JPS5834610B2 - Riverbed dam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a riverbed dam for allowing sand and gravel on a riverbed to flow down while providing resistance to the sand and gravel.

Conventionally, as a riverbed dam that allows sand and gravel to flow down while providing resistance, a large number of steel gravel flow resistors are arranged at regular intervals in the river width direction, and the lower part of each steel gravel flow resistor is Embedded and fixed in a concrete foundation poured into the riverbed,
Under normal conditions, gravel flows down between the gravel flow resistors along with surface water, and when a rapid flow accompanied by sand and gravel occurs, small-sized gravel flows down from between the gravel flow resistors, and large-diameter gravel flows down from between the gravel flow resistors. A structure has been proposed in which the gravel flow is dammed by a gravel flow resistor to reduce the energy of the gravel flow.

However, in the case of the above-mentioned conventional riverbed dam, in order to (1) construct a large concrete foundation that fixes the lower part (joist part) of the gravel flow resistor, a large amount of cement, cross-conducting equipment, etc. must be transported to the dam construction site; (2) Excavating the river bed and placing it there Since a large concrete foundation will be constructed, a large amount of sand and gravel excavated from the river bed foundation construction site must be disposed of. (3) The lower part of the gravel flow resistor is rigidly fixed to the concrete foundation. Therefore, there is no buffering ability when heavy rocks collide with the gravel flow resistor, and as a result, the gravel flow resistor is easily damaged or greatly deformed by collision with heavy rocks. When the gravel flow resistor is damaged or deformed due to collision with heavy rocks, there are problems such as that it is difficult to replace the gravel flow resistor.

The object of the present invention is to provide a riverbed dam that can advantageously solve the above-mentioned problems.

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

1 to 4 show a first embodiment of the present invention. First, at a location where a riverbed dam is to be installed, a bed is excavated with a predetermined width extending toward the bath, and an inclined steel pipe is The tops of the column 6 made of steel and the inclined steel pipe brace 7 are connected to each other with bolts, and the ends of the connecting member 8 made of steel pipe fixed to the intermediate portions of the column 6 and the brace 7 are butted against each other and connected with bolts. Steel gravel flow resistor 3
Further, a base member 4 made of a steel plate is fixed to the lower ends of the pillar 6 and the brace 7 by welding.

The gravel flow resistors 3 with base members configured in this way are erected at regular intervals in the direction of the hot water at the middle part of the bottom surface of the bed excavation in the river bed flow direction, and each gravel flow resistor 3
In order to reliably prevent displacement and overturning of the sand and gravel flow resistors 3, the embedded portions (embedded fixing portions) of the struts 6 and braces 7 of each gravel flow resistor 3 are connected by steel joints 10 and bolts.

Upstream and downstream steel box frames 11A and downstream steel box frames 11B and river bank side steel box frames 11 each have water permeability on the upstream and downstream sides of the bottom of the floor excavation and on the river bank side.
C is installed so that the upper surface of the upstream steel box frame 11A and the upper surface of the downstream steel box frame 11B almost match the river bed surface 120 level, and on the river bank side, the steel box frame 11
The steel box frames 11A to 11C are filled with filler material 5 such as sandstone and gravel generated during floor excavation, and the bottom surface of the floor excavation part and each of the steel box frames 11A are stacked one on top of the other. Filling material 5 such as sandstone and gravel produced during bed excavation is also used in the recess formed by ~11C.
Fill it.

The lower part of each gravel flow resistor 3 is fixed by the filler 5, and the upstream steel box frame 11A and the filler 13 therein are fixed.
The river bed upstream of the gravel flow resistor 3 is protected by the upstream river bed protector 1, which is constructed of the above, and the downstream river bed is constructed by the downstream steel box frame 11B and the filler 13 therein. The riverbed on the downstream side of the gravel flow resistor 3 is protected by the protector 2, and the riverbank is protected by the riverbank protector 14, which is constituted by a riverbank-side steel box frame 11C and a filler 13 therein.

Furthermore, the gravel flow resistor 3 is held in a stable state by the pressure of the filler 5 acting on the lower circumferential surfaces of the struts 6 and the braces 7 and the load of the filler 5 acting on the base member 4, and from the direction of arrow A. In response to the impact force of the sand and gravel flow acting on the pillar 6, the filler material 5 acting on the base member 4 at the lower end of the pillar 6
Zero weight resists and prevents the gravel flow resistor 3 from tilting in the downstream direction.

FIGS. 5 to 8 show a second embodiment of the present invention, in which a part is placed on the bottom of the bed excavation between the upstream river bed protector 1 and the downstream river bed protector 2 in the river flow direction. A large number of vertical frame rods 15 made of H-shaped steel extending in the direction of the hot water are laid at intervals, and a large number of horizontal frame rods 16 made of H-shaped steel extending in the direction of the hot water are installed at each vertical frame rod 15. The cross sections of each vertical frame rod 15 and each horizontal frame rod 16 are connected by U bolts 17 to form a lattice-shaped base member 4, which is arranged at intervals in the river flow direction on the upper surface.

The lower end of the support column 6 and the brace 7 in the gravel flow resistor 3
A mounting steel seat plate 18 fixed to the lower end by welding is placed over the upper surface of the plurality of horizontal frame rods 16 and is attached to the bolt 1.
9, and is configured so that the load of the filler 5 acts on the wide lattice-shaped base member 4 made up of a large number of vertical frame rods 15 and a large number of horizontal frame rods 16, but the other configuration is as follows. This is the same as in the first embodiment.

In the case of the second embodiment, since the gravel flow resistor 3 is fixed to a significantly wide grid-like base member on which the load of the filler 5 is applied, the stability of the gravel flow resistor 30 is significantly improved. I can do it.

9 to 12 show a third embodiment of the present invention, in which the lower parts of the struts 6 and the braces 7 of the gravel flow resistor 3 are connected to the upstream river bed protector 1 and the downstream river bed protector 1. Intermediate steel box frame 2 with water permeability arranged between 20
The struts 6 of the gravel flow resistance member 3 are inserted into the box frame 20, and the support columns 6 of the gravel flow resistance member 3 are placed on the upper surface of the base member 4 consisting of the bottom frame of the box frame 20.
A steel seat plate 18 fixed to the lower end of the brace 7 is placed and fixed with bolts 19, and the intermediate steel box frame 2
0 is also filled with filler material 5 made of earthen gravel,
The other configurations are the same as in the first embodiment.

In the case of the third embodiment, the total weight of the intermediate steel box frame 20 and the total weight of the filler material 5 therein acts on the gravel flow resistor 3, so that its stability can be further improved.

13 to 17 show 30 examples of various types of gravel flow resistors, and in the case of FIG. Both ends of a horizontal steel splicing material 210 are connected to the upper end of the retainer 7 with bolts to form a trapezoidal gravel flow resistor 3, and in the case of FIG. 14, vertical steel supports 6 and steel Both ends of a horizontal steel joint 210 are connected to the upper end of the brace 7 with bolts to form a gate-shaped gravel flow resistor 3.

In the case of Fig. 15, the upper end portion of the steel brace 7 whose upper part is inclined in the direction of falling downstream is connected to the middle part of the steel support 6 whose upper part is inclined in the direction of falling downstream. A gravel flow resistor 3 is constructed.

Fig. 16 shows the gravel flow resistor 3 made of vertical steel columns, and Fig. 17 shows the lower end of the split type A-shaped steel unit 3A assembled with bolts and the split type A-shaped steel unit 3A assembled with bolts. A composite type gravel flow resistor 3 is shown which is connected to the upper end of a type H-shaped steel unit 3B with bolts.

When carrying out this invention, the purpose of the invention can be achieved by simply installing river bed protectors only on the upstream and downstream sides of the row of gravel flow resistors, so even if the river bed protector 14 on the riverbank side is omitted. Also, the joint material 1 shown in the first embodiment
0 may be omitted.

If the river flow is fast and there is a risk that the filler inside the box frame will be washed away, or if the particle size of the filler is small and there is a risk of it slipping out of the water passage gap in the box frame, check the area around the box frame. A steel expanded metal or punched metal may be attached to the surface to prevent the filling material from flowing out.

Each box frame is, for example, a bolt-assembled box frame in which rods made of a large number of section steels are arranged in parallel at the bottom and top of the peripheral side of a bolt-assembly cubic frame made of section steel and attached with bolts. use.

Furthermore, if a box frame that is flexible in the length direction as shown in Japanese Utility Model Publication No. 52-39298 is used, the box frame will have the advantage of following the fluctuations of the ground on the riverbed and becoming stable. However, a simple rigid box frame may be used as the box frame.

In the case of the above embodiment, there is no need to use concrete at all for fixing the gravel flow resistor and constructing each river bed protector, and all the sand and gravel generated during bed excavation can be used for constructing the dam. The most preferable example is to install the upstream river bed protector 1, the downstream river bed protector 2, and the river bed protector 14 by arranging a large number of concrete blocks or using concrete cast in place. You may.

Further, in the case of the above embodiment, only one row of gravel flow resistors arranged in series in the direction of the seamount is provided between the upstream river bed protector 1 and the downstream river bed protector 2. Gravel flow resistors may be provided at intervals in the river flow direction.

When using concrete blocks or cast-in-place concrete to install each of the riverbed protection materials mentioned above, the vertical cross-sectional shape of the riverbed protection material should be shaped like an inverted letter in order to reduce the amount of materials carried to the dam construction site. Alternatively, it is preferable to reduce the cross-sectional area by forming it into a T-shape.

Furthermore, when constructing each of the river bed protectors with cast-in-place concrete 1, if the construction is completed in a season other than winter, the installation and fixing of the gravel flow resistors can be carried out even in winter.

According to this invention, the lower part of the steel gravel flow resistor 3 having the steel base member 4 fixed to the lower end is placed in the recess between the upstream river bed protector 1 and the downstream river bed protector 2 buried in the river bed. At the same time, a filler 5 such as sand and gravel was placed, and the lower part of the gravel flow resistor 3 was embedded in the filler 5, and the filler 5 was placed on the base member 4. To easily and economically fix the lower part of a steel gravel flow resistor 3 by using 50 weight of filler made of sand, stone, gravel, etc. produced by floor excavation without constructing a concrete foundation for fixing the flow resistor. In addition, the gravel flow resistor 3 can be fixedly constructed even in winter, and the gravel flow resistance dam can be easily constructed even in places where there is no bedrock or where there is bedrock at a deep position. Since the gravel flow resistor 3 can be moved laterally freely before being filled with the filler 5, its installation position can be adjusted as desired.

In addition, the lower part of the gravel flow resistor is not rigidly fixed to the concrete foundation, and if a large horizontal force is applied to the upper protrusion of the gravel flow resistor, the gravel flow resistor may move slightly laterally or tilt. It can buffer the impact energy of heavy rocks against the gravel flow resistor, reducing the risk of damage or large deformation of the gravel flow resistor due to the collision, and in the event that the gravel flow resistor is damaged. If the gravel flow resistor is damaged or deformed significantly, the damaged or deformed gravel flow resistor can be easily replaced with another new one by simply removing the filler 5, and then backfilled with sand, gravel, etc. Therefore, effects such as being able to easily complete the repair of the dam can be obtained.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a longitudinal cross-sectional side view of a riverbed dam, and FIG. 2 shows each box frame filled with filler and gravel flow resistance. FIG. 3 is a front view thereof, and FIG. 4 is a side view of the gravel flow resistor. 5 to 8 show a second embodiment of the present invention, in which FIG. 5 is a longitudinal cross-sectional side view of a riverbed dam, and FIG. 6 is a perspective view showing the support state of the lower part of the gravel flow resistor. FIG. 7 is a side view thereof, and FIG. 8 is a front view thereof. 9 to 12 show a third embodiment of the present invention, in which FIG. 9 is a longitudinal cross-sectional side view of a riverbed dam, and FIG.
The figure is a perspective view showing the relationship between the lower part of the gravel flow resistor and the intermediate steel box frame, Figure 11 is a cross-sectional view taken along line A-A, and Figure 12 is a cross-sectional view taken along line B-B of Figure 10. . 13 to 17 are side views showing examples of various types of gravel flow resistors. In the figure, 1 is an upstream river bed protector, 2 is a downstream river bed protector, 3 is a steel gravel flow resistor, 4 is a steel base member, and 5 is a steel base member.
is a filling material, 6 is a support, 7 is a retainer, 10 is a steel joint material,
11A to 11C are steel box materials, 12 is a river bed surface, 13 is a filler material, 14 is a river bank protector, 15 is a vertical frame rod, 16 is a horizontal frame rod, 18 is a steel seat plate, and 20 is an intermediate steel box. It is a frame.

Claims (1)

[Claims] 1. A lower part of a steel gravel flow resistor 3 is installed in a recess between an upstream riverbed protector 1 and a downstream riverbed protector 2 buried in the river bed, and the gravel flow resistor A steel base member 4 is connected to the lower end of 3, a filler 5 such as sand and gravel is filled in the recess, and a lower part of the gravel flow resistor 3 is buried in the filler 5. A river bed dam. 2 The upstream river bed protector 1 and the downstream river bed protector 2
2. The riverbed dam according to claim 1, wherein the riverbed dam is comprised of a water-permeable steel box frame and a filler such as sand and gravel filled therein.