JPH03228909A - Sliding type scour preventing device - Google Patents

Abstract

PURPOSE:To prevent scouring of the water-bottom ground by installing a fixed scour preventing box and movable scour preventing boxes on the ground of a riverbed, and also by lowerably and turnably connecting the upper end of the movable scour preventing box on the upstream side with the end of the fixed scour preventing box on the downstream side. CONSTITUTION:A fixed scour preventing box 3 made up of a water-passable steel box body 1 and stones 2 filled therein is installed on the ground 18 of a riverbed so as to be adjacent to the downstream side of a dam structure 4. Then, movable scour preventing boxes 7 each of which is made up of a water-passable steel box body 5 and stones 6 filled therein are installed on the riverbed ground 18 so as to be adjacent to the downstream side of the fixed scour preventing box 3. And the upper end of the movable scour preventing box 7 is lowerably and turnably connected with the end of the fixed scour preventing box 3 on the downstream side. Thus, when scouring reaches up to the bottom of the movable scour preventing box 7, the movable scour preventing box 7 lowers itself by its own weight, and a scour preventing screen can be automatically formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a sliding scouring prevention device that prevents scouring of river bed ground downstream of a dam structure or scour of water bottom ground near a revetment structure. It is related to.

[Conventional technology]

Conventionally, in order to prevent scouring of the river bed ground on the downstream side of a dam structure or to prevent scouring of the water bottom ground near a revetment structure, (1) (2) A scour prevention means in which a scour prevention box is placed in a water-permeable steel box body filled with stones. has been adopted.

[Problem to be solved by the invention]

In the case of the scouring prevention means (1), the iron wire corrodes early, so the durability is short.

In addition, in the case of the scour prevention means (2) above, when the river bed ground at the lower downstream side of the scour prevention box or the water bottom ground at the offshore lower part of the scour prevention box is scoured, the lower part of the scour prevention box As the scouring of the ground spreads, the portion of the scouring prevention box that is not supported by the ground expands, and the large load from the large amount of stones acts as a bending force on the water permeable steel box, causing water permeability to deteriorate. The steel box may be damaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sliding type scour prevention device that can advantageously solve the above-mentioned problems.

[Means to solve the problem]

In order to achieve the above object, in the sliding type scour prevention device of the present invention, a fixed scour prevention box 3 consisting of a water-permeable steel box body 1 and stones 2 filled therein is installed at a dam. A movable scour prevention box 7 placed on the river bed adjacent to the downstream side of the structure 4 and consisting of a water-permeable steel box body 5 and stones 6 filled therein serves as the fixed scour prevention method. It is placed on the riverbed ground adjacent to the downstream side of the box 3, and the upper end of the upstream side of the movable scour prevention box 7 is connected to the downstream end of the fixed scour prevention box 3 so that it can be lowered and rotated. has been done.

In addition, a fixed scour prevention box 3 consisting of a water-permeable mesh box 1 and stones 2 filled therein is placed on the water bottom ground in close proximity to the seawall structure 8. 5 and stones 6 filled therein is placed on the underwater ground close to the offshore side of the fixed scour prevention box 3. The above object can also be achieved by connecting the land-side upper end to the offshore-side end of the fixed scour prevention box 3 so as to be able to descend and rotate.

〔Example〕

Next, the present invention will be explained in detail using illustrated examples.

1 to 8 show an embodiment of the first invention, in which a box-shaped frame body 9 is constructed by joining steel frame members by welding or bolts, and the box-shaped frame body 9 is A large number of steel intermediate frame rods 10 are fixed to the peripheral wall and the bottom with bolts to form a water-permeable steel box 1 with an open top. Type 2 is filled to form a fixed scour prevention box 3, and a number of steel upper frame rods are fixed to the upper part of the water-permeable steel box 1 with bolts.

Also, the steel frame materials are joined by welding or bolts,
A box-shaped frame body 11 is constructed, and an upstream slope part 12 is provided on the lower side of the upstream side of the box-shaped frame body 11, and is inclined so as to be deviated from the upper part toward the lower part to the downstream side, and A large number of steel intermediate frame rods 13 are fixed to the walls on both sides of the box-shaped frame 11 in the bay flow direction (front-back direction), and a plurality of steel intermediate frame rods 13 are fixed to the bottom and inclined parts 12 of the box-shaped frame 11. The intermediate frame rod 14 is fixed, and a wire mesh 15 made of expanded metal is fixed to the walls on both sides of the box-shaped frame 11 in the cylinder direction (left and right direction), and the upper part is open. A box body 5 is constructed, and stones 6 made of chestnut stone are filled in the water permeable steel box body 5 to constitute a movable scour prevention box 7. A steel upper frame rod 16 is fixed with bolts 17.

The fixed scour prevention box 3 is placed close to the downstream side of the dam structure 4 and placed on the river bed ground 18, and the movable scour prevention box 7 is placed downstream of the fixed scour prevention box 3. The movable scour prevention boxes 7 are arranged in two rows in close proximity to each other in the direction of the cylinder and placed on the river bed ground 18, and steel brackets 19 protruding upstream are fixed by welding to both sides of the upper part of each movable scour prevention box 7 in the direction of the cylinder. A screw punch 21 connected to a steel guide member 20 having a circular cross section is inserted into the protrusion of the bracket 19, and a nut 22 screwed into the screw punch 21 is used to tighten the guide member 20.
is fixed to the bracket 19.

A vertical steel plate with a groove-shaped cross section that opens toward the inside of the cylinder is installed on both sides of the downstream end of the fixed scour prevention box 3 and the downstream end of the upstream movable scour prevention box 7 in the direction of the inside of the cylinder. A guide frame member 23 is fixed with bolts 24, the guide member 20 is placed in the groove of the vertical guide frame member 23, and stones 25 are filled between the fixed scour prevention box 3 and the dam structure 4. .

A water-permeable steel box body 1 to which a steel vertical guide frame member 23 is fixed;
Guide member 20. The water-permeable steel box body 5 to which the vertical guide frame member 23 is attached is manufactured in advance at a factory or on land. The stones 2 and 6 may be filled into the water-permeable steel boxes 1 and 5 on land near the scour prevention device installation site, or the water-permeable steel boxes 1 and 5 may be filled in the river bed ground 18. After installing it at a predetermined position, the boxes 1 and 5 may be filled with stones 2 and 6.

Further, as the stones 2 and 6, crushed concrete blocks may be used.

When the sliding type scour prevention device is initially installed, the fixed scour prevention box 3 and each movable scour prevention box 7 are placed side by side on the surface of the flat riverbed ground 18, and the downstream side of the slide type scour prevention device is placed side by side on the surface of the flat riverbed ground 18. When the river bed ground 18 is scoured and the scour reaches the lower part of the movable scour prevention box 7, as shown in FIGS. 7 and 8, The movable scour prevention box 7 on the downstream side is lowered and rotated slightly toward the downstream side about the guide member 20, and the movable scour prevention box 7 on the upstream side is lowered with respect to the fixed scour prevention box 3.

Furthermore, the movable scour prevention box 7 on the upstream side can also rotate downstream around the guide member 20.

When the movable scour prevention box 7 is lowered relative to the fixed scour prevention box 3, the movable scour prevention box 7 is bent downward and connected downstream of the fixed scour prevention box 3. 7 prevents the river bed ground 18 below the fixed scour prevention box 3 from being scoured.

In the case of this embodiment, the number of movable scour prevention boxes 7 arranged in the Gulf stream direction may be one, or three or more.

9 to 12 show an embodiment of the second invention, in which a fixed scour prevention box 3 is placed close to the seawall structure 8 and placed on the underwater ground 26, and a movable scour A prevention box 7 is placed close to the offshore side of the fixed scour prevention box 3 and placed on the underwater ground 26, and a steel vertical guide member 23 is fixed to the offshore end of the fixed scour prevention box 3. A steel bracket 19 that protrudes toward the land side is fixed to the upper part of the land side end of the movable scour prevention box 7, and a guide member 20 is fixed to the protrusion of the bracket 19. 20 is disposed within the groove of the vertical guide frame member 23, but the other configurations and functions are the same as in the embodiment of the first invention.

9 and 10 show the state of the slide type scouring prevention device when it was first installed, and FIGS. 11 and 12 show the state in which the movable scouring prevention box 7 has been lowered due to scouring of the underwater ground 26. There is. When carrying out the second invention, a plurality of movable anti-scouring boxes 7 may be provided side by side toward the offshore side as in the embodiment of the first invention.

If the inclined part 12 is provided at the lower part of the fixed scour prevention box side of the movable scour prevention box 7 as in the above embodiment, even if the surface of the river bed ground 18 or the water bottom ground 26 is inclined due to scour, The movable scour prevention box 7 can be grounded in a stable state.

When carrying out this invention, a plurality of intermediate steel frame rods are fixed to the wall portions of the box-shaped frame 11 on both sides in the underwater direction by welding or bolts, and the gold 1i! 15 may be omitted.

〔Effect of the invention〕

Since this invention is configured as described above, it produces the effects described below.

When the river bed ground 18 or the water bottom ground 26 is scoured and the scour reaches the lower part of the movable scour prevention box 7, the movable scour prevention box 7 is lowered relative to the fixed scour prevention box 3, and the movable scour prevention box 7 is lowered to prevent its fixation. Since a scour prevention barrier consisting of a movable scour prevention box 7 is automatically formed at the end of the scour prevention box 3, the fixed scour prevention box 3
It is possible to prevent the river bed ground 18 or water bottom ground 26 at the lower part of the river from being scoured, and the movable scour prevention box 7 can be rotated relative to the fixed scour prevention box 3, so the movable scour prevention box 7 can be rotated relative to the fixed scour prevention box 3. Even if the surface of the scoured river bed ground 18 or water bottom ground 26 at the bottom of the digging prevention box 7 is sloped, the movable scour prevention box 7 is automatically rotated to remove the river bed ground 18 or the water bottom ground 2.
6 can be grounded in a stable state, and the movable scour prevention box 7 can be lowered relative to the fixed scour prevention box 3.
The amount of downward protrusion of the movable scour prevention box 7 from the fixed scour prevention box 3 is increased (so that the river bed ground 1 under the fixed scour prevention box 3 is
8 or scouring of the water bottom ground 26 can be reliably prevented.

[Brief explanation of drawings]

1 to 8 show an embodiment of the first invention, in which FIG. 1 is a side view of the sliding type scour prevention device, and FIG.
The figure is a plan view, Figure 3 is a sectional view taken along the line A-A in Figure 2, Figure 4 is a front view of the slide type scour prevention device, and Figure 5 is an enlarged view of the sliding part of the slide type scour prevention device. 6 is a schematic side view showing the state of the sliding type scouring prevention device at the time of installation. FIG. 7 is a schematic side view showing the state of the sliding type scouring prevention device after scouring. FIG. 8 is a side view showing the state of the movable scour prevention box after scour. Figures 9 to 12 show an embodiment of the second invention, in which Figure 9 is a schematic side view showing the initial state of the sliding type scour prevention device, and Figure 10 shows a part of it. FIG. 11 is a schematic side view showing the state of the slide-type scour prevention device after scouring, and FIG. 12 is a side view partially enlarged. In the figure, 1 is a water permeable steel box, 2 is a stone, 3 is a fixed scour prevention box, 4 is a dam structure, 5 is a water permeable steel box, 6
is stone, 7 is a movable scour prevention box, 8 is a revetment structure, 9 is a box-shaped frame, 10 is an intermediate frame rod, 11 is a box-shaped frame, 12 is a slope, 13 and 14 are intermediate frame rods. , 15 is a wire mesh, 16 is an upper frame rod, 18 is a river bed ground, 19 is a bracket, 20 is a guide member, 23 is a vertical guide frame material, and 26 is a water bottom ground. Unexamined Japanese Patent Publication No. 3-? :? 89U9 (IZJ

Claims (2)

[Claims] (1) A fixed scour prevention box 3 consisting of a water-permeable steel box 1 and stones 2 filled therein is placed on the river bed adjacent to the downstream side of the dam structure 4, and A movable scour prevention box 7 consisting of a water-based steel box 5 and stones 6 filled therein,
The upper end of the movable scour prevention box 7 on the upstream side is placed on the riverbed ground adjacent to the downstream side of the fixed scour prevention box 3.
A sliding scouring prevention device connected to the downstream end of the fixed scouring prevention box 3 so that it can be lowered and rotated. (2) A fixed scour prevention box 3 consisting of a water-permeable steel box 1 and stones 2 filled therein is placed on the underwater ground in close proximity to the revetment structure 8, and is made of water-permeable steel. A movable scour prevention box 7 consisting of a box body 5 and rocks 6 filled therein is placed on the underwater ground close to the offshore side of the fixed scour prevention box 3, and is a movable scour prevention box. A slide type scour prevention device in which the land side upper end of the fixed scour prevention box 3 is connected to the offshore side end of the fixed scour prevention box 3 so that it can be lowered and rotated.