JPH0560005B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a breakwater as a sea area control structure for the purpose of creating a calm sea area for harbors, fishing, marine sports, etc.

[Conventional technology and its problems]

As is well known, the role of a breakwater is to restrict the ocean floor and prevent rough waves, as well as to keep the waves that return offshore to a low level, ensuring the safety of ship navigation and port stays.

There are two types of breakwaters: the so-called impermeable type, which completely protects against waves, and the so-called permeable type, which allows part of the waves to pass through. Of these, impermeable breakwaters obstruct the exchange of seawater within the port. This can cause water pollution, red tide, and the death of seafood.

On the other hand, as transparent breakwaters, there are floating breakwaters that are used in bays where the wave height and wave period are small, but these floating breakwaters have a high wave transmission rate due to their instability, and drift sand flows into the port. There is a risk that the sea route will become shallow.

The transparent breakwater is made of reinforced concrete.
There is a hybrid embankment using caissons, and Figures 6 and 7
As shown in the figure, it is also possible to form slits 17 in the front and rear walls of the caisson 16 facing the inside and outside of the embankment, but in this case, the inside of the caisson 16 will be completely hollow, so only the front and rear sides of the embankment will be formed. It cannot be said to be sufficient as it does not have the effect of controlling waves and drifting sand.

The purpose of the present invention is to eliminate the disadvantages of the conventional example,
In addition to greatly reducing the wave force that the embankment receives,
To provide a highly stable wave-dissipating levee that allows slow flow to flow smoothly in a port to enable exchange of seawater and effectively prevents the inflow of drifting sand.

[Means for solving problems]

In order to achieve the above object, the present invention includes a box-shaped caisson made of reinforced concrete installed on a foundation on the seabed, and a plurality of bulkheads made of reinforced concrete arranged in parallel on the front and rear walls of the caisson. In addition, a large number of window-like penetration holes were formed in a staggered manner between the walls, rubble was piled up in a mountain shape inside the caisson, and a stepped reinforced concrete parapet was installed on the upper surface of the caisson's ceiling wall. The main points are as follows.

[Effect]

According to the present invention, penetration holes are provided in the front and rear walls and bulkheads of the caisson, through which part of the rough waves from the open sea pass through.However, since the penetration holes are shifted from each other, the passage of the waves is prevented. The reflectance of the water is reduced step by step, and the energy is absorbed and the water flows into the port as a slow flow. In this way, the slow flow flows smoothly and the seawater can be exchanged. On the other hand, the piles of rubble piled up inside the caisson stabilize the caisson, and combine with the front and rear walls and bulkheads to prevent drifting sand from flowing into the port. Make sure to prevent the inflow.

Furthermore, the parapets on the embankment divide the shock wave force into several parts and impact the vertical surface, and when falling, the impact is divided into several parts and hits the horizontal surface, so the energy of the waves can be effectively reduced.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figure 1 is a vertical side view showing one embodiment of the wave-dissipating levee of the present invention, and 1 in the figure shows a box-shaped caisson that is installed on rubble ground 2 buried in the seabed as a foundation and forms the levee body. show. This caisson 1 is made of reinforced concrete, and before constructing its ceiling wall, the front wall 11
and the rear wall 15 with substantially equal intervals between the front and rear walls 1.
Partition walls 12, 13, 1 of appropriate thickness parallel to 1, 15
Arrange 4. These bulkheads 12 to 14 are also made of reinforced concrete, and if they are ordered including the front wall 11 of the caisson 1, and the bulkheads 12 and 14 are called the even-numbered bulkheads and the bulkhead 13 is called the odd-numbered bulkhead, the caisson 1 The front wall 11, the rear wall 15, and the odd-numbered partition walls 13 are formed into a lattice body having a large number of window-shaped transparent holes 10 located horizontally so that they can be seen through (see Fig. 2). The partition walls 12 and 14 are formed into a lattice structure having the transmission holes 10 of the same shape as the odd-numbered walls 13 but at different positions, and the even-numbered partition walls 12 and 14 have the transmission holes 10 in the same position. (See Figure 3). That is, in the front and rear walls 11, 15 and the partition walls 12 to 14, window-shaped transmission holes 10 are arranged in a staggered manner for each wall.

Note that it is also possible to form the opening portion of each transmission hole 10 into a tapered shape, or to change the shape and dimensions. Moreover, the even number of all bulkheads can be increased or decreased depending on the construction row of the wave-dissipating levee.

Further, rubble 3 is deposited in a mountain shape inside the caisson 1. Immediately after the flexi-reinforced concrete caisson 1 is installed on the rubble ground 2, this rubble 3 is thrown into the caisson 1 to ensure stability.

Reference numeral 4 in the figure indicates a parapet wall that will be constructed along the open sea side edge of the ceiling wall of the caisson 1 after the construction of the ceiling wall is completed.The parapet wall 4 is made of reinforced concrete and has the shape of multiple steps, with the stepped surface facing the open sea. did.

Further, in order to increase the stability of the caisson 1, a concrete block 7 for preventing scour is provided on the front surface of the base of the caisson 1 as necessary.

By the way, since caisson 1 is lighter than the filled caisson, the required width of the embankment must be wider, but the 4th caisson
The front wall 11 and rear wall 15 of the caisson 1 as shown in the figure.
A sleeve pipe 5 is buried upright in each corner of the caisson 1, and immediately after the caisson 1 sinks into the sea,
Steel pipe piles 6 are passed through the sleeve pipes 5, and their tips are inserted into the ground to a required length, and the steel pipe piles 6 are filled with concrete.

In this way, it is possible to increase the stability of the caisson 1 by imparting shear force due to sliding to the steel pipe pile 6, and as a result, it is possible to suppress the required width of the cross section of the embankment body of the caisson 1 to a certain degree. Become.

Next, to explain how to use it, the caisson has a wide embankment body due to its weight, but as shown in Fig. 5, it can be used as a pier, and a fender 19 is attached to the port side to support the ship 20. It can be used as a mooring quay for mooring.

Incidentally, the impactful high-speed waves that come from the open sea collide with the front wall 11 of the caisson 1 and are blocked, but some of the waves pass through the transmission holes 10 in the front wall 11. When the water reaches the next even-numbered partition wall 12, the permeation holes 10 of the partition wall 12 are misaligned, so the liquid collides with it and then branches into the permeation holes 10 near it. Then, the wave flow that has passed through the even-numbered partition wall 12 collides with the next odd-numbered partition wall 13, and the wave flow that has passed through the nearby transmission hole 10 and is split off collides with the next even-numbered partition wall 14.
Thereafter, the flow repeatedly collides with the partition wall and is divided into the permeation hole 10, and finally flows into the port through the permeation hole 10 in the rear wall 15 of the caisson 1. , the collision with the rear wall 15 gradually absorbs the wave energy and eliminates the wave force.

On the other hand, the mountain-shaped rubble 3 inside the caisson 1 increases the weight of the embankment body, and the number of permeation holes 10 is gradually reduced in the open sea side half of the caisson 1.
The wave forces applied to the partition walls 12 and 13 are equalized. In addition, the transmitted wave current collides with the front slope of the rubble 3, and a downward component of the wave force is generated, which helps the stability of the embankment body.
In addition, since the number of transmission holes 10 is gradually increased in the port side half of the caisson 1, as the wave flow passes through the partition wall 14 and the transmission holes 10 in the rear wall 15 of the caisson 1, the wave force is dispersed, reduced, and eliminated. .

Furthermore, the slope of the rubble 3 on the open sea side prevents drifting sand from entering the caisson 1 with waves, thereby preventing drifting sand from flowing into the harbor.

On the other hand, the parapet 4 on the caisson 1 side receives the horizontal impact force of the shock wave by dividing it into a plurality of vertical surfaces at each stage, and further receives the vertical impact force of the falling wave by the horizontal surface at each stage. It protects the safety of the levee body by reducing wave energy and reducing the maximum wave force that the levee body receives.

〔Effect of the invention〕

As described above, the wave-dissipating levee of the present invention has the effect of transmitting a part of the rough waves hitting the levee body and suppressing the reflected waves caused by the impact to a small level. In the process of passing through the intermediate bulkhead, wave energy is gradually absorbed, making the inside of the port a calm sea area, and changing the ocean current to a slow one, exchanging seawater inside and outside the levee.
This prevents water quality from deteriorating within the port.

Furthermore, the rubble inside the caisson and the stepped reinforced concrete parapet on the top of the caisson increase the weight of the embankment body, making it highly stable, and the parapet effectively reduces the maximum wave force that the embankment receives. Therefore, economical design is possible.

Moreover, the levee body has a simple overall structure and is easy to construct, so it has the advantage of lower construction costs.

On the other hand, the bulkheads and rubble inside the caissons serve as artificial fishing reefs, which are useful for fisheries, and the stepped parapets can also be used as benches for fishing or marine sports when the open sea is calm, contributing to the leisure industry. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing one embodiment of the wave-dissipating bank of the present invention, FIG. 2 is a sectional view taken along the line A-A in FIG.
The figure is a sectional view taken along line B-B, FIG. 4 is a side view of another embodiment, FIG. 5 is a vertical sectional side view showing an example of use, FIG. 6 is a side view of a conventional example, and FIG. 7 is a front view of the same as above. It is a diagram. 1...Caisson, 2...Rubble ground, 3...Rubble, 4...Parade wall, 5...Sleeve pipe, 6...Steel pipe pile, 7...Concrete block, 10...Permeation hole, 11...Caisson front Wall, 12... Even numbered partition wall, 13... Odd numbered partition wall, 14... Even numbered partition wall,
15... Caisson rear wall, 16... Caisson, 17
...slits, 18 ... battlements, 19 ... fenders,
20...Ship.

Claims (1)

[Claims] 1 A box-shaped caisson made of reinforced concrete is installed on a foundation on the seabed, and a plurality of reinforced concrete bulkheads are arranged in parallel on the front and rear walls of the box-shaped caisson, and transparent windows are formed in the front and rear walls of the caisson and the bulkhead. It is characterized by having a large number of holes lined up in a staggered manner between the walls, piles of rubble within the caisson, and reinforced concrete parapets arranged in a stepped manner on the upper surface of the ceiling wall of the caisson. Wave bank.