JP3760738B2 - Harbor structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a harbor structure such as a quay or a revetment.
[0002]
[Prior art]
FIG. 12 shows a pile-type horizontal pier 31 which is most common as a conventional pier. The pile-type horizontal jetty 31 is provided with a earth retaining work 35 on the revetment structure 33, a plurality of pile bodies 37 are placed on the seabed 38 as pedestals, and a slab 39 is formed thereon to form a jetty. ing.
Another example of the quay is a jacket-type quay 41 shown in FIG. The jacket type quay means that a frame structure 43 made of steel pipe, steel frame or the like as shown in FIG. 14 is fixed to the seabed ground 38 in a skewered manner by a pile body 37 and a floor slab 39 is attached to the upper surface of the frame structure 43. Formed.
Further, as another quay type, there is a caisson type quay using a slit type caisson 51 as shown in FIG.
[0003]
In such a quay, the purpose is only for the berthing and cargo handling of ships, and the wave-dissipating function is rarely considered.
However, in reality, in the harbor water areas where quays and revetments are provided, there is a high demand for quietness from the viewpoints of port cargo handling work and safe navigation of small vessels.
[0004]
When the wave-dissipating function is added to the above-mentioned three types of quay, in the case of a caisson quay having a gravitational structure, as shown in FIG. 15, a slit wall 51a and a water reserving chamber 51b are provided on the sea side of the caisson. This can be easily handled by using the slit caisson 51 provided.
On the other hand, in the case of a pile-type horizontal jetty, it is not very common to have a wave-dissipating function, but as an example having a wave-dissipating function, a wave-dissipating pier described in Japanese Patent Application Laid-Open No. 7-247527 There is. As shown in FIG. 16, this wave-dissipating pier is a pier in which a floor slab 39 is formed on an upper part of a pile 37 and a floor slab 53 is provided below the surface of the pile 37 to form a water reclaiming part.
In addition, as far as the inventor knows, no jacket type revetment has been developed as far as the inventor knows.
[0005]
[Problems to be solved by the invention]
When building with a gravitational structure, it is possible to easily provide a wave-dissipating function by using a slit caisson, etc. Is required.
And the wave-dissipating pier of JP-A-7-247527 has a structure in which a floor slab 53 is provided under the surface of the water, and an underwater operation of integrating the floor slab 53 and the pile 37 in water is necessary. turn into.
Moreover, since the wave height increases even in the harbor water area during a storm, the floor slab 53 may receive a strong lifting pressure, and the joint with the pile 37 may be broken. Furthermore, the floor slab 53 will be installed at a predetermined depth below the surface of the water, but the water level changes due to tidal fluctuations, especially in the case of the inland sea, where the tidal range may reach several meters. In other places, the floor slab 5 may be higher than the water surface, and there is a problem that the wave-absorbing function cannot be exhibited.
[0006]
The present invention has been made to solve such problems, and it is an object of the present invention to provide a harbor structure such as a quay or a revetment having a wave-dissipating function that minimizes the influence of tides and minimizes local construction. It is said.
[0007]
[Means for Solving the Problems]
The harbor structure according to the present invention is a jacket-type structure that does not have a bottom plate under the water surface,
A wave-dissipating panel having an opening portion disposed so that the opening portion is positioned at the water surface in a shape that blocks waves in a vertical direction on the sea side of the jacket-type structure;
An impermeable wall disposed below the wave-extinguishing panel,
A back wall installed behind the wave-dissipating panel so as to block the waves in the vertical direction;
The relationship between the distance B between the back wall and the wave-dissipating panel and the wavelength L of the wave to be wave-dissipated is B / L = 0.1 to 0.3.
[0008]
Also, it is a jacket type structure that does not have a bottom plate under the water surface,
A wave-dissipating panel having an opening portion disposed so that the opening portion is positioned at the water surface in a shape that blocks waves in a vertical direction on the sea side of the jacket-type structure;
An impermeable wall disposed below the wave-extinguishing panel and extending therethrough,
The distance B between the earth retaining work installed on the land side of the jacket structure and the wave-dissipating panel has a relationship with the wavelength L of the wave to be wave-dissipated, and B / L = 0.1 to 0.3. It is characterized by that.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a side view. The basic structure of the quay 1 of the present embodiment is a structure in which a jacket structure 7 having a wave-dissipating function is fixed to a seabed ground 3 by a pile body 5.
The jacket structure 7 has a frame structure made of steel pipes, steel frames, and the like, and is installed on the sloped shaping surface 9 of the seabed along the earth retaining work 8, so that the bottom part is along the sloped shaping surface 9 of the seabed at the time of installation. The sea side is deep and the inside of the port is shallow. A floor slab 11 is installed on the upper surface of the jacket structure 7.
[0012]
The wave-dissipating function includes a wave-dissipating panel 15 having an opening 13 vertically installed on the sea side of the jacket structure 7, a non-transparent wall 17 disposed below the wave-dissipating wall 17, and a predetermined distance behind the wave-dissipating panel 15. This is realized by the rear wall 19 installed at a distance.
[0013]
The wave-dissipating panel 15, the impermeable wall 17, and the back wall 19 are made of steel, concrete, resin, or the like, and the material is not particularly limited as long as there is no problem in durability.
In addition, any method may be used for attaching these to the jacket structure 7. For example, an engagement groove for engaging both sides of the wave-dissipating panel 15 and the like is provided in advance on the jacket structure side. The wave-dissipating panel 15 or the like may be inserted into this. However, since the basic structure is a jacket structure, the wave-dissipating panel 15 can be installed in advance in a factory or the like, or on-site construction can be simplified, so that there is no complicated work in water and there is a great merit in construction.
[0014]
In addition, the opening 13 of the wave-dissipating panel 15 is provided with a vertically long rectangular shape in the present embodiment, but other than a rectangular shape, a circular shape or the like can be freely determined.
[0015]
Here, the aperture ratio of the opening 13 provided in the wave-dissipating panel 15 (ratio of the opening 13 in the entire wave-dissipating panel 15 and the non-transparent wall 17), and the wave-dissipating panel 15 and the back wall 19 installed behind it. Will be described.
In the quay 1, when the waves coming from the sea side pass through the opening 13 of the wave-dissipating panel 15, a vortex is generated by the rapid contraction and rapid expansion of the flow path, thereby consuming energy and quenching. . Therefore, the aperture ratio has an influence on the wave-dissipating performance, and it is necessary to appropriately determine the aperture ratio. And although an aperture ratio changes also with wave conditions, as a standard, an aperture ratio should be about 10%-20%.
[0016]
In order to improve the wave-dissipating performance, it is necessary to effectively generate vortices. For that purpose, it is necessary to increase the flow velocity when passing through the wave-dissipating panel 15, and for that purpose, the wave-dissipating panel 15 It is necessary to increase the water level difference between the front and rear. And in order to enlarge this water level difference, what is necessary is just to produce a phase difference in the wave before and behind the wave-dissipating panel 15 so that the water level difference before and after the wave-dissipating panel 15 becomes large. This phase difference is defined by the wavelength L of the wave to be wave-dissipated and the distance B between the back wall 19 and the wave-dissipating panel 15. Therefore, when the wavelength L of the wave to be quenched is determined, the distance B between the back wall 19 and the wave-dissipating panel 15 is set corresponding to the wavelength L of the wave to be quenched. Specifically, the distance B between the back wall and the wave-dissipating panel is preferably such that the relationship with the wavelength L of the wave to be wave-dissipated is B / L = 0.1 to 0.3.
[0017]
When constructing the quay 1 configured as described above, the wave-dissipating panel 15, the impermeable wall 17, and the back wall 19 are installed in the jacket structure 7 in advance. And the jacket structure 7 provided with the wave-dissipating function in this way is fixed to the seabed ground by the pile body 5 in the same manner as the normal construction. Thus, the wave-dissipating panel 15, the opaque wall 17 and the back wall 19 which are members for demonstrating the wave-dissipating function can be installed in advance in a factory or the like, and since there is no work in the water, the work can be facilitated accordingly. Cost can be reduced.
[0018]
In addition, only the installation part, such as a wave-dissipating panel, may be provided in advance, and the installation itself of the wave-dissipating panel may be performed locally. Even in this case, since the jacket structure 7 is a basic structure, an installation part such as a wave-dissipating panel can be easily provided in advance, and on-site construction can be simplified. Can demonstrate.
[0019]
In order to confirm the wave-dissipating effect of the present invention, a model was installed in the wave-making channel and the wave-dissipating performance was examined. 3A and 3B are explanatory diagrams of the cross section of the test object. FIG. 3A is a cross-sectional view of the test object, and FIG. 3B is a view of a part of the wave-dissipating panel 15 and the opaque wall 17 as viewed from the front. is there.
As shown in FIG. 3 (a), the depth of the floor slab is 20 m, the depth of the seabed ground is 14.5 m, and the depth of the submerged portion of the wave-dissipating panel 15 is 4.5 m, as shown in FIG. The depth of the opaque wall 17 is 13.0 m, and the distance B between the back wall 19 and the wave-dissipating panel 15 is 8 m.
As shown in FIG. 3B, the wave-dissipating panel 15 has an opaque portion of 0.5 m at the upper and lower edges. The dimensions of the wave-dissipating panel 15 and the impermeable wall 17 are as described in the drawing. Further, the relationship between l ₁ and l _{2 in} the figure is l ₂ / l ₁ = 0.3. As can be seen from these, the aperture ratio of the wave-dissipating panel 15 of this example is 5.5 × 0.3 / 15 × 100 = 11%.
[0020]
The experiment was conducted using a model in which this cross section was modeled at a 1/30 scale. As shown in FIG. 4, the outline of the experimental apparatus is a model 25 in a wave-making channel 23 in which a wave-making apparatus 21 is installed. , A wave height meter 27 is installed between the wave making device 21 and the model 25, and a wave extinguishing device 29 is installed behind the model 25. In FIG. 4, the distance (unit: mm) between the devices is indicated by an arrow and a number.
[0021]
FIG. 5 is a graph showing experimental results. Here, all are shown on a real scale. In the graph of FIG. 5, the vertical axis indicates the reflectance Kr, which is the ratio of the incident wave and the reflected wave height, and the horizontal axis indicates the distance (B) between the wave-dissipating panel 15 and the back wall 19 and the wave wavelength (L). The value (B / L) divided by is shown. The horizontal axis also shows the wave period (seconds). In the graph, points indicated by black squares indicate conventional examples (only the jacket structure), and white circles indicate the present embodiment.
[0022]
As can be seen from FIG. 5, in the present embodiment, the reflectivity is 0.6 or less for all targeted waves in the range of B / L of 0.1 to 0.3, and the wave-absorbing function is sufficiently exhibited. I understand that. In the field construction, if the value of B is set so that B / L is about 0.07 or about 0.2 in relation to the wavelength of the target wave, a remarkable wave-dissipating effect can be obtained. In this embodiment, the back wall 19 can be installed in advance in a factory or the like. Therefore, it is possible to set the distance B, which is difficult when performing on-site construction, and it is possible to exhibit an efficient wave-dissipating function. .
[0023]
Embodiment 2. FIG.
FIG. 6 is a side view of the second embodiment of the present invention, and the same reference numerals are given to the same parts as those of the first embodiment and corresponding parts.
In the present embodiment, the wave-absorbing panel 15 is installed in the middle portion of the jacket structure 7, thereby eliminating the impermeable wall 17 and the back wall 19 in the first embodiment.
The concept of this embodiment will be described. When considering only the surface of the wave-dissipating function, it is preferable to provide the non-transparent wall 17 below the wave-dissipating panel 15 and further provide the back wall 19 as in the first embodiment. However, the simpler the configuration, the better the cost.
[0024]
By the way, the bottom of the sea where the quay is installed is usually an inclined shaping surface 9 whose land side is raised, and there is a feature of the earth shape that a earth retaining work 8 is provided behind the quay. If the wave-dissipating panel 15 is installed in the middle part of the jacket-type structure because there is an inclined surface on the sea floor, this means that it is in the middle of the inclined surface, and this inclined surface functions to a certain extent as an impermeable wall. It is also possible to omit the impermeable wall.
Further, since there is the earth retaining work 8, it is possible to omit the back wall by giving it a function as a back wall.
Based on such knowledge, the impermeable wall 17 and the back wall 19 are omitted.
[0025]
Therefore, in the second embodiment, the inclined shaping surface functions as an impermeable wall, and the earth retaining wall functions as a back wall.
[0026]
FIG. 7 is an explanatory diagram of a cross section of an experiment target in the second embodiment, FIG. 7A is a cross sectional view of the test target, and FIG. 7B is a view of a part of the wave-dissipating panel 15 as viewed from the front. It is.
As shown in FIG. 7 (a), the depth of the floor slab is 20m, the depth of the seabed ground is 14.5m, the depth of the submerged portion of the wave-dissipating panel 15 is 3.1m, as shown in FIG. The distance B between the earth retaining work 8 and the wave-dissipating panel 15 is 8 m.
As shown in FIG. 7B, the wave-dissipating panel 15 has a non-transparent portion of 0.5 m at the upper and lower edges. Moreover, each dimension of the wave-dissipating panel 15 is as having added in the figure. Further, the relationship between l ₁ and l _{2 in} the figure is l ₂ / l ₁ = 0.15. As can be seen from these, the aperture ratio of the wave-dissipating panel 15 of this example is 4.4 × 0.15 / 5.4 × 100 = 12.2%.
The experiment was performed using a model obtained by modeling this cross section at 1/30 scale, and the experimental apparatus is the same as that shown in FIG.
[0027]
FIG. 8 is a graph showing experimental results. The axes of the graph are the same as those in FIG.
As can be seen from FIG. 8, it can be seen that the B / L is sufficiently exhibiting the wave-absorbing function in the range of 0.1 to 0.3.
And according to this Embodiment, a wave-dissipating function can be exhibited only by providing the wave-dissipating panel 15, and the merit in cost is large.
[0028]
Embodiment 3 FIG.
FIG. 9 is a side view of Embodiment 3 of the present invention. In the present embodiment, an opaque portion 15a is provided at the lower part of the wave-dissipating panel 15 in the second embodiment. Although it has been found that the wave-dissipating effect can be sufficiently exhibited even in the second embodiment, when the wave-dissipating panel 15 is provided in the middle part of the jacket structure, the seabed ground is inclined and the distance to the seabed Therefore, by slightly extending the wave-dissipating panel, it can be made substantially equal to the non-transparent wall 17 of the first embodiment.
[0029]
FIG. 10 is an explanatory diagram of an experiment target according to the third embodiment. FIG. 10A is a cross-sectional view of the experiment target, and FIG. 10B is a view of a part of the wave-dissipating panel 15 as viewed from the front. is there. It is basically the same as FIG. 7 showing the second embodiment except that the opaque portion 15a is provided at the lower part of the wave-dissipating panel 15.
Each dimension of the wave-dissipating panel 15 is as indicated in the drawing. Also, the relationship between l ₁ and l _{2 in} the figure is l ₂ / l ₁ = 0.15. As can be seen from these, the aperture ratio of the wave-dissipating panel 15 of this example is 4.4 × 0.15 / 8.1 × 100 = 8.1%.
[0030]
Here, as in Example 1, the experiment was conducted by modeling at a scale of 1/30. FIG. 11 is a graph showing experimental results. The axes of the graph are the same as those in FIG.
As can be seen from FIG. 11, when the B / L is in the range of 0.1 to 0.3, it can be seen that the wave-breaking function is sufficiently exhibited as compared with the conventional one having no wave-breaking function. In addition, it can be seen that the wave-dissipating performance is improved as compared with the second embodiment. When B / L is set to about 0.17, the wave extinction function is the highest.
According to the present embodiment, the cost can be reduced while improving the wave-dissipating function.
[0031]
In the above embodiment, the quay has been described as an example. However, the present invention is not limited to this, and the same effect can be obtained with the same configuration in other harbor structures such as a seawall. be able to.
[0032]
Further, in the second and third embodiments, the example in which the wave-dissipating panel 15 is provided in the middle part of the jacket structure 7 has been shown. This is because the floor slab 11 has a wide depth of 20 m, so In order to function as a back wall, the position of the wave-dissipating panel 15 is consequently arranged in the middle part of the jacket structure.
Therefore, when the depth of the floor slab 11 is narrow, the position of the wave-dissipating panel 15 is arranged closer to the front of the jacket structure. For example, when the depth of the floor slab is 10 m, the wave-dissipating panel 15 is disposed on the front surface of the jacket structure.
[0033]
【The invention's effect】
As described above, in the present invention, by installing a wave-dissipating panel having an opening in a jacket-type structure in the vertical direction, a harbor structure that can exhibit a wave-dissipating function with a simple structure is obtained. In addition, since the jacket structure is a basic structure, it is possible to install a wave-dissipating panel in advance, which eliminates the need for complicated construction in water and suppresses an increase in cost for adding a wave-dissipating function. it can.
[Brief description of the drawings]
FIG. 1 is a perspective view of a first embodiment of the present invention.
FIG. 2 is a side cross-sectional view of Embodiment 1 of the present invention.
FIG. 3 is an explanatory diagram of a cross section of an experiment target according to the first embodiment of the present invention.
FIG. 4 is an explanatory diagram of an experimental apparatus according to Embodiment 1 of the present invention.
FIG. 5 is a graph showing an experimental result of the first embodiment of the present invention.
FIG. 6 is a side sectional view of Embodiment 2 of the present invention.
FIG. 7 is an explanatory diagram of a cross section of an experiment target according to Embodiment 2 of the present invention.
FIG. 8 is a graph showing an experimental result of the second embodiment of the present invention.
FIG. 9 is a side sectional view of Embodiment 3 of the present invention.
FIG. 10 is an explanatory diagram of a cross section of an experiment target according to the third embodiment of the present invention.
FIG. 11 is a graph showing an experimental result of the third embodiment of the present invention.
FIG. 12 is a side sectional view of a conventional jetty.
FIG. 13 is a side sectional view of a conventional jacket type quay.
FIG. 14 is a perspective view of a jacket structure.
FIG. 15 is a side sectional view of a conventional caisson quay.
FIG. 16 is a side cross-sectional view of a pier having a conventional wave-dissipating function.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Quay wall 5 Pile body 7 Jacket structure 13 Opening part 15 Wave extinguishing panel 17 Impervious wall 19 Back wall

Claims (2)

It is a jacket type structure that does not have a bottom plate under the water surface,
A wave-dissipating panel having an opening portion disposed so that the opening portion is positioned at the water surface in a shape that blocks waves in a vertical direction on the sea side of the jacket-type structure;
An impermeable wall disposed below the wave-extinguishing panel,
A back wall installed behind the wave-dissipating panel so as to block the waves in the vertical direction;
The port structure according to claim 1, wherein the distance B between the back wall and the wave-dissipating panel has a relationship of B / L = 0.1 to 0.3 with the wavelength L of the wave to be wave-dissipated. It is a jacket type structure that does not have a bottom plate under the water surface,
A wave-dissipating panel having an opening portion disposed so that the opening portion is positioned at the water surface in a shape that blocks waves in a vertical direction on the sea side of the jacket-type structure;
An impermeable wall disposed below the wave-extinguishing panel and extending therethrough,
The distance B between the earth retaining work installed on the land side of the jacket structure and the wave-dissipating panel has a relationship with the wavelength L of the wave to be wave-dissipated, and B / L = 0.1 to 0.3. A port structure characterized by that. "

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