JPH08177024A - Groyne work - Google Patents

Abstract

PURPOSE: To control a groyne in response to a water level, a flow rate and flow velocity while preventing an adverse effect on a water-surface landscape in a river and a water channel. CONSTITUTION: Movable bed bodies 3 arranged in a required number of recessed sections 2 formed to a riverbed 1 or a water channel bed are borne by elastic bodies 4, and the movable bed bodies 3 are bore at an almost the same level as the riverbed 1 or the water channel bend at the time of a normal low water level. When the water level rises and a flow rate and flow velocity are increased, the movable bed bodies 3 are lowered and displaced in the recessed sections 2, and resistance against a water flow is augmented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water control system for controlling a flow rate, a flow velocity, etc. of a water flow in a river, an irrigation canal or a drainage canal.

[0002]

2. Description of the Related Art A river, irrigation canal, drainage canal is provided for the purpose of mitigating the risk of erosion caused by a severe water flow during flooding that collides with river banks or levees, and for keeping the direction of water flow constant. As a typical conventional example of water work, for example, a weir or a jetty is provided in a direction crossing the river or the waterway, or a plurality of steps or irregularities are formed on the riverbed or the waterway floor, so that the flow rate and the flow velocity are increased. The method of controlling the flow direction (river line) is widely adopted. Also, in the traditional flood control of ancient Japan, a frame such as a triangular pyramid shape called "cow frame" or a frame called "gassho frame" is made of wood, and stones etc. are attached to it. There is also a method of increasing the flow resistance by sinking a large number of places at a high flow rate and mitigating a violent flow velocity.

[0003]

However, all of the above-described conventional water works are fixedly installed in rivers and waterways except some parts such as movable weirs. Therefore, it does not enable control according to the water level, flow rate, or flow velocity. Further, these water works are not always preferable in view of the scenery because they are often exposed on the water surface especially when the water level is lowered.

Therefore, the main technical problem to be solved by the present invention is to enable water control according to the water level, flow rate, and flow velocity in rivers, irrigation channels, drainage channels, etc., and to adversely affect the landscape on the water. It is to provide water control without water.

[0005]

In order to effectively solve the above-mentioned technical problems, a water control system according to the present invention is provided with a required number of recesses formed in a river bed or a waterway floor, and is vertically movable in the recesses. In addition, the movable floor body is arranged so as to close the concave portion, and an elastic body for biasing and supporting the movable floor body toward the upper end position of the concave portion. In this case, the movable floor body may be cantilevered and supported by a part of the upper end opening of the recess via a hinge.

[0006]

In the water control system of the present invention, the movable floor body disposed in the recess so as to close the space in the recess forms a part of the bottom surface of the running water channel together with the river bed or the water channel floor. When the water level is low, it is floated up to the upper end position of the recess by the urging force of the elastic body and is supported at almost the same level as the riverbed or the channel floor, so that the resistance to the water flow becomes small. Further, when the water level rises and the flow rate and flow velocity increase, the elastic body is deformed by the increase in the load acting on the upper surface of the movable floor body, so that the movable floor body is displaced downward in the recessed portion, and the riverbed or the watercourse floor. Since it becomes lower than that, the bottom surface of the flowing water channel is partially depressed, so that the resistance against the water flow becomes large and the increase of the flow velocity is suppressed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view showing a first embodiment of a water control system according to the present invention, wherein reference numeral 1 is a river bed of a river or an irrigation canal or a drainage canal (hereinafter, simply referred to as a river bed), W
Indicates water flowing on the river bed 1, and F indicates the direction of the flow. A plurality of recesses 2 (only one is shown in the figure) having a rectangular planar shape and a rectangular cross-sectional shape are formed in the river bed 1. This concave portion 2 is formed in advance in a precast concrete molded body and the molded body is installed in the riverbed 1 in an embedded state, or a part of the river is closed during the dry season and concrete is poured into the riverbed. It will be constructed.

A movable floor 3 is housed in each recess 2 so as to be vertically movable. The movable floor body 3 is made of a precast concrete plate or a steel plate having a rectangular shape whose plane shape is slightly smaller than the opening shape of the recess 2 and is arranged so as to close the space inside the recess 2. The lower surface is elastically supported by a plurality of elastic bodies whose lower ends are fixed to the bottom surface 2a of the recess 2, for example, a steel coil spring 4, and the upper surface of the movable floor body 3 is almost flush with the river bed 1 at a normal low water level. It is at the same level.

Therefore, according to the first embodiment, when the water level rises and the flow rate increases due to heavy rain, snowmelt water, etc., as shown in the cross-sectional view at the time of increasing water in FIG. Due to the increase in the applied load, the movable floor body 3 is displaced downward in the recess 2 while compressing the coil spring 4, and a step is generated between the river bed 1 and the movable floor body 3 which is lower than the river bed 1. For this reason, a plurality of depressions corresponding to the recesses 2 are formed on the river bottom, and the steps become larger as the water level rises, causing remarkable turbulence in the water flow and increasing flow resistance, increasing the flow velocity. Can be effectively suppressed. Further, when the water level eventually decreases, the movable floor body 3 is levitated by the elastic restoring force of the coil spring 4 and returns to the original position shown in FIG. 1, so that the water flow suppressing function is canceled. In addition, preferably, in order to prevent the operation of the movable floor body 3 from being hindered by the accumulation of earth and sand in the concave portion 2, a suitable sealing means may be provided around the movable floor body 3.

FIG. 3 is a sectional view showing a second embodiment of the water control system according to the present invention. The difference from the first embodiment is that one end of the movable floor 3 is one of the upper end openings of the recesses 2. Water flow direction F
The point is that it is cantilevered via a hinge 5 at the downstream edge. In this case, when the water level rises and the flow rate increases, as shown in FIG. 4, the movable floor body 3 is swung downward about the hinge 5 while compressing the coil spring 4, and the upstream side in the recess 2 is moved. A depressed step portion that becomes deeper is formed.

FIG. 5 is a cross-sectional view showing a third embodiment of the water control system according to the present invention, in which one end of the movable floor 3 has the upper end opening of the recess 2 contrary to the second embodiment. Water flow direction F
On the other hand, it is supported in a cantilever manner at the edge on the upstream side via a hinge 5. In this case, when the water level rises and the flow rate increases, as shown in FIG. While being compressed, it is oscillated and displaced downward about the hinge 5 to form a depressed step portion such that the downstream side in the recess 2 becomes deep.

FIG. 7 shows an example of the arrangement pattern of the concave portions 2 in each of the above-mentioned embodiments, that is, in the river bed 1,
By forming a large number of recesses 2 in a checkered flag pattern, it is possible to increase the flow resistance in this portion when the flow velocity increases due to increased water, and to effectively control the distribution of the water flow.

The plane shape, cross-sectional shape, depth, number of arrangements and arrangement pattern of the concave portions 2, the set displacement amount of the movable floor 3, etc., should be taken into consideration in consideration of the width, flow rate, water level or flow velocity of the flow to be controlled. It is decided as appropriate. Further, in the above-mentioned embodiment, the coil spring 4 is used as the elastic body for supporting the movable floor body 3. However, as long as it has elasticity capable of elastically returning the movable floor body 3 to the origin position, the material is It does not matter, for example, if a bellows-like or expandable bag-like thing containing a compressive fluid such as air is used as an elastic body,
The movable floor body 3 can be moved up and down according to the change in water pressure due to the increase or decrease in the water level.

[0014]

EFFECTS OF THE INVENTION According to the water control system of the present invention, the movable floor body in the recess formed in the riverbed or channel floor is supported at almost the same level as the riverbed or channel floor at a normal low water level. When it rises and the flow rate and flow velocity increase, it is displaced downward to increase the resistance to water flow, so it is possible to automatically perform control according to the water level, flow rate, and flow velocity.
Moreover, since this water work is provided on the riverbed or the waterway floor, the effect that the landscape on the water is not adversely affected is realized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a water control system according to the present invention at a low water level.

FIG. 2 is a cross-sectional view showing an operating state when increasing water in the first embodiment.

FIG. 3 is a sectional view at a low water level showing a second embodiment of the water control system according to the present invention.

FIG. 4 is a cross-sectional view showing an operating state at the time of increasing water in the second embodiment.

FIG. 5 is a sectional view at a low water level showing a third embodiment of the water control system according to the present invention.

FIG. 6 is a cross-sectional view showing an operating state when increasing water in the third embodiment.

FIG. 7 is an explanatory diagram showing an example of an arrangement pattern of recesses in each of the above embodiments.

[Explanation of symbols]

 1 Riverbed (fluid floor) 2 Recessed portion 3 Movable floor body 4 Coil spring (elastic body) 5 Hinge

Claims (2)

[Claims] 1. A required number of recesses formed in a river bed or a waterway bed, a movable floor body which is vertically movable in the recessed portion and arranged so as to close the recessed portion, and the movable floor body is provided at an upper end position of the recessed portion. A water control system characterized by comprising an elastic body for urging and supporting the water flow. 2. The water control system according to claim 1, wherein the movable floor is swingably and cantilevered by a part of an upper end opening of the recess via a hinge.