JPS5944445B2 - Construction method for offshore structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for marine structures, and more particularly to a construction method for pile-type marine structures such as breakwaters and breakwaters installed in shallow ocean waters. It is.

Conventional construction methods for pile-type offshore structures usually involve driving steel pipe piles 1 as shown in Figure 1, and then connecting the upper parts of the piles with connecting members 1.
5, by welding on site, etc., or by temporarily installing a guide or jacket structure on the seabed ground in advance as shown in Figure 2, and inserting and driving the pile 1 into this. method has been adopted.

However, in the case of the former construction method, it is difficult to ensure the precision of driving the coffin, and the construction work itself depends on the precision of piling, so it is difficult to shorten the construction period on site. This method has the advantage of ensuring pile driving accuracy, but it is structurally complex, expensive, and inferior in terms of construction workability, so it is particularly important for offshore applications where wave-dissipating panels near the sea surface, such as wave-dissipating levees, are important. For structures, it is desired to develop a construction method that is simpler in terms of structure and workability.

This invention was devised in view of the shortcomings of the prior art, and its purpose is to shorten the construction period by reducing on-site offshore/underwater construction work, and also to reduce the need for construction work to be performed with such strict precision at sea, where work is difficult. An object of the present invention is to provide a construction method 1 for marine structures that can fully install the desired structure.

The details of the present invention will be explained below, taking as an example the method of constructing a curtain-type wave-dissipating levee shown in FIGS. 3 and 4.

In the figure, 1 is a steel pipe pile, 2 is a steel pipe outer pipe 3 of a predetermined length having an inner diameter larger than the outer diameter of the steel pipe pile 1 by a predetermined dimension, and each outer pipe 3 is inserted at the same driving interval as the designed steel pipe pile. A steel welded structure with a panel structure that is integrally formed with connecting panels for forming wave-absorbing plates 4 that are connected at predetermined intervals, and 5 is an outer pipe equipped with a mortar injection port (not shown) at a predetermined position on the outer circumference. The upper cover 6 is an annular mortar receiving plate which can be fitted onto the circumferential surface of the resistor 1 and can close the lower surface of the outer tube 3 when the outer tube is fitted, and the receiving plate 6 is provided on the upper surface thereof. Locking metal fitting T
It is held in close contact with the lower surface of the outer tube by being locked to a locking fitting 9 provided on the lower end side circumferential surface of the outer tube 3 via a hanging fitting 8.

Reference numeral 10 denotes mortar that is filled from the mortar injection port into the annular gap formed by the resistor 1, the outer tube 3, and the mortar receiving plate 6 after the outer tube 3 is placed over the resistor 1. 1 and are integrally joined.

Reference numeral 11 denotes an upper corrugation work installed on the upper part of the outer pipe 3.

A protrusion may be provided on the inside of the outer tube 3 to increase the adhesion force between the mortar and the piles, and an appropriate positioning member may be attached to a predetermined position on the outer circumference of the lower surface of the upper lid of the outer tube, so that the outer tube can be fixed. When placed over a steel pipe pile, the gap between the two can be made almost constant.

Of course, when the protrusion or positioning member is provided, the inner diameter of the outer tube, the length of the protrusion, etc. should be set appropriately so that the outer tube can be fitted to the upper part of the pile with an error in driving.

Next, the construction procedure according to this invention will be explained with reference to FIG.

■ First, the coffin boat 12 drives the columns 1 at predetermined intervals at the site (Fig. 4A).

■ Next, the panel structure 2 (in the illustrated example, it is made up of four outer tubes 3 and three wave-dissipating panels 4), which has been preassembled into an integral structure and given a paint finish, is shown in Figure 4. The panel structure 2 is sequentially lifted up by a crane ship 12, and each outer tube 3 of the panel structure 2 is fitted into its corresponding pile 1 and installed.

■ Next, the connecting wave-dissipating panels 4' are lifted up by a crane ship, and lowered between each panel structure 2 as shown in Fig. 4, and each panel structure is joined via the similar wave-dissipating panels 4'.
The pile and the panel structure are integrally joined by injecting mortar 10 into the gap between the shaft 1 and the outer pipe 3 from a mortar injection port in the upper cover.

■ Next, the construction of the wave-dissipating bank is completed by placing the upper wave return work 11 on the outer pipe 3 (Fig. 4-2).

In the above explanation, a panel-structured breakwater was used as an example of the construction method for marine structures, but it goes without saying that the method is not limited to this scope and can be effectively used, for example, in the construction of jacket-type panel structures. do not have.

That is, the construction method of the present invention can be applied to any marine structure in a sea area where pile driving or pile erecting (when the seabed is bedrock) is possible, and its economic efficiency can be demonstrated.

For example, port structures such as bridges, dolphins, rock walls, small platforms for oil drilling, foundations of bridges on the sea surface, marine leisure facilities, partition fences around water reservoirs, openings above floater gates, and all other marine structures. Can be applied to things.

In the present invention, after driving the pile as described above, the outer pipe of the panel structure or jacket type panel structure is fitted to the pile head,
By inserting a mortar plate into the gap between each pile and each outer pipe to connect the piles and the panel structure, offshore work is not only easier, but also almost no underwater work is required, shortening the construction period. This greatly contributes to reducing construction costs and improving safety.

Furthermore, in the past, the biggest problem in the construction of pile structures was how to absorb errors in the piles that were driven.
According to the present invention, by appropriately selecting and setting the inner diameter of the outer tube, in other words, the gap between the pile and the outer tube, the tolerance for driving accuracy of the pile can be increased, which has the advantage of making offshore work extremely easy.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams showing the conventional construction method, respectively, Figure 3A is a partial perspective view showing a wave-dissipating levee constructed by the method of the present invention, and the opening in the figure is the A breakwater section in Figure A; Figure 4 is A2
2B and 2B are schematic diagrams showing the procedure for constructing a wave-dissipating levee according to the method of the present invention. 1: Pile, 2: Panel structure, 3: Outer pipe, 4, 41: Wave-dissipating plate (connected panel), 5: Upper cover, 6: Mortar receiving plate, 10
: Mortar, 12: Pile driver, S: Water surface, L: Seabed surface.

Claims (1)

[Claims] 1 Two or more outer pipes of a predetermined length, each having an inner diameter larger than the outer diameter of the pile and having a mortar receiver at the lower end that can be fitted onto the surrounding surface of the pile, are connected through connecting panels to drive the pile according to the design. After connecting the panels at the same intervals as the gaps between the questions to form an integrated panel structure, and driving multiple piles into the seabed soil at predetermined intervals,
After each outer pipe of the panel structure is placed over the upper end of each of the piles, each gap between the outer pipe and the pile is filled with mortar to connect the pile and the panel structure. construction method for marine structures.