JPH0313363B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in ship intrusion protection facilities.

[Conventional technology]

In recent years, long bridges and the like have been constructed in sea areas where there is a large amount of ship traffic, and as a result, the risk of ships accidentally colliding with underwater structures such as bridge piers has increased.

Therefore, a protection facility is installed around the underwater structure, and when a ship enters the underwater structure, this protection facility will catch the ship and absorb the collision energy of the ship, preventing the ship from colliding with the underwater structure. death,
The aim is to minimize damage to underwater structures and ships.

However, conventional protection facilities of this type
As shown in the figure, the ground Ga around the underwater structure G
A plurality of tensile cables B such as wire ropes are attached to each of these supports A at appropriate vertical intervals in front of the underwater structure G where ships are expected to enter. Both ends of the tensile cable b are arranged in parallel in the horizontal direction and are tensioned and connected to each other by a cable tensioning device c such as a turnbuckle.

However, the above-mentioned protective facility A has the following problems. That is, (1) This type of protection facility A absorbs the collision energy of the ship S only by elastic deformation of the tensile cable b. However, tensile cable b
Since the amount of displacement is relatively small, the energy absorbed by the protection facility is small, and when tension is applied to the tensile cable b, the tension increases approximately in proportion to the amount of strain in the elastic deformation region of the tensile cable b. , the reaction force from the tensile cable b generated at the contact portion of the hull with the tensile cable b increases, and the risk of destroying the hull also increases.

(2) In addition, this type of protection facility A is limited to applicable ships because if a ship S with less than the assumed hull strength comes into contact with the ship, the reaction force from the tensile cable b may damage the ship S. and cannot respond to a wide range of collision conditions.

(3) Furthermore, in order for the strut a supporting the tensile rope b to withstand the horizontal external force based on the tension acting on the tensile rope b during a ship collision, the cross-sectional area of the strut a must be increased. , it is necessary to increase the penetration length into the underwater ground Ga, and it is necessary to arrange a high-bearing-strength pile support a.

In addition, as shown in Fig. 2, as another type of conventional protection facility of this type, a tensile cable b is passed through a plurality of elastic floats d, and buoys e are attached to both sides of the cable. Furthermore, each buoy e is moored to the bottom of the water by a movable anchor 5 via a mooring rope g, so that when the ship S accidentally enters an underwater structure G such as a pier, the ship S First, the tensile cable b provided with the float d
The impact force at this time is absorbed by the change in the buoyancy of the float d and the buoy e and the movable anchor 5, so that the ship can be braked.

However, such protection facility B has the following problems. That is, (1) A ship S intruding into an underwater structure G is first hit by a float d that covers the outer surface of a tensile cable b, then moves along a row of floats d in the intrusion direction, and then passes through a row of floats d and d. Submerge buoy e one by one,
A reaction force is obtained by gradually increasing the tension of the tensile cable b as the buoyancy of the float d and buoy e increases,
Furthermore, the ability to absorb collision energy is obtained by the sliding resistance when moving the movable anchor 5 on the bottom of the water. Therefore, since the damping can be performed in stages, the reaction force on the colliding vessel can also be made relatively small in accordance with the collision energy. However, in order to stop the colliding vessel in front of the underwater structure G, it is necessary to move the row of floats d, the buoy e, and even the anchor 5, so the protective facility B must be moved to a position considerably far from the underwater structure G. Therefore, the exclusive area of the protective facility becomes large.

(2) Also, if the colliding bow runs aground on the row of floats d, the buffering function cannot be achieved.

(3) Furthermore, after anchor f has been moved, if this protective facility B is to be used again, it is necessary to return anchor f to its original position.

[Purpose of the invention]

The present invention was developed as a result of studies to solve the above-mentioned problems.

Therefore, an object of the present invention is to minimize the installation area of a protection facility, reduce the reaction force to the hull, reduce the risk of hull destruction, and be applicable to collisions between various ships with different hull strengths. Our goal is to provide excellent ship intrusion protection facilities.

[Structure of the invention]

That is, the present invention provides a structure in which a plurality of supports are erected at intervals at least on the ship intrusion side of an underwater structure,
A tensile cable is strung through a sliding member near the water line of each strut, and at least one end of the tensile cable is connected to a weight to constantly apply tension to the tensile cable. The gist of this article is a ship intrusion protection facility that is characterized by:

[Embodiments of the invention]

Hereinafter, the present invention will be specifically described by way of examples with reference to the drawings.

3 and 5 show ship intrusion protection facilities comprising each embodiment of the present invention, FIG. 3 is a perspective explanatory view of the first embodiment, and FIG. 5 is a perspective explanatory view of the second embodiment. Furthermore, FIG. 4 is a diagram showing the relationship between the vessel plunge length and the tension of the tensile cable material.

In the figure, E denotes a ship intrusion protection facility consisting of each embodiment of the present invention, in which a plurality of columns 10 are erected at intervals at least on the ship intrusion side of the underwater structure G, and a water line W of each column 10 is provided. Sliding member 1 nearby
1, and at least one end of the tensile rope 20 is connected to a weight 30, so that a tensile force can be applied to the tensile rope 20 at all times. has been done.

To further explain this structure, in the first embodiment shown in FIG. Water line W of pillar 10
A plurality of tensile cables 2 are connected nearby via a sliding member 11.
0 is stretched horizontally, and both ends of each tensile cable material 20 are connected to a weight 30.

The pillars 10 are made of steel pipe piles or reinforced concrete piles, as in this embodiment, and are attached to the ground at the bottom of the water.
It may be erected directly on Ga, or underwater structure G.
An arm (not shown) may be provided on the ship entry side, and the support 10 may be erected on this arm.

The former is used when the water depth near underwater structure G is relatively shallow or the construction conditions are such that pile driving is easy.The latter is used when the water depth near underwater structure G is deep or when pile driving work such as rock etc. It is recommended to use this method when it is difficult to do so.

The strength of the strut 10 is only required to withstand the external force applied through the tensile cable material 20 at the time of a ship collision. In addition, the position of the strut 10 is set so that the protective surface of the underwater structure G can be surrounded by the tensile rope 20 at a depth that is longer than the hull penetration length calculated from the amount of movement of the tensile rope 20 at the time of a ship collision. Arrange them at an appropriate pitch depending on the size, shape, strength of the support, etc. Furthermore, 10 pillars
The cross-sectional shape of is such that the struts located at the corners bend the tension cable 20 in a horizontal plane according to the shape of the underwater structure G, and smoothly slide and deform the tension cable 20 in the event of a ship collision. A cross-sectional shape with an appropriate curvature, such as a circular cross-section, is preferable so that a locally concentrated reaction force is not generated on the tensile cable material 20.

As the tensile cable material 20, wire rope,
There are strand cables, synthetic fiber ropes, chains, etc., which are selected according to the tension conditions. Wire rope is superior in that it is easy to bend and has strong tensile strength, but
Since it will be stretched over a long period of time in a splash zone that is prone to corrosion, a wire rope with good corrosion resistance, such as a wire rope, is passed through a flexible hollow cylindrical body such as a rubber hose, and an elastic material such as urethane is used in the gap between the wire rope and the hollow cylindrical body. It is best to use a wire rope filled with anti-corrosion injection material or coated with nylon or the like on the outer surface of the wire rope.

The arrangement of the tensile cable material 20 is
It is preferable to arrange one or a plurality of tensile cables 20 horizontally near the water surface using the water as a fulcrum, so that intruding vessels can be reliably caught.

In particular, when the ship entry position changes in the vertical direction due to changes in the tide level, etc., a plurality of tensile cables 20 should be arranged in multiple stages in the vertical direction. It is desirable to connect the horizontally arranged tensile cables of each stage with short cables arranged vertically at intervals of several meters to form a lattice shape, as this will further improve the effectiveness of catching intruding vessels.

In this embodiment, the sliding member 11 is formed into a cylindrical shape, bent to match the curvature of the outer circumference of the support column 10, and has a tensile cable passed through it as described above. 11a
Although it is a sliding member, it is bent vertically downward at an appropriate curvature in order to guide the tensile cable 20 vertically downward. In the case of this embodiment, the heavy cone 30 is composed of two conical cones 31 and 32 that are connected to each other by a connecting cable 33, both of which are placed on the bottom of the water, and in their original form, they cannot be used as tensile cables. Assume that there is no tension or slack.

FIG. 4 illustrates the relationship between the plunge length of the ship and the tension of the tensile cable when the ship rushes into the protection facility E of this embodiment.

When the ship S rushes into the protection facility E from the direction of the arrow in FIG. contact and elastically deform (stretch) the tensile cable 20 until the tension of the tensile cable 20 reaches the underwater weight W1 of the heavy pyramid 31 (Fig. 4 O to A
while). Next, the heavy cone 31 is lifted until the connecting rope 33 connecting each of the conical cones 31 and 32 is tensed (A
~B). Then, the tension of the tensile cable material 20 is increased by the heavy cone 31,
The sum of the underwater weights of 32 is W1 + W2, and the connecting cable 33
The tensile cable material 20 and the connecting cable 33 are elastically deformed (stretched) until the tension reaches the underwater weight W2 of the heavy pyramid 32. (Between B and C) The heavy cone 32 is also lifted until it absorbs the ship's collision energy. (Between C and D) The stopped ship is pushed back by the reaction force from the tensile line 20 and leaves the protection facility E, the heavy cone 30 returns to the bottom of the water, and the tensile line 20 also returns to its original shape before the ship entered. do.

In other words, since this protection facility E mainly absorbs the collision energy of the ship by replacing it with the potential energy of the heavy cone, the buffering capacity can be designed as appropriate by increasing or decreasing the movement amount and weight of the heavy cone, and the ship Optimal protection facilities can be easily designed according to collision conditions and the allowable plunge length of the vessel (allowable length of distance between underwater structure and protection facility). In addition, a protection facility that can be applied to a relatively wide range of ship collisions due to the size of the hull strength and the size of the collision energy can be easily designed by combining heavy cones of different weights. Furthermore, the structure is simple and maintenance is easy.

In addition, the protection facility E according to the present invention is composed of small cross-section members such as cables and columns that are not easily affected by external weather and sea forces such as tidal currents and waves, so it can be used for a long period of time as a protection facility installed in water areas with severe natural conditions. This is particularly advantageous in terms of durability.

FIG. 5 shows a second embodiment of the invention. In this embodiment, three struts 10 are built on the entire surface of the ship entry surface of the underwater structure G in a triangular shape in plan view as shown in the figure, and tensile cables 20 are stretched around each strut 10 in a triangular shape. Both ends of each tensile cable 20 are drawn diagonally downward and connected to cable-shaped heavy pyramids 34 under water, and the cable-shaped heavy pyramids 34 are converged to a steel block-shaped heavy pyramid 31. In this case, a chain is used as the rope-like cone 34.

Further, the heavy cone 31 is placed stationary on the water bottom approximately in the center between the two columns on the side of the underwater structure G, and the chain 34, which is a cable-like heavy cone, draws a catenary curve in the water near the bottom. The tensile cable material 20 is tensed to some extent.

When the ship S enters the protection facility E from the direction of the arrow in Fig. 5, the tensile cable 20 stretched horizontally
The hull S comes into contact with and pulls the tensile cable 20 in the direction of travel of the ship. Chain 34 in the water at this time
The shape of the catenary curve approaches a straight line, and the tension of the tensile cable material 20 is gradually increased. Furthermore, as the ship S intrudes into the protection facility E, the sum of the vertical components of each chain 34 of the connection part of the heavy cone 31 increases.
When the underwater weight exceeds , the heavy cone 31 is lifted from the water bottom to further increase the tension of the tensile cable 20 and absorb the collision energy of the ship. The stopped ship is pushed back by the reaction force from the tensile cable material 20 and leaves the protection facility E, the heavy cone 31 returns to its original position on the water bottom, the chain 34 also returns to its original catenary curve, and the tensile cable The material 20 also recovers to its original shape before the ship collision.

In the case of this embodiment, the tension of the tensile rope material 20 is reduced by making the curve of the chain 34, which is a cable-like cone with a catenary curve, as the primary buffer in the event of a ship collision, approach a straight line as the ship enters. This is to obtain a reaction force to the hull S by gradually increasing it, and has the advantage of not applying a shock to the hull at the initial stage of a collision. Further, the buffering capacity can be appropriately designed by adjusting the length, weight, combination, etc. of the cable-like heavy pyramid 34 and the block-like heavy pyramid 31. In particular, waste wood from chains can be used as a rope-like cone, allowing for effective use of resources.

In addition, when installing on underwater structures G where there are many cases of ship intrusion from specific directions, such as drifting ships that are carried by the tide and ships that are drowsy driving that enter parallel to the navigation route, As in the present embodiment described above, the tensile line material 20 is stretched in a triangular shape, and the tensile line material 20 is stretched at a certain angle with respect to the main intrusion direction of the ship 20, so that the intruding ship is protected from the tensile line material 20. Preferably, the course change can be facilitated by a reaction force from the vehicle. If the course of the intruding vessel is changed in this way, it is not necessary for the protection facility to absorb all of the collision energy of the intruding vessel, and it is possible to reduce the scale of the protection facility, which is effective.

〔Effect of the invention〕

As described above, the present invention includes a plurality of struts erected at intervals at least on the ship intrusion side of an underwater structure, and tensile cables are stretched around the water line of each strut via sliding members. In addition, at least one end of this tensile cable material is connected to a weight to constantly apply a tensile force to the tensile cable material, so that the following effects are achieved. In other words, (1) Since the collision energy of the ship can be absorbed mainly by replacing it with the potential energy of the weight, the buffering capacity can be designed as appropriate by increasing or decreasing the movement amount and weight of the weight, increasing the degree of freedom in design. can be improved.

(2) By combining heavy cones with different weights or adjusting the mutual connection state of the conical cones, it is possible to respond to a relatively wide range of ship collisions depending on the strength of the hull or the magnitude of collision energy.

(3) After absorbing the ship's collision energy,
The ship can be automatically pushed back and removed from the protective facility by the reaction force of the tensile line, and the heavy cone automatically returns to the bottom and initial position underwater, and the tensile line also returns to its original shape before the ship enters. Since it can be recovered, it eliminates the need to reinstall protective facilities every time there is a collision.

(4) Since tensile cables, struts, heavy cone, etc. can be constructed mainly from civil engineering materials that are often used in water bodies, reliability and durability can be improved, and it can be constructed relatively easily. The structure allows for easy replacement and maintenance of parts.

(5) It is made of small cross-section members that are less susceptible to external weather and sea forces such as tidal currents and waves, making it suitable as a protective facility installed in water areas with severe natural conditions.

[Brief explanation of the drawing]

1 and 2 are perspective explanatory views showing conventional ship intrusion protection facilities of this type, FIGS. 3 and 5 show ship intrusion protection facilities according to embodiments of the present invention, and FIG. 5 is a perspective explanatory view of the first embodiment, FIG. 5 is a perspective explanatory view of the second embodiment, and FIG. 4 is a diagram showing the relationship between the vessel plunge length and the tension of the tensile cable material. 10... Strut, 10w... Strut water line, 11
... Sliding member, 20 ... Tensile cable material, 30 ... Weight, G ... Underwater structure.

Claims (1)

[Claims] 1 A plurality of struts are erected at intervals on at least the ship entry side of the underwater structure, tensile cables are strung through sliding members near the waterline of each strut, and the tensile cables are A ship intrusion protection facility characterized in that at least one end of the cable is connected to a weight to constantly apply tension to the tensile cable.