JPH0451611B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for constructing a floating concrete structure such as a concrete floating pier or a large caisson on the ocean.

(Prior art) Conventional construction of this type of floating concrete structure involves forming a ramp extending underwater in a caisson manufacturing yard on land facing the coast, and constructing a large concrete structure on the ramp. There are two methods: floating the concrete structure on the ocean by sliding it on a ramp, constructing it in a dry dog and pouring water into the dry dog to float the concrete structure and pulling it out to sea, or constructing a small unit structure in a caisson yard or on a ship. However, a method is being used to float them on the ocean and connect them to form a large structure.

(Problems to be Solved by the Invention) Among these conventional methods, in the method of using a ramp extended from land into the water, an unreasonable load is likely to be applied to the structure during the process of sliding the ramp. would require an unnecessary extra design load,
There are problems in that the cost is high and there are only a few ramps suitable for constructing particularly large ones, requiring a lot of money to construct them.

In addition, although the method of using a dry dog is currently the most common and highly reliable method, the dry dog itself is expensive and the usage fee is high, especially if a large dog is used. Furthermore, even when using a simple dry dog, there are many locational restrictions. Furthermore, in the method of connecting small unit structures at sea, the connection cannot be performed in dry conditions, resulting in a lack of reliability at the joint, and each unit structure must be box-shaped, requiring buoyancy. Therefore, there were problems such as the need for extra materials.

The present invention solves all of the problems of these conventional methods, does not require large equipment such as dry dogs or slopes, does not require consideration of extra design loads that are not necessary at sea, and is highly reliable. This was done for the purpose of providing a method for constructing a floating concrete structure.

(Means for Solving the Problems) As described above, the configuration of the present invention for solving the conventional problems and achieving the intended purpose is as follows:
A small prefabricated concrete basic floating body is floated on the ocean, and watertight enclosure walls are attached to the extended ends of the basic floating body to drain the internal water and create a dry work space. , constructing an extended concrete structure of a certain length in continuity with the basic floating body within the working space, and then shifting the enclosing wall to the end of the extended concrete structure to form a dry working space again; The present invention resides in a method for constructing a floating concrete structure in which a concrete structure of a desired length is constructed by successively forming extended concrete structure sections in the same way as described above.

(Function) This method of constructing a floating concrete structure ensures high reliability in terms of integrity because everything except the basic floating structure is constructed offshore, and the construction is carried out in a dry working space within the enclosure wall. Furthermore, the same formwork can be used for the extended concrete structure that is successively formed, and the necessary equipment can be small and simple.

(Example) Next, an example of implementation of the present invention will be described with reference to the drawings.

In this method, a basic floating body 1 made of concrete is formed. This basic floating body 1 is formed to have the same width and height as the large structure to be constructed, and is formed hollow so that it floats on the ocean.

In addition, the basic floating body 1 is formed in a caisson production yard on land, similar to ordinary small caissons.
This will either be floated and towed out to sea, or loaded onto a ship and transported to the construction site.

This basic floating body 1 is floated on the ocean as shown in FIG. As shown in FIG. 2, frames 3, 3 for forming a work space are fixed under the extended ends of both wagons 2, 2, respectively. Each frame 3 has a bottom plate 4a on all sides except one side and the top surface on the basic floating body 1 side, side plates 4b, 4c, and end plate 4d.
A surrounding plate 4 consisting of is fixed to maintain watertightness, and the wagons 2, 2 and frames 3, 3 are fixed to the basic floating body 1 with both ends of the basic floating body 1 surrounded by the surrounding plates 4, 4. do.

In addition, an inflatable water-stop gasket 5 is attached to the inner surface of the frame 3 and the basic floating body 1, which maintains watertightness by filling air and inflating it. After fixing to the floating body 1, air is pressurized into the inflatable water-stop gasket 5 to maintain watertightness between the basic floating body 1 and the frame body 3.

In this way, the water inside the shroud 4 is discharged while maintaining the watertightness inside the shroud 4, and a dry work space 6 is formed inside the shroud 4. In this work space 6, a concrete formwork (not shown) for creating an extended concrete structure part 1a connected to the basic floating body 1 is constructed, and concrete is poured into it.
The extended concrete structure 1a is integrally formed with the basic floating body 1. Although it is not shown in the diagram, the integration of the two is done by extending the concrete structure part 1 by extending the anchor bars or steel frames that have been set up in advance from the basic floating body 1.
Various methods can be used, such as connecting it to the reinforcing bars in a, or connecting it to a steel frame, or tensioning a continuous prestressing steel material between the two. After constructing the extended concrete structures 1a, 1a in this way, the formwork is removed after a certain level of strength is developed, the air is removed from the inflatable water-stop packing 5 in the shrouding plate 4, and watertightness is released. As shown in Figure 1B and Figure 3, the wagons 2, 2 and the frames 3, 3 are moved to the ends of the extended concrete structures 1a, 1a, fixed in the same way as for the basic floating body 1 described above, and then enclosed. The outer ends of the extended concrete structures 1a, 1a are surrounded by the plates 4, water is stopped by the inflatable gaskets 5, and the water inside is drained to form a dry working space 6 again, and the extended concrete structures are constructed in the same manner as described above. Create 1b, 1b. Similarly, as shown in FIG. 1C, extended concrete structure parts 1a, 1b, 1c, .

(Effects of the Invention) The method for constructing a floating concrete structure of the present invention is configured as described above, and unlike the conventional method, only a small basic floating body is formed in a caisson yard on land, and all other parts are Since it is constructed floating on the ocean, there is no need to consider extra design loads for transportation, etc., and a dry work space is created by using shrouds that move the extended concrete structure in sequence each time it is constructed. Since the construction work is carried out while performing the construction work, the required equipment is significantly simpler than when using a conventional dry dog, and the construction can therefore be performed significantly more economically than the conventional method.

Furthermore, since the extension concrete structure is created in a dry working space, the reliability of the joints is almost the same as when the whole is integrally formed in a dry dog, making it economically highly reliable. This made it possible to construct floating concrete structures.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and are shown in Figures 1-A.
C is a side view showing each process, FIG. 2 is a perspective view of the shroud portion, and FIG. 3 is a perspective view showing the state in which the shroud is attached. 1...Basic floating body, 1a, 1b, 1c...Extended concrete structure part, 3...Frame body, 4...Shrouding board,
6...Work space.

Claims (1)

[Claims] 1. Floating a prefabricated small concrete basic floating body on the ocean, attaching watertight enclosure walls to both ends of the basic floating body, and draining the internal water to create a dry work space. Then, an extended concrete structure of a certain length is constructed in continuity with the basic floating body within the working space, and then the enclosing wall is shifted to the end of the extended concrete structure to form a dry working space again. , A method for constructing a floating concrete structure in which a concrete structure of a desired length is constructed by successively forming extended concrete structure parts in the same manner as described above.