JP5983436B2 - Gravity breakwater - Google Patents

Description

  The present invention relates to a gravity breakwater formed by a caisson made of concrete, for example, and more particularly to a gravity breakwater having a structure that is tough against waves having large energy such as a tsunami.

  A breakwater using a concrete caisson, widely known as a gravity breakwater, is a structure that resists loads acting on energy such as waves by filling the caisson with gravel and water. In general, stabilization is achieved by the frictional force generated between the ground where the caisson is installed and the mound built on the ground due to the gravity.

By the way, the gravitational breakwaters as described above are usually used for loads associated with energy such as waves (including storm surges) caused by typhoons and developed low pressures, or tsunamis caused by earthquakes, which are likely to occur during the service period. Is designed to be safe.
However, when a load with energy more than expected is applied, sliding failure may occur due to insufficient frictional force between the caisson and the ground or mound.
In fact, in the Great East Japan Earthquake that occurred in 2011, a tsunami larger than expected occurred, and a load exceeding the expected level was applied to the caisson. Occurred and destroyed so that the function of the breakwater was lost in an instant, and suffered enormous damage, resulting in a situation where the function as a breakwater could not be guaranteed at all.

  For this reason, when a load associated with energy such as tsunami assumed in the conventional design is applied, even if a certain amount of damage is caused, avoid breakage that suddenly loses the function as a breakwater, and slightly enhance the function of the breakwater However, there is a demand for a persistent breakwater structure that can be maintained.

In response to this, as shown in FIG. 7, in the gravity type breakwater 11, a backfill stone is placed on the rear surface side (inside the harbor) of a heavy structure 14 such as a caisson disposed on a mound 13 formed on the ground 12. A reinforcing structure 15 for reinforcing a breakwater has been proposed in which a reinforcing base 15 formed in an inclined surface shape is stacked to thereby suppress the movement of the heavy structure 14.
However, according to this reinforcing structure, although it can resist a larger load depending on the weight of the reinforcing table 15, the type of failure in the case of the breakwater 11 having this reinforcing structure is represented by sliding failure. Once destruction begins, it becomes destruction that loses function in an instant. That is, when a heavy load is applied to the heavy structure by a tsunami or the like and the reinforcement base that should receive this load is broken without being able to withstand the load, the heavy structure slides and is swept away at once, Because it loses its function instantly, it is hard to say that it has a tenacious structure.
In addition, the method of stacking backfill stones inside the port to form the reinforcement stand 15 reduces the effective area in the port and also changes the water depth in each place, thus drastically changing the operation in the port. There is a high possibility that the necessity will arise, and there is a possibility that problems such as many restrictions will occur in the utilization of port facilities.

Moreover, as a proposal of a tenacious structure, the method of utilizing the steel building materials which have high toughness, such as a steel pipe pile and a steel sheet pile other than the above-mentioned thing exists.
For example, Patent Document 1 describes a revetment structure in which a cell is formed using a steel pipe sheet pile or the like, and a filling soil is filled in the cell. The technique of this Patent Document 1 can realize a very useful and tenacious structure when constructing a new structure related to a revetment structure, but cannot be applied to the structure of a heavyweight breakwater using a caisson. .

Patent Document 2 describes a revetment structure in which a wall-like structure composed of a steel sheet pile or a steel pipe sheet pile is placed on the front side and the rear side of a caisson, and the wall-like structure is connected to the caisson. Yes.
However, this revetment structure has no problem in terms of structural stability, but because the wall structure and caisson are connected, the construction of this point is complicated and the installation work becomes very troublesome, and the installation cost Has the disadvantage of rising. In addition, since the technology of Patent Document 2 is a revetment structure, the front side of the caisson is the sea or river while the rear side is land, the installation work is accessed from the land on the revetment side. Therefore, simplification of installation work is not essential. On the other hand, in the case of a breakwater installed in the sea area sandwiched between the front side and the rear side, the installation work is very large and difficult in the first place compared to the above-mentioned revetment structure. The construction of connecting the caisson and the wall-like structure is very burdensome both in terms of labor and cost. Therefore, there is a great need from the engineer for a technology that can guarantee the performance without such connection work.
In addition, the technology of Patent Document 2 is used for a seawall where the front side of the caisson is the sea or river and the rear side is a land, and both the front side and the back side have a tenacious structure with the breakwater facing the sea. Since this basic idea is completely different, this technology cannot be used as it is for breakwaters.

By the way, in gravity type breakwaters, it is common to place multiple caisons as heavy structures at regular intervals, but in the case of such gravity type breakwaters, when waves and tsunamis have come in In general, an abrupt flow field is formed in a gap between adjacent heavy structures.
For example, when a tsunami or the like comes in from the front side of the caisson, a flow field in the rear side direction is generated in the gap between the caisons, and the water flow from this flow field spreads near the rear side of each caisson. This water flow may scour the mound and ground on the back side of the caisson. In addition, a sudden flow field in the opposite direction to that described above is formed during the pulling wave, so that the mound and the ground on the front side of each caisson may be scoured by the water flow.
If the mound and ground before and after the heavy structure are scoured in this way, the bearing capacity for the heavy structure will be reduced, causing the heavy structure to be swept away, causing sliding failure, and the function of the breakwater for a moment. Is likely to be lost. However, since the countermeasures described in Patent Documents 1 and 2 do not take any measures against the influence of the water flow from the flow field generated in the gap between the caissons, the influence of the water flow from the flow field is suppressed. This is considered difficult.

JP 2003-253644 A Japanese Patent Laid-Open No. 9-13343

  The technical problem of the present invention is to provide a gravitational breakwater that has a tenacious structure that does not lose all its functions in an instant even when a load accompanying large energy such as an unexpected tsunami acts.

  In view of the above, as a result of earnest research to find a tenacious structure in a breakwater equipped with a heavy structure such as caisson, the present inventors have found that a steel sheet pile in which the front side and the rear side of the heavy structure are placed on the ground It has been found that it is effective to support by a wall-like support structure formed by a steel pipe sheet pile or the like so that the support structure directly receives the horizontal force from the heavy structure.

On the other hand, a support structure that supports the weight structure is protruded from the mound in the immediate vicinity of the weight structure placed on the mound formed on the ground, and the protruding portion is When placed on the ground in direct contact with the heavy structure, the heavy structure is easily affected by changes in the ground properties associated with the placement of the support structure, and the ground and mound may loosen. Conceivable.
Doing so may cause the installation of heavy structures to become unstable or make it easier to slide, so in the case of a breakwater with a structure that allows the support structure to directly receive the horizontal force from the heavy structure, It was found that it is important to minimize the influence of changes in ground properties due to the placement of structures locally and minimally.

Furthermore, when the heavy structure receives a load accompanying energy such as a tsunami, it is considered that the heavy structure moves in the direction of the support structure and presses the support structure. A force that causes elastic deformation that curves so as to be convex in the direction of the heavy structure acts on the received support structure.
At this time, if the entire support structure is greatly elastically deformed, the protruding portion of the support structure pressed by the heavy structure presses the mound on the back side and a part of the ground and destroys the part. there is a possibility. In the embedded portion of the support structure, the elastic deformation of the support structure causes a decrease in strength or a slip failure due to the release of the restraining pressure in the vicinity of the support structure, that is, the ground or mound directly under the heavy structure. Therefore, as a result, it was found by the inventors' analysis that the heavy structure slides or sinks.
Therefore, it has been found that the support structure needs to have a configuration that can suppress the elastic deformation as a whole as much as possible when the force from the heavy structure is received.

In addition, in order to make a breakwater with a structure that is more resistant to tsunamis than expected, water flow due to a rapid flow field formed in the gap between adjacent heavy structures can cause mounds and ground before and after the heavy structures to move. It is also important to suppress scouring and suppress as much as possible the decrease in bearing capacity for heavy structures.
Therefore, we obtained the knowledge that it is necessary to control the direction of water flow from the above flow field by the support structure itself and to prevent scouring of the mound and ground on the rear side and / or front side near the heavy structure. .

The present invention has been completed based on the above findings.
That is, in order to solve the above-described problem, the gravity breakwater of the present invention includes a heavyweight structure for wave protection disposed on the ground or a mound provided on the ground, and a front side of the heavyweight structure. A wall-like support structure extending in the vertical direction, which is disposed on at least one side of the rear surface side and receives the force in the horizontal direction from the weight structure to support the weight structure; The support structure is formed in a curved shape that protrudes in a direction opposite to the heavy structure in plan view, the both ends abut against the heavy structure, and the ground on which the heavy structure is disposed Alternatively, it is characterized in that it is placed on the ground with the upper end side protruding upward from the mound.

In the present invention, the support structure may be in contact with the heavy structure in an unconnected state.
Furthermore, in this invention, it is preferable that the said support structure shall be made to contact | abut the both ends side to the position of the both ends side of the horizontal width direction in the front surface or / and the rear surface of the said heavy structure, respectively.

Further, in the present invention, the height of the protruding portion from the ground or mound in the support structure is lower than the vertical height of the weight structure in a state of being disposed on the ground or mound. can do.
Furthermore, in the present invention, the support structure is formed of a plurality of steel pipe sheet piles or steel sheet piles, and the adjacent steel pipe sheet piles or steel sheet piles are fixed so that their mutual positions are immobile. Accordingly, it is preferable that in-plane shear deformation hardly occurs in the support structure.

In the present invention, the support structure may be provided with a connecting member that connects the both ends of the support structure and reinforces the support structure on both ends.
Furthermore, according to a specific configuration aspect of the present invention, the weight structure is formed in a rectangular parallelepiped shape, and the support structure is formed in a semicircular shape in plan view.

According to the present invention, the support structure that supports the heavy structure is formed in a curved shape that is convex in a direction opposite to the heavy structure in plan view, and both ends abut against the heavy structure, and By placing on the ground with the upper end projecting upward from the ground or mound, the horizontal force from the heavy structure can be directly received to prevent breakage of the breakwater.
In addition, since only the both end sides of the support structure are in contact with the heavy structure, the influence of changes in the ground properties of the mound immediately adjacent to the heavy structure and the ground due to the placement of the support structure is locally affected. Thus, sliding and sinking of the heavy structure due to the placement of the support structure can be suppressed.

Furthermore, since the support structure is formed in a curved shape that protrudes in a direction opposite to the heavy structure in a plan view, the pressure receiving area for the ground and the mound can be increased due to the arch effect, and the weight High rigidity can be ensured with respect to the force from the direction of the structure. As a result, a large force from the heavy structure can be received reliably and stably, and the large elastic deformation of the support structure as a whole can be suppressed, and the mound and ground can be destroyed by the support structure and the restraint pressure can be reduced. Generation | occurrence | production of the fall of the intensity | strength by a release, a sliding fracture, etc. is suppressed, and the sliding and sinking of a heavy structure can be suppressed.
In addition, even if an abrupt flow field formed in a gap between adjacent heavy structures occurs, the support structure controls the water flow from the flow field so that the water flow is on the rear side in the immediate vicinity of the heavy structure. Therefore, it is possible to prevent a decrease in the supporting force with respect to the heavy-weight structure because the scouring of the mound and the ground is suppressed.

  Therefore, even if a load accompanying large energy such as an unexpected tsunami acts and the heavy structure moves, the support structure can prevent complete breakage of the breakwater due to the heavy structure sliding or sinking. Thus, it is possible to obtain a gravitational breakwater having a tenacious structure that does not lose all the breakwater functions in an instant.

1 is a partially broken perspective view schematically showing an embodiment of a gravity breakwater according to the present invention. FIG. It is the same top view. It is a schematic diagram explaining the water flow from the flow field which generate | occur | produces in the clearance gap between heavy weight structures. It is sectional drawing which shows typically different embodiment of the gravity type breakwater which concerns on this invention. It is the (a) perspective view and (b) top view showing typically the state where the connecting member was attached to the support structure in the gravity type breakwater concerning the present invention. It is sectional drawing which shows typically an example of the reinforcement structure of the conventional weight type breakwater.

1 to 3 show an embodiment of a gravity breakwater according to the present invention. A breakwater 1 according to this embodiment is disposed on a mound 3 formed on a ground 2 in the sea. A weight structure 4 for preventing waves and a wall-like support structure 5 extending in the vertical direction are provided on the rear surface side of the weight structure 4.
In the present invention, the front side of the heavy structure is basically the direction opposite to the land (in the case of a port, the outside of the port), and the rear side of the heavy structure is basically the land. It points to the opposite direction (in the case of a port, the inner side of the port). Moreover, the breakwater in this invention points out the thing by which the front side and rear surface side of a heavyweight structure face the sea, and also contains what is called a wave breakwater notionally.

The weight structure 4 is, for example, a caisson formed in a concrete box shape and filled with crushed stone or the like, or a stacked block formed of concrete. It resists by receiving the received load.
In this embodiment, a concrete caisson formed in a substantially rectangular parallelepiped shape is used, and is placed on the mound 3 with a part of the upper end side protruding upward from the sea surface S. Further, as shown in FIG. 2, the breakwater 1 has a configuration in which a plurality of caissons as the heavy structure 4 are arranged side by side in a state where gaps 6 having a predetermined interval are provided.
The mound 3 is formed of crushed stone or the like piled up to a predetermined height on the ground 2 in the sea. The upper end portion is a flat surface, and the heavy structure 4 is stably placed thereon. Can be done.

The support structure 5 has a function of receiving the horizontal force from the heavy structure 4 and supporting the heavy structure 4.
Specifically, the support structure 5 is formed in a curved shape (arch shape) that protrudes in a direction opposite to the weight structure 4 in plan view, and both ends are on the rear surface side of the weight structure 4. In the state where the upper end side protrudes upward from the mound 3 on which the heavy structure 4 is disposed, that is, in the state where the protruding portion 5a is formed, and is placed on the ground 2 with a sufficient amount of penetration. Yes.
In this embodiment, the support structure 5 has a substantially semicircular shape in plan view in which the diameter of the wall surface (outer peripheral surface in plan view) opposite to the weight structure 4 is substantially the same as the lateral width of the weight structure 4. It is formed in a shape, and both end sides thereof are in contact with positions on both end sides in the lateral width direction on the rear surface of the weight structure 4 and are placed in a state of being not connected to the weight structure 4.
Further, the support structure 5 of this embodiment is formed of a plurality of steel pipe sheet piles, and the adjacent steel pipe sheet piles are, for example, welded, or a connecting portion such as a joint is hardened with a solidified material such as concrete, etc. It connects using arbitrary means and these adjacent steel pipe sheet piles are mutually fixed so that a mutual position may not be fixed. Thereby, it has the structure where the in-plane shear deformation in the support structure 5 is suppressed as much as possible.

Here, the support structure 5 is formed in a curved shape (arch shape) that protrudes in a direction opposite to the heavy structure 4 in plan view, and both ends are on the rear surface side of the heavy structure. The reason for making contact with 4 is as follows.
First, the first reason is to reliably and stably receive the force from the heavy structure and to suppress the elastic deformation of the entire support structure 5 as much as possible.
As described above, when a heavy structure receives a load accompanying energy such as a tsunami, the heavy structure moves in the direction of the support structure and presses the support structure. A force that causes elastic deformation that curves so as to be convex in the direction of the heavy structure acts on the received support structure. At this time, if the entire support structure is greatly elastically deformed, the protruding portion of the support structure pressed by the heavy structure presses and destroys a part of the mound and the ground on the back side, or the support structure In the buried part of the body, the elastic deformation of the support structure causes a decrease in strength or slip failure due to the release of restraint pressure in the vicinity of the support structure, that is, the ground or mound directly under the heavy structure, and the weight This may cause the structure to slide or sink.

Therefore, in the present invention, the support structure is formed in a curved shape that protrudes in a direction opposite to the heavy structure in plan view, and is in conflict with the heavy structure as compared with the lateral width of the heavy structure. The area of the side wall is increased, and the pressure receiving area of the support structure against the ground and mound can be increased by the arch effect, so that it can be supported reliably and stably against the large force from the heavy structure. The high rigidity can be secured against the force from the direction of the heavy structure.
In particular, since the support structure 5 of this embodiment is formed in a substantially semicircular shape in plan view, the arch effect can be enjoyed stably and efficiently.

The second reason is to suppress the influence of the change in the ground properties of the mound 3 and the ground 2 caused by the placement of the support structure 5 on the heavy structure 4 as much as possible.
That is, when the support structure is placed in the immediate vicinity of the heavy structure, it is considered that the ground and the ground properties of the mound and the ground accompanying the placement of the support structure are changed, and the ground and the mound are loosened. Doing so makes the installation of heavy structures on the mound or the ground unstable and makes it easier to slide.Therefore, the heavy structures are affected by changes in the ground properties due to the placement of the support structure. It is necessary to suppress as much as possible.
Therefore, in the present invention, by placing the support structure on the mound or ground with only the both ends of the curved support structure in contact with the heavy structure, the change in the ground properties accompanying the placement of the support structure In such a way that it falls within a very small range in the immediate vicinity of the heavy structure. Thereby, the influence on the heavy structure is suppressed as much as possible by minimizing the influence of the change in the ground property locally and to the minimum.

Further, as a third reason, the load in the horizontal direction of the heavy structure 4 is received in a well-balanced manner to prevent the heavy structure 4 from sliding, and abruptly formed in a gap between adjacent heavy structures. This is to control the direction of the water flow from the proper flow field and suppress the influence of the water flow on the heavy structure or the like.
The influence of the water flow from the flow field will be described in detail. When a plurality of heavy structures are arranged at a certain interval, such as a gravity breakwater as in the present invention, when waves and tsunamis are approached, A steep flow field is formed in the gap between adjacent heavy structures.
For example, as shown in FIG. 4, when a tsunami or the like comes from the front side of the heavy structure 4, the gap 6 between the heavy structures 4, 4 has a rear side direction (indicated by a white arrow in FIG. 4). Direction) flow field. And since the water flow from this flow field tends to flow so that it may spread near the rear surface side of each heavy structure 4,4 as the arrow in FIG. 4, the rear surface of each heavy structure 4,4 The side mound 3 and the ground 2 may be scoured. On the other hand, in the case of a pulling wave, a rapid flow field in the direction from the rear side to the front side of the heavy structure is formed in the gap between adjacent heavy structures, and the water flow flows to each heavy structure. Since it flows so that it may spread near the front side of the mound, the mound and ground on the front side of each heavy structure may be scoured.
As described above, when the mound and the ground before and after the heavy structure are scoured, the supporting force for the heavy structure is greatly reduced and the heavy structure is likely to be swept away. The function of the breakwater can be lost in an instant.

Therefore, in the present invention, the support structure is formed in a curved shape that protrudes in a direction opposite to the heavy structure in plan view, and both end sides are formed on the rear surface side of the heavy structure. By abutting, the direction of the water flow is controlled so that the water flow from the abrupt flow field formed in the gap between adjacent heavy structures does not flow near the rear surface of the heavy structure. As a result, the surface side of the support structure facing the heavy structure (the inner peripheral surface side in plan view) is not affected by water flow, so the mound and ground near the rear surface of the heavy structure and in the vicinity thereof can be scoured. It is suppressed so that the occurrence of sliding destruction can be suppressed.
In particular, in the case of this embodiment, the support structure 5 is formed in a substantially semicircular shape in plan view in which the diameter of the wall surface on the side opposite to the heavy structure is substantially the same as the lateral width of the heavy structure. Therefore, it is possible to reliably prevent the water flow from the flow field of the gap 6 between the heavy structures 4 and 4 from flowing into the immediate vicinity of the entire rear surface of the heavy structure 4.

Further, in this embodiment, the both ends of the support structure 5 are brought into contact with the heavy structure 4 in a non-connected state in order to simplify the installation work and reduce the installation cost.
That is, in the prior art, a heavy structure such as a caisson is connected to a wall-like structure that supports the heavy structure, so that the configuration of this point is complicated and the installation work is very troublesome. There were drawbacks. In addition, as in the present invention, in the case of a breakwater installed in a sea area sandwiched between the front and both sides of the front side and the rear side, the front side is the sea and river, while the rear side is land-based compared to the seawall structure Since the installation work is very large and difficult, the work for connecting the heavy structure and the wall-like structure as described above is very burdensome both in terms of labor and cost.

Therefore, in the embodiment, by omitting the connection work between the heavy structure 4 and the support structure 5 and simplifying the configuration of the entire breakwater, while ensuring the performance as a breakwater, The construction can be performed very easily as compared with a configuration requiring a simple connection.
As a result, it is possible to save the labor of construction work as compared with the prior art, and it is possible to reduce construction costs accordingly.

By the way, the height of the protruding portion 5 a protruding from the mound 3 in the support structure 5, that is, the height of the upper end of the placed support structure 5 is the height of the weight structure 4 placed on the mound 3. It is lower than this. In the case of what is shown in FIG. 1, the protrusion height of the protrusion part 5a of the support structure 5 is less than or equal to half the height of the heavy structure 4, and therefore the support structure 5 is located in the sea as a whole. Yes.
As described above, the projecting height of the projecting portion 5a of the support structure 5 is lower than the height of the weight structure 4 placed on the mound 3 because the support structure is mainly formed from the weight structure. This is because a structure that can support the horizontal load and obtain the effect of suppressing horizontal displacement such as sliding of the heavy structure and that can ensure at least the effect is sufficient.

In constructing a breakwater having the above-described structure, first, a mound 3 having a predetermined height is formed on the ground 2, and a heavy structure 4 is placed and disposed on the mound 3. The mound 3 and the heavy structure 4 at this time may be newly established, but may be an existing mound and heavy structure. Therefore, the already built breakwater mound and heavy structure are used. can do.
Thereafter, the support structure 5 extending in the front-rear direction of the weight structure 4 on the rear surface side of the weight structure 4, more specifically in the direction orthogonal to the rear surface of the weight structure 4, One end side is in contact with the heavy structure 4 in a non-connected state, and is placed in the vertical direction on the ground 2 with the upper end side protruding upward from the mound 3 on which the heavy structure 4 is disposed. As a result, the breakwater 1 having a tenacious structure is completed.

At this time, when the tsunami or the like approaches, the support structure 5 directly receives the horizontal force from the heavy structure 4 and supports the heavy structure 4. Can be destructed without losing it in an instant.
Further, the support structure 5 is formed in a curved shape that is convex in a direction opposite to the weight structure 4 in plan view, and only both end sides are in contact with the rear surface side of the weight structure 4. The influence of changes in the ground properties of the mound 3 and the ground 2 in the immediate vicinity of the heavy structure 4 due to the placement of the support structure 5 is locally and minimized. Thereby, the sliding and sinking of the heavy structure 4 accompanying the change of the ground property resulting from placement of the support structure 5 can be suppressed.

Furthermore, since the support structure 5 is formed in a curved shape that is convex in a direction opposite to the heavy structure 4 in plan view, the pressure receiving area for the ground 2 and the mound 3 can be increased by the arch effect. In addition, high rigidity can be secured against the force from the direction of the heavy structure.
Therefore, even if a large force is applied to the heavy structure 4 due to an unexpected tsunami or the like, the force from the heavy structure 4 can be reliably and stably received. In addition, the elastic deformation of the support structure 5 as a whole is suppressed, and the mound 3 and the ground 2 are destroyed due to the elastic deformation of the support structure 5, the strength is reduced due to the release of the restraint pressure, and the sliding failure occurs. Is suppressed, and sliding and sinking of the heavy structure 4 can be suppressed.

  Furthermore, even if an abrupt flow field formed in the gap 6 between the adjacent heavy structures 4 and 4 occurs, the support structure controls the direction of the water flow from the flow field so that the water flow In order to prevent the water structure from flowing into the rear surface immediately adjacent to the heavy structure, scouring of the mound and ground near the heavy structure due to the water flow can be suppressed, and a decrease in the supporting force for the heavy structure can be suppressed.

  As a result, even if a heavy energy load such as an unexpected tsunami acts on the heavy structure 4 and the heavy structure 4 moves, the support structure 5 slides or sinks the heavy structure 4. Since the complete breakage of the breakwater due to the damage is suppressed, it is possible to obtain a gravitational breakwater with a tenacious structure that does not lose all the breakwater functions in an instant.

In the above embodiment, the support structure 5 is disposed only on the rear surface side of the heavy structure 4, but the support structure may be disposed on the front surface side of the heavy structure.
Furthermore, as shown in FIG. 5, the support structure may be disposed on both the front side and the back side of the heavy structure. In this way, when the support structure is provided on both the front side and the rear side of the heavy structure, the effect of the present invention is exhibited even in the case of a tsunami or the like. Useful. In addition, about each structure of the ground structure and mound in FIG. 5, the weight structure which forms a gravity type breakwater, and a support structure, it is substantially the same as the said embodiment fundamentally, and the same In order to achieve the effect, the same reference numerals are given and detailed description is omitted.

Further, in the above-described embodiment, the support structure 5 is formed in a substantially semicircular shape in plan view. However, the support structure is curved so as to protrude in a direction opposite to the heavy structure in plan view. If it is formed in a shape, it does not necessarily have a substantially semicircular shape in plan view, and may be a shape that is curved with an arbitrary curvature.
Moreover, in the case of the said embodiment, although the said support structure 5 is making the both ends contact | abut to the position of the both ends of the width direction in the rear surface of the said heavy structure 4, respectively, Depending on the size and the like, it is not always necessary to bring both ends into contact with the positions on both ends in the width direction of the heavy structure.
Furthermore, in the said embodiment, although the both ends of the said support structure 5 are set as the structure contact | abutted with the said heavy structure 4 in the non-connecting state, a support structure and a heavy structure are not necessarily connected. It is not necessary to be in a state, and they may be connected to each other.

Moreover, in the said embodiment, although the said support structure 5 is laid in the ground 2 in the state which penetrated the mound 3, depending on the magnitude | size of a support structure or a mound, one part or all part is a mound. It may be placed directly on the outside ground.
Furthermore, in the above embodiment, the heavy structure 4 is placed on the mound 3 formed on the ground 2. However, depending on various conditions such as the shape of the ground surface and the ground properties, the heavy structure is You may make it mount directly on.

Moreover, about the height of the protrusion part 5a which protruded from the ground 2 or the mound 3 in the said support structure 5, like the said embodiment, the said heavy structure in the state arrange | positioned on the ground or a mound The height does not need to be less than half of the height in the vertical direction, and does not necessarily need to be lower than the height in the vertical direction of the heavy structure, and can be set appropriately.
Further, when placing the support structure 5 on the ground 2, unlike a normal steel pipe pile or the like, it is not always necessary to root the lower end side of the support structure up to the support layer of the ground, and the depth of penetration Alternatively, the amount of penetration can be arbitrarily set within a range that does not hinder, according to various conditions such as the surrounding environment.

  Moreover, in the said embodiment, although it is set as the thing of the structure formed in the wall shape curved using the some steel pipe sheet pile, as a support structure, fundamentally in planar view It is formed in a curved shape that protrudes in a direction opposite to the heavy structure, and can have any configuration as long as it has high rigidity and is less likely to cause in-plane shearing. For example, it is formed using a steel sheet pile or the like. It may be a thing.

Further, as shown in FIG. 6, the support structure is connected to the both ends so as to bridge both ends of the support structure 5 so as to reinforce the support structure. The connecting member 7 may be attached. As a result, the support structure has higher strength against the compressive force and tensile force in the radial direction, and the shape retaining property is further improved. Therefore, the support structure more stably resists the large force from the heavy structure, and the weight It becomes possible to effectively support the structure.
In the example shown in FIG. 6, the upper ends of both ends of the support structure 5 are connected to each other by the connecting members 7, but the connecting members may be arranged at a plurality of locations of the support structure.

DESCRIPTION OF SYMBOLS 1 Breakwater 2 Ground 3 Mound 4 Heavy structure 5 Support structure 6 Crevice 7 Connection member

Claims (7)

A weight structure for wave protection disposed on the ground or a mound provided on the ground, and a weight structure disposed on at least one of the front side and the rear side of the weight structure. A wall-like support structure extending in the vertical direction that supports the weight structure by receiving a horizontal force from the object,
The support structure is formed in a curved shape that protrudes in a direction opposite to the heavy structure in plan view, the both ends abut against the heavy structure, and the ground on which the heavy structure is disposed Or the gravity type breakwater characterized by being laid in the ground with the upper end side protruding upward from the mound.   The gravity type breakwater according to claim 1, wherein the support structure is in contact with the heavy structure in an unconnected state.   3. The support structure according to claim 1, wherein both ends of the support structure are brought into contact with positions on both ends in the lateral width direction on the front surface and / or rear surface of the heavy structure. Gravity breakwater.   The height of the protruding portion from the ground or mound in the support structure is lower than the height in the vertical direction of the heavy structure in a state of being disposed on the ground or mound. The gravity type breakwater according to claim 3.   The said support structure is formed with several steel pipe sheet piles or steel sheet piles, and the adjacent steel pipe sheet piles or steel sheet piles are being fixed so that a mutual position may not be fixed. The gravity type breakwater according to claim 4.   6. The support structure according to any one of claims 1 to 5, wherein a connecting member that reinforces the support structure by connecting both ends of the support structure to each other is attached to both ends. Gravity breakwater described in Crab.   The gravitational breakwater according to any one of claims 1 to 6, wherein the weight structure is formed in a rectangular parallelepiped shape, and the support structure is formed in a semicircular shape in plan view. .

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