JPH0713364B2 - Rotating scour prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a slide type scour prevention device for preventing scour of a river bed ground on the downstream side of a dam structure or scour of a water bottom ground near a revetment structure. It is about.

[Prior art] Conventionally, to prevent scouring of the river bed ground on the downstream side of the dam structure or to prevent scouring of the water bed ground near the revetment structure, the river bed ground or water bed ground at the scouring prevention place should be used. , (1) a digging prevention means for laying out gabions formed by filling stones in an iron wire bag, and (2) placing a scour prevention box formed by filling stones in a water-permeable steel box body. Scour prevention measures have been adopted.

[Problems to be Solved by the Invention]

In the case of the scour preventive means of the above (1), the iron wire corrodes at an early stage, so that there is a drawback that durability is short. Further, in the case of the scour prevention means of the above (2), when the riverbed ground on the downstream lower side of the scour prevention box or the water bottom ground on the offshore lower side of the scour prevention box is scourd, the bottom of the scour prevention box is The scouring of the ground spreads, and the part of the scouring prevention box that is not supported by the ground expands.Therefore, a large load of a large amount of stone acts as a bending force on the water-permeable steel box, and The steel box may be damaged.

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

[Means for Solving the Problems]

In order to achieve the above object, in the rotary scour preventive device of the present invention, the fixed scour preventive box 3 composed of the water-permeable steel box body 1 and the stones 2 filled therein is a dam. Structure 4
The water-permeable steel box body 6 having an upstream inclined portion 5 which is placed on the riverbed ground in the vicinity of the downstream side of the river and is inclined so as to deviate from the upper side toward the lower side toward the downstream side, and the filling therein. A rotating scour prevention box 8 composed of the removed stones 7 is placed on the riverbed ground in the vicinity of the downstream side of the fixed scour prevention box 3, and the upper part of the rotating scour prevention box 8 on the upstream side. But fixed scour prevention box 3
In the upper part on the downstream side of, a wedge-shaped gap 22 is provided which is pivotally attached by a horizontal shaft 9 and which spreads downwardly between the fixed scour prevention box 3 and the rotary scour prevention box 8.

Further, a fixed scour prevention box 3 composed of a water-permeable steel box body 1 and stones 2 filled therein is placed close to the revetment structure 10 on the bottom of the sea floor, and goes from the upper part to the lower part. A rotating scour prevention box 8 comprising a water-permeable steel box body 6 having a land-side inclined portion 5 inclined so as to be offset to the offshore side, and stones 7 filled therein is the fixed washing machine. The excavation prevention box 3 is placed on the bottom of the sea in the vicinity of the offshore side, and the land-side upper portion of the rotary scour prevention box 8 is located on the offshore side of the fixed scour prevention box 3 on the horizontal axis 9
Fixed scour prevention box 3 and rotating scour prevention box 8
The above-mentioned object can also be achieved by providing a wedge-shaped gap 22 that expands downwardly between the two.

〔Example〕

 The present invention will now be described in detail with reference to the illustrated example.

1 to 7 show an embodiment of the first invention, in which a box-shaped frame body 11 is constructed by welding or connecting steel frame members by bolts. A large number of steel intermediate frame rods 12 are fixed to the peripheral wall and the bottom by welding or bolts, and a water-permeable steel box body 1 having an open upper part is formed. A fixed scour prevention box 3 is formed by filling stones 2 made of crushed stone, and a large number of steel upper frame rods are fixed to the upper portion of the water-permeable steel box body 1 by bolts.

Also, steel frame materials are welded or joined by bolts,
A box-shaped frame body 13 is configured, and the box-shaped frame body 13 has an upstream-side inclined portion 5 that is inclined so as to deviate from an upper portion to a lower portion toward the downstream side. A large number of steel intermediate frame rods 14 are fixed to the wall portion on the downstream side, and a plurality of steel intermediate frame rods 15 are attached to the bottom portion and the inclined portion 5 of the box-shaped frame body 13.
Is fixed, and wire meshes 16 made of expanded metal are fixed to the walls on both sides of the box-shaped frame 13 in the river width direction to form a water-permeable steel box 6 having an open upper part, Stones 7 made of rubble in the water-permeable steel box 6
To form a rotary scour prevention box 8, and a large number of steel upper frame rods 17 are provided on the upper portion of the water-permeable steel box body 6 with bolts 18
Fixed by.

The fixed scour prevention box 3 is placed close to the downstream side of the dam structure 4 and placed on the riverbed ground 19, and the rotating scour prevention box 8 is the downstream side of the fixed scour prevention box 3. Are placed side by side in two rows in the river width direction and placed on the riverbed ground 19, and are arranged at intervals in the river width direction on the upper side of the upstream side of each rotary scour prevention box 8 on the upstream side. A plurality of bearings 20 are fixed, and a bearing 21 arranged on a side portion of the bearing 20 is fixed to an upper portion of the fixed scour prevention box 3 on the downstream side.
A horizontal axis 9 extending in the river direction over 20 and 21 is inserted, and by the horizontal axis 9, the upper part of the rotating scour prevention box 8 on the upstream side is located on the upper side of the fixed scour prevention box 3 on the downstream side. The upper part on the downstream side of the pivoting scour protection box 8 on the upstream side and the upper part on the upstream side of the rotary scour prevention box 8 on the downstream side are connected via bearings 20 and 21 and the horizontal shaft 9. Is pivotally connected.

At the beginning of installation of the rotary scour prevention device, as shown in FIGS. 1 and 5, the rotation between the fixed scour prevention box 3 and the rotary scour prevention box 8 and adjacent to each other in the river direction is performed. A wedge-shaped gap 22 is provided between the scour prevention boxes 8 to expand downward. Further, stones 23 are filled between the fixed scour prevention box 3 and the dam structure 4.

The water-permeable steel box body 6 with the bearing 20 fixed and the water-permeable steel box body 1 with the bearing 21 fixed are manufactured in advance in a factory or on land. The stones 2 and 7 may be filled into the water-permeable steel boxes 1 and 6 on land near the scour prevention installation site, or the water-permeable steel boxes 1 and 6 may be placed on the riverbed ground 19 The stones 2 and 7 may be filled in the boxes 1 and 6 after being installed at the predetermined positions. Further, as the stones 2 and 7, crushed concrete lumps may be used.

At the beginning of the installation of the rotary scour prevention device, the riverbed ground was almost flat.
Fixed scour prevention box 3 and each rotating scour prevention box 8 on the surface of 19
Are placed side by side, the riverbed 19 on the downstream side of the rotary scour prevention device is scour, and when the scour reaches the lower part of the swivel scour prevention box 8, FIG. 6 and FIG. As shown in FIG. 4, the rotary scour prevention box 8 on the downstream side pivoted downward about the horizontal axis 9 with respect to the rotary scour prevention box 8 on the upstream side, and the scour progressed further upstream. In this case, the rotating scour prevention box 8 on the upstream side of the fixed scour prevention box 3 rotates downward about the horizontal shaft 9.

When the rotating scour prevention box 8 rotates downward about the horizontal axis 9, the rotating scour prevention box 8 is bent downwardly and continuously connected to the downstream side of the fixed scour prevention box 3, so that the rotation The scour prevention box 8 prevents scour of the riverbed 19 below the fixed scour prevention box 3.

In the case of this embodiment, the number of the rotary scour prevention boxes 8 arranged in the river direction may be one, or may be three or more.

FIGS. 8 to 11 show an embodiment of the second invention, in which the fixed scour prevention box 3 is placed in proximity to the revetment structure 10 and placed on the submerged ground 24, from the top to the bottom. A stone 7 is filled in a water-permeable steel box body 6 having a land-side inclined portion 5 that is inclined so as to deviate toward the sea toward A plurality of moving scour prevention boxes 8 are arranged close to the offshore side of the fixed scour prevention box 3 and placed on the subseabed 24, and fixed to the upper part of the rotary scour prevention box 8 on the land side. A horizontal shaft 9 extending in the longitudinal direction of the revetment structure is inserted between the bearing and the bearing fixed to the upper part of the fixed scour prevention box 3 on the offshore side. The upper part of the land side of the fixed scour prevention box 3 is pivotally attached to the upper part of the fixed scour prevention box 3, but other configurations and actions are the first invention. It is the same as in Example.

8 and 9 show the initial state of the installation of the rotary scour preventive device, and FIGS. 10 and 11 show that the swivel preventive box 8 rotates diagonally downward due to the scour of the submarine ground 24. It shows a moving state. When carrying out the second invention, as in the case of the embodiment of the first invention, a plurality of rotating scour prevention boxes 8 may be arranged side by side toward the offshore side.

When carrying out the present invention, a plurality of steel intermediate frame rods may be welded or fixed to the wall portions on both sides of the box-shaped frame body 13 in the river width direction by welding or the like, and the wire net 16 may be omitted.

〔The invention's effect〕

Since the present invention is configured as described above, it has the following effects.

When the riverbed ground 19 or the water bottom ground 24 is scourd and the scour reaches the lower part of the rotary scour prevention box 8, the rotary scour prevention box 8 is attached to the fixed scour prevention box 3 along the horizontal axis 9 Is rotated obliquely downward about the center of the fixed scour prevention box 3, and a gently inclined scour prevention barrier composed of the swivel scour prevention box 8 is automatically formed at the end of the fixed scour prevention box 3. Riverbed below the digging prevention box 3
It is possible to prevent scouring of the 19 or the submarine ground 24 by simple means.

[Brief description of drawings]

1 to 7 show an embodiment of the first invention, wherein FIG. 1 is a side view of a rotary scour preventive device, FIG. 2 is its plan view, and FIG. FIG. 4 is a front view of the rotary scour preventive apparatus, FIG. 5 is a schematic side view showing the initial state of installation of the rotary scour preventive apparatus, and FIG. FIG. 7 is a schematic side view showing the state of the rotary scour prevention device after scour, and FIG. 7 is a side view showing the state of the movable scour prevention box after scour. FIGS. 8 to 11 show an embodiment of the second invention, FIG. 8 is a schematic side view showing the initial state of installation of the rotary scour preventive device, and FIG. 9 is a part thereof. FIG. 10 is an enlarged side view showing FIG. 10, FIG. 10 is a schematic side view showing a state of the rotary scour prevention device after scour, and FIG. 11 is an enlarged side view showing a part thereof. In the figure, 1 is a water-permeable steel box, 2 is stones, 3 is a fixed scour prevention box, 4 is a dam structure, 5 is an inclined part, 6 is a water-permeable steel box, 7 is stone, 8 is a rotating scour prevention box, 9 is the horizontal axis,
10 is a revetment structure, 11 is a box frame, 12 is an intermediate frame rod, 13 is a box frame, 14 and 15 are intermediate frame rods, 16 is a wire mesh, 17 is an upper frame rod, 19 is a riverbed, 20 And 21 are bearings, 22 is a wedge gap,
24 is the subsoil.

Claims (2)

[Claims] 1. A fixed scour prevention box 3 composed of a water-permeable steel box 1 and stones 2 filled therein is placed on the bed of the river in the vicinity of the downstream side of the dam structure 4. , A rotary scour prevention comprising a water-permeable steel box body 6 having an upstream inclined portion 5 which is inclined so as to be displaced toward the downstream side from the upper portion to the lower portion, and stones 7 filled therein The box 8 is placed on the riverbed in the vicinity of the downstream side of the fixed scour prevention box 3, and the upper part of the rotary scour prevention box 8 on the upstream side is the upper part of the fixed scour prevention box 3 on the downstream side. In addition, a rotary scour prevention in which a wedge-shaped gap 22 that expands downward is provided between the fixed scour prevention box 3 and the rotary scour prevention box 8 that is pivotally connected by a horizontal shaft 9. apparatus. 2. A fixed scour prevention box 3 comprising a water-permeable steel box body 1 and stones 2 filled therein is placed on the water bottom ground in the vicinity of the revetment structure 10 and from above. A rotating scour prevention box 8 comprising a water-permeable steel box body 6 having a land-side inclined portion 5 inclined so as to deviate toward the lower side toward the lower part and stones 7 filled therein , Which is placed on the bottom of the sea close to the offshore side of the fixed scour prevention box 3, and the upper part on the land side of the rotating scour prevention box 8 is on the offshore side of the fixed scour prevention box 3,
A rotary scour preventive device which is pivotally mounted by a horizontal shaft 9 and has a wedge-shaped gap 22 which expands downward between the fixed scour preventive box 3 and the rotary scour preventive box 8.