JP5421830B2 - Revetment with curved floating body - Google Patents

Description

  Since structures such as revetments and breakwaters have shallow water depths in front of them, waves that reach the structure break and wave on the front of the structure and act on the structure. At this time, the waves run up and overwhelm the front wall of the structure, so the back ground may be inundated and damage may increase. Today, where sea level rise due to global warming is a concern, it is required to reduce the amount of overtopping and reduce disasters.

If you simply raise the top of the revetment or install a panel to prevent storm surges in front of the revetment, the landscape and hydrophilicity will be hindered. In addition, when the scale of the raising is increased, there is a problem that the area occupied by the back ground of the structure is increased, and it extends to a sidewalk or a road that is provided in the vicinity, thereby reducing an effective use area of the sidewalk or the road.
These sidewalks and roads between disaster prevention facilities such as revetments and the residential area serve as buffers in the event of a disaster, and if this area narrows or disappears, the damage will directly reach the residential area. It becomes.

As shown in FIG. 3A, in order to solve the landscape problem, a structure for forming a groove for holding the floating structure 4 is provided on the front surface of the revetment 1, and the inside of this groove is moved up and down in conjunction with the water level. It has been proposed to install a floating structure 4 that moves to prevent overtopping and overflowing. Normally, the floating structure does not protrude from the top of the revetment and does not adversely affect the landscape, so the problem of damaging the landscape can be solved, but it is necessary to build a strong wall in front of the revetment. There will be problems of change, disappearance of sea areas and impact on ecosystems.
As shown in FIG. 3 (b), the type in which the structure of the revetment 1 is dug to form a groove and the floating structure 4 is installed in the groove does not have a structure in front of the revetment 1. Therefore, the impact of changes in the coastline is small, but the construction of the revetment structure is complicated, and it cannot be applied to a revetment that has deteriorated due to its strength or a narrow revetment because there is no room for forming grooves.

  Also, marine organisms adhere to the groove where the floating structure is installed, narrowing the width of the groove, increasing the resistance to the floating structure for the floating structure to move up and down, and the floating structure responds to fluctuations in the water level. Therefore, it is necessary to perform maintenance management such as removal of attached organisms, but it is troublesome to remove marine organisms attached to the inside of narrow grooves, and maintenance costs are required.

JP-A-10-298952 JP 2006-70536 A JP 2007-126945 A JP 2008-57311 A JP 2007-39921 A US Pat. No. 6,338,594

  The present invention solves the above-described problems, and suppresses overtopping caused by storm surges by using a floating structure, and the marine organisms attached to the floating structure and the structure serving as a guide for the floating structure. In addition to facilitating removal, repairs are easily made when a disaster occurs, and the current state can be restored in a short period of time.

The revetment is a revetment in which a grid-like frame is provided in front of the revetment, and a plurality of floating structures that can move up and down according to the sea level change are provided along the revetment.
Moreover, it is a revetment in which a concave portion is formed on the sea side wall surface of the floating structure, and an upper portion and a lower portion project toward the sea side.

Since the floating structure is stored in a lattice frame, there is less adhesion of marine organisms than the type in which the floating structure is installed in the groove, and there is no groove that is difficult for humans to reach. Maintenance such as removal of attached organisms is easy.
Since the concave portion is formed on the sea side wall surface of the floating structure and there are overhanging portions, waves that collide with the wall surface are rebounded offshore, and overtopping can be reduced at a lower height than the upright wall.
Most of the components that make up the floating structure and the grid frame are manufactured at the factory, so there is little variation in quality, and the offshore construction can be shortened, so the construction period can be shortened, and measures against storm surges can be made at low cost. be able to.
The overtopping reduction effect of the floating structure is the same as the effect of raising the existing revetment top.
Even if the floating structure is damaged and damaged, it can be easily replaced, so that it can be repaired in a short period of time, and can cope with typhoons that continuously hit.

The side view of the Example of this invention. The front view of the Example of this invention. Side view of revetment using conventional floating body.

DESCRIPTION OF SYMBOLS 1 Revetment 10, 11 Column row 2 H-section steel 3 Lattice frame 4 Floating structure 40 Recess 41 Upper projecting part 42 Lower projecting part

As shown in FIG.1 and FIG.2, the column row | line | column 10 which installed the H-section steel 2 with the space | interval of about 5 m along the front wall surface of the revetment 1 of an upright wall is formed. A column 11 of H-section steel 2 is provided on the sea side of the column 10 about 1 m. In the column rows 10 and 11, horizontal members 21 are provided at intervals of 1 to 2 m in the height direction, and the H-section steel 2 of the column members is connected and reinforced to form a lattice frame 3.
The column material is not limited to the H-shaped steel, and may be a steel pipe having a circular cross section, and the material may be a steel material or stainless steel.
The pillar material and the horizontal material are preferably made of a material containing components that are difficult to attach marine organisms. Further, a marine organism adhesion prevention film may be formed on the surface of these members, and no protruding portion is formed on the member due to adhesion of marine organisms. Moreover, since it is as the grid | lattice body 3, the circumference | surroundings of a member are opened, and even if a marine organism adheres, removal work is easy to perform and the movement interlock | cooperated up and down of the sea surface of the floating structure is performed smoothly.

A plurality of floating structures 4 are installed along the revetment 1 inside a lattice body 3 composed of a pillar material and a horizontal material 21. The size of the floating structure 4 can be accommodated inside the lattice body 3 so that there is a margin of about 5 to 10 mm with respect to the members of the lattice body 3, and the width is 5 to 10 m and the height is 4 to 5 m. is there.
The floating structure 4 is made of steel, reinforced concrete, high-strength fiber reinforced concrete, etc., and can secure sufficient strength against storm surges and tsunami shocks. Provide ribs and partitions.
The floating structure 4 can be filled with water or a weight can be added, and the top height can be adjusted by adjusting the buoyancy. The floating structure 4 is installed in the lattice frame so that the top end of the revetment 1 and the top end of the floating structure 4 substantially coincide with each other so that the landscape is not adversely affected.

A concave portion 40 is formed on the sea side wall surface of the floating structure 4, and overhang portions 41 and 42 in which an upper portion and a lower portion protrude to the sea side are formed. By doing in this way, the wave which collides with the wall surface of the floating structure 4 and goes up the wall surface is prevented from overtopping.
Moreover, since it is curving upwards, the amount of overtopping is further reduced by returning the water mass colliding with the wall surface to the offshore side. The floating structure moves up following the ups and downs of the waves and the average water level rises such as storm surges, so the height from the water surface to the floating structure is kept constant, and splash overtopping is suppressed. Can do.
Due to the overtopping prevention effect of the upper overhanging portion 41, the portion where the floating structure 4 protrudes above the sea surface can be made relatively small.
In addition, a box shape may be sufficient without providing a recessed part in a floating structure.

  The design average tide level is determined in consideration of the past high tide level, etc., but it is expected to become larger in the future due to the rise in sea level due to the effects of global warming and the increase in storm surge deviation due to the increase in typhoon scale. Since the height (hc) from the sea level to the top of the floating structure can be considered constant, the overtopping flow rate does not change.

Claims (4)

A revetment in which a lattice frame is provided in front of the revetment, and a plurality of floating structures that can move up and down according to the sea level change are provided along the revetment. 2. The revetment according to claim 1, wherein the floating structure has a concave portion formed on the sea side wall surface, and an upper portion and a lower portion project toward the sea side. The revetment according to claim 1 or 2, wherein the buoyancy of the floating structure is adjustable. The revetment according to any one of claims 1 to 3, wherein the lattice frame body and the floating structure are subjected to a treatment for preventing attachment of marine organisms.

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