study on economic partnership projects

Source: Study Team
Figure 3-32 Side View of the Second My Thuan Bridge
The plan and profile drawings of Types 3 and 4 are shown in Figure 3-34 to Figure 3-37. Meanwhile, the
quantities of superstructure and substructure of said types are shown in Table 3-19 and Table 3-.
As discussed in Section 3.2.3(2) Geological Survey, the thick soft stratums are layered in the site ground
and the bearing stratum was found at a great depth. The right bank (BH1 and LK4) is especially poor and
the ground with N value of 50 appears only below -70 m. On the left bank (BH2 and LK1), the ground with
N value of 40 appears to be below -40 m.
Due to the ground conditions, it was estimated that 32 bored piles with φ2.5 m and 80 m length are needed
for the foundation of A-shaped towers on both banks. On the other hand, 28 piles are needed for the single
column towers on both banks.
φ3.0m piles are also investigated for the foundation, but there are no previous examples and the almost all
of the necessary machines need to be imported from Japan or other overseas countries. Hence it is
concluded there is no merit to adopt φ3.0m piles. φ2.5 m piles are adopted because of the former example
of the Can Tho Bridge Project.
The end piers of the main bridges are planned to be provided with φ1.5 m and 60 m long bored piles. Same
type of pile foundation is adopted for the approach viaducts. The approach viaducts are planned to be
provided with φ 1.2 m and 60 m long bored piles. This plan is adopted from the design of the approach
viaducts of the Can Tho Bridge.
The ground around the bridge site is very soft so that the limit height of the embankment is decided to be
5m based on the former examples of the embankment height around this area. The section of the approach
road, which is higher than 5m, is planned as the approach viaduct. The bridge type of the viaduct is planned
as the 40m span Super T girder bridge, which is widely adopted in Vietnam. In Figure 3-33, one example
of pier of the Nhat Tan Bridge is shown. The width of the Nhat Tan Bridge is 33.2m whereas the width of
the Second My Thuan Bridge is 31m so that the piers of this viaduct is slightly smaller than this pier but
almost a same size of piers are needed for this viaduct.
Quantities and construction cost of the main bridge are summarized in Tables 3-19 and 3-20 . The general
views of the main bridge are also shown in the following figures (Figures 3-34 to 3-37).
In Figure 3-39 and Figure 3-40, the perspective images of the selected bridge type are superimposed.
3-42