JPH0663211B2 - Flexible mound - Google Patents

Description

TECHNICAL FIELD The present invention relates to a submerged submerged dike which controls the propagation of waves near the coast and the movement of sand such as the seabed, and is particularly useful for flexible submersible materials. Flexible mound (flexible submerged dike) using a bag

“Prior art” Conventionally, as a submerged dike for controlling waves and sand near the coast, a method of using caisson or a method of stacking wave-dissipating blocks in the sea is generally used.

By the way, in the above-mentioned submerged dike, caisson and a large amount of wave-dissipating blocks must be transported to the site, and foundation work such as seabed leveling and mound at the construction site is required, resulting in a long construction period and high costs. There is a problem such as. Further, if it is necessary to move or remove the structure after installation, the work requires a very long period and cost.

Moreover, it's built with caisson and wave-dissipating blocks,
A so-called rigid structure submerged dike breaks the waves on the top of the crest and continues the turbulence due to the breaking on a wide range of the top of the crest to eliminate the energy loss of the wave. Therefore, in order to obtain a sufficient wave-dissipating effect with such a submerged dike, the top of the submerged dike is raised close to the water surface, the submerged dike becomes very large, and the navigation of vessels etc. There is a problem that it becomes an obstacle.

Therefore, the present applicant has, as an effective means for solving the above-mentioned problems, a bag body made of a sheet-shaped flexible material fixed and held by an anchor or the like on the seabed, and is injected into the bag body. We proposed a flexible mound (soft structure submerged dike) consisting of a fluid such as seawater or air that inflates the bag (Japanese Patent Application No. 60-280790). This flexible mound facilitates work such as transportation, construction, movement, or removal, and expects effective wave-dissipating effect even on a small scale by utilizing the flexibility of the flexible mound itself. it can. That is, since waves can be controlled by a small structure sufficiently submerged below the sea surface, it is rational that the sea area in which the flexible mound is installed can be effectively used, and attention has begun.

Here, the principle of wave cancellation of this flexible mound will be described.

As shown in FIG. 10, it is assumed that a flexible mound 20 in which a fluid such as seawater is injected into a bag made of a flexible material is installed on the seabed G. At this time, when the incident wave W arrives at the flexible mound 20 along the sea surface S, the energy of the incident wave W is transmitted to the flexible mound 20, and the flexible mound 20 changes as shown by the dotted line in FIG. . Along with this change, a radiation wave R is radiated from the flexible mound 20 itself toward the sea surface S as shown by an arrow A in the figure, and the radiation wave R and the incident wave W interfere with each other to cancel the wave. At the same time, the energy of the incident wave W is consumed to deform the flexible mound 20, and the energy of the incident wave W is attenuated, so that the incident wave W is extinguished.

Therefore, the flexible mound 20 made of a flexible material
As in the case of the conventional rigid structure submerged dike, as described above, the incident wave is broken at the crown of the submerged dike, and the disturbance due to the breaking wave is continued over the width direction of the submerged dike to cancel the wave. Since it is not necessary to do so, the water depth at the top of the flexible mound 20 can be deepened and the scale in the bank width direction can be made small.

By the way, when fixing and fixing such a flexible mound on the seabed, first make a bag on land and fix the bag to the seabed with an anchor or the like via a concrete foundation, or Means such as so-called gravity-type fixing, which is to fill up with earth and sand etc., can be considered.

An embodiment of a method of constructing a flexible mound using this gravity type fixing method will be described with reference to FIGS. 11 to 14.

First, an upper bag and a lower sheet are joined together to produce an integrated bag body 21 on land O, and the bag 21 is pulled out to the sea. Next,
The bag body 21 is supported by the mooring lines F, F laid on the two work boats D, D. In this case, the seawater B can be appropriately stored in the bag 21.
It is preferable to inject (or seawater B and air A) into the shape of the bag 21 and adjust the injection amount so that the specific gravity of the bag 21 is slightly smaller than that of seawater. While preparing the bag body 21 in this way, in the planned sea area, the concrete foundations C, C for installing the bag body 21 are fixed by driving the piles K, K onto the seabed ground G. . Then, the bag body 21 towed by the work vessels D, D and carried to the planned sea area is sunk to the sea bottom by slowly extending the mooring search F, F of the two work vessels D, D, and the seabed ground. The concrete foundations C, C provided on G are connected to each other using connecting means such as bolts and nuts. afterwards,
The work boat E equipped with the pump P is operated to the sea area where the flexible mound 20 composed of the bag body 21 is installed, and the pump P is used to fill the sand H from the filling valve 22 into the bag body 21.
Excess seawater B is discharged while injecting the mixture of water and seawater B
When the bag 21 is discharged to the outside, the bag 21 is filled with a predetermined amount of a mixture of sand H and seawater B, and the bag 21 is inflated to a predetermined shape.

[Problems to be Solved by the Invention] However, in the method of constructing a flexible mound as described above, in order to tow the bag body while submerged in seawater by the work boat, resistance of seawater to the bag body and In consideration of balance, balance, etc., it is necessary to perform work such as injecting seawater into the bag, work to transport materials such as concrete foundation to the planned sea area, installation of concrete foundation, and installation of this foundation. Submarine work such as fixing the bag is required. Therefore, the construction of this flexible mound is very time-consuming, and the construction period becomes long, which may result in high cost.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a flexible mound that can be easily and quickly transported to a planned sea area, fixed to the seabed, and installed.

"Means for Solving the Problem" In the flexible mound of the present invention, a bag body made of a sheet-shaped flexible material and inflated by injecting a fluid, and the bag body disposed on the outer periphery of the bottom portion of the bag body. And an anchor block body having a hollow steel caisson provided with an opening penetrating inward and outward in its upper part.

[Operation] To anchor the flexible mound to the planned sea area by arranging the anchor block body made of steel caisson on the bottom of the bag and using this anchor block body as a towing floater on land. In particular, since the anchor block serving as a towing floating body is arranged on the outer periphery of the bag body, the towing state is extremely stable. Further, the bag body may be connected to the anchor block body not only on the ground but also on the sea surface with the anchor block body floating above the sea surface. In the sea area where the installation is planned, the hollow inside of the block body for anchor of this flexible mount is filled with a filling material such as concrete and rubble stone from the opening, and the fluid is injected into the bag body, and the flexible mound is sunk to the seabed. The flexible mound is fixed by fixing the anchor block body by staking it on the seabed.

[Examples] Examples of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention.
Reference numeral 1 in the figure is a flexible mound of the present invention.

As shown in FIGS. 1 and 2, the flexible mound 1 is roughly composed of a bag body 2 forming an outer shell and an anchor block body 3 arranged at the bottom of the bag body 2.

The bag 2 is made of a rubber sheet, as shown in FIG.
An upper sheet 4 which is made of a sheet-like flexible material such as a vinyl chloride sheet and has a flat and convex upper surface, an anchor block body 3, and a lower sheet 5 which is in contact with the seabed G However, the structure is such that these edge portions are integrally joined. Below the upper sheet 4 of the bag body 2, a filling valve 6 for injecting and filling seawater and sand into the bag body 2 and a discharge valve 7 for discharging the extra seawater injected inside to the outside. And are provided respectively.

As the lower sheet 5 of the bag body 2, it is preferable to use a highly flexible sheet that can follow unevenness of the seabed particularly better than the upper sheet 4 and the like. The flexible material to be formed is not limited to the above-mentioned rubber or vinyl chloride, but may be a synthetic resin such as polyethylene or a rubberized cloth. Furthermore, the planar shape of the bag body 2 is, for example, a circle, an ellipse, an oval, or the like, but is not limited thereto.
However, when there is a longitudinal direction in the shape of the bag body 2 such as an elliptical shape or an oval shape, it is preferable that the longitudinal direction is made substantially orthogonal to the traveling direction of the incident wave that arrives along the sea surface.

Further, the lower sheet 5 of the bag body 2 is provided with a mounting piece 8 to be fixed to the anchor block body 3 at a peripheral portion joined to the upper sheet 4, and the mounting piece 8
Are provided with connection holes 9, 9, ....

As shown in FIG. 4, the anchor block body 3 includes two block portions 10 and 10 each made of a hollow caustic steel caisson.
And a bag support portion 11 which is framed by strip steel plates and has two block portions 10, 10 fixed at both ends. The block parts 10 and 10 penetrate from the top surface to the bottom surface and are provided with several watertight pile driving holes 12, 12, ... And the top surface is filled with a filling material such as concrete or rubble. Are provided with penetrating openings 13, 13 ,. The flexible mound 1 is fixed on the seabed ground by driving the piles into the seabed ground through the pile driving holes 12, 12, .... Further, on the upper surfaces of the block portions 10, 10, there are provided connection holes 14, 14, ... For attaching the bag body 2 along the longitudinal direction thereof. The connection holes 14, 14,
And a connecting hole 9 provided in the attachment piece 9 of the bag body 2,
, 9 and so on, and the bag body 2 and the anchor block body 3 can be connected by connecting means such as bolts and nuts.

Next, an example of the method for constructing the flexible mound of the present invention will be described with reference to FIGS. 5 to 9.

First, as shown in FIG. 5, an upper bag 4 and a lower sheet 5 are joined to form an integrated bag body 2 on land O, and this bag body 2 is used as an anchor block body 3. Install it. At this time, the insides of the block portions 10 and 10 of the bag body 2 and the anchor block body 3 are empty.

Next, the anchor block body 3 to which the bag body 2 is attached is pulled out to the sea, and the anchor block body 3 is connected to the mooring line F laid on the work boat D as shown in FIG. In this case, seawater B is appropriately injected as ballast into the bag body 2 and air A is filled in the voids inside the bag body 2 to adjust the shape and balance of the bag body 2 and facilitate the towing by the work boat D. Is preferred.

Next, the anchor block body 3 with the bag body 2 attached
Is towed by the work vessel D to the planned sea area. At this time, although the longitudinal direction of the anchor block body 3 is perpendicular to the traveling direction of the work boat D in the figure,
If the towing is performed such that the traveling direction and the longitudinal direction are parallel to each other, the resistance of seawater is reduced and the towing by the work boat D becomes easier. When the flexible mount is towed, the block portions 10 and 10 of the anchor block body 3 can be effectively used as a floating body for towing, and the block portions 10 and 10 are arranged on the outer periphery of the bag body 2 and are connected to each other. The towed condition is extremely stable because it is operated. Since the block portions 10, 10 of the anchor block body 3 are floating bodies in this manner, first, the anchor block body 3 is towed to the planned sea area and the bag body 2 is anchored to the anchor block body 3 on the ocean.
It may be attached to.

Then, when the water arrives at the planned sea area, the opening 1 is formed inside the block parts 10 and 10 of the anchor block body 3 and inside the bag body 2.
3, 13, ... and seawater are injected from the filling valve 6 and the air A
The anchor block body 3 to which the bag body 2 is attached is sunk to the seabed by increasing the specific gravity while removing the water from the discharge valve 7. The anchor block body 3 is supported by the mooring lines F and F of the two work boats D and D, and as shown in FIG.
Even by anchoring the anchor block body 3 to which the bag body 2 is attached on the seabed ground G by slowly extending the mooring lines F, F,
Piles K, K in the pile driving holes 12, 12, ... Of the anchor block body 3.
Then, the piles K, K are driven and fixed on the seabed G. Further, a filling material such as underwater concrete or rubble is filled into the hollow interiors of the block portions 10 through the openings 13 on the upper surface to form the foundation of the flexible mound 1.

When the flexible mound is settled on the seabed as described above, as shown in FIG. 8, the work boat E equipped with the pump P is operated to the sea area where the flexible mound 1 is installed, and The filling valve 6 and the discharge valve 7 of the bag body 2 are opened, and while the mixture of sand H and seawater B is injected into the bag body 2 from the filling valve 6 by the pump P, the excess seawater B is discharged from the discharge valve 7. By discharging to the outside, a predetermined amount of sand H and seawater B are injected into the bag body 2 and filled,
With this, the bag body 2 is inflated to a predetermined shape. This sand H
Needless to say, it may be sediment on the seabed in the flexible mound installation area, or sediment transported from another place.

By the construction method described above, the flexible mound 1 is installed on the seabed G as shown in FIG.

Here, since this flexible mound 1 is fixed by driving a pile into the seabed ground G, it can be installed regardless of the soil quality of the seabed ground G. In addition, by obtaining a foundation of a structure in which a filling material such as underwater concrete and rubble is filled in the hollow inside of the block portion 10 of the anchor block body 3 from the upper opening portions 13, 13 ,.
The installation condition is stable for a long period of time, and the wave-dissipating function is maintained for a long time.

The details of the flexible mound of the present invention are not limited to those in the above embodiment, and various modifications are possible.
As an example, the flexible mound is not limited to a single bag body, and may have a configuration in which a large number of bag bodies are continuously provided. Further, the fluid injected and filled in the bag body may be a fluid other than seawater such as air, and similarly, the filler filled in the bottom portion of the bag body is not only sand but also sand sand muddy water or the like having a larger specific gravity. In other words, the structure may be such that the filler is omitted.

Further, the anchor block body used in the present invention,
The present invention is not limited to the above-described embodiment, and for example, by using a steel caisson formed in a ring shape, it is possible to prevent scour at the lower portion of the bag body.

"Effects of the Invention" As described above, the flexible mound of the present invention is made of a sheet-shaped flexible material and swells by injecting a fluid, and the bag is disposed on the outer periphery of the bottom of the bag. It is composed of an anchor block body having a hollow steel caisson with a bag body connected to the bag body and an opening penetrating the inside and the outside of the bag body.If only the bag body can be attached to the floating body on the ground. The anchor block body can be used as a floating body when transported by towing to the planned sea area, and this anchor block body is arranged and connected to the outer periphery of the bag body, so that the towing state is extremely stable. At the same time, it is possible to float the anchor block body on the sea surface and connect the bag body to the sea surface, etc., so that it can be transported to the planned sea area, fixed to the seabed, and installed. The work will be simple, safe and quick. In addition, when anchoring on the seabed, not only fixing the anchor block body to the seabed ground by means such as pile driving, but also filling the anchor block body with a filler such as concrete and rubble from the upper opening. By filling, the installation condition is stable for a long period of time, and the wave-dissipating function is maintained for a long time.

[Brief description of drawings]

1 to 4 are views showing an embodiment of the flexible mound of the present invention. FIG. 1 is a top view showing the structure of the present invention, and FIG. 2 is taken along the line II-II of FIG. Sectional view, FIG. 3 is a perspective view of a bag body, FIG. 4 is a perspective view of a block body for anchors, and FIGS. 5 to 9 are diagrams for explaining a flexible mound construction method of the present invention. FIG. 11 is a diagram for explaining the wave-dissipating principle of a flexible mound, and FIGS. 11 to 14 are diagrams for explaining a conventional flexible mound construction method. G: Submarine ground, 1 ... Flexible mound, 2 ... Bag, 3 ... Anchor block, 13 ... Opening.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Tanaka 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Takumi Oyama 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Building Co., Ltd. (72) Inventor Tadashi Ono 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Satoshi Kiyokawa 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Building (72) Inventor Hiroshi Ouchida 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Hisao Abe 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Stocks In-house (56) References JP-A-62-141209 (JP, A)

Claims (1)

[Claims] 1. A bag body which is made of a sheet-shaped flexible material and swells by injecting a fluid, and an opening which is arranged on the outer periphery of the bottom portion of the bag body and which is connected to the bag body and which penetrates the inside and outside of the upper part thereof. A flexible mound, which comprises an anchor block body having a hollow steel caisson provided with a portion.