JP2000034717A - Wave dissipation block with through hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exchange seawater inside and outside of a breakwater by arranging the projecting part around the body shaft part forming a straight line-shaped through hole in the lengthwise directional center. SOLUTION: At least a single projecting part having at least a single projection is arranged around the body shaft part forming a straight line-shaped through hole in the lengthwise directional center to constitute a wave dissipating block with a through hole. Next, the end part on the side turning to the inside of a breakwater of the through hole is chamfered, the chamfering part is rounded as required or is formed in a bell-mouth shape to reduce an inflow loss of seawater so that the seawater smoothly flows in a pipe. When constructing a rubble-mounted bank, for example, wave dissipating blocks with through holes are heaped up in plural stages in the bank lower part, the through holes are arranged so as to communicate with the inside and the outside of the bank, and conventional wave absorbing blocks having no ordinary through hole are heaped up on them. Thus, inside and outside seawater of the bank can be sufficiently exchanged by the range of tide of a sea level so that a water quality inside of the bank can be easily preserved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave breaking block with a through hole used for a transmission type wave breaking wall.

[0002]

2. Description of the Related Art (First Invention) Conventionally, in a fishing port or aquaculture facility, a wave-dissipating block (hereinafter, referred to as a tetra-pot) has been used to prevent strong waves from the open sea.
Breakwaters or caisson embankments made by stacking rubble and rubble are provided. or,
In recent years, the construction of marine recreation bases has been active, and in this case also, the breakwaters described above have been used to create a comfortable waterside space or to cooperate with the fishing industry. In a fishing port, a farm, etc., there is a breakwater as shown in FIG. 4 (b), for example, as a breakwater for preventing the intrusion of waves from the open sea and ensuring the entry and exit of fishing boats and the stability of the farm. Usually, such a breakwater is provided with a breakwater (hereinafter referred to as a rubble breakwater) made by stacking stones brought from a mountain or the like in a shallow water area close to land and within a water depth of about 5 m or less. Many.

As a structure of a rubble dike, as shown in FIG. 5 (d), a relatively fine foundation stone is piled in the center, a top concrete is placed thereon, and furthermore, a wave around the foundation stone is broken. A large covering stone is arranged in a portion in contact with to cover the wave force. In order to stabilize the embankment as a whole, the embankment is constructed by stacking rubble in a shape having a substantially equilateral trapezoidal cross section.
As shown in (d), since a stable slope is required,
The length of the base of the levee and its vicinity is longer than when conventional wave-dissipating blocks are stacked. Furthermore, as mentioned above,
The base stone used in the central part of the rubble dike is fine and piled up in a packed state, so that seawater hardly circulates outside and inside the rubble dike. In particular, it is not an exaggeration to say that there is no circulation at the bottom of the long rubble dike.

Accordingly, when a rubble dike as shown in FIG. 4 (b) is provided at a shallow portion near the land and at a shallow depth of the water to serve as a breakwater, the rubble dike is similar to the caisson dike at the tip. Even in parts, there is virtually no distribution of Shanghai water inside and outside the embankment. In FIG. 4B, solid arrows indicate the direction of change in the tide when the tide changes from low tide to high tide, and dotted arrows indicate the direction of the change in the tide when the tide changes from high tide to low tide.
The usual breakwater has a narrow entrance and exit as shown in Fig. 4 (b) so that strong waves do not enter the bay, but the tide level in the shaded area in the figure The tide is not enough due to the difference. Usually, a tidal range of about 1.8 to 2 m is recognized at the seaside, but the tidal range also causes seawater to stay in the hatched area without being exchanged. As a result, in this shaded area,
Seawater is not sufficiently exchanged by the power of nature on a daily basis, causing a phenomenon that water quality deteriorates. That is, as shown in FIG. 4B, when a breakwater is provided at a fishing port or the like,
In the area near the rubble dike near the land in the fishing port, the exchange of seawater stagnates between the inside and outside of the rubble dike, and adverse conditions such as inflow of domestic wastewater from the land side overlap, so the outside of the dike There is a phenomenon that the water quality in the bay is much worse than the water quality in the open sea.

[0005] Such deterioration of the water quality in the bay may cause bad odors in the fishing port, and may cause serious problems such as the occurrence of fish and shellfish diseases and the death of seagrass in the fish farm. Furthermore, the problem of destruction of the living environment of such living organisms is not just a matter of preserving water quality only in the bay, but has recently started to be regarded as having a great effect on the global natural environment.

(Second Invention) Conventionally, nuclear power plants and thermal power plants that require a large amount of cooling water rely on seawater for cooling water, so that they are often located on the coast.
In these power plants, a large amount of seawater is taken, and a large amount of used warm seawater is discharged to the sea. However, the discharge of a large amount of hot wastewater from this power plant causes phenomena such as concentration and bubbling, and the vessels that sail in the area where the water is discharged, and fisheries operating in this area This has a negative effect on the industry, as well as on drifting sand and creatures in the natural world. Therefore, to prevent phenomena such as concentration of the flow that occurs at the time of discharge and the occurrence of bubbling,
Conversely, in order to prevent the influence of the wave force from the open sea to the water discharge garden, a wave-dissipating block is piled up near the outlet of the water discharge garden to provide a transmission type wave-dissipating block embankment.

However, for example, a breakwater made by stacking conventional breakwater blocks (hereinafter referred to as a breakwater block dyke) has been developed for the purpose of reducing wave power from the open sea. However, when this is used as it is as a means for diffusing a large amount of discharged water, there are many functional problems. That is, in this case, it is necessary to have an excellent wave-dissipating function against the waves of the open sea generated outside the embankment, and at the same time,
Efficient permeability to the open sea needs to be satisfied for the discharge of a large amount of hot wastewater that is performed inside the dike. Each of these actions has conflicting elements with each other, and it has been difficult to satisfy them at the same time.

That is, in the conventional transmission type wave-dissipating block embankment, a plurality of wave-dissipation blocks are formed in such a shape that the cross section in the flow direction of the discharged water is substantially a trapezoidal shape in order to stabilize the transmission dike itself. It is configured to be stacked. At that time, since a stable slope is required, the length of the bottom of the embankment and its vicinity becomes considerably long. However, such an increase in the length of the lower part of the embankment is not only unnecessary for the wave-breaking function, but rather impairs the transmission function significantly.

This will be described with reference to FIG.
A conventional breakwater block dyke is constructed by stacking a plurality of breakwater blocks of uniform size over the entire dyke, for example, a plurality of tetrapods of the same size.
Regardless of the size of the tetrapot used, it is about 50% in any place. However, as described above, the slope near the bottom of the embankment is widened due to the slope of the slope generated when the wave-dissipating blocks such as tetrapots are stably stacked, so that the permeation distance increases at the bottom of the embankment and the resistance to the permeated flow decreases. growing. On the other hand, the structure has a structure in which the permeation distance becomes shorter toward the upper part of the embankment and the resistance of the permeated flow decreases at the upper part of the embankment.

When a conventional transmission type wave-dissipating block embankment constructed by stacking a plurality of conventional wave-dissipating blocks as described above is installed in the vicinity of an outlet of a water discharge garden for hot wastewater discharged from a power plant. Causes the following phenomena. In other words, a large amount of effluent flowing from the discharge port to the permeation dike is concentrated on the upper part of the dike with less hydraulic resistance due to hydraulic balance, and the permeation flow rate is extremely small at the lower part of the dike with large hydraulic resistance. Occurs. As a result, as shown in FIG. 16B, the flow velocity becomes extremely high near the water surface, while the flow velocity decreases rapidly as the water depth increases. This means that in the water discharge garden where a large amount of hot waste water is discharged as described above,
This indicates that the installation of a conventional transmission type wave-breaking block levee does not function efficiently as a transmission levee over the entire cross section of the levee, and causes a large loss head (ΔH) as a whole. ing. The large head loss (ΔH) that occurs at this time is that when the seawater is used as the cooling water on the side that supplies the cooling water, the seawater must be pumped to a level higher than the sea level in the water discharge garden. For this reason, an excessive load is applied to the pump for pumping seawater, which causes a great loss in the function of the pump or in the operation cost. Here, the head loss (ΔH) is the difference between the height of the water surface inside the embankment and the height of the surface of the open sea outside the embankment in the section where the embankment is located. Means the energy lost consumed.

[0011]

SUMMARY OF THE INVENTION (First Invention) Accordingly, an object of the first invention of the present invention is to solve the above-mentioned problems of the prior art, and to provide the inside and outside of a breakwater, in particular, a rubble dike. It is an object of the present invention to provide a wave-dissipating block with a through-hole that enables daily exchange of seawater in the bay using natural force and effectively prevents the problem of water quality deterioration in the bay inside the dike.

(Second invention) An object of a second invention of the present invention is to solve the above-mentioned problems of the prior art, and to reduce the resistance of a permeation flow flowing through a lower part of the permeation type wave-dissipating block near the bottom surface. By increasing the permeation flow through the lower part of the embankment, it is possible to discharge deep water and reduce the head loss, thereby improving economic efficiency and promptly mixing and diluting large amounts of hot wastewater into natural waters. Another object of the present invention is to provide a functional and economical transmission type wave-dissipating block levee that is capable of controlling the three-dimensional diffusion of hot effluent discharged into a water discharge yard. .

[0013]

Means for Solving the Problems (First Invention) The above object is achieved by the present invention described below. That is, the first invention of the present invention provides a trunk shaft having at least a straight through hole at the center in the longitudinal direction, and at least one projection having at least one projection provided around the trunk shaft. It is a wave-eliminating block with a through-hole, comprising a projection.

(Second Invention) A second invention of the present invention relates to a transmission type wave-breaking block embankment provided by stacking a plurality of wave-breaking blocks near an outlet of a water discharge garden.
The resistance of at least the permeation flow flowing through the lower part of the embankment is smaller than the resistance of the permeation flow flowing through the lower part of the permeation type wave-dissipating block embankment constructed by stacking the wave-dissipating blocks determined by the wave force in the same manner as the embankment. A transmissive wave-breaking block embankment characterized by being constructed in such a way as to reduce the head loss of the permeated flow permeating the lower part of the embankment. It is a transmission type wave-dissipating block embankment.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION (First Invention) The present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art,
If through-holes can be provided in the breakwater, especially in the lower part of the rubble dike, by simple means and reliably, seawater can be exchanged between the inside and outside of the breakwater through these through-holes, Considering that the problem of the deterioration of the water quality that has occurred is solved, when used together with rubble, the familiarity with rubble is good, and the seawater near the rubble embankment where seawater stays is surely replaced. The present invention has been made by devising a wave-dissipating block with a through hole having a new shape that can be used.

That is, when the wave-dissipating block with a through-hole according to the first invention of the present invention is used for a part of a rubble dike, the wave-dissipating block with a through-hole according to the present invention has a straight line at the center in the longitudinal direction. Since there is a trunk shaft part with a through hole, wave-dissipating blocks with through holes are arranged at the bottom of the embankment so that the through hole is in the direction connecting the outside and the inside of the embankment, and rubble is piled on it to form the embankment For example, a structure in which seawater flows between the rubble embankments can be used, and the wave-dissipating block with through-holes of the present invention has a protrusion around the trunk shaft, so that it is well-adapted to rubble. There is no discomfort as part of the rubble embankment, and the block is stably maintained in the formed embankment.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the first invention of the present invention. The wave-dissipating block with a through-hole according to the first invention of the present invention includes a trunk shaft having a straight through-hole at least in the center in the longitudinal direction, and at least one projection provided around the trunk shaft. And a protrusion having the same.

Hereinafter, description will be made with reference to the drawings. FIG.
(A) is a perspective view illustrating the basic shape of the wave-dissipating block with through-holes according to the first invention of the present invention. It consists of two parts. 1A and FIG. 1A.
As shown in (d), one direction is longer than the other direction and has a structure having a longitudinal direction which is the axis of the block, and a straight through hole is provided at the center in the longitudinal direction. I have.
In addition, if such a through hole is provided, the strength of the block is inferior to the block in which all the concrete is filled, so in the present invention, the trunk portion of the block is formed sufficiently thick, It is preferable that the through hole is formed so that the periphery of the hole is thick even when the through hole is provided. Further, in order to reinforce the strength, a reinforcing bar may be embedded inside the block (not shown).

The wave-dissipating block with through-holes according to the present invention is arranged such that the longitudinal direction is horizontal to the crossing direction of the embankment and horizontal to the ground when the embankment is formed. It is sufficient that at least one through-hole is provided along the axis of the block in the longitudinal direction, that is, at a position that is horizontal with the ground when the bank is formed. However, the present invention is not limited to this, and further holes may be provided in the direction intersecting with the through holes, that is, in a position that is upward, downward, or oblique to the block when the bank is formed.

Furthermore, the above-mentioned through hole provided in the longitudinal direction of the block may have a shape of an end portion, for example, a corner end in which the end portion is simply formed by simply punching out a trunk shaft portion like an earthen pipe. However, it is preferable that at least one end is chamfered. Further, it is more preferable that the end portion is chamfered and rounded, and it is more preferable that the rounded shape is a bell mouth type as shown in FIG. In this way, when flowing water into the through-hole, the inflow loss is reduced, and seawater can be smoothly flowed into the pipe. That is, the head loss h _e by flowing in line given by the following equation, the inflow loss coefficient f _e at that time, in the case of a square end while 0.5 was rounded In this case, it is about 0.1 to 0.2, and when the bell mouth type is used, 0.01 to 0.0
5, the loss can be reduced to about 1/10 of that at the corner end. In other words, if the chamfered end with a small inflow loss is installed so as to face the inside of the embankment, the seawater whose water quality in the embankment has deteriorated can flow more smoothly out of the embankment through the through hole. As for the intrusion of waves from outside the embankment, the base length of the rubble embankment is sufficiently long, and the extension of the through-hole is also long, so that the wave force is attenuated while passing through the through-hole and adversely affects the inside of the embankment. Absent.

In the wave-breaking block with through-holes according to the first invention of the present invention, a projection having at least one projection is provided around the above-mentioned trunk shaft. The protrusion is
It is preferable to provide at least one location, more preferably two or more locations, in one block. For example, as shown in FIG. 1, two protrusions are provided at both ends of the trunk shaft, or as shown in FIG. 2, protrusions are provided at both ends and at the center of the trunk shaft. Of course,
The present invention is not limited to this, and four or more protrusions may be provided. However, it is preferable to provide two or three protrusions from the viewpoint of ease of manufacture and ease of handling.

Further, the number of protrusions constituting the protrusions may be at least one, for example, three protrusions as shown in FIGS. 1 and 2, or three protrusions as shown in FIG. As shown in the above, four may be provided around the trunk shaft portion. Further, although not shown, as a modification thereof, for example, one having only two feet installed on the ground may be used. In particular, three or four protrusions are preferable because they can be stably placed, and when a plurality of protrusions are stacked, the individual blocks do not mesh and do not collapse.
Further, when one block has a plurality of protrusions, the number of protrusions of each protrusion may be the same as shown in FIGS. 1 to 3, or may be different. For example,
In FIG. 1, both projections each have three projections, but unlike this, one projection has three projections and the other projection has one or two projections. May be provided.

The shape of the projections constituting the projections is not limited at all, but is preferably a rectangular column as shown in FIGS. 1 and 2, a triangular column as shown in FIG.
In order to reduce the resistance of seawater, the protrusion may have a rounded shape, for example, a columnar shape or a conical shape. It is preferable that the sizes of the projections having these various shapes are configured such that when the blocks are stacked, the projections are exactly fitted into the recesses where the projections are not provided, as shown in FIG. .

If the projecting portion of the wave-breaking block with a through-hole according to the present invention is constituted as described above, for example, when it is used for a part of a rubble dike, as shown in FIG. It is easy to place all the through holes in a fixed direction, and it is easy to be used with various types of rubble, it is easy to install during construction, and stable rubble embankment is easy Can be formed. Further, even when the wave-dissipating blocks with through holes according to the present invention are stacked to form a transparent levee, the blocks can be stably stacked in a plurality of stages as shown in FIG. Even when used in combination with a wave-dissipating block of another shape, the block is well-adapted to these blocks, and the whole embankment is not stably deformed and does not impair the wave-dissipating function.

Next, the seawater exchange type breakwater according to the first invention of the present invention will be described. The seawater exchange type breakwater of the present invention,
It is characterized in that at least one block having through holes in the levee is stacked, and seawater can be exchanged between the outside and the levee through the block layer. The block having a through-hole used at this time may be a cylinder or a box having at least one through-hole such as a conventionally known fume tube or the like. It is preferable to use the wave-dissipating block with through holes according to the invention. That is, the wave-dissipating block with a through-hole according to the first invention of the present invention can reliably secure a through-hole connecting the inside and the outside of the bank, and unlike the fume tube or the like, the block itself has good stability, In addition, it is well-suited to other shapes such as wave-dissipating blocks and rubble, so that it is most suitable as a block having through holes that can achieve the intended purpose.

As the seawater exchange type breakwater of the first invention of the present invention, for example, a wavebreak block having a through hole is used for all or a part of the breakwater, and a conventional waterbreak block such as a tetrapot is used. In the same manner as in the above, the porosity of the embankment is increased to increase the porosity of the embankment, so that the seawater is more easily permeated than the conventional permeation-type breakwater. A block having a through hole at the lower part of a conventional rubble embankment is provided with about one or two steps, and a seawater exchange type breakwater that can easily and surely exchange seawater is used as an embankment where seawater exchange is not performed at all. Is mentioned.

FIG. 5 (a) shows the above-described one-layer wave-dissipating block with a through-hole according to the present invention provided below the conventional rubble embankment shown in FIG. This is an example of a bank. HWL shown in FIG. 5A indicates the water level at the time of high tide when the tide is full, and LWL indicates the water level at the time of low tide when the tide is low. As shown in d), the conventional rubble embankment has a structure in which the seawater near the seabed is difficult to be exchanged due to a tidal level due to the large width of the embankment.
In contrast, in the seawater exchange type breakwater described above,
Because a wave-dissipating block with a through-hole with a through-hole is arranged in this part, the natural force of the tide level,
Seawater can easily move from the inside of the embankment to the outside of the embankment or from the outside of the embankment to the inside of the embankment through the through hole. At this time, as shown in FIG. 5 (a), each block may be arranged so that the through-holes are arranged in a straight line, but the present invention is not limited to this. What is necessary is just to be arrange | positioned so that it may face each other facing the dike, and may be arrange | positioned scatteredly.

(Second Invention) The present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art, and as a result, in a commonly used wave-eliminating block, for example, in the case of a tetrapod, the size of the block is large. Regardless of the size, the porosity of the levee when this is piled up to form a transparent levee is constant at about 50%. In consideration of the fact that the width is larger than the upper part of the embankment and the cause of the remarkable increase in the head loss, the resistance of the permeated dike structure to at least the discharge water permeating the lower part of the embankment is determined by the wave force If the resistance to the discharge water flowing through the lower part of the conventional transmission-type wave-dissipating block embankment constructed by stacking wave-dissipating blocks is made smaller, the water will flow more easily through the lower part of the embankment. Can be reduced This has led to finding a that can be quickly mixed and diluted with the heated effluent which is discharged into the natural waters present invention.

For example, if the upper part of the embankment is formed by using a wave-dissipating block determined by the wave force and the lower part of the embankment is formed by using a larger wave-dissipating block, the size of the gap between the blocks at the lower part of the embankment can be increased. As a result, water flows easily under the bank. That is, if the penetrating levee is configured as described above, even if the porosity of the entire penetrating levee is the same, the size of the gap per location generated by the combination of the wave-dissipating blocks increases at the bottom of the levee, As for the loss head of the permeation flow flowing through the gap, the ratio of the cross-sectional area of the gap to be the permeation flow path to its peripheral length (junction) is reduced, and as a result, hydraulic efficiency is significantly improved for the following reasons. Diameter R representing hydraulic efficiency
Is R = (permeation area / junction), and the hydraulic efficiency is proportional to R ^2/3. Therefore, the larger the cross-sectional area of the gap as the water flow channel, the better the hydraulic efficiency. Therefore, in order to further increase the hydraulic efficiency, a block having a through hole having a larger gap through which water passes may be used together with the wave-dissipating block to form the lower part of the embankment.

Hereinafter, the second invention of the present invention will be described in more detail with reference to preferred embodiments. The transmission type wave-dissipating block embankment of the present invention is configured such that a plurality of wave-dissipating blocks are provided in the vicinity of the outlet of the water discharge garden in a stack in the form of a bank, so that the water flow can pass between the banks. Further, at least the resistance of the permeation flow flowing through the lower portion of the embankment is lower than the resistance of the permeation flow flowing through the lower portion of the permeation type water-dissipation block embankment configured by stacking the wave-dissipating blocks determined by the wave force in the same manner as the above-mentioned dike. Is also reduced. As a result, the efficiency of the entire transparent levee is improved.

As the wave-dissipating block used in the transmission-type wave-dissipating block embankment of the present invention, any of conventionally-known wave-dissipating blocks can be used. For example, tetrapods, hexapod blocks, Any of the blocks having a large porosity between the stacked blocks, such as an aerial triangular block, can be preferably used. Further, in the present invention, in addition to the above-described wave-dissipating block, it is also preferable to use a block having at least one through hole having a large porosity and good hydraulic efficiency as a constituent member at the lower part of the bank. As such a block, for example, a hollow block having a box-shaped or cylindrical cylindrical body or a plurality of through holes, or
The above-described wave-dissipating block with a through-hole according to the first invention of the present invention can also be preferably used.

Hereinafter, a specific method for reducing the resistance of the permeate flowing through the lower part of the bank located near the water bottom will be described with reference to the drawings. First, the first method will be described. Similar to a breakwater, a conventional transmission-type breakwater block constructed using a wavebreak block determined by wave power has a slope slope due to its structure. Since the width of the cross section increases in proportion to the water depth, the permeation function near the bottom of the embankment is remarkably reduced, and the velocity of the discharged water near this is slow. On the other hand, when a large amount of hot effluent is discharged, it is necessary to quickly mix and dilute the hot effluent into natural waters. For this purpose, it is preferable to make the surface flow velocity of the water discharge stream as small as possible, and to perform deep water discharge in a deep water layer. According to the first method described below, this deep discharge is possible.

In the first method described above, the width of the bottom side increases in proportion to the water depth due to the slope, and the transmission function at the lower part of the embankment is significantly reduced. In order to drastically improve the defects, increase the permeation cross section and reduce the head loss, as shown in FIG. Coexist. With this configuration, the head loss is reduced, and a permeation levee is formed in which the amount of permeate flowing through the vicinity of the lower part of the levee located at the bottom of the water is much larger than the amount of water permeating the upper part of the levee located near the water surface Is done.

As a block having a through hole used at this time, a hollow cylinder having one through hole (see FIG. 6 (d)) or a hollow box (FIG. 6 (c)) as shown in FIG. It is effective to arrange these hollow blocks at the lower part of the bank so that the through-holes face in the direction of the permeation flow (see FIG. 6 (a)). For example, as shown in FIG. 6 and FIG. 7, only one such hollow block may be provided in the bank in the permeation direction, or as shown in FIG. It may be arranged. Further, as a method of arranging the hollow blocks, when the hollow blocks are arranged, the through holes may be connected in a straight line, and the through holes may be arranged so as to be tight, as shown in FIG. 8B. Thus, the through holes may be arranged so as to face in the direction of the permeation flow, and the through holes are connected substantially in a straight line. In this case, the water around the hollow block is easily sucked into the water flowing through the through hole formed at the lower part of the levee, and the permeable levee has a smaller head loss.

In the second invention of the present invention, in particular, from the viewpoint of stability when disposed and maintenance of the wave-damping function, the through-hole according to the first invention of the present invention described above as a block having a through-hole is provided. It is preferable to use a blocker block. For example, FIG. 9 shows an example in which the wave-dissipating block with through-holes according to the first invention of the present invention is arranged in a three-tiered structure at the lower part of a bank.
As shown in FIG. 9 (b), the use of the wave-dissipating block with a through hole according to the first invention of the present invention not only makes the whole embankment have a gap due to the projections of the block, but also The porosity of the lower part of the embankment can be remarkably improved as compared with the upper part of the embankment by the through-holes of the trunk shaft portion constituting the block. As a result, a permeation levee in which the amount of permeate flowing through the vicinity of the lower part of the levee is significantly large.

Further, in the conventional transmission type wave-breaking block embankment, when wave force is applied for many years, the meshing between the wave-breaking blocks is tightened and the meshing state is changed, and the gap between the bank is reduced. There was a defect that the flow of the effluent was obstructed and the head loss increased. On the other hand, in the transmission type wave-dissipating block embankment of the present invention having the above-described configuration, the gap between the embankments mainly has a through-hole, as in the case where the above-described wave-dissipating block with through holes in FIG. 9B is used. Since it depends on the wave-dissipating block, the through-hole does not change even if the meshing state between the respective wave-dissipating blocks changes. Therefore, the gap between the permeation levees will not be lost in the future, and it is possible to maintain a much larger permeation flow rate. In the second invention of the present invention, a cylinder having a conventionally known fume tube or cast iron tube may of course be used as the block having a through hole.

As a method of using the wave-dissipating block with a through-hole according to the first invention of the present invention, specifically, for example, as shown in FIG. A plurality of wave-dissipating blocks with through holes may be stacked, and a conventional type wave-dissipating block having no ordinary through holes may be stacked thereon. In this case, since the wave-breaking block with through-holes of the first invention is provided with the projection, the familiarity with the other blocks is good, and when the blocks are stacked, the projections mesh with each other. As a result, the transparent levee can be formed stably. Further, in the case of forming the above-described transparent levee, as shown in FIG. 10, a conventional wave-dissipating block such as a tetrapod is disposed on the open sea side at the downstream end of a block having a through hole on the open sea side. Instead, the entire lower part of the embankment may be constituted by the wave-dissipating block with the through-hole of the present invention, and the inside of the embankment and the open sea may be directly connected by the through-hole. Such a method is an effective method depending on the sea area where waves are small or the size and arrangement of the wave-dissipating block with through holes.

Further, the position of the downstream end of the block having the through hole is adjusted so as to keep the distance L from the slope of the bank as shown in FIGS. 6 (a), 8 (a) and 9 (a). If a normal wave-dissipating block having no through-hole is arranged in this part, the discharged water that has passed through the through-hole collides with the wave-dissipating block such as a tetrapot and is diffused and flows to the open sea side. To go. At this time, it is preferable that the distance L is specifically a distance corresponding to the thickness of the two or three layers of the wave-eliminating blocks.
With this configuration, the conventional wave-dissipating block having a thickness of two to three layers can sufficiently satisfy the wave-dissipating effect against waves from the open sea, while FIG. (A)
As shown in (b), the discharged water that has passed through the through-hole passes through the gaps of the conventional two-layer wave-dissipating block, and during this time, flows out into the open sea as a diffused flow. It is quickly diluted and mixed in the sea area (see Fig. 7).

In the first method as described above, the discharged water flows through the through hole of the hydraulically efficient hollow block placed at the lower part of the bank, so that the resistance to the permeated flow near the lower part of the bank is significantly reduced, The permeate flow is concentrated around the deep bottom portion, and as shown in FIG. 6B, a very favorable flow velocity distribution is obtained in which the lower part of the embankment suitable for deep discharge is faster than the upper part. Furthermore, since the discharge water flows through the through holes of the hollow block, the size of the through hole of the hollow block,
By appropriately selecting the installation position, it is possible to obtain an arbitrary flow velocity distribution in three dimensions, and it is also possible to smoothly diffuse three-dimensionally the hot waste water.

Further, the block having a through-hole used in the present invention is not limited to the above-mentioned block, but is shown in FIG.
It is also preferable to use blocks having a plurality of through holes of various shapes as shown in FIG. If this is done, the size of the through-hole and the installation position of the through-hole are appropriately designed in advance, and a box is created in advance. It is possible to easily realize the seepage embankment.

Hereinafter, the effectiveness of the present invention in the case of the first method shown in FIG. 6 will be described in detail with reference to the drawings.
As described above, when constructing a transparent embankment, as shown in FIG. 6 (a), if a block having a hydraulically efficient through hole coexists with the wave-dissipating block constituting the lower part of the embankment, The flow rate near the lower part of the seepage embankment can be greatly increased, and the flow velocity is dominated by the deep flow as shown in Fig. 6 (b), which greatly reduces the mixing, dilution, and head loss of hot wastewater in the open sea. I can do it.

As a result, for example, an example of a nuclear power plant (Kashiwazaki-Kariwa) with 1.1 million Kw × 8 units will be described.
The total amount of cooling water used in this case is 624 m ³ / sec. Therefore, the same amount of used hot wastewater is discharged from the power plant into the water discharge garden. At a depth of 3.5 m near the outlet of the water discharge garden, as shown in FIG. 17 (a), an 8 t tetrapot is a constituent member, and a dike on which this is stacked is provided over the width of the water discharge garden. (Figure 7
reference). In the actual example, the width of the embankment is 4.6 m at the upper part and 25 m at the lower part, and a substantially embankment-shaped penetrating embankment having a 300 m embankment length is provided. In this case, the measured head loss is 2 m. It is about 0.0 m. In addition, the flow velocity distribution of the discharged water is such that the flow velocity sharply decreases as the water depth increases from the surface flow as shown in FIG. In other words, it can be seen that the large amount of hot wastewater discharged in the above example is dominated by the surface flow, which is contradictory to the object of making deep water discharge preferable.

The above phenomenon is caused by a structural defect in the conventional permeation block levee in which the head loss for the permeation flow near the bottom of the levee becomes extremely large. In the above case, for example, 624 m ^When a water discharge rate of ³ / sec is discharged, a loss head of about 2.0 m occurs. This means that on the cooling water supply side, the seawater for the cooling water must be pumped by a pump for pumping at least the head difference, but the power loss required for operating this pump is equivalent to 15,288 Kw. I do. Also, when this is calculated assuming that the power rate in the power plant is 10 yen / Kwh,
It is a big economic loss of 1.19 billion yen / year.

On the other hand, for example, as shown in FIGS. 6 (a) and 6 (c), a 12 m long hollow cylinder having a 1.5 m square through hole in the lower part of the seepage bank is shown. If it is assumed that they are arranged at 6 m intervals as shown in FIG. 7, FIG.
The preferred flow velocity distribution suitable for deep discharge as shown in FIG. As a result, it is considered that the loss head is also halved to be about 1.0 m.
This will reduce electricity costs by about 590 million yen / year. According to the results of the hydraulic experiments described below, according to the present invention, it is possible to further reduce the head loss by about 1/3.

Next, the second method will be described.
According to the method, the size of the wave-dissipating block, which is a constituent member of the embankment, is changed, and at least the wave-dissipating block constituting the lower part of the embankment is increased in size. The structure is such that the head loss is equal between the upper part and the lower part, whereby the permeated flow passing through the embankment can obtain a uniform flow velocity with respect to the water depth.

That is, as shown in FIG. 12, the size of the wave-dissipating block, which is a component of the lower part of the embankment near the bottom of the embankment, is reduced as the wave-dissipating block constituting the dike. Make it larger than the size of the wave block. For the upper part of the embankment, a wave-dissipating block having a size determined by the wave force, which is used when a conventional transparent embankment is designed, is used. In this way, the size of the gap between each block near the bottom of the embankment caused by the combination of the large wave-dissipating blocks is formed by stacking the wave-dissipating blocks of the size determined by the wave force. It is larger than that near the top of the embankment. As a result, water flows easily in the vicinity of the lower part of the permeation levee, and the flow velocity of the permeate flow becomes substantially constant between the upper part and the lower part of the levee as shown in FIG. Thus, the head loss (ΔH) can be reduced.

In the example described above, only the wave-dissipating block constituting the lower part of the embankment is enlarged, but the present invention is not limited to this, and the wave-dissipating block for the entire transparent embankment may be enlarged. That is, in the case of providing a transmission type breakwater block embankment conventionally, as in the case of the breakwater, the size of the wavebreak block to be used is determined by the wave force at the place where the breakwater is provided, and the material is used as a forming material. However, in the present invention, by using a wave-dissipating block that is larger than the material determined by the wave force for the entire permeation levee, the resistance of the permeation flow permeating through the permeation levee is lower than in the conventional case. The size may be reduced to facilitate transmission.

The third method, which will be described next, is different from the second method in that the shape of the wave-dissipating block, which is a constituent material of the bank, is the same as before, and the method of stacking the wave-dissipating blocks is changed. The cross section of the embankment is not made into an equal-leg trapezoidal shape, and the width in the flow direction of the embankment is made substantially the same between the upper portion and the lower portion of the embankment.
By stacking the wave-dissipating blocks so as to have such a shape, the cross-sectional shape in the flow direction of the embankment is made substantially vertical without making the skirt spread with the slope of the slope. As a result,
The permeate flow length at the lower part of the embankment is shorter than that of the conventional permeate embankment, and can be almost the same as the permeate flow length at the upper part of the embankment. Therefore, the head loss for the permeate flow can be reduced.

More specifically, for example, as shown in FIG. 13 (a), first, at the part of the embankment facing the water discharge garden side and the open sea side,
A pile is driven upright on the sea floor with an appropriate gap in the longitudinal direction of the embankment, facing the position separated by the width of the embankment, and a pile is driven into the space sandwiched by these piles to form a transparent embankment I do. In this way, the stacked wave-dissipating blocks are stably present, and the width of the levee in the flow direction is substantially the same. Therefore, as shown in FIG. The flow velocity becomes almost constant, and the head loss (ΔH) can be remarkably reduced as shown in FIG.

The fourth method shown in FIG. 14 is a combination of the above-described second and third methods. In order to shorten the permeation flow length at the lower part of the embankment, the fourth method is similar to the third method. Pile standing upright on the seabed are driven into the two sides at regular intervals, and wave-dissipating blocks are piled up in the space between these piles. The wave block is used as a constituent material, and a large wave-dissipating block is used as a constituent material below the embankment. This reduces the head loss to the bottom of the dike. As a result, as shown in FIG. 14 (b), the velocity of the permeated flow at the lower part of the embankment is somewhat faster than that at the upper part of the embankment, and the deep discharge is performed. The head loss can be further reduced than in the case of the above method, which is a very favorable situation.

Further, instead of providing piles for supporting the wave-dissipating blocks on both sides of the bank as in the third and fourth methods, FIG.
As shown in (1), piles may be provided only on the water discharge garden side, and the wave-dissipating blocks may be stacked so that the side surface of the embankment placed on the open sea side has the same slope as the conventional transmission type embankment. or,
Also in this case, the stacked wave-dissipating blocks may be composed of a small wave-dissipating block in the upper part of the embankment and a large waves-dissipating block in the lower part of the embankment, as in the second method. As a result, similarly to the third method, the width of the lower part of the embankment can be reduced, and the permeation flow length can be reduced.
The head loss is reduced accordingly. Further, when a large block is used in the lower part of the bank, the head loss can be reduced by making the gap between the wave-dissipating blocks larger than that in the upper part of the bank.

[0052]

EXAMPLE Next, the effect of applying the transmission type wave-dissipating block embankment of the second invention of the present invention to a water discharge yard planned for the extension work of the Fukushima Daiichi Nuclear Power Station currently being planned is confirmed. In order to do this, a hydraulic experiment was conducted using a 1/20 model of the above water discharge garden. Hereinafter, this will be described, and the present invention will be described in more detail. The present inventors have proposed a case where a water-permeable garden having a standard water depth of 4 m as shown in FIG. A model having a size of / 20 was made, and the following hydraulic experiment was performed (hereinafter, the actual size will be described).

First, the flow velocity V passing through the levee is a value Q / A obtained by dividing the total amount of discharged water Q by the flow area A of the levee.
Note that the flow area A of the bank is a value obtained by the water depth S × the bank length L. Here, since the total water amount Q is determined according to the capacity of the power plant, if it is possible to confirm how the head loss changes depending on the flow velocity V, it becomes possible to design a more effective embankment. Therefore, as an experiment, the flow area A of the embankment was set to 4 m (water depth) × 200 m (embank length) = 800 m ² , the total amount of water Q flowing to the water discharge garden was set to 480 m ³ , and the flow velocity V passing through the embankment was 0.6 m / sec. A hydraulic experiment was performed for the case (1), and the head loss was measured. At this time, as the transmission type wave-dissipating block embankment of the present invention, the hollow block shown in FIG. 1 was used, and the four blocks were stacked up to the top as shown in FIG. The size of the used block is as follows. In the transmission type wave-dissipating block embankment of the present invention, the diameter of the through-hole is 110 cm, the outer diameter of the trunk shaft is 187 cm, and the length between the outer periphery of the through-hole and the tip of the projection is 108 cm. , Length 474
cm, and a size of 1/20 of this was used in the experiment. Moreover, in the conventional breakwater, the thing of 1/20 size of the tetraton of 8t was used.

As a result, the flow velocity V passing through the bank is 0.6 m
In the case of the seawater breakwater of the conventional tetrapot, as shown in FIG.
While a head loss of about 8 m was observed, the transmission type breakwater block embankment of the present invention showed a loss head of 3 m as shown in FIG.
It was about 5 cm, and it was confirmed that the head loss could be suppressed to 1/5 or less. 16 (c) and FIG.
The vertical axis and horizontal axis of 7 (c) are shown by converting the actual scale based on experimental values.

These facts indicate that, when the same breakwater length is provided, if the transmission type breakwater block embankment of the present invention is provided instead of the conventional breakwater, the head loss can be reduced to 1/5 or less. As described above, this means that the power required for pump operation when pumping seawater for cooling water by a pump for pumping can be significantly reduced. That is, in the above case, when a breakwater using a conventional tetrapot is provided, the electric power fee is ¥ 6.59 billion / year, whereas the transmission type breakwater block embankment of the present invention is provided. If it is provided, the electricity fee will be 128 million yen / year. Furthermore, the above-mentioned fact is that the breakwater is designed using the transmission type breakwater block levee of the present invention so as to have the same value as the head loss generated when the breakwater using the conventional tetrapot is provided. If so, in the case of the transmission type breakwater block embankment of the present invention, it means that the length of the embankment can be made half or less than that of the conventional breakwater. As a result, the cost for the construction of the dike can be significantly reduced. In addition, when the influence of the waves from the open sea on the water discharge garden was examined by the above experiment, even if the design wave height was set to 4 m, the wave-breaking function of the transmission type wave-breaking block embankment of the present invention was Compared with the breakwater function of a breakwater using, there was no inferiority, and it was confirmed that the function was sufficient.

[0056]

(First Invention) As described above, according to the first invention of the present invention, seawater exchange between the inside and outside of the embankment is carried out on a daily basis by the natural force of the tidal level. The seawater exchange type breakwater which can be sufficiently improved is provided by simple means, and water quality conservation in the bay inside the breakwater can be easily achieved.

(Second Invention) As described above, according to the second invention of the present invention, not only does it have an effective wave-dissipating function against waves from the open sea, but it also transmits a large amount of discharged water. The present invention provides an excellent transmission type wave-dissipating block embankment with a small head loss that allows quick permeation. By using the above-mentioned transmission type wave-dissipating block embankment of the second invention of the present invention, particularly, a thermal power plant or a nuclear power plant using a large amount of cooling water and discharging used wastewater into natural waters. Power plant operation and construction costs are reduced, and the hot water
Achieving dilution can eliminate adverse effects on fisheries, vessel navigation and the natural environment.

[Brief description of the drawings]

FIG. 1 is a perspective view of a wave-dissipating block with through holes according to the first invention of the present invention.

FIG. 2 is a perspective view of a wave-dissipating block with through holes according to the first invention of the present invention.

FIG. 3 is a perspective view of the wave-dissipating block with through holes according to the first invention of the present invention.

FIG. 4A is a diagram illustrating a seawater exchange type breakwater according to the first invention of the present invention, and FIG. 4B is a diagram illustrating a conventional breakwater.

5 (a) to 5 (c) are sectional views of a seawater exchange type breakwater according to the first invention of the present invention, and FIG. 5 (d) is a sectional view of a conventional breakwater.

FIG. 6 is a diagram illustrating a transmission type wave-dissipating block embankment of the second invention of the present invention.

FIG. 7 is a diagram illustrating a use state of a transmission type wave-dissipating block embankment of the second invention of the present invention.

FIG. 8 is a diagram illustrating a transmission type wave-dissipating block embankment of the second invention of the present invention.

9 is a diagram illustrating a transmission type wave-dissipating block embankment of the second invention of the present invention to which the wave-dissipating block with through holes of the first invention of the present invention shown in FIG. 1 is applied.

FIG. 10 is a diagram illustrating a transmission type wave-dissipating block embankment of the second invention of the present invention to which the wave-dissipating block with through holes of the first invention of the present invention shown in FIG. 1 is applied.

FIG. 11 is a view for explaining another transmission type wave breaking block embankment of the second invention of the present invention.

FIG. 12 is a view for explaining another transmission type wave-dissipating block embankment of the second invention of the present invention.

FIG. 13 is a diagram illustrating another transmission type wave-dissipating block embankment of the second invention of the present invention.

FIG. 14 is a view for explaining another transmission type wave-dissipating block embankment of the second invention of the present invention.

FIG. 15 is a view for explaining another transmission type wave-dissipating block embankment of the second invention of the present invention.

FIG. 16 is an experimental data showing a configuration of an experimental levee and a loss head when a transmission type wave-dissipating block levee of the present invention is used.

FIG. 17 is an experimental data showing a configuration of an experimental levee and a head loss when a conventional wave breaking block levee is used.

Claims (2)

[Claims] 1. A body shaft having at least a straight through hole at the center in a longitudinal direction, and at least one protrusion having at least one protrusion provided around the body shaft. Wave-dissipating block with through-holes. 2. The wave-dissipating block with through-hole according to claim 1, wherein at least one end of the through-hole has a chamfered shape.