway 7.5m, arch rib
2m, carriageway 7.5m, bicycle lane 1.5m, arch rib 2m
and sidewalk 3m.
The section of arch rib comprises three tubes. The
advantages of this solution include:
a) Low centre of gravity and excellent lateral
stability.
b) Significant saving in temporary lateral stability
works.
c) Decrease in the number of lateral braces between
the arch ribs.
Instead of using a simply supported deck structure,
the longitudinal girders are made structurally
continuous between the adjacent lateral beams.
This means that any excess traffic load, which is an
increasingly common occurrence in China, can be
distributed to 2 - 3 suspenders along the longitudinal
girder, which will then decrease the over-stress on the
suspender.
This also has the advantage of the longitudinal girder
and lateral beam forming a continuous frame, and
with the continuous bridge decks, will overcome the
cracking and potential slippage of at the edges of a
simply-supported deck system.
If the conventional longitudinal girders are set below
the arch rib, they cannot be continuous due to
interference with the arch ribs. To overcome this they
are split into two halves passing either side of the arch
rib.
After years of study, a new floating system was
proposed in the design of the bridge deck.
The floating continuous frame system with the length
of 127m and the width of 26.8m is supported by 16
rows of suspenders and 4 rows of columns, as shown
in Figure 10.
The system comprises six longitudinal girders and 20
lateral beams. The arch ribs go through the frame, the
clearance width to the frame is 0.2m.
The bridge deck has a thickness of 0.28m made up of
precast panels set within the frame. With temporary
support to the deck panels, insitu concrete joints then
connect the panels to both the longitudinal and
lateral beams.
4/2018