JPH045553Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hood that absorbs the impact energy and alleviates the collision when a ship collides with an underwater structure such as a bridge pier. More specifically, when various types of ships, ranging from small ships to large ships, collide with underwater structures at different speeds, the damage to the ships is reduced by a rational combination of shock absorbers with different load-deformation characteristics. The present invention also relates to a hood for protecting underwater structures.

[Conventional technology]

Conventionally, as shown in Fig. 5, this type of hood has been divided into a brittle fracture block e formed mainly of a brittle fracture material c and having a low reaction force elastic body f on the front surface, and a plastically deformable body g. There is a floating type hood which consists of a plastic deformation block h which is formed mainly from a plastically deformed block h which can be provided with a low reaction force elastic body f on the front surface. These blocks can be connected by integrating the reinforcing material d forming the surface layer of the brittle fracture block e with the surface layer of the plastic deformation block h, or by connecting the brittle fracture block e and the plastic deformation block h with bolts and nuts. A method of joining was used.

However, the brittle fracture material c, which is the main material of the brittle fracture block e, has lower tensile strength, bending strength, etc. than compressive strength, and therefore does not function as a strength member. Therefore, the reinforcing material d forming the surface layer of the brittle fracture block e is made to have strength to withstand external forces when a ship does not collide.

On the other hand, the main function of the entrance hood in the event of a ship collision is to collapse the entrance hood and absorb the energy of the collision without damaging the colliding ship. Therefore, if the crushing strength of the impact surface of the entrance hood is suppressed to at least below the strength of the ship's side, it will not be possible to ensure the safety factor against external forces during non-ship collisions, which is generally required for offshore structures. On the other hand,
To ensure a safety factor against external forces when a ship does not collide, the reinforcing material d that forms the surface layer must be made stronger, and the crushing strength of the collision surface of the hood exceeds the hull strength of the ship, making it impossible to function as a hood. There was a problem.

In addition, if the brittle fracture block e is damaged due to a ship collision, in a structure in which the brittle fracture block e and the plastic deformation block h are covered and integrated with the reinforcing material d, it is necessary to replace the brittle fracture block e. After removing the reinforcing material d covering the surface of the brittle fracture block e, it is necessary to install a new one, making it difficult to replace the brittle fracture block e. Furthermore, in a structure in which the brittle fracture blocks e are joined by bolts and nuts, the buoyant force acting on the brittle fracture blocks e is large, and in order to support the buoyant force only on the bottom surface of the brittle fracture blocks e, the joints of the bolts and nuts must be made quite strong. There is a high risk of damaging the hull in the event of a collision, and the bolted joints are underwater, making them difficult to replace.

Therefore, as shown in FIG. 6, a brittle fracture block e is formed mainly of a brittle fracture material c and can be provided with a low reaction force elastic body f, and a plastic deformation block e is formed mainly of a plastically deformable body g. A floating hood is constructed by removably attaching a brittle fracture block e and a plastic deformation block h to a mounting rigid body i in which a shock absorption block consisting of a block h is provided between an underwater structure a and the shock absorption block. devised.

In this hood, the rigidity of the mounting rigid body i can provide strength against external forces in non-collision situations, especially against sagging and hogging, which become noticeable when the length of the hood exceeds a certain length. It is now possible to weaken the reinforcing layers of the fracture block e and the plastic deformation block h to some extent, improving the buffering function in the event of a ship collision, and in the event that the brittle fracture block e is damaged, it can be replaced by adding a hanging tool to the mounting rigid body i. This can be easily carried out on the water surface by providing a

However, this hood is constructed by individually fabricating the brittle fracture block e, plastic deformation block h, and rigid mounting body i, and then connecting them. In order to function properly, the brittle fracture block e, the plastic deformation block h, and the mounting rigid body i must be mounted so that they can resist external forces as one body. For this purpose, mutual attachment of the brittle fracture block e and the plastic deformation block h,
Furthermore, the mounting portion between these two blocks and the mounting rigid body i requires strong reinforcement, which deteriorates the buffering performance in the event of a ship collision. In addition, vertical forces such as eccentric external forces such as wave force and tidal current force from the front, buoyancy (including sagging and hogging caused by changes in buoyancy), and uplift force act on the entrance hood, and these external forces cause brittle fracture blocks. and a plastically deformed block h, as well as these two blocks and a rigid body i for attachment.
Stress concentration occurs at the connection between the parts, and the mounting part is likely to be damaged.

In addition, when a large ship collides with the entrance hood, the brittle fracture block e and the plastic deformation block h are crushed, and the upper and lower blocks e and h are fixedly connected to the mounting rigid body i, so the mounting Deform rigid body i. Therefore, when replacing the entrance hood, it is necessary to replace the entire structure. moreover,
If the mounting rigid body i has a frame structure as shown in the figure, the ship body, especially the ship side part, may be damaged.

Furthermore, in order to provide the mounting rigid body i with the strength to withstand external forces in the event of a non-collision, considerable structural dimensions are required, and the width of the hood overhanging the underwater structure is determined by the width necessary to absorb collision energy. Since it is the sum of the overhanging width of the upper and lower two blocks and the overhanging width of the mounting rigid body i, it may hinder the navigation of ships, especially if it is installed in a sea area where the channel width is narrow and there is a lot of ship traffic. There were some shortcomings.

[The problem that the idea aims to solve]

The present invention was devised to eliminate such conventional drawbacks, and is capable of withstanding external forces in non-collision situations, without impairing the shock absorbing performance of a composite block consisting of a brittle fracture block and a plastically deformed block. The purpose of this invention is to provide a hood whose overhanging width is minimized.

[Means to solve the problem]

That is, the hood of the present invention consists of a brittle fracture block formed mainly of a brittle fracture material and equipped with a low reaction force elastic body on the front surface, and a plastically deformed block mainly formed of a plastically deformable body. The plastically deformed block is formed to have an L or U-shaped cross section, and the brittle fracture block is removably attached to an L- or U-shaped recess provided on the front surface of the plastically deformed block. It is.

In this way, the plastically deformed block is formed to have an L or U-shaped cross section, and the brittle fracture block is removably attached to the L- or U-shaped recess provided on the front surface of the plastically deformed block. The rigidity of the plastically deformed block, which has greater strength than the brittle fracture block, can withstand external forces during a collision, and the compressive strength of the brittle fracture block is uniform, which impairs the shock absorbing performance, which has excellent energy absorption performance. Never. Furthermore, since the plastic deformation block serves as a strength member against external forces in the event of a non-collision, there is no need to provide a separate strength member, and the overhanging width of the entrance hood can be kept to the minimum necessary, preventing obstacles to ship navigation. Never. Furthermore, manufacturing costs can be reduced and it is economical.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 2 is a diagram showing the state in which the hood according to the present invention is attached to an underwater structure, in which the hood is composed of a brittle fracture block 20 with a low reaction force elastic body 10 on the front surface and a plastic deformation block 30. E is installed in a floating manner surrounding the pier G, which is an underwater structure.

As shown in FIG. 1, the brittle fracture block 20 has a brittle fracture material 25 enclosed within a box-shaped outer shell 24 made of steel, FRP, concrete, rubber, or the like. Typical examples of the brittle fracture material 25 include synthetic resin foams such as hard urethane foam and phenol foam, and inorganic foams such as foamed concrete, perlite, and foamed glass.

On the other hand, the plastically deformed block 30 is mainly formed of a plastically deformed body 30a so as to form an air chamber 32, and in order to adjust the hydration, the air chamber 32 includes:
The structure is such that ballast such as concrete can be injected as needed. As the plastically deformed body 32, metal materials such as thin steel plates, various steel shapes, steel pipes, FRP, etc.
Representative examples include synthetic resin materials such as PVC.

The aforementioned brittle fracture block 20 absorbs the collision energy of the ship mainly through brittle fracture of the brittle fracture material 25, and the plastic deformation block 30 absorbs it through plastic deformation of the plastically deformed body 30a.

The low reaction force elastic body 10 is intended for cushioning small ships, and is attached to the front surface 2 of the brittle fracture block 20.
It is mounted near the water surface W of No. 1 by means of mounting means such as bolts and nuts. The low reaction force elastic body 10 is mainly formed of a rubber-like elastic material such as a rubber fender or a polyethylene foam material, and the brittle fracture block 2
The compression reaction force per unit impact receiving area is smaller than 0.

The plastic deformation block 30 is a large ship (ship side strength
20 to 30t/m ² ) and has an L-shaped cross section. Furthermore, an L-shaped recess 33 provided at the upper front end of the plastic deformation block 30
A brittle fracture block 20, which is intended for use as a shock absorber for medium-sized ships that have the highest frequency of collisions, is removably attached using attachment means such as bolts and nuts. At this time, the back surface 22 and bottom surface 23 of the brittle fracture block 20 are in close contact with the L-shaped wall surface of the recess 33. Moreover, as shown in FIG.
3) brittle fracture blocks 20 are attached.

Since the strength of the entrance hood E is designed to be less than the ship side strength, the strength of the plastic deformation block 30 intended for large ships is greater than the strength of the brittle fracture block 20 intended for medium-sized ships. Further, since the plastic deformation block 30 is integrally formed in an L-shape and has a multi-chamber structure having many air chambers 32, it has high rigidity and can sufficiently withstand external forces during non-collision. As a result, brittle fracture block 2
Since the rigidity of the zero outer shell 24 can be made small, the buffering performance of the brittle fracture block 20 is not impaired.

Furthermore, by arranging a plurality of brittle fracture blocks 20 with a length shorter than that of the plastic deformation blocks 30, stress caused by sagging or hogging acting on the brittle fracture blocks 20 can be reduced, so that the outer shell 24 In addition to reducing rigidity,
Since the reinforcement of the mounting portion of the plastic deformation block 30 is also reduced, the cushioning performance is improved.

Further, since the plastic deformation block 30 has both a buffering function and a strength function against external forces when a ship does not collide, the overhang width l of the entrance hood E can be suppressed to the necessary minimum. As a result, it is economical because it does not interfere with ship navigation and the manufacturing cost can be reduced. Here, 31 indicates the front surface of the plastic deformation block 30, and Ea indicates the back surface.

Brittle fracture block 20 and plastic deformation block 30
For installation methods, see Figure 3a, Figure 3b, and Figure 3.
There is something like the one shown in Figure c.

That is, in FIG. 3a, a brittle fracture block 20 is provided with a flange 23a at the lower front and a flange 22a at the rear of the upper surface, which are detachably attached using fixing means such as bolts.

FIG. 3b shows a brittle fracture block 20 removably attached to a plastic deformation block 30 using the same fixing means as in FIG. 3a and a tension member 40 such as a wire rope. This method reduces the buoyant force acting on the brittle fracture block 20 to the tensile member 4.
0, and forward movement of the brittle fracture block 20 is suppressed by fixing means such as bolts. Since the tension member 40 is disposed in a direction perpendicular to the direction of the ship's collision, it does not impair the buffering performance of the brittle fracture block 20 in the event of a ship's collision. In addition, since the buoyancy is supported by the tension member 40,
Since the force acting on the fixing means such as bolts is smaller than that shown in FIG. 3a, the reduction in shock absorbing performance due to the use of the bolt or other fixing means is smaller than that shown in FIG. 3a.

Furthermore, FIG. 3c shows an L-shaped holding arm 5 which is attached to the upper part of the plastic deformation block 30 so as to be able to rise and fall, and which suppresses the forward movement of the brittle fracture block 20.
0. The brittle fracture block 20 can be attached to and detached from the plastic deformation block 30 by the receiving metal fitting 51 attached to the front surface 31 of the plastic deforming block 30 and the holding wire 52 provided between the receiving metal fitting 51 and the L-shaped holding arm 50. It was attached to. This mounting method requires that members be placed on the top and front surfaces of the brittle fracture block 20, but it not only impairs the buffering performance of the brittle fracture block 20 in the event of a ship collision, but also In comparison, the replaceability of the brittle fracture block 20 is improved.

FIG. 4 is a sectional view of a hood showing a second embodiment of the present invention, and the plastic deformation block 30 has a U-shaped cross section. Further, a U-shaped recess 3 provided on the front surface of the plastic deformation block 30
A brittle fracture block 20 is removably incorporated into the recess 33, and its top surface 26, back surface 22, and bottom surface 23 are in close contact with the U-shaped wall surface of the recess 33. 10
is a low reaction force elastic body attached to the front surface of the brittle fracture block 20.

In this example, the plastic deformation block 30 has sufficient rigidity to withstand the external force when the ship does not collide, and the buoyant force acting on the brittle fracture block 20 is absorbed by the recess 35.
Because it is supported by the plastic deformation block directly above,
The rigidity of the brittle fracture block 20 can be reduced without impairing the buffering performance of the brittle fracture block.

[Effect of idea]

As described above, the present invention forms a plastic deformation block with an L or U-shaped cross section, and detachably attaches the brittle fracture block to the L- or U-shaped recess provided on the front surface of the plastic deformation block. Therefore, the rigidity of the plastic deformation block, which has greater strength than the brittle fracture block, can withstand external forces when a ship does not collide, and the compressive strength of the brittle fracture block is uniform, resulting in excellent energy absorption performance. buffering performance is not impaired. Furthermore, since the plastic deformation block serves as a strength member against external forces in the event of a non-collision, there is no need to provide a separate strength member, and the overhanging width of the entrance hood can be kept to the minimum necessary, ensuring no hindrance to ship navigation. There's nothing wrong with that. Furthermore, manufacturing costs can be reduced and it is economical.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a first embodiment of the hood hood according to the present invention, FIG. 2 is a perspective view showing the hood hood according to the present invention arranged around a pier, and FIG.
Figures a to 3c are explanatory diagrams showing a method of attaching a brittle fracture block to a plastic deformation block, Figure 4 is a cross-sectional view showing a second embodiment of the hood of the present invention, Figures 5 and 3c are Figure 6 is a cross-sectional view of a conventional entrance hood. 10...Low reaction force elastic body, 20...Brittle fracture block, 25...Brittle fracture material, 30...Plastic deformation block, 30a...Plastic deformation body, 33, 35...
recess.

Claims (1)

[Scope of utility model registration request] In the hood, which consists of a brittle fracture block formed mainly of a brittle fracture material and equipped with a low reaction force elastic body on the front surface, and a plastic deformation block formed mainly of a plastic deformation body, the plastic deformation block has a cross section L or 1. A buffer structure characterized in that the brittle fracture block is removably attached to an L- or U-shaped recess formed on the front surface of the plastically deformable block.