JPS61106812A - Scouring preventing device for submerged structure - Google Patents

Abstract

PURPOSE:To prevent scouring of a spot below a structure, by a method wherein sheets, laid on the bottom of a submerged structure, are extended from the structure, heavy objects, connected in parallel to free edges of the sheets for extension, are placed on the upper surface of the sheets to couple the weight objects to the sheets. CONSTITUTION:Sheets 3 are laid between a submerged structure 1 and a sea bottom 2, and the sheets 3 are extended from the structure 1 to form an extension part 4. Heavy objects 5, each made of an H-steel, are placed in the vicinity of the forward end of the extension part 4, and the heavy objects 5 are intermittently coupled to sheet parts 8 through coupling tools 10. A spot below an edge part 6 of the sheet 3 and a spot below the heavy object 5 are scoured by a water flow or waves, and the sheet 3 is buried in earth in the sea bottom 2 togetherewith the heavy object 5 for stabilization.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method of cleaning a structure by scouring the bottom of an underwater structure by water currents or waves in a seawall, embankment, etc. of a river, a harbor, etc. Or it relates to a device for preventing tilting.

" Yone Gokun As a scouring prevention device for such underwater structures, conventionally, the edge of the protruding part of the flexible sheet body, which is laid and fixed at the bottom of the underwater structure, protrudes from the structure. It is known to prevent the scouring of the earth and sand of the #If structure by attaching heavy objects to the ground and scouring and burying the heavy objects in the earth and sand. No. 45-35990 and Japanese Patent Publication No. 45-35990.

In other words, the former of the above-mentioned publication discloses a structure in which a cylinder is attached to the back side of the free edge of the seat body, leaving gaps here and there, and the cylinder is filled with heavy objects such as crushed stone, concrete, iron material, etc. Such a sheet body is laid on the bottom of the water with the cylindrical body filled with the heavy object facing downward. This cylindrical body moves up and down along with the seat body due to the water flow or waves, and due to the free movement and the scour on the bottom surface of the tip of the seat body caused by the water flow, the seat body curves downward with the cylindrical body filled with heavy objects at the tip. It is buried in the soil at the bottom of the water, and once it is buried to a certain extent, it becomes stable and further scouring and burial do not proceed.

Furthermore, in the latter of the above-mentioned publication, a flexible seat body is laid on the bottom of a structure, and an ornament is attached by means of a connector to the free edge of the swingable protrusion of the seat body that protrudes from the structure. A device is shown in which the protrusion is movably attached, and the protrusion and heavy objects are buried and fixed in the earth and sand by the rocking of the protrusion caused by water currents and waves.

However, in such conventional scouring prevention devices, the heavy objects are disposed intermittently with gaps remaining in the width direction of the sheet body, so the lower part of the heavy object at the tip of the sheet, The progress of scouring is different in the lower part of the part where there is no heavy object, so the sheet body is not buried uniformly, causing local distortion, and the load is concentrated in this part, or the water flow is caused by the electric field object. There were problems such as unnecessarily scouring to the back of the seat body through non-existent parts.

Therefore, the present invention improves the conventional scour prevention device as described above so that the entire sheet is buried evenly and without difficulty. Because, 1...“1
Oh JIl! 1llll,: 12, ka, □. Yo,
1) A sheet is extended from the structure, and a heavy object is placed on the upper surface of the sheet, extending continuously from the free edge of the sheet substantially parallel to the free edge at a distance from the free edge of the sheet toward the structure. and the heavy object is intermittently connected to the sheet.

According to the present invention, the heavy object is continuous over substantially the entire width of the sheet, and the edge of the sheet extends further outward from the heavy object, so that the edge of the sheet is protected by water currents or waves. The movement of the edge ensures that the bottom of the heavy object is
In addition, the entire width of the sheet is scoured evenly, and the sheet is buried uniformly in the bottom of the water without local deformation or distortion, and concentrated loads are not applied to the connection between the heavy object and the sheet. do not have.

1 blind The present invention will be described below with reference to the illustrated embodiments.

In Figure 1, 1 is an underwater structure such as a caisson;
It is installed on the water bottom E to constitute a seawall, embankment, etc. in a port, and a sheet 3, which is part of the scour prevention device according to the present invention, is laid between this structure 1 and the water bottom 2. ing. The sheet 3 is a flexible sheet made of synthetic resin, rubber, or the like, and has an extension 4 extending from the structure 1 along the water bottom 2. A heavy object 5 made of H-shaped steel or the like is placed near the tip of the extending portion 4, and the extending portion 4 has an edge portion 6 that protrudes further outward from the heavy object 5, and has a free end. It ends at edge 7.

As shown in FIG. 4, the sheet 3 is formed by connecting a large number of sheet pieces 8 laterally along the structure 1, and the sheet pieces 8 are connected to each other by connectors 9. . Each sheet piece 8 has, for example, a width B of about 6 m, a length of about 15 m, a thickness of about 5IIIR, and sufficient flexibility.

Near the free edge 7 of each sheet piece 8, the weight and jujube 5 are placed at a distance from the free edge 7 toward the structure 1 and approximately parallel to the free edge 7. An edge portion 6 is formed on the outer side of the heavy object 5.

The heavy object 5 is made of H-shaped steel as described above, and extends substantially throughout the entire seat piece 8.

Then, this heavy object 5 is connected to the sheet portion 8 via the connector 10 intermittently along its longitudinal direction, that is, intermittently.
is connected to. The length j of the edge 6 from the heavy object 5 to the free edge 7 should be such that the edge 6 is not bent inside the electric field object 5, that is, toward the structure 1 side, by water currents and waves. be.

FIG. 5 shows the connection 10 between the heavy object 5 and the seat piece 8 in more detail. As shown in the figure, 1
A hook 11 is fixed to the ffi product 5 by welding or the like, while a reinforcing sheet 12 is attached to the sheet piece 8, and a mounting piece 14 having an engagement hole 13 is attached to the reinforcing sheet 12. is fixed.

By locking the triangular ring 15 in the engagement hole 13 and passing the shackle 16 through the triangular ring 15 and the hook 11, the heavy object 5 is movably connected to the seat piece 8.

FIG. 6 shows details of the connecting device 9 for connecting adjacent sheet pieces 8, in which a mounting piece 17, 18 similar to the above-mentioned mounting piece 14 is fixed to each sheet piece 8, and one The loaves 19 are passed through the attachment piece 11 and the triangular ring 20 is passed through the other attachment piece 18.
and triangular rings 20 are connected by ring pieces 21.

Since this embodiment is configured as described above, the extension portion 4
When laid along the water bottom 2 as shown in Figure 1, the edge 6 at the tip moves due to the water flow or waves, and the edge 6 and the lower part of the heavy object 5 are washed away as shown in Figure 2. be dug. In this case, since the heavy object 5 extends continuously over the entire width of the sheet 3, the scour is performed evenly in the width direction of the sheet 3, and even if the edge 6 is rolled up, the scouring is carried out evenly in the width direction of the sheet 3. The scouring action progresses reliably because the object 1 is holding down the entire surface.

In this way, the sheet 3 sinks into the soil of the water bottom 2 together with the heavy object 5, and becomes stable as shown in Fig. 3.
This prevents scouring of the lower part of the structure 1, but since the scouring of the lower part of the sheet 3 is done evenly as shown in L, the sheet 3 sinks and is buried uniformly as a whole.
0i''''1 big 2 change Jf5 e t L; r II I
There is no risk of L/ic Q breakage. Further, there is no fear that a concentrated load will act on the connecting portion between the heavy object 5 and the seat 3.

As described above, in the present invention, a sheet laid at the bottom of an underwater structure is extended from the structure, and the
A heavy object is placed on the H surface, extending continuously and substantially parallel to the free end edge at a distance from the free end edge toward the structure,
Since the heavy object was intermittently connected to the sheet, the water bottom of the five parts of the sheet was scoured evenly and reliably in the width direction of the sheet, so that the entire sheet was evenly and effortlessly immersed in the soil at the water bottom. There is no fear that the structure will sink and be buried, resulting in excessive local deformation or damage due to the application of an excessive load, and it is possible to reliably prevent the lower part of the underwater structure from being scoured.

In addition, since the edge of the sheet protrudes in front of the heavy object, the movement of the edge promotes scouring of the heavy object at the bottom of the water, causing the heavy object to sink quickly. reaches a steady state early.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIGS. 1 to 3 are longitudinal sectional views showing the state of the device installed on the bottom of the water at various stages, FIG. 4 is a plan view of the device, and FIG. @A perspective view showing a connecting part between an accessory and a sheet piece; FIG. 6 is a perspective view showing a connecting part between sheet pieces. 1... Structure, 2... Underwater, 3... Sheet, 4...
...Extending portion, 5...Heavy object, 6...Edge portion, 7...
- Free end edge, 8... Seat piece, 9... Connection tool, 10
... Connector, 11...-Hook, 12... Reinforcement sheet, 13... Engagement hole, 14... Mounting piece, 1,5...
...Triangular ring, 16...Shackle, 17.18.
... Mounting piece, 19... Lobe, 20... Triangular ring, 20... Ring piece.

Claims (1)

[Claims] A sheet laid at the bottom of an underwater structure is extended from the structure, and the sheet extends continuously from the free end edge of the sheet substantially parallel to the free end edge at a distance from the free end edge toward the structure. A scouring prevention device for an underwater structure, comprising a heavy object placed thereon, and the heavy object is intermittently connected to the sheet.