HULHULE-MALE’ BRIDGE PROJECT

EIA for the proposed Hulhule-Male’ Bridge Project
3. Compared to the other 2 schemes, Scheme C requires less construction equipment.
4. From an aesthetic point of view, the V-type rigid frame with a 180 m main span causes
minimal impact and is in more balance with the nature compared to the other 2 schemes.
5. From an environmental perspective, a V-type rigid frame with a 180 m main span has the
least number of piers, thereby having the least footprint on the sea bed and in turn
causing the least amount of disturbances to the marine benthic habitat down below.
7.4 Foundation Scheme Comparison
7.4.1 Foundation Scheme Introduction
The special geological conditions and hydrological environment of the project area determines
that the main point of discussion for selection of a scheme is based upon the practicability of the
proposed scheme. Based on researches carried out on the construction technologies implemented
during the development of many sea-crossing bridges in China, alternative schemes of the
foundation for the main bridges are suggested as (1) Scheme A: Pile-group foundation scheme,
and (2) Scheme B: Set Caisson foundation scheme.
1. Pile-group foundation: 12 of 2.5 to 2.8 m variable sectional bored piles are mounted
under each main pier; the profile dimension of the bearing platform plane is 23.25 ×
10.75 m. Thickness of the bearing platform is 5.0 m, the top elevation is 4.0 m, the
bottom elevation is -1.0 m, and the bottom sealing concrete thickness is 0.8 m.
2. Caisson foundation: main pier caisson foundation is adopted to have a round-ended
cross section with good flow adaptability. Dimension of the plane is 41×35 m, the height
is 9 m, the dimension of chamfer in lateral direction is 13×3 m, the dimension of chamfer
along the bridge is 13×3 m. Baseboard of caisson is 0.6 m in thickness, the exterior plate
is 0.6 m in thickness, partition wall is 0.5 m in thickness, and top plate is 0.4 m in
thickness. The dead weight of caisson is about 7,300 tons. The bridge pier is adopted to
have a round-ended cross section; the cross-section dimension is 15×9 m, the wall is 0.8
m in thickness. The depth of foundation excavation is 9 m, slope cutting excavation is by
1:2 from position above 5 m outside the excavation of the plane scope of the basement
outline, the foundation pit is filled with sand and a scour protection layer is paved on the
sand after completion of infrastructure.
Prepared by: CDE Consulting & China Shipping Environment Technology
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