JPS6294607A - Wave dissipation caisson and its manufacture - Google Patents

Abstract

PURPOSE:To permit incoming waves to be broken by a method in which front and back blades are continuously set in a state of being turned at 90 deg. mutually in the incoming direction of waves and the bottom sides of the blades are fixed to the columns and frames of a skeleton. CONSTITUTION:Two sets of blades 2 are set in a box-like skeleton 1 having a bottom face 5 and consisting of only edge lines. The blades 2 consists of a set of two blade pieces of a trapezoidal from, which top sides are connected with each other and distances between the bottom sides is expanded. The two sets of the blades 2 are connected at their tops in state of being turned at 90 deg. mutually, and bottoms of the blades 2 are fixed to the columns and frames of the skeleton 1. Holes 4 are also provided in the blades 2 and bottom faces 5. in coming waves are vertically and bilaterally dispersed by the front and back blades 2 to come in turbulent flows and are finally broken.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission type wave-dissipating caisson that disperses and eliminates waves, and a method for manufacturing the same.

[Prior art] There are various types of wave-dissipating structures installed along the coastline, and wave-dissipating blocks such as relatively small-scale structures and wave-dissipating blocks with a simple structure are molded in large quantities by factory production, etc. They were transported to the site and used by arranging or stacking them as appropriate.

[Problems to be solved by the invention] By the way, when carrying out new construction, repair, or improvement work on ports, fishing ports, general beaches, rivers, coastal roads, fishery structures, etc., the scale of installation of wave-dissipating caissons gradually increases. , something that is permanent rather than something that is ad hoc is desired.

Although some methods have appeared that can somewhat meet these demands, they are still not sufficient.

For example, 3 x 3 x 4.5 m of wave-dissipating caisson
.

When installing a device measuring 5 x 5 x 7.5 m or more in a necessary location, stability is required more than ever due to the size or weight of the outer casing.

Specifically, at this scale, the desired shape is obtained by forming the foundation in advance and pouring concrete on top of it.
The structural integrity of each part was not necessarily completely achieved.

[Means for Solving the Problems] The present invention was arrived at as a result of careful consideration of the surrounding circumstances as described above, and is a box-shaped skeleton l having a bottom surface and consisting only of ridge lines. A wing body 3.3 in which two trapezoidal wing pieces 2.2" and 12.12" apex are fitted together.
Two sets of 2.2° angles are rotated 90 degrees to each other and the top parts are joined together, and the bases of each wing piece 2.2° are fixed to each beam of the skeleton, respectively. A wave-dissipating caisson is formed by drilling an appropriate number of holes 4 in the bottom surface 5 of the skeleton, and a reinforced concrete bottom plate portion having a notch is formed by pouring concrete to form this wave-dissipating caisson. Then, after assembling reinforcing bars corresponding to the column, upper traverse, and wing part, the wing frame, left and right side frames, front frame, rear frame, and upper frame are formed, and concrete is poured. The present invention relates to a method for manufacturing a wave-dissipating caisson, which comprises cutting and removing the frame.

[About this wave-dissipating caisson] As shown in Figs. 1 and 2, inside the box-shaped skeleton l with the bottom left, there are trapezoidal wing pieces 2.2 as shown in Fig. 2.
3. Wing body with the top sides of 12.12 and 12.
A structure in which the blades 3' are rotated and shifted by 90 degrees and the top parts are joined together is built in, and the bottom of each wing piece is fixed to each beam of the skeleton.

A hole is also made in the bottom surface 5 of the box-shaped skeleton 6
In the figure, two square holes are drilled in each hole, but they could also be circular, and in addition, a suitable number of holes 4 are drilled in the blades 2.2' and 12.12''. There is.

Since the present invention is configured in this way, waves that enter from the direction of the arrow not only move up and down in the first half wing body 3, but also pass through the holes 4 at 2° and 2° of each wing piece, and can also move in the left and right directions. proceed.

The wave that passed through the first half wing body 3 is transmitted to the following half wing body 3°.
But in the same way, the wave flow is dispersed vertically and horizontally. Therefore, the waves become turbulent within the skeleton and are almost completely dissipated.

[Function] Since the wave-dissipating caisson according to the present invention has the above-described configuration, when waves generated offshore propagate and approach the shore or marine structure, the wave-dissipating caisson according to the present invention can spread not only vertically but also horizontally by the opening. By dispersing it, the wave energy can be eliminated or extremely attenuated.

More specifically, when the wave-dissipating caisson according to the present invention is used as a breakwater or seawall, various experiments were conducted on wave reflection by changing the water depth, wave height, and period, with the incident wave height as Hl and the reflected wave height as HR. (Healey
) calculation from the old Hla Sumire + Hlin formula, HR = 0.2 to 0.4 when used as a breakwater, and HR = 0.35 to 0.5 when used as a seawall. It was confirmed that it could be sufficiently reduced. Furthermore, when looking at the wave transmissibility Hl at the rear surface of the embankment body, it was confirmed that KT was within the range of 0.1 to 0.3.

[Example] (Example 1) As shown in FIGS. 3 and 4 (side view), 12. O
cmX 12. OcmX 18. A wave-dissipating caisson model with a size of Ocm was used.

This material is made of aluminum alloy, and its specific gravity is 2.
48, volume is 1449c,rn'', specific gravity is 3 in air
．． 61 Kg, and 2.15 Kg in water. This model was installed in an experimental two-dimensional wave-making channel with a total length of 30 m, and an experiment was conducted. In addition, various conditions are as follows.

(Leave below) Water level (height from the top of the caisson to the water surface he) Experiment (
cm) Corresponding value of actual scale (■) B, OQ
1.503.00
0.75 o, o o, o.

Wave period (seconds) 0.80 4.001.20
6.001.80
8.001°90 9.50 waves
High (c+a)
(+s)1.85 0.
As a result of conducting experiments and measuring the radiance while changing various factors such as 50S S 1.94 4.90 or more,
The behavior shown in Figure 5 was obtained.

In this case, the incident wave height was converted to the offshore wave equivalent wave height HO using the shallow water coefficient KS, and the relationship between the relative crest height he/HO and the reflectance KR was determined using the offshore wave waveform gradient [0/LO as a parameter.

Furthermore, using the same experimental equipment, we conducted an experiment on the wave transmissibility, and the results are shown in Figure 6.

On the other hand, various specifications for a seawall constructed by stacking a plurality of wave-dissipating caissons of the present invention were investigated, and the results shown in the following table were obtained.

In addition, the embankment body was placed on the gravel mound of slope device 2, and experiments were conducted on two-tiered and three-tiered embankments.

The water depth is the distance from the top of the caisson, and the results observed to obtain the Hudson formula KP value from the measurement results under each condition are shown in Figures 7 and 8.

Figures 5 and 6 both show the top tier of the seawall with a single row stacking type; ),
Also, almost the same results were obtained in the case of a vertical embankment (same row from top to bottom).

(Example 2) The procedure for creating an actual-scale wave-dissipating caisson is shown.

l) Reinforcement assembly Assemble the reinforcing bars for forming the bottom plate part, column part, upper twill part, and wing piece part from the preformed bottom plate part.

2) Concreting the bottom plate.

3) After about 20 to 24 hours have elapsed after pouring, the bottom hole frame is removed.

4) Assemble the lower wing frame and install it in the specified position on the bottom plate.

5) Assemble formwork for both left and right sides, front, and back.

6) Assemble the upper frame.

7) Place concrete.

In this case, it is preferable that Ock=210 Kg/crn', slump 8 to 12 cm, and coarse aggregate maximum dimension of about 2511 mm.

8) Air conditioning is performed using a vibrator, and the concrete is poured and cured to prevent the formation of slabs.

9) After about 48 to 96 hours have elapsed after pouring, remove the frame.

By taking the above steps, a wave-dissipating caisson is formed.

[Effects of the Invention] The wave-dissipating caisson obtained by the present invention has a certain shape, so that when stacked or lined up, it forms an orderly form and blends easily with natural spaces. Since it is formed in advance, molding can be easily performed. Furthermore, since it has such a space, it also has a great side effect of being able to effectively catch fish when placed in the sea.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of the wave-dissipating caisson of the present invention, FIG. 2 is a perspective view showing only the internal structure of the wave-dissipating caisson shown in FIG. 1, and FIG. Figure and 4th
The figures are a plan view and a side view of a wave-dissipating caisson formed according to the present invention, and Fig. 5 is a graph showing the transmissibility. Figure 6 is a graph showing the reflectance, in the section of the offshore breakwater,
Figure 7 shows the distribution of reflectance (0.2 to 0.4), and
The figure is a graph showing the distribution of the wave height transmissibility (0.2 to 0.4). 1... Skeleton, 2.2゛, 12.12°... Wing piece, 3.3'.
... Wing body, 4 ... Hole, 5 ... Bottom surface

Claims (1)

[Claims] 1. Two airfoils each formed by extending the bases of two trapezoidal airfoils in a box-shaped skeleton consisting only of ridgelines and fixing the tops of the airfoils to each other by 90 degrees in the direction of wave ingress. A wave-dissipating caisson characterized by being arranged in a continuous manner rotated about a degree axis, with each base fixed to a skeleton column or crosspiece. 2. The wave-dissipating caisson according to claim 1, wherein the two wing bodies are arranged with their heads adjacent to each other. 3. The wave-dissipating caisson according to claim 1, characterized in that the two wing bodies are arranged with their heads facing the reflection direction. 4. The wave-dissipating caisson according to claim 1, wherein the two wing bodies are arranged with their heads facing in the same direction. 5. Two sets of wing bodies 3, 3', in which the top sides of two trapezoidal wing pieces 2, 2' and 12, 12' are aligned with each other, are placed inside a box-shaped skeleton 1 having a bottom surface and consisting only of ridge lines. Each wing piece 2 is rotated 90 degrees and joined together at the top.
, 2' and 12, 12' are fixed to each beam of the skeleton, respectively, and each of the wing pieces 2, 2' and 12
, 12' and a suitable number of holes 4 in the bottom surface 5 of the skeleton.
A wave-dissipating caisson characterized by being opened. 6. A reinforced concrete bottom plate with cutouts is formed by pouring concrete, and on top of it are pillars, upper ridges,
After assembling the reinforcing bars corresponding to the wing segments, the wing frame, left and right side frames, front frame, back frame, and upper frame are formed, concrete is poured, and the frames are then removed. A method for manufacturing a wave-dissipating caisson.