JPH0136717Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to marine structures, particularly marine structures whose outer walls, on which water pressure, ice pressure, etc. are directly applied, are structured to withstand large loads. It is something.

[Conventional technology]

2. Description of the Related Art Marine structures are being actively developed for the purpose of developing marine resources and utilizing marine space.

Offshore structures, such as general offshore oil storage facilities built offshore, receive water pressure loads from waves etc. on their outer walls, and for example, offshore structures such as artificial islands for oil drilling in the Arctic Circle. When a structure is installed and used in shallow water, the outer wall is subjected to impact from ice.

It is necessary that the wall members constituting the outer walls of marine structures that directly receive the loads of water pressure and ice pressure have a structure that can support these loads.

In order to make the outer wall members of the marine structures mentioned above capable of withstanding large loads, various efforts have been made in the past, including steel structures and concrete structures, but each has its advantages and disadvantages. In recent years, as a structure that takes advantage of the respective characteristics of steel structure and concrete structure, a so-called Sanderutsch type composite structure, in which the outside and inside of concrete are sandwiched between steel plates, has been proposed.
That is, as shown in an example in FIG.
and inner steel plate b, concrete c and steel webs d as partition walls are arranged, and support points e are provided so that a plurality of webs d are within the support interval L to support them from the inside. , or in addition to the above configuration, as shown in Fig. 4, in order to protect the concrete c which is weak against shearing force, a steel rib f as a slip prevention material of the concrete c is attached to an inner steel plate b.
There are wall structures that can be attached to the outside of a marine structure, or reinforced concrete c by placing reinforcing bars g, etc., and a wall structure in which such a wall structure is applied to the outside wall of an offshore structure has been proposed and is already well known. (Refer to Proceedings of the Society of Naval Architects of Japan, No. 141).

When a composite structural member of an offshore structure has a structure as shown in Figs. 3 and 4, when an external force is applied, an arch h as shown by a chain double-dashed line is formed in the concrete c, and this concrete c exerts an arch effect, and the base (foot) of arch h concentrates on support point e, making it able to withstand external forces.

[Problems to be solved by the invention] However, in the conventionally known structure mentioned above, since the support part is a point support, the concrete can exert an arch effect and withstand external force, but the width of the arch h is narrow. Therefore, it cannot be made strong enough to withstand large loads,
The spacing between the support points e (support spacing) must be narrowed. Reducing the support spacing means that more support members are required, which increases the weight and cost.
In addition, in the conventional composite structure in which the inside and outside of concrete are sandwiched between steel plates, the thickness of the concrete c is kept thin to maintain strength, so when external force is applied, the thin concrete c has a truss effect, etc. I am trying to make it durable. If the concrete is thin, there will be multiple steel webs d between steel plates a and b.
In order to achieve a truss effect by arranging the concrete, it is necessary to insert many reinforcing webs d into the concrete c for reinforcement. Therefore, a large number of webs are required, which complicates the structure and increases material costs.

Therefore, the present invention makes it possible to widen the support spacing of composite structural members, thereby reducing the number of support members and weight. It also makes it possible to increase the strength of the arch by widening the width of the arch, making concrete more effective. To provide a marine structure that exhibits an arch effect and simplifies the structure by eliminating the need for any anti-slip material for webs between supporting parts, and solving problems associated with conventionally known marine structure members. This is what I am trying to do.

[Means for solving problems]

The present invention is a composite structural member for marine structures that has a composite structure in which concrete is sandwiched between steel plates on the outside and inside. A structure in which support plates are arranged parallel to the hand direction so that the support plate supports a wide range of support parts, a partition is provided only in the support part by the support plate, and the thickness is increased in the inner and outer directions of the concrete. shall be.

[Effect]

When an external force acts on the outer steel plate, a wide arch is effectively formed due to the wide bearing part and thick concrete, greatly increasing the strength, and simply installing a bulkhead only at the bearing part can handle a large load. can withstand.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figure 1 shows a cross section of the outer wall of the offshore structure of the present invention, and the wall is made of Sanderutsch type composite structure by covering the outside of the concrete 3 with the outer steel plate 1 and the inner side with the inner steel plate 2. In the member, the support part 4 of the wall member supported from inside the offshore structure is made to have a thickness several times the thickness of the inner steel plate 2 and a wide support plate 5, and a support plate 5 that is perpendicular to the inner surface on the center line of the support plate 5. It consists of a support member 6 attached in the direction, and reinforcing members 7 arranged at appropriate intervals in the longitudinal direction of the support plate 5 for reinforcing the support plate 5 by being arranged between the support plate 5 and the support member 6. However, the steel web 8 as a transverse bulkhead is provided only on the support portion 4 having the wide support plate 5, and the thickness of the concrete 3 is
The distance between the supporting parts 4 (supporting distance) is made thicker than the distance L,
The arch effect within the concrete 3 can be used to support the load.

The total width L' of the support plate 5 of the wide bearing part 4 is approximately 10 to 40% of the bearing interval L, and the concrete 3 divided by the steel webs 8 on each adjacent bearing part 4 is The supporting plate 5 of the supporting portion 4 is about 5 to 20% of the half. The width of one side of the support plate 5 is approximately 5 with respect to the support spacing L.
The reason why it is set at ~20% is that if it is less than 5%, the support width will become close to a point, and the width of the arch effect within the concrete 3 will become narrower, which will be disadvantageous in terms of strength.If it is wider than 20%, the arch effect will change. This is because it would end up being a waste of material instead.

Further, the concrete 3 is made thicker than the bearing spacing, and the optimal thickness T is approximately 40% of the bearing spacing L from the viewpoint of construction and economy. However, it is natural that the value is not limited to this value.

Now, when an external force 10 acts on the surface of the outer steel plate 1,
Since the concrete 3 is thicker than the bearing spacing L and the bearing part 4 is wide, an arch 9 is formed in the concrete 3 in which the load is evenly distributed on the wide support plate 5, and the concrete 3 is made wider. Demonstrates an effective arch effect. Moreover,
Since the arch 9 is formed to have a wide width with the wide support plate 5 as its base, the support interval L can be increased as the strength is improved. Even if only the thickness of the concrete 3 is increased, the strength will not increase in proportion to the increase in the thickness of the concrete because the width of the arch is small if the support part is of a single point support structure. In this invention,
As described above, since the support part 4 is wide and the concrete 3 is thick,
The width of the arch is wide, and the concrete 3 exhibits an effective arch effect and can bear a large load.

Note that the support plate 5 is not limited to a flat plate as shown in the figure, but may have both side edges bent inward and reinforced with reinforcing members 7. Also, the web 8 may be made of a steel truss. Alternatively, it is of course possible to replace the inner and outer plate connecting members, and to make various other changes without departing from the gist of the present invention.

[Effect of idea]

As described above, according to the marine structure of the present invention, the structural members on which water pressure, ice pressure, etc. act are made thicker with concrete sandwiched between the inner and outer sides by steel plates, and the width of the supporting part is widened, so that external forces can be applied. Because a wider arch is formed in the concrete, the concrete can exhibit a more effective arch effect and can withstand large loads such as ice pressure. As a result, the strength can be improved, and the use of steel partition walls for reinforcement between adjacent bearing parts can be omitted, reducing the number of parts, reducing the number of installation steps, improving the workability of concrete pouring work, and reducing costs. etc., and the spacing between the bearings can be increased, reducing the number of supporting members and the weight. Also, the steel partition wall can be provided on the bearing part in only one direction, and the steel partition wall can be provided in only one direction on the bearing part. There is no need for a steel partition wall, and together with the fact that the steel partition wall between the supporting parts is not required, the structure can be simplified and increased in strength. Furthermore, by widening the width of the support plate of the bearing part, it is possible to effectively prevent the destruction of concrete, and there is no need for anti-slip materials such as ribs or reinforcing bars on the inner steel plate. It is also possible to prevent the occurrence of cracks in the base of the concrete arch due to cracks occurring in the vicinity.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the main parts of the present invention, Figure 2 is a sectional view showing the state of the concrete arch according to the present invention, and Figures 3 and 4 are cross sections of structural members of conventional marine structures. It is a diagram. 1 is an outer steel plate, 2 is an inner steel plate, 3 is concrete, 4 is a bearing part, 5 is a support plate, 8 is a steel web, and 9 is an arch.

Claims (1)

[Scope of utility model registration request] In a marine structure formed by a composite structural member of concrete and steel plates with steel plates sandwiching the inside and outside of the concrete, the bearing part that supports the composite structural member is used as a wide support surface, and a steel partition is installed only at the bearing part. What is claimed is: 1. A marine structure characterized in that it is formed of a composite structural member formed by increasing the thickness of concrete that is provided and sandwiched between the steel plates.