PENTA-OCEAN CONSTRUCTION CO., LTD. Conventionally, the superstructure of a pier is constructed through a series of offshore operations, including the assembly and disassembly of scaffolding and formwork support, the assembly of reinforcing bars, and the placement of concrete after driving steel pipe piles. In recent years, the use of precast concrete for construction has attracted attention from the perspective of improving productivity and shortening the construction period. The site precast construction method, which is erected and integrated, is generally used.
'PC-Unit Jetty Construction Method ' is a construction method in which a unitized superstructure of a size that can be transported by land is manufactured at a factory, and the precast members are assembled on-site. By devising the shapes of the pile head members and beam members, we have made it possible to assemble the structure without the need for shoring. By using a prestressed concrete structure *1 for the beam members of the superstructure and making the cross-sectional shape an inverted U-shape, weight can be reduced. can do. The precast method is often said to be more costly than conventional on-site concrete placement, but by reducing the number of piles, it has become possible to keep the total cost down to the same level as before. .
According to the results of a performance verification assuming a straight pile pier (width 33m x length 125m) (water depth 10m), the superstructure of this construction method is 15% lighter than the conventional on-site concrete placement, and the number of piles is reduced. can be reduced by 33%. In addition, since it is possible to largely omit the work at sea, such as the assembly and disassembly of formwork supports, the assembly of reinforcing bars, and the placement of concrete, the construction period is shortened by approximately 50%, and productivity is expected to be improved by reducing the number of local workers by 66%. increase.
In this way, in addition to shortening the construction period, precasting has a high 'labor saving effect' in on-site work, resulting in a high 'contribution to work style reform' and shortening of marine work. It also leads to 'environmental load reduction' by 'improving safety' and reducing CO2 emissions from work ships. From the viewpoint of VFM (Value for Money), the
We plan to add the 'PC-Unit Jetty Construction Method ' to our menu of precast construction methods and contribute to further productivity improvements in harbor construction.
1 Concrete structure in which compressive stress is introduced in advance for the purpose of canceling the tensile stress that occurs in concrete
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