JPS5833155B2 - 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, the Purge, known as a floating offshore structure that houses various plant facilities such as chemical plants and power generation plants, has its sides and bottom covered with concrete outer panels, and its interior space is reinforced. A steel internal frame for general use is placed as appropriate, making it a so-called composite structure of steel and concrete.

Therefore, when constructing such a composite marine structure, the steel inner frame is assembled and arranged in the desired condition, and then concrete is successively poured around it to form a concrete outer panel. However, in this case, since the size of this type of structure itself is quite large, the concrete shell is usually constructed using the cast-in-place method at a dock or ship's slipway. Therefore, the construction work is troublesome and the construction period is long, which increases the construction cost.Moreover, it is difficult to obtain the necessary strength and watertightness for the outer panel of this type of structure. There was a problem that it was difficult to

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 space for pouring concrete under the frame, which is not only a tedious task, but also requires a considerable amount of effort to support the jig due to the weight of the internal frame, and furthermore, its installation and removal are complicated. However, there was a problem in that the construction costs increased.

With the method of using such a support jig, it is almost impossible to construct a large offshore structure due to problems such as the size and weight of the internal frame.

Furthermore, when constructing the aforementioned concrete exterior panels using the cast-in-place method, it is difficult to make the concrete homogeneous over the entire surface due to issues such as the pouring area. In the case of molding, this was particularly noticeable because the casting height was sufficiently high compared to the casting area.

Furthermore, the above-mentioned cast-in-place exterior panel forming work takes a long time depending on the size of the structure, and this is especially noticeable when forming the side concrete. fully occupy the
Not only did the construction cost increase, but there were also problems such as interfering with other construction work.

Furthermore, the above-mentioned outer panels are generally made of prestressed concrete or reinforced concrete with dense reinforcing bars, which requires placing reinforcing bars, sheaths, etc. within the concrete pouring space, making the construction work cumbersome. This had a particularly large impact on the construction period.

In addition, there are few examples of such synthetic marine structures,
Furthermore, since there are almost no full-scale large-scale structures, it is impossible to apply conventional construction methods as they are, and there is a demand for new construction methods for these types of structures.

The present invention has been made in view of the above-mentioned circumstances, and consists of appropriately forming a steel internal frame of a marine structure into blocks, supporting these blocks sequentially at regular intervals on a formwork for forming bottom concrete, and are integrated by welding or the like, concrete is poured below it to form the bottom concrete, one side concrete is divided and formed into a plurality of precast panels in advance, and these are joined to the internal frame, Concrete is poured into the gaps created between each precast panel to integrate them, making it possible to construct an offshore structure with simple construction work, while significantly shortening the construction period. To provide a method for constructing a marine structure that further reduces construction costs.

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

Figures 1 to 4 show an embodiment of the method for constructing a marine structure according to the present invention, and in this embodiment, a large marine structure having a generally rectangular parallelepiped shape, such as a purge, is constructed. This refers to the case where a structure is constructed in which the sides and bottom are covered with a concrete outer plate, the deck is covered with a steel outer plate, and a steel internal frame is appropriately placed inside. ing.

Now, the feature of the present invention is that the entire structure is made into blocks, and these are sequentially connected.
The bottom concrete corresponding to each was formed in sequence, and the side concrete was composed of a plurality of side precast panels.
The following description will be made in accordance with the construction order shown in steps CI) to VI) in the figure.

FIG. 1 is a diagram showing the process of constructing the central part of a structure, and the one designated by reference numeral 1 is a central part made by assembling a steel internal frame 2 and a corresponding steel deck 3 in advance. This central block 1 is initially shown as (I-A) in the figure.
As shown in , a large number of assembled units are prepared with the deck 3 placed on the lower side, and as shown in CI-B), these are inverted and transported to the dock, berth, etc. where the structure will be constructed, and the crane 4 As shown by CI) in the figure, they are sequentially placed at predetermined locations on the formwork 5 for forming the bottom concrete.

At this time, a support stand 6 is placed below these central blocks 1.
are lined up, thereby securing a casting space 8 for the bottom concrete 7, as shown in FIG. 4(I).

Note that the weight of the center block 1 supported by the support stand 6 is sufficiently small, so that a simple structure can be used, for example, a support stand with a height adjustment function may be used.

In addition, each joint of the central blocks 1 arranged on the formwork 5 is sequentially connected by welding or the like to form a solid-bottomed central block connected body X, and furthermore, concrete is poured into the pouring space 8, As shown in FIG. 1 (If) and FIG. 4 [■], a bottom concavity IJ-1-7 corresponding to this central block connected body X is molded.

At this time, if reinforcing bars, sheaths, etc. are buried in the bottom concrete 7 and this is to be prestressed reinforced concrete, a rond etc. is provided in advance to protrude from the lower part of the internal frame 2 of the central block 1 and stretched. By doing so, the construction of the bottom concrete 7 can be speeded up, and the construction period can be shortened.

FIG. 2 shows the construction order for connecting the side blocks 9 to both sides of the central block connector X, and in the figure (
1-A) to 1-D, 1 shows the assembled state of the side block 9.

That is, the side block 9 is an integral combination of a plurality of side precast panels 11 formed by separating and molding the side concrete IJ-NO, and a portion of the corresponding internal frame 2 and deck 3. It is something that

The side precast panel 11 is manufactured at another construction site using the outer part 2a of the inner frame 2 shown in (1-A) in the figure and the formwork 11 placed between them. In this case, a part of the bottom concrete 7 is integrally provided as a bent part 11a on the lower side, thereby making it self-supporting, and a part of the deck 3 is previously provided on the upper side.

The side precast panel 11 has better homogeneity than cast-in-place side concrete, and can be expected to have sufficient strength.

In addition, since the internal frame 2 and the external parts 2a and 3a of the deck 3 are joined in advance to the inside of the side precast panel 11, as shown in FIGS. 2 and 4 (low D), the internal frame is attached to this. 2 and a part of the deck 3 to assemble the side block 9, the steel outer part 2a,
Due to the overhanging structure of 3a, the concrete is not affected by heat, and its quality can be improved.

In this case, the construction period can be shortened by simultaneously performing the molding of the side precast panels 11 and their assembly at another site in conjunction with the construction of the central block 1.

The side blocks 9 assembled as described above are connected to the central block connector X in the following manner.

That is, the side block 9 is shown in FIGS. 2 and 4 (1).
As shown in FIG. 2, the blocks are carried by a crane 4 to the side of the central block connector X and placed on the formwork 5 one after another.

At this time, the side block 9 is the side precast panel 1
One side of the one-way frame 2 is self-supporting by its bent portion 11a, and the other end of the one-way frame 2 is also supported by the support stand 6 that supports the center block 1, so that the bottom concrete is supported as shown in FIG. 4 (opening). A placement space 13 for IJ-1-12 is secured.

Then, during the installation work of the side block 9, the internal frame 2 and the deck 3 are sequentially welded and connected to the central block 1 side, and after the support base 6 is removed, the casting space 13 is
Concrete was poured into the
As shown in the figure, the bottom concrete 12 is formed and joined to the bottom concrete 7 on the center side to be integrated.

On the other hand, a desired gap 14 is provided between the side precast panels 11 of the side block 9, and concrete is successively poured into this gap 14 to integrate them. Side concrete 1
0 is configured.

Incidentally, the deck 3 of the side block 9 has side precast panels 11 as shown in FIGS. 2(1-D) and (1).
The side concrete 10 is configured to protrude from both sides of the deck, and is sequentially welded and integrated with the other deck 3, and is integrated with the side concrete 10 described above.
Together, they form a side block connector Y.

Furthermore, similar to the central block 1, reinforcing bars, sheaths, etc. may be provided in advance at the lower part of the internal frame 2 of the side blocks 9, thereby shortening the construction period.

FIG. 3 shows the aforementioned central and side block connection body X,
The final step of sealing both ends of Y with side end concrete IJ-N6 is shown, and what is indicated by the reference numeral 17 is a side end precast panel formed similarly to the side precast panel 11 constituting the side block 9. 18 are corner precast members to be placed at the corners of the structure, which are previously assembled and formed at another site and cast by crane 4 in the same manner as the central and side blocks 1, 9 described above. It is carried and placed on the frame.

At this time, the inner frame 2 and the outer parts 2a, 3a of the deck 3 are joined to these side end precast panels 17 and corner precast members 18, and are thereby welded and connected to the main body side.

Moreover, these each have bending parts 17a and 18a,
These bent portions 17a stand independently on the formwork 5.
.

Concrete is placed in the gap between 18a and the bottom concrete 7.12 to integrate them with the bottom concrete.

Furthermore, voids 19 are formed between these side end precast panels 17 and corner precast members 18, similar to the side precast panels 11, and concrete is sequentially poured into these voids 19. integrated,
By this poured concrete 20, the side end concrete 1
6 is molded, thereby forming the side end connecting body 2.

Then, through the above-described construction work, the central part, side block connectors X, Y, and side end connectors 2 are integrated, thereby completing the marine structure shown in FIG. 3 (Vl).

Therefore, in the above-mentioned method of constructing an offshore structure, each part of the structure is made into blocks, each part is molded at a different location, and then these parts are transported to a dock, a berth, etc., and sequentially connected and integrated. Therefore, its construction is easy, and the construction period for docks, berths, etc. can be significantly shortened, and the construction period for the entire structure can also be shortened.
This will greatly reduce construction costs.

In addition, in the above-mentioned embodiment, the construction method according to the present invention is
For example, the case where it is applied to a rectangular parallelepiped marine structure such as a purge has been explained, but it is not limited to this, and can be applied to various marine structures, and it can be applied as appropriate. Just change it.

In short, each part of the structure can be made into blocks and assembled in sequence.

As explained above, in the method for constructing a marine structure according to the present invention, the steel internal frame placed inside the concrete outer plate is appropriately divided into blocks, and these blocks are sequentially assembled to form the internal frame. At the same time, the bottom concrete is formed on the underside accordingly,
On the other hand, the side concrete is divided and formed into multiple side precast panels in advance, and these are sequentially joined to the internal frame, and concrete is poured into each gap to integrate the side precast panels. Since this is configured to form the side concrete, the inner frame, bottom concrete and side concrete can be easily assembled and formed by a simple method, which simplifies the construction of offshore structures and It has excellent effects such as reducing the number of man-hours required for construction work on docks, docks, etc., significantly shortening the construction period, and further reducing construction costs.

Further, according to the present invention, since the internal frame is supported by a simple support stand on the block-forming formwork, there is no need for a large-scale support jig as in the past.
A simple support stand is sufficient, and by providing the side precast panel with a bent part that forms part of the bottom concrete, it can stand on its own on the formwork, making it unnecessary to use special jigs, etc. This has advantages such as being advantageous during assembly.

Further, according to the present invention, a part of the internal frame is joined to the side precast panel in advance, and this is welded to other parts of the internal frame with sufficient overhang to integrate it. There is no heat effect on the concrete and it can be easily connected.Furthermore, since the side concrete is composed of side precast panels, it is easy to form and its homogeneity can be improved. There are advantages such as a good degree of bonding with the material.

In addition, according to the present invention, by placing and retaining reinforcing bars, sheaths, etc. buried in the bottom concrete in advance on the underside of the block-shaped internal frame, the construction can be performed more easily and the construction period can be significantly reduced. It has the advantage of being shortened.

[Brief explanation of drawings]

The figures show an embodiment of the method for constructing a marine structure according to the present invention, in which Figure 1 is a schematic diagram for explaining the construction order of the central block, and Figures 2 and 3 are side blocks. FIG. 4 is a schematic diagram for explaining the construction order of the construction, and FIG. 4 is a cross-sectional side view for explaining the state of pouring the bottom concrete.

Claims (1)

[Claims] 1. A method of constructing a marine structure having a concrete outer plate and a steel inner frame appropriately arranged inside the outer plate, the center part of the inner frame being made into a block, and the center block A plurality of pieces are sequentially arranged side by side on a formwork for forming the bottom concrete constituting the outer panel so as to be supported at regular intervals by a support stand,
Thereafter, the joints of each central block are welded and integrated, and concrete is poured into the casting space below the central block to form a bottom concrete corresponding to the central part of the internal frame. A side precast member formed by integrally combining a part of the side concrete constituting the plate and a corresponding part of the outer part and bottom concrete of the internal frame, and the corresponding side of the internal frame. The side blocks are arranged side by side with a predetermined gap on the sides of the central block, and the joints of the respective internal frames are welded to form a single body. pouring concrete on the lower side of the side blocks, forming a corresponding bottom concrete, and pouring concrete into the gaps between the respective side precast members to integrate the side concrete; A method of constructing a marine structure characterized by comprising: