JPH036663Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a steel/concrete hybrid structure used as the foundation of offshore structures such as floating islands, and in particular can reduce weight while maintaining strength. steel·
Concerning concrete hybrid structures.

[Prior Art] In general, in the case of huge offshore structures such as oil drilling bases, the outer walls of the foundations are subject to large loads due to weather conditions, so it is necessary to form the outer walls strongly. , excessive weight gain must be prevented. In particular, for marine structures in polar regions that are subject to huge ice loads from drift ice,
The strength must be maintained high.

In this structure, an outer steel plate a and an inner steel plate b are connected by a web steel plate c, and the inside is filled with concrete to form a concrete layer d.Furthermore, the inner steel plate b has a support girder e that supports the load. It is configured by installing.

In such a sandwich structure, when a load f is applied to the outer steel plate a, the concrete layer d
An inverted V-shaped or arch-shaped concrete arch rib g as shown by diagonal lines is formed inside, and the load transmitted to this is received by the support girder e.

[Problems to be solved by the invention] By the way, in the above-mentioned conventional steel/concrete hybrid structure, when a load f acts on the outer steel plate a at the center of the span of the support girders e and e, as shown in Fig. 1, , an arch rib g is formed in the concrete layer d, and the load f is transmitted from the center of the span in the direction of this arch rib g, and is transmitted to the support girders e, e.

In conventional steel/concrete hybrid structures, depending on the support conditions, especially the bearing width,
Changes were occurring in the strength of steel/concrete hybrid structures.

In addition, the width of the arch rib g is narrow, and the support girders e, e
Because stress concentration occurs at the attachment part of support girder e, e
There was a problem that the bearing width had to be widened.

[Purpose of the invention] The present invention was devised to solve the above conventional problems, and the purpose of the present invention is to improve the strength of the steel/concrete hybrid structure when a load is applied to the outer steel plate. By increasing the strength of the support girder and avoiding stress concentration at the attachment part of the support girder, the yield strength is
Especially steel that is not affected by bearing width and has high yield strength.
The objective is to provide a concrete hybrid structure.

[Summary of the invention] In order to achieve the above object, the present invention consists of an outer steel plate that directly receives a load, an inner steel plate that is joined to this via a concrete layer, and a steel plate that is spaced apart from each other by a predetermined distance. A support girder provided with
In a steel/concrete hybrid structure having a web steel plate connecting the outer steel plate and the inner steel plate on an extension of the support girder, the side of the inner steel plate at both ends of the concrete arch rib that occurs when a load is applied to the outer steel plate. A swash plate is installed at the intersection of the steel and web steel plates, and the steel/concrete hybrid structure has a high yield strength that is not affected by the support conditions, and also reduces stress concentration at the support girder attachment part. It can be avoided.

[Embodiment] A preferred embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows one embodiment, in which an outer steel plate 1 and a land side steel plate 2 are arranged in parallel, and concrete is filled between them to form a concrete layer 3.

Further, support girders 4 are arranged at predetermined intervals and connected at right angles to the inner steel plate 2, and a web steel plate 5 connecting the outer steel plate 1 and the inner steel plate 2 is provided on an extension of the support girder 4. It is provided.

Swash plates 6 are fixed to both sides of the web steel plate 5 so as to connect a predetermined position of the web steel plate 5 and a predetermined position of the inner steel plate 2.

This arrangement of the swash plate 6 is a feature of the present invention.

This swash plate 6 is buried in the concrete layer 3, and one end of the swash plate 6 is fixed to the web steel plate 5, and the other end is fixed to the inner steel plate 2.

It goes without saying that the space surrounded by the swash plate 6, the inner steel plate 2, and the web steel plate 5 is also filled with concrete. Incidentally, holes for filling concrete may be arranged in this swash plate 6 at appropriate intervals as necessary.

That is, as shown in FIG. 2, this swash plate 6 is located at a position where it almost enters both ends of an arch rib 8 formed in the concrete layer 3 when a load 7 is applied to the outer steel plate 1 at the center of the span of the support girder 4. Place it in
It is fixed to the web steel plate 5 and the inner steel plate 2.

In this way, in the steel/concrete hybrid structure, when the load 7 acts on the outer steel plate 1 near the middle of the spacing between the support girders 4 as shown in the figure, the end of the arch rib 8, which is the path through which the load is transmitted to the support girder 4, is the position where the swash plate 6 is located, so the swash plate 6
By resisting external force, a wide arch rib 8 is formed, and the shearing force of the inner steel plate 2 is dispersed.
Stress concentration occurring at the joint between the support girder 4 and the inner steel plate 2 can be avoided. In addition, since no large external force acts on the concrete layer, the strength of the steel/concrete hybrid structure is improved, and a steel/concrete hybrid structure that is not affected by the conditions of the support girder 4 can be obtained. The required width 9 of the arch rib can be clearly set.

FIG. 3 is a diagram showing the results of FEM analysis of the structure of the present invention.

As shown in the figure, by providing the swash plate 6, the principal stress indicating the flow direction of the force is confirmed to be compressive force in a wide range due to the swash plate 6, and the arch rib 8
The width can be easily set.

In addition, in the figure, the length of the line indicates the magnitude of the compressive force.

[Effects of the invention] As described above, the steel/concrete hybrid structure of the invention exhibits various excellent effects as described below.

(1) When a load is applied near the middle of the support girder spacing, in addition to the concrete arch ribs, the swash plates placed at both ends of the arch ribs resist the external force, increasing the yield strength. A concrete hybrid structure is obtained.

(2) As a result of the above, stress concentration at the support girder joints can be avoided, so the support girder can be provided without particularly increasing the bearing width of the support girder.

(3) The width of the arch rib required for calculating the strength can be easily and clearly set.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is an explanatory diagram showing the external force transmission state of the one in Figure 1,
FIG. 3 is an FEM analysis diagram of FIG. 1, and FIG. 4 is a sectional view of the conventional example. In the figure, 1... outer steel plate, 2... inner steel plate, 3...
...Concrete layer, 4... Support girder, 5... Web steel plate, 6... Swash plate, 7... Load, 8... Arch rib, 9... Arch rib width.

Claims (1)

[Scope of utility model registration request] An outer steel plate that directly receives a load, an inner steel plate that is connected to the inner steel plate through a concrete layer, a support girder provided at a predetermined distance from each other on the inner steel plate, and an outer steel plate on an extension of the support girder. In a steel/concrete hybrid structure having a web steel plate that connects the inner steel plate and the outer steel plate, a slant occurs at the intersection of the inner steel plate side and the web steel plate at both ends of the concrete arch rib, which occurs when a load is applied to the outer steel plate. A steel/concrete hybrid structure characterized by being configured with plates.