JPH0125843B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a wave-dissipating structure that is installed in front of a breakwater or seawall in a port and consumes wave energy. This invention relates to a wave-dissipating structure for installation in a water-dissipating structure.

(Conventional technology) Generally, large wave-dissipating structures installed in front of seawalls and breakwaters use large concrete caissons, which have an internal space and a large number of through holes leading to the internal space in the front. Many models with an opening have been proposed and installed.

(Problem to be Solved by the Invention) This conventional large wave dissipating structure using a caisson uses the weight of the caisson to withstand wave impact, so it uses wave energy in the most efficient manner. Even if it is consumed, it must have a large weight to prevent it from sliding and falling, and therefore a foundation with a large supporting capacity is required when installing it on the seabed, especially on soft ground. The problem is that construction work is required, and the width of the caisson in the wave intrusion direction must be increased to reduce the load per unit area on the ground, which increases construction costs and takes a long time. It was hot.

In view of the above-mentioned conventional problems, the present invention has a wave-dissipating structure that is lightweight as a whole, does not sink even when installed on soft seabed ground, and does not slide or overturn due to wave force. The object of the present invention is to provide a wave-dissipating structure that can obtain a wave-dissipating effect comparable to that of a body.

(Means for Solving the Problems) Therefore, in order to solve the above-mentioned problems, the present invention includes an arch-shaped wall body having a substantially semi-cylindrical shape, and integrally provided at both ends of the arch-shaped wall body. A precast block for wave dissipation is provided with a footing formed in the arched wall body, and a large number of through holes formed on one side of the arched wall body, with the side having the through holes facing in the direction of wave propagation. A wave-dissipating structure was constructed by installing a large number of precast blocks facing each other on the seabed and connecting them to form a continuous approximately semi-cylindrical wave-dissipating wall and an internal space.

(Function) Since this wave-dissipating structure has a continuous substantially semi-cylindrical shape, the impact force caused by the waves hitting the front surface acts in the direction of the center of curvature of the substantially semi-circular shape, and therefore,
It is distributed over the entire bottom surface of the substantially semi-cylindrical shape, so that the effects in the sliding and overturning directions are reduced, and a sufficient wave-dampening effect can be obtained even though the entire body is lightweight.

(Example) Next, an example of implementation of the present invention will be described with reference to the drawings.

In the figure, reference numeral 1 indicates a wave-dissipating precast block constituting the wave-dissipating structure of this embodiment. This precast block has an arched wall 1a which is approximately semi-cylindrical and is formed by forming a rectangular plate into an arched shape. A large number of through holes 2 are formed at one side thereof so as to pass through the front and back sides. At both ends of this arch-shaped wall 1, substantially flat footings 1b, 1b are integrally formed, which project inwardly and outwardly in the direction of the radius of curvature. Furthermore, this footing 1
A plurality of support pile insertion holes 3 are formed in the footings 1b and 1b, penetrating the footings 1b and 1b vertically, and PC steel material insertion holes 4 are formed through the footings 1b and 1b in the same center line arrangement. 1b,
1b and the arched wall 1a in the width direction, a large number of PC steel material insertion holes 5 are opened through them.

The wave-dissipating structure according to the present invention is constructed using the precast block constructed in this way. First, 10 rubble stones are placed on the seabed ground at the construction site.
and level the surface. Note that the rubble stones 10 are not thrown in to form a strong foundation mound as in the construction of a conventional caisson embankment, but are arranged in such a way as to level the seabed surface.

On the other hand, the precast block has a strut 11 made of a columnar concrete precast member interposed between the footings 1b and 1b at both ends thereof, and is connected to each PC steel insertion hole that has been previously opened through both the footings 1b and 1b and the strut 11. A prestressed steel material 12 is inserted, and both ends of the prestressed steel material 12 are tensioned and fixed on the outside of the footing 1b.
Apply prestress to the whole. After applying prestress between the footings 1b, 1b in this way, the precast block 1 is suspended from a ship and installed on the rubble 10 described above.
After installation, the support piles 13 are driven into the seabed ground through the support pile insertion holes 3 of both footings 1b, 1b to prevent the precast block 1 from slipping.

In this way, the precast blocks 1, 1,
1... are placed side by side on the rubble 10, and the PC steel material 14 is continuously inserted into the precast steel material insertion holes 5, 5... of each precast block 1, 1..., and the multiple precast blocks are combined into one unit. The tension settles.

Incidentally, the tension fixing between each precast block may be performed by sequentially connecting adjacent precast blocks and integrating all precast blocks 1, 1, . . . . Furthermore, the aforementioned PC steel materials 12 and 14 are buried with concrete so that their ends are not exposed to the outside, and grout is injected into each of the PC steel material insertion holes to prevent seawater from entering.

In this way, a large number of through holes 2, 2,...
A wave-dissipating structure is constructed which has an arc-shaped transparent wall section A having an opening, and a water retarding section B having a substantially semi-cylindrical shape inside the back surface thereof.

In addition, numeral 15 in the figure is a block for hardening the roots.

Although the above-mentioned embodiment shows the case where it is used as a single breakwater, the present invention may also be used as a seawall.
In this case, as shown in Fig. 6, the wave-breaking wall 1c is integrally formed on the top of the precast block 1, and the wave-dissipating structure is constructed in the same manner as described above with the through holes 2 facing the sea side. Then, an embankment C is applied on the land side from the top breakwater wall 1c, and the wave-dissipating structure itself becomes a quay.

When a wave hits the front surface of the wave-dissipating structure constructed in this manner, the wave acting force P is A part of the force acts as a vertical force, and the resultant force of the vertical force _P1 and the horizontal force _P2 acts toward the center of curvature of the approximately semicircular shape.

(Effects of the Invention) The wave-dissipating structure of the present invention is constructed as described above, and has a structure in which a transmission hole is formed in the front face of a substantially semi-cylindrical wall, so that the force of waves acting on it is The vertical component force acts on the seabed surface in a distribution similar to the weight of the entire wave-dissipating structure, and this acting force is generated in accordance with the magnitude of wave energy. Therefore, the horizontal component force acting on the wave-dissipating structure as an overturning force becomes smaller. In addition, the energy of the waves that hit the transparent wall acts on the center of curvature of the wave-dissipating structure, so the stress is dispersed over the entire bottom surface, and the entire bottom surface counteracts the energy, resulting in the dissipation. Even if the entire wave structure is lightweight and has a relatively small width, it will not slide or overturn;
Even if the bearing capacity of the ground is small, it can be constructed without special ground improvement or building a strong foundation.

Furthermore, since the permeable wall portion with the permeable holes has a substantially semi-cylindrical shape, the area can be increased compared to the conventional one with an upright permeable wall portion, and therefore the same wave-absorbing effect as the conventional one can be obtained. It will be done.

Furthermore, since it is constructed by connecting precast blocks consisting of a roughly semi-cylindrical arched wall and a footing, each precast block is lighter than a conventional large caisson. It is easy to handle, and the construction work can be completed in a short period of time.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view of a wave-dissipating precast block used in the present invention, FIG. 2 is a side view of the same, and FIG. 3 is a front view of the same.
FIG. 4 is a partial front view of the wave-dissipating structure, FIG. 5 is a longitudinal sectional view thereof, and FIG. 6 is a longitudinal sectional view of another embodiment. 1... precast block for wave dissipation, 1b...
Arched wall, 1b...footing, 2...through hole, 3...support pile insertion hole, 4, 5...PC steel material insertion hole, 10...rubble, 11...strut, 1
2, 14...PC steel material, 13...Support pile.

Claims (1)

[Claims] 1 It has an arch-shaped wall body having a substantially semi-cylindrical shape, and footings integrally provided at both ends of the arch-shaped wall body, and the arch-shaped wall body has a large number of transparent walls on one side with the top as a boundary. A large number of wave-dissipating precast blocks with holes formed therein are sequentially arranged and installed on the seabed with the side with the holes facing the direction of wave propagation, and each of the precast blocks is connected to form a continuous approximately semi-cylindrical block. A wave-dissipating structure with a shaped wave-dissipating wall and an internal space.