JPH0714404Y2 - Buffer material for piers - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a cushioning material used for a bridge pier to protect a ship, and the cushioning material is sufficient within the surface pressure strength of the ship at the time of collision of the ship. It protects the ship by absorbing the collision energy by transforming into.

[Conventional technology]

Some of the cushioning materials currently in practical use for large bridge piers are composed of iron materials combined under strength calculation to protect the ship by damaging it during collision and absorbing the collision energy.

In addition, various rubber fenders have been conventionally known as berthing or fenders for berths, but compared to the contact between the ship and the quay during normal berthing, the collision of the ship with the pier due to some accident. The impact energy is orders of magnitude greater.

[Problems to be solved by the device]

The conventional shock absorbers made of iron for bridge piers are excellent in that the target energy absorption is quite accurate, but they require countermeasures against corrosion due to seawater, and if left unattended for many years, their external appearance will be extremely deteriorated and the landscape etc. There is a problem that damages. It is not practical to repeat coating for the maintenance of the appearance of this type of cushioning material because of the high cost. In addition to painting, surface treatment technology for anticorrosion is being researched, but it seems that none of them are sufficiently cost effective to obtain sufficient effects.

Therefore, a rubber cushioning material that has a proven track record in fenders can be considered, but in order to be able to absorb impact energy that is significantly larger than in the case of conventional fenders, the conventional fender is simply made larger. Doing so alone does not provide a preferable pier cushion material. Normal fenders are used within the range of elastic deformation, and the maximum displacement during shock absorption is about 50%. In the case of using the elastic foam having a relatively large displacement amount, when the expansion ratio is 50 times the limit for obtaining uniform foaming, the maximum displacement amount is 65% and the surface pressure is about 15 ton / m ² . The production limit of elastic foam is about 80 mm. On the other hand, the bow of the ship to be protected is, for example, 10
It is designed to be crushed with a surface pressure of about ton / m ^{2, and when} the surface pressure of 15 ton / m ² or more acts, the crushing will reach inside the ship.

Therefore, in order to increase the absorption of impact energy, it is desirable to increase the maximum displacement of the cushioning material, but the expansion ratio of the elastic foam is 50 times, which is the manufacturing limit. There is also a limit to the surface pressure.

For this reason, this device uses an elastic foam with a large expansion ratio, and the maximum displacement (%) is greater than that of conventional fenders.
It is an object of the present invention to provide a shock absorbing structure for a bridge pier having a large impact energy absorption amount by obtaining a shock absorbing structure capable of reducing the surface pressure at that time to 15ton / m ² or less.

[Means for Solving the Problems]

The cushioning material for bridge piers of the present invention is a foam structure in which a large number of elastic foam blocks are adhered so that voids partially remain,
An outer layer body formed of a rubber layer having a reinforcing layer attached to the outer surface of the foam structure.

[Action]

According to the above means, when an elastic foam block having uniform expansion and a high expansion ratio such as polyethylene foam or polyurethane foam is used, the elasticity when the cushioning material is pressed due to the presence of the voids between the elastic blocks. The maximum displacement within the limit can be increased to about 80%. Then, the elastic modulus of the foam structure can be arbitrarily changed by changing the size of the voids between the blocks. As a result, it is possible to achieve an appropriate surface pressure of 15ton / m ² or less, which corresponds to the strength of the ship, up to a maximum displacement of 80%. That is, as the cushioning material, it is possible to absorb a large amount of collision energy by largely displacing the surface pressure so that the ship will not be seriously damaged during a collision. The provision of the reinforcing layer on the outer layer body suppresses the expansion of the outer layer body so that the foamed structure in a wide range can effectively act as a buffer.

〔Example〕

A first embodiment is shown in FIGS. 1 and 2. In the figure, 1 is a foam structure, and 2 is an outer layer body.

As shown in the cross-section in FIG. 1, the foam structure 1 is formed by stacking foam blocks 3 in layers with a gap 4 between them, with the positions of the gap 4 being different between layers, and adhering them at their respective contact surfaces. is there. As shown in FIG. 1, the foam block 3 has a rectangular cross section and is formed so as to be long and continuous in the direction perpendicular to the paper surface. The foam block 3 is a polyethylene foam, the cells of which are closed cells, and the foaming ratio is 50 times. Further, the ratio of the voids 4 in the foam structure 1 is about 25%.

The outer layer body 2 has a constant thickness formed by embedding a reinforcing cloth 6 at a position close to the inside of the rubber layer 5, and is provided so as to cover the entire outer surface of the foam structure 1 formed in a desired shape. Structure 1
It is glued to. The surface shown in FIG. 1 is the impact surface 7.
Is. As the cushioning material 11 for one pier, for example, as shown in FIG. 2, the overall shape of the pier 10 having a circular cross section is a cylinder that surrounds the pier 10 near the water surface. A large number of divided blocks 12 each having a shape in which a cylinder is equally divided along the axis are attached to the pier 10 with anchor bolts as shown in the figure to form a cylinder.
Therefore, the shape of the foam structure 1 substantially corresponds to the shape of the divided block 12, and is a substantially rectangular parallelepiped.

The second embodiment is shown in FIG. Compared to the first embodiment, this embodiment is different from the first embodiment in that the layer of the foam blocks 3a forming the foam structure 1a is in a direction perpendicular to the impact receiving surface 7a, and the void 4a is large and the foam structure 1a is large. Is about 30% of the outer layer
2a is different from the rubber layer 5a is formed thicker inward,
Everything else is the same. The arrangement and direction of the foam blocks 3a of the second embodiment are designed so that buckling occurs in order to increase the displacement amount.

A third embodiment is shown in FIG. In this embodiment, as compared with the first embodiment, a rigid foam layer formed of a foam that is harder than the foam in which the foam block 3 is formed between the foam structure 1 and the outer layer body 2 in the first embodiment. The only difference is that the foam structure 1b is formed by interposing 13 therebetween, and the others are the same.
In the case of local contact, this is a wider range of foam structure 1.
Is to be transformed. 4 and 5, the same parts are designated by the same reference numerals, and the usage forms of the cushioning materials of the second and third embodiments are the same as those of the second embodiment shown in the first embodiment.
It is similar to the figure.

In the first, second and third embodiments, when an impact load is applied to the impact receiving surfaces 7, 7a, 7b, the relationship between the reaction force and the displacement amount (%) tends to be as shown in the graph in FIG. Becomes Therefore, if the maximum reaction force until the displacement amount reaches 80% is made smaller than the hull strength, the impact energy is effectively absorbed until the displacement amount reaches 80% without damaging the hull. To do. Although the cushioning material of each example is elastically deformed up to a displacement amount of 80%, this kind of pier cushioning material also takes into consideration the fact that energy is absorbed by destruction. In that case, it is preferable that the reaction force rises to some extent, that is, breakage occurs in the foam structure, for example, between the adhering surfaces at a portion having a gentle slope in the graph. This further suppresses the increase in reaction force.

Although not described in the above embodiment, the outer layer body 2, 2a
Since the rubber layer is airtight, it is better to install a safety valve like a pneumatic fender when an increase in internal air pressure becomes a problem.

Further, in the structure of the foam structure of the above-mentioned embodiment, the foam blocks shown in the figure are long continuous in the direction perpendicular to the paper surface, but the adjacent ones in each layer are separated at different positions via small intervals. This may be provided, and since the gaps 4 or 4a are communicated with each other, it is sufficient to provide one safety valve for each divided block in the configuration in which the safety valve is provided.

Further, although the cloth is used as the reinforcing layer of the outer layer body, a wire or the like may be used in combination.

〔effect〕

According to this invention, the displacement amount can be made larger than that of the conventional fender by using the foamed structure having the voids, and the expansion is suppressed by providing the outer layer with the reinforcing layer to suppress the expansion. The structure effectively buffers over a wide range, and a cushioning material having a large energy absorption amount can be obtained. Further, since the outer layer body is made of rubber, there is no fear that the appearance will deteriorate even if left for many years. Therefore, the optimum cushioning material for bridge piers can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view of an impact receiving surface portion of a first embodiment of the present invention, FIG. 2 is a schematic plan view showing a state of being installed on a pier of the first embodiment, and FIG. 3 is a cushion of the embodiment. A graph showing the tendency of the relationship between the reaction force of the material and the amount of displacement, FIG. 4 is a cross-sectional partial plan view of a portion similar to FIG. 1 of the second embodiment, and FIG. 5 is FIG. 1 of the third embodiment. It is a transverse plane partial view of a portion similar to. 1, 1a ... Foam structure, 2, 2a ... Outer layer body, 3, 3a ... Elastic foam block, 4, 4a ... Void, 5, 5a ... Rubber layer, 6 ... Reinforcing layer, 7, 7a , 7b …… Impacting surface, 10 …… Bridge, 11 …… Cushioning material for bridge, 12 …… Divided block.

Claims (1)

[Scope of utility model registration request] 1. An outer layer body formed by a foam structure in which a large number of elastic foam blocks are adhered so that voids are partially left, and a rubber layer having a reinforcing layer which is adhered to the outer surface of the foam structure. A cushioning material for piers.