JPS5853625B2 - How to build offshore structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for constructing composite marine structures using a combination of steel and concrete.

For example, in the Purge, which is a floating offshore structure that houses various plant facilities such as chemical plants and power generation plants, its outer surface is covered with a concrete outer panel, and the internal space that forms the flotation chamber is A steel internal frame is appropriately placed for reinforcement, making it a so-called composite structure of steel and concrete.

Therefore, when constructing such a composite marine structure, the steel internal frame is assembled and placed in the entire structure or in blocks, and then concrete is sequentially poured around the frame to form a concrete outer panel. However, in this case, because the size of this type of structure itself is quite large, the concrete skin is usually constructed using the cast-in-place method at a dock or ship's slipway. As a result, the construction work is troublesome, the construction period is long, and it is difficult to obtain the required strength, watertightness, etc. for the outer panel of this type of structure.

That is, when forming the bottom concrete that constitutes the concrete outer panel, the steel internal frame described above is suspended above the forming formwork using some kind of construction support jig, and the internal It is necessary to secure a space for pouring concrete under the frame, which is not only troublesome, but also requires a fairly large support jig, which requires complicated installation and removal, which increases construction costs. Put it away.

With the method of using such support jigs, it is almost impossible to construct a large offshore structure due to problems such as the size and weight of the internal frame. When constructing the outer panel by casting in place, it is difficult to make the concrete homogeneous over the entire surface due to problems such as the pouring area, and this is particularly noticeable when forming the side concrete.

Furthermore, the above-mentioned cast-in-place molding work for the outer panels takes a long time depending on the size of the structure, etc. During this period, the dock and berth are occupied, resulting in a very high construction cost.

Therefore, in order to build such offshore structures,
It is conceivable to use the precast construction method normally used for land-based structures such as bridges, but in this case, the bonding relationship between the steel internal frame and the concrete outer plate, which is not required for the above-mentioned land-based structures, may be considered. etc., and the above-mentioned precast construction method could not be applied as is.

The present invention has been made in view of the above-mentioned circumstances, and is made by attaching a part of the bottom concrete constituting the concrete outer plate to the lower part of the steel inner frame of a marine structure in an inverted state. The side concrete that forms the outer panel is divided and formed into a plurality of side precast blocks, and a bent part that forms part of the bottom concrete is provided on the lower side. The bottom and side precaster blocks are integrated by constructing them so that they can stand on their own, and placing them in their respective assembly positions and pouring concrete into their respective gaps. It is possible to significantly shorten the construction period by forming the concrete skin of an offshore structure during construction work, and it also improves the homogeneity of the concrete skin and easily achieves the desired strength, watertightness, etc. The present invention provides a method for constructing a marine structure that can be obtained easily and reliably.

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 shows an embodiment of a marine structure to which the construction method according to the present invention is applied, and in the figure, this marine structure 1 is
The whole is in the shape of a rectangular parallelepiped, and its large outer surface is covered by a concrete outer panel 2, and the inner space covered by this outer panel 2 has partition walls and ribs for reinforcement. A steel internal frame 3 made of a combination of materials and the like is appropriately arranged.

In this case, the concrete outer plate 2 is composed of a bottom concrete 4, a side concrete 5 consisting of four sides, and an upper concrete 6, and these are formed by a formwork T for forming the bottom concrete provided at a dock or a ship's slipway. It is poured and molded in sequence on the top.

Now, according to the present invention, when constructing the concrete outer panel 2 of the marine structure 1 by casting in place at a dock or a slipway, as shown in FIG. 2 and FIG. The structure is characterized in that the bottom precast block 8 is connected in advance to the lower side of the internal frame 3, and the side concrete 5 is formed into a plurality of side precast blocks 9.

That is, when forming the bottom concrete 4 of the outer panel 2, the inner frame 3 is assembled over the entire structure on the formwork 7, and the bottom concrete 4 is separated by the thickness. In this case, the internal frame 3 and the bottom concrete 4 must be tightly connected with the required strength.

To this end, according to the present invention, as shown in FIG. 2, a part of the bottom concrete 4 is placed on the lower side 3a of the internal frame 3 which is arranged in combination for the entire structure or for each block. They are joined together as a bottom precast block 8.

Then, the inner frame 3 is supported on the formwork 7 at regular intervals using the bottom precast blocks 8 to secure a space for pouring concrete at the bottom, and to fill the voids 10 formed between the bottom precast blocks 8 described above. The bottom concrete 4 is formed by sequentially pouring concrete.

Therefore, the above-mentioned bottom precast block 8 eliminates the need for the conventionally used hanging support jig, and also eliminates the troublesome work of attaching and removing it, thereby simplifying the forming work of the bottom concrete 4. becomes.

The reference numeral 11 in FIGS. 7 and 10 indicates the concrete poured into the void 10, whereby the bent portions 9a of the bottom precast block 8 and the side precast blocks 9, which will be described later, are integrated. The bottom concrete 4 is formed.

In addition, when molding the bottom precast block 8, the inner frame 3 is placed in combination with the entire structure or each block, and then the lower part 3a placed above the inner frame 3 is turned upside down. As shown in FIGS. 4 and 5, concrete is placed on the upper part using formwork 12.

By doing this, it is possible to easily compact the concrete that is difficult to cast in place, and this makes it possible to compact the concrete that is difficult to cast in place.
The bottom precast block 8 can be tightly bonded to the bottom precast block 8 and has the desired strength by increasing its homogeneity.

Then, after the concrete has hardened, the formwork 12 is removed,
What is necessary is to invert the inner frame 3 together with the bottom precast block 8 and place the bottom concrete 4 on the forming form 7, as shown in FIG.

In this case, the corbel 8a can be easily formed on the bottom precast block 8, and its strength can be made as desired.

In addition, as mentioned above, when forming the bottom precaster block 8, the internal frames 3 are disposed as a whole or in combination for each block, so the mutual positioning of the internal frames 3 can be performed with high precision, resulting in a structural It becomes possible to improve the accuracy of the object itself and create a concrete structure similar to that of a steel ship.

Further, according to the present invention, as shown in FIG. 3, the side concrete 5 is divided and the side precast blocks 9 are prepared in advance.
It is molded as

This is to solve the problem that when pouring the side concrete 5 entirely by pouring in place, it is troublesome due to problems such as the pour height, and it is difficult to obtain homogeneity. It is molded in another factory or the like into a shape that has a size that matches the shape of the marine structure 1 and is homogeneous.

Then, these plurality of side precast blocks 9 are transported to the construction site of the marine structure 1, ie, a dock, a dock, etc., and as shown in FIG.
are sequentially arranged in their respective arrangement positions on the formwork 7 on which they are placed.

In this case, the side precast block 9 has a bent portion 9a on its lower side, and is configured to be able to stand on the formwork 7 by itself.

Therefore, when erecting such a side precast block 9 on the formwork 7, it can be easily done without using a special support jig, and when molding the side precast block 9 described above. If a large number of these parts are manufactured in the same shape, the molding becomes easy.

In this case, the bent portion 9a of the side precast block 9 is a part that constitutes a part of the bottom concrete 4 together with the bottom precast block 8, as is clear from FIG.

Then, as shown in FIG. 8, by pouring concrete into the voids 14 formed between the side precast blocks 9, the side precast blocks 9 are formed as shown in FIGS. 6 and 9. The blocks 9 are integrated and form the side concrete 5 together with the poured concrete 15.

Therefore, when constructing the marine structure 1 using the bottom precast block 8 and the side precast blocks 9 described above, the lower part 3a of the steel internal frame 3 is
A bottom precast block 8 is joined to the bottom precast block 8, and this is used to form a bottom concrete IJ prepared in a dock, etc., as shown in FIG. After the inner frame 3 has been placed on the frame 7 in the desired assembled state, the side precast blocks 9 are sequentially placed into predetermined positions by a crane 13, as shown in FIG.

Then, concrete is poured into the voids 10 for the bottom concrete 4 formed between the eight bottom precast blocks and the bent portions 9a of the side precast blocks 9, as shown in FIGS. 7 and 10. As shown in FIG. 6 and FIG. As shown in FIG. 9 and FIG. 9, side concrete 5 is formed.

Thereafter, concrete is poured on the upper part of the internal frame 3 and an upper concrete 6 is formed to complete the offshore structure as shown in FIG. However, these operations may be performed after the structure 1 is pulled out to sea from a dock or the like.

In the above-described method of constructing an offshore structure, the concrete outer plate 2 is difficult to be cast in place at a dock, etc., and the steel inner frame 3 is required to have a high degree of bonding. The parts to be cast are homogeneously formed in advance as precast blocks 8 and 9, and only the parts that can be easily cast in the dock are cast in place.
The marine structure 1 can be easily constructed, and the period during which a dock or the like is used can be significantly shortened.

Furthermore, the cast concrete IJ-411, 15 etc. that integrate the precast blocks 8, 9 can be formed uniformly due to their ease of casting, thereby improving the strength and watertightness of the outer panel 2. Furthermore, since the mutual positioning of the steel internal frames 3 can be carried out with high precision, the precision of the outer plate 2 can also be improved, thereby making it possible to make the marine structure 1 as precise as a steel ship. can.

As explained above, according to the method for constructing a marine structure according to the present invention, a part of the bottom concrete of the concrete outer panel is precast as a bottom precast block on the lower side of the steel internal frame. After forming the side concrete of the outer panel into a plurality of side precast blocks so that they can stand on their own, and placing them in their respective assembly positions. Concrete is poured into each gap and integrated to form the bottom and side concrete of the marine structure, making it easy to construct marine structures, especially on docks or slipways. To facilitate casting work in place, significantly shorten the period of use, thereby significantly reducing construction costs, and further improve the homogeneity of the concrete outer panel to obtain desired strength, watertightness, etc. It has excellent effects such as:

Further, according to the present invention, when forming the bottom precast block, the steel internal frame is installed in combination with the entire structure or each block, and then the steel internal frame is turned in the opposite direction and concrete is poured directly into the structure. This allows the concrete in this area to be sufficiently compacted to securely bond it to the internal frame, and to obtain the desired strength.The bottom precast block can also be skillfully used to facilitate concrete pouring. The inner frame can be placed in the desired assembled state on the bottom concrete molding formwork without using construction support jigs that require troublesome attachment and detachment work as in the past. This simplifies the work and improves the precision of the positional relationship between the internal frames, making it possible to create a concrete structure with precision comparable to that of a steel ship.

[Brief explanation of drawings]

The figures show an embodiment of the method for constructing a marine structure according to the present invention, and FIG. FIG. 3 is a perspective view illustrating a side precast block that also characterizes the present invention, FIG. 4 is a flat cylindrical view illustrating a method of forming the bottom precast block Figure 5 is the ■− of Figure 4.
6 is a cross-sectional view showing the relationship between the steel internal frame and the concrete outer plate; FIG. 7 is a cross-sectional view of the middle part showing the relationship with the bottom and side precast blocks; Figure 8 is a front view showing the relationship with the bottom and side precast blocks, Figure 9 is a sectional view taken along the line ■-■ after pouring concrete in Figure 8, and Figure 10 is a cross-sectional view of Figures 6 and 7. FIG. 3 is a longitudinal cross-sectional view taken along the line XX in the figure. 1...Marine structure, 2...Concrete outer plate, 3...Steel internal frame, 3a.
...Lower part, 4...Bottom concrete,
5...Side concrete, 7...Formwork, 8...Bottom precast block, 9...
...Side precast block, 9a...Bending part, 10.14...Gap part, 11.15...
...Poured concrete.

Claims (1)

[Claims] 1. A method of constructing a marine structure having a concrete outer panel and appropriately arranging a steel inner frame inside the outer panel, the inner frame being combined into the entire structure or each block. After placing it, the lower part thereof is turned upward, and by pouring concrete on the upper part, a part of the bottom concrete constituting the outer panel is joined to the lower part of the inner frame as a bottom precast block. and the inner frame is inverted and supported by its bottom precast block in an assembled state on a formwork for forming the bottom concrete, with a thickness separation of the bottom concrete IJ-t; A portion of the side concrete to be formed is formed into a plurality of side precast blocks, and is placed on the formwork by a bending part integrally provided at the lower side thereof, and then the bottom precast blocks are placed on the formwork. and a bent part of the side precast block,
and pouring concrete into the gaps formed between each of the side precast blocks, and the poured concrete integrates the bottom and side precast blocks to form the bottom concrete and side walls forming the outer panel. A method for constructing a marine structure characterized by forming a concrete part.