JP2001040632A - Caisson - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a caisson which eliminates incident waves and reduces reflected waves, and allows seawater to pass therethrough from a bay to open sea, or vise versa. SOLUTION: A caisson 1 is comprised of a caisson main body 2, a retarding chamber 2B, and a flow passage opening 2C. The caisson main body 2 is formed into a hollow body with a void interior, and has a wall surface facing open sea, in which a plurality of openings 2a are formed in a manner tapering down from an external surface to the interior of the main body 2. The retarding chamber 2B is formed per the plurality of openings 2a which are horizontally arranged in the caisson main body 2. The flow passage opening 2C is formed at a portion of the caisson main body 2, which faces the bay, and communicates the retarding chamber 2B. The retarding chamber 2B is provided with a lower surface gradient portion 2Ba formed into a descending gradient toward one wall surface, an upper surface gradient portion 2Bb formed into an ascending gradient toward the one wall surface, and a plurality of projections 2Bc formed on the lower and upper surface gradient portions 2Ba, 2Bb.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caisson capable of distributing seawater between a bay and the open sea together with wave extinction.

[0002]

2. Description of the Related Art In a harbor, a breakwater is provided to separate the inside of the bay from the open sea and to prevent waves from entering the bay. As shown in FIG. 4, a conventional breakwater has a predetermined foundation rubble 40 on the sea floor and an asphalt mattress 4 on it.
1 are laid in order and, for example, in the state shown in the figure,
The partition wall 42a and the outer surface 42b, which divide the interior into three layers, are made of concrete. The three layers are filled with sand 42c, the main body is sunk, and the upper concrete 42d is cast on site to a predetermined size. The breakwater main body 42 is constructed.

[0003] The breakwater body described above is different from a caisson in a narrow sense, but is generally called a caisson in a broad sense. Therefore, in the present application, the breakwater main body is hereinafter referred to as a caisson.

[0004]

However, in the conventional caisson, since the side wall facing the seawater is vertical, when a wave enters the caisson, the wave bounces off the side wall of the caisson and the height of the incident wave increases. On the other hand, the wave height is almost twice as high and reflected. When the wave height is large, unexpected waves may act on a ship navigating in the open sea or a ship approaching the shore. In severe cases, an event such as overturning of the ship may occur.

Further, the conventional caisson has a problem that the circulation of seawater between the bay and the open sea is completely interrupted, and the seawater does not circulate between the bay and the open sea, so that the seawater in the bay is spoiled. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a caisson that eliminates an incident wave to reduce a reflected wave and that enables seawater to flow between a bay and the open sea. Aim.

[0007]

In order to achieve the above-mentioned object, a caisson according to the present invention is formed such that a caisson body having a hollow inside is tapered from the outer surface to the inside on one wall surface facing the open sea. A plurality of openings, a single water-supply chamber formed therein corresponding to the plural openings, and a distribution port communicating the water-recharge chamber with the inside of the bay. It has a lower surface gradient portion that has been made downward slope, an upper surface gradient portion that has been made upward gradient toward one side surface, and a plurality of protrusions provided on each of the lower surface gradient portion and the upper surface gradient portion. is there. By doing so, it is possible to suppress as much as possible the waves that bounce off the caisson.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A caisson according to the present invention comprises a caisson body having a plurality of openings formed in one wall facing the open sea from the outer surface to the inside and having a hollow inside and a caisson body. A water-supply chamber formed one corresponding to a plurality of openings positioned in the horizontal direction of the caisson body in the main body, and a distribution port formed in a part of the caisson body facing the bay and communicating with the water-reduction chamber. In the water retarding chamber, a lower surface inclined portion that is inclined downward toward one wall surface, an upper surface inclined portion that is inclined upward toward one wall surface, and provided on each of these lower surface inclined portion and upper surface inclined portion And a plurality of projections.

According to the above configuration, the wave introduced into the caisson body first has a flow contraction effect at the tapered opening from the outer surface to the inside. The speed increases, and the flow of the wave that has passed through the opening slows down in a water retarding chamber, which will be described later. At this time, energy loss occurs and the wave is eliminated.

[0010] In the water-reducing chamber, the upper surface gradient portion and the lower surface gradient portion reduce the area to the other wall surface in the caisson main body. Since the seawater flows quickly and the projections are formed on the upper and lower slopes, the flow is disturbed, energy loss of the waves occurs, and the waves are further eliminated.

Then, the wave (seawater) which has been wave-dissipated and has reached the other wall surface of the water retarding chamber flows from the distribution port into the bay, and when the wave is drawn, the seawater in the bay flows from the distribution port to the open sea. . As described above, since seawater can be exchanged between the bay and the open sea, the seawater in the bay can be prevented from being spoiled.

Further, in the present invention, in the above structure, the tops of the plurality of projections respectively provided on the lower surface gradient portion and the upper surface gradient portion are tilted toward the inner wall surface of the caisson body. By doing so, the projections become caught when the waves are pulled, whereby the flow is disturbed even when the waves are pulled, and the wave is more reliably eliminated.

Further, according to the present invention, in the above structure, the plurality of openings are arranged in multiple stages in the vertical direction of the caisson main body, and the water-reducing chamber is multistaged in the vertical direction of the caisson main body corresponding to the arrangement of these openings. In the arrangement, the rear surface side of the upper surface slope portion of the uppermost water chamber is hollow, and a plurality of openings communicating with the hollow are formed in the upper surface slope portion of the upper water stage. By doing so, it is possible to reliably function regardless of the level of the water level, and when the water level is high, the wave crest can be eliminated by the opening formed in the upper slope section of the uppermost water-reducing chamber.

[0014] Further, the present invention, in any one of the above-described structures, is provided with a panel in which a hole for adjusting the amount of seawater flowing is formed in a flow path connecting the water retarding chamber and the flow opening. is there. In this way, the amount of seawater flowing between the bay and the open sea can be set according to the size of the bay.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a caisson according to the present invention will be described below with reference to FIGS. 1 and 2 show a schematic configuration of a caisson of the present invention. FIG. 3 shows a caisson installation procedure of the present invention. The caisson 1 of the present invention is installed on the shore so as to partition the inside of the bay from the open sea, and prevents waves from entering the bay, and is configured as follows.

Reference numeral 2 denotes a caisson body having a plurality of openings 2a tapered from the outer surface to the inside on one wall surface facing the open sea and having a hollow inside. For example, the outer surface is formed of a so-called hybrid panel in which a steel plate and reinforced concrete are integrally laminated on a foundation base. In the present embodiment, the openings 2a are formed, for example, in a state in which the openings 2a are horizontally aligned in two stages, an upper stage and a lower stage.

Further, the caisson body 2 is formed in two stages corresponding to the plurality of openings 2a located in the horizontal direction, for example, corresponding to the upper opening 2a and the lower opening 2a. The free water chambers 2A and 2B are formed. Also,
In the caisson main body 2, a flow opening 2 </ b> C is formed in a part of the caisson main body 2 facing the inside of the bay, and the communication ports 2 </ b> A and 2 </ b> B communicate with each other via the flow path 2 b.

The water-reducing chambers 2A and 2B have lower slopes 2Aa and 2Ba inclined downward toward the wall surface of the caisson body 2 having the opening 2a formed therein, and the wall surface of the caisson body 2 having the opening 2a formed therein. And upper surface gradient portions 2Ab and 2Bb which are inclined upward.

In these water-reducing chambers 2A and 2B, the uppermost water-reducing chamber 2A has a hollow caisson body 2 on the back surface side of the upper sloped portion 2Ab, and a plurality of openings 2Ad communicating with the hollow are formed in the upper sloped portion 2Ab. Have been. On the other hand, the lower water-retention chamber 2B is provided on the surface of the upper sloped portion 2Bb, the top of which is inclined toward the inside of the bay of the caisson main body 2, and, for example, on the open sea side where the opening 2a in the caisson main body 2 is formed. A plurality of protrusions 2Bc are arranged in a row from the wall to the inside of the bay.
Are formed.

Also, the lower sloped portion 2A of the water-reducing chambers 2A and 2B.
Each of the a and 2Ba has its top inclined to the inside of the bay of the caisson body 2 and, for example, forms a line from the wall on the open sea side where the opening 2a is formed in the caisson body 2 to the inside of the bay. A plurality of projections 2Ac and 2Bc are formed.

Reference numeral 3 denotes a panel provided inside the caisson main body 2 in a flow path 2b connecting the water retarding chambers 2A, 2B and the circulation port 2C, and having a plurality of holes 3a for adjusting the amount of seawater flowing. It is. In this embodiment, the panel 3 is provided near the water-reducing chamber 2A in the flow path 2b and at the boundary between the flow path 2b and the water-reducing chamber 2B.

The caisson 1 having the above structure is laid on the seabed as shown in FIG. First, a caisson 1 having a predetermined size is constructed, and thereafter, a water blocking material 4 shown in FIG. 3A for closing the opening 2a is fitted and attached. Although not shown, the water-stopping material 4 is provided with a wire for removing and recovering the caisson 1 from the opening 2a when the caisson 1 described below is laid down. And now, in this state, air is contained in the water play chambers 2A and 2B of the caisson 1.

Then, as shown in FIG. 3 (b), the caisson 1 is towed to a predetermined location, and then water (seawater) flows through an inflow port 5 formed on the upper surface of the caisson main body 2 as shown in FIG. 3 (c). Is filled, the water pressure of the filled water (seawater) is increased, and the water-stopping material 4 is removed from the opening 2a by pulling the above-mentioned wire. As a result, the caisson 1 gradually sinks to the seabed, and FIG. The caisson 1 is submerged on the sea floor as shown in ()).

In the caisson 1, when a wave enters from the opening 2a, the opening 2a is tapered from the outer surface to the inside. , 2B, the lower surface slope 2
In Aa, 2Ba and upper surface gradient parts 2Ab, 2Bb,
In the place where the projections 2Ac and 2Bc are arranged, the lower surface slope 2A
Since the distance between a and 2Ba and the upper sloped portions 2Ab and 2Bb is narrow, the flow contraction effect also occurs here.

When the wave passes over the protrusions 2Ac and 2Bc, the lower surface gradient portions 2Aa and 2Ba and the upper surface gradient portion 2A
Since the interval between b and 2Bb is widened, a vortex is generated which is orthogonal to the direction in which the wave advances and retreats, the flow is released, the flow velocity is reduced, and the wave is eliminated. Also, at this time, in the upper water-reducing chamber 2A,
A wave that is going to jump upward flows into the hollow at the top of the caisson body 2 from the opening 2Ad and is eliminated.

Further, the lower sloped portion 2Aa of the water retarding chamber 2A,
In the lower slope section 2Ba and the upper slope section 2Bb of the water retarding chamber 2B, the projections 2Ac and 2Bc disturb and cancel the waves. And the water retarding chambers 2A and 2B are provided with the lower surface gradient portions 2Aa,
Since the area is reduced toward the inner side of the bay in the caisson body 2 by the 2Ba and the upper sloped portions 2Aa and 2Bb, seawater quickly flows into the flow path 2b due to the flow contraction effect as described above.

The seawater that has passed through the water retarding chambers 2A and 2B flows into the bay from the distribution port 2C through the flow path 2b while the flow rate is adjusted to the holes 3a of the panel 3. And when a wave is drawn, the distribution port 2C, the flow path 2b, and the retarding chamber 2
Seawater flows into the open sea via A and 2B. As described above, since the seawater in the bay and the seawater are exchanged, the seawater in the bay is prevented from being rotten due to being blocked from the sea.

As described above, the caisson 1 causes the wave to flow into the caisson main body 2, and the opening 2a, the water-reducing chambers 2A and 2B,
Since the waves are eliminated by the projections 2Ac, 2Bc and the opening 2Ad, the wave height becomes larger with a caisson, which affects a ship navigating in the open sea or a ship trying to berth, as in the past. In addition, since the seawater between the inside of the bay and the outside sea is circulated by the circulation port 2C, it is possible to prevent the seawater in the bay from being spoiled.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the shape of the opening 2a may be not a rectangle but a circle, for example.
The number and the number of stages are not limited to two. At that time, the water chamber 2A (2B) is appropriately increased or decreased according to the number of stages of the opening 2a. Further, the protrusions 2Ac and 2Bc may not be arranged in a row, and may be provided independently, for example, one by one. Even in such a case, the same operation and effect as the above embodiment can be obtained.

[0030]

As described above, the caisson according to claim 1 of the present invention has a plurality of openings formed in one wall surface facing the open sea in a tapered shape from the outer surface to the inside, and the inside is hollow. A water retarding chamber formed in the caisson main body, one for the plurality of openings located in the horizontal direction of the caisson main body,
And a distribution port formed in a part of the caisson body facing the bay so as to communicate with the water retarding chamber, and the water retarding chamber is inclined downward toward one wall surface and upward toward the one wall surface. It is composed of a sloped upper surface gradient portion and a plurality of protrusions provided on each of the lower surface gradient portion and the upper surface gradient portion.

With the above structure, the opening, the upper and lower slopes of the water retarding chamber, the projections, and the projections can be operated to surely cancel waves, so that a ship navigating in the open sea, By preventing the effect of waves on the vessel that is to be attempted, and by forming a distribution port, the distribution of seawater in the bay and the open sea is not completely shut off, and the seawater always flows between the bay and the open sea. Due to the circulation, the seawater in the bay can be prevented from spoiling.

In the caisson according to a second aspect of the present invention, in the above configuration, the tops of the plurality of projections provided on the lower sloped portion and the upper sloped portion, respectively, are directed toward the bay inner wall surface of the caisson body. The tilting allows the protrusions to catch in the direction in which the waves are drawn, further disturbing the flow, and therefore, the wave extinction is more reliable.

In a caisson according to a third aspect of the present invention, in any of the above-described configurations, the plurality of openings are arranged in multiple stages in the vertical direction of the caisson main body, and the arrangement corresponds to the arrangement of these openings. In the case where the water retarding chambers are arranged in multiple stages in the vertical direction of the caisson body, the back side of the upper surface gradient part of the uppermost water retarding chamber is hollow, and an opening communicating with the hollow is formed in the upper surface gradient part of the uppermost water retarding chamber. Therefore, it is possible to function reliably regardless of the level of the water level, and when the water level is high, the wave front can be eliminated by the opening formed in the upper surface gradient portion in the uppermost water-reducing chamber.

In the caisson according to a fourth aspect of the present invention, in any one of the above-described structures, a hole for adjusting the amount of seawater flowing is formed in a flow path connecting the water retarding chamber and the flow opening. Since the panels are provided, the amount of seawater flowing between the bay and the open sea can be set according to the size of the bay.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a caisson of the present invention.

FIGS. 2A and 2B show the configuration of the caisson of the present invention, wherein FIG. 2A is a view from the open sea side, FIG. 2B is a partial cross-sectional view of FIG. 2A, and FIG. 2C is an enlarged view showing the shape of an opening. is there.

FIG. 3 shows a procedure for installing a caisson of the present invention, wherein (a) shows a water-stopping material used when installing the caisson of the present invention;
(B) is a diagram showing a state in which the caisson of the present invention is towed, (c) is a diagram showing a state in which the caisson of the present invention is sinking, and (d) is a diagram in which the caisson of the present invention is sunk on the seabed. It is a figure showing a state.

FIG. 4 is a view showing a conventional caisson.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Caisson 2 Caisson main body 2a Opening 2b Flow path 2A (uppermost stage) Suction chamber 2Aa Lower surface slope 2Ab Upper surface slope 2Ac Projection 2Ad Opening 2B Water play chamber 2Ba Lower surface slope 2Bb Upper surface slope 2Bc Projection 2C Distribution port 3 Panel 3a hole

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Tanaka 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka F-term in Hitachi Zosen Corporation 2D018 BA12

Claims (4)

[Claims] 1. A caisson that is installed on a coastal area so as to separate the inside of a bay from the outside sea and prevents waves from entering the inside of the bay, and is tapered from an outer surface to an inside on one wall surface facing the outside sea. A caisson main body having a plurality of openings formed therein and having a hollow inside, and a water-reservoir chamber formed in the caisson main body corresponding to the plurality of openings positioned in the horizontal direction of the caisson main body. And a distribution port formed in a part of the caisson body facing the bay and communicating with the water-reducing chamber, wherein the water-reducing chamber has a lower-side slope part that is inclined downward toward the one wall surface, A caisson comprising: an upper slope portion inclined upwardly toward one wall surface; and a plurality of protrusions provided on each of the lower slope portion and the upper slope portion. 2. The caisson according to claim 1, wherein the tops of the plurality of projections respectively provided on the lower surface gradient portion and the upper surface gradient portion are tilted toward the inner wall surface of the caisson body. 3. A caisson according to claim 1 or 2, wherein a plurality of openings are arranged in multiple stages in the vertical direction of the caisson body, and a water-reservoir chamber is arranged in multiple stages in the vertical direction of the caisson body in accordance with the arrangement of the openings. A caisson wherein, when arranged, the back surface side of the upper surface gradient portion of the uppermost water-reducing chamber is hollow, and a plurality of openings communicating with the hollow are formed in the upper surface gradient portion of the uppermost water-reducing chamber. 4. The panel according to claim 1, wherein a panel formed with a hole for adjusting an amount of seawater flowing is provided in a flow path connecting the water retarding chamber and the flow opening. The caisson described.