JP2007217942A - Columnar structure in water area - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a columnar structure in a water area, which can prevent flow-down matter such as drift wood from gathering on the periphery of the same such as a bridge pier erected in the water area such as a river. <P>SOLUTION: The columnar structure or the bridge pier 1 is erected in the river 4, and a rotary body 2 rotating along an outer periphery of a main body 1a is formed thereon. The rotary body 2 has a plurality of blade portions 3 formed on a surface thereof, for rotating the rotary body 2 in one direction upon reception of a force by a stream spaced apart by an interval in a peripheral direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a columnar structure in a water area such as a pier standing in a water area such as a river.

  When the amount of surface water and rainwater flowing into the river due to typhoons and heavy rain increases, the river level rises and large falling objects such as driftwood that cannot be seen in normal times will flow out.

  Also, if the slope collapses due to heavy rain, the trees that grew on the slope will fall into the river and flow into the river, or the trees that grew on the riverbank where water will not flow normally will be washed down by the flood and run off. Therefore, the amount of driftwood flowing down the river during flooding is much larger than normal.

  When driftwood is caught on the bridge piers etc. standing in the river, the driftwood that has flowed down one after another accumulates around the pier, eventually destroying the bridge girder and pier, or flooding the river blocked by driftwood. The bank will be destroyed.

In order to prevent such damage caused by driftwood, as described in Patent Document 1, generation of driftwood is suppressed by slope stabilization work, revetment work, etc. Driftwood countermeasures are known.
JP-A-6-330515

  However, the conventional driftwood countermeasures are roughly divided into a method for preventing the occurrence of driftwood and a method for capturing the generated driftwood, and does not prevent the driftwood actually flowing down from being caught on the pier. .

  In other words, even if conventional driftwood countermeasures are implemented, it is difficult to completely eliminate the flow of driftwood during floods, and it is necessary to develop countermeasures that effectively prevent the above-mentioned disasters that may occur due to the driftwood that has occurred. It has been.

  Therefore, an object of the present invention is to provide a column structure in a water area that can reduce the accumulation of falling objects such as driftwood around a column structure such as a bridge pier standing in a water area such as a river.

  In order to achieve the above object, the present invention is a columnar structure in a water area in which a rotating body that surrounds at least a part of the outer periphery of the main body portion in the circumferential direction and rotates along the outer periphery is formed. It is characterized by.

  Here, it is preferable that a force receiving portion for rotating the rotating body in one direction by receiving a force of a water flow is provided on the surface of the rotating body. Moreover, it can be set as the structure which provided multiple blade | wing parts which protrude from the surface of the said rotary body as the said force receiving part at intervals in the circumferential direction.

  Furthermore, the rotating body surrounds the outer periphery of the main body portion in the circumferential direction, is fixed to the main body portion, and is disposed in the groove portion, and has a base portion formed with a groove portion extending in the circumferential direction on the outer peripheral surface side. The plurality of ball portions and the moving portion that moves around the base portion with the inner peripheral surface abutting against the ball portions.

  Further, the rotating body may be composed of a sprocket portion that is rotatably arranged on the main body portion, and an endless track band that meshes with the sprocket portion and rotates.

  In the present invention configured as described above, a rotating body that rotates along the outer periphery of the main body of the columnar structure is provided.

  And if the rotating body is rotating, there is a low possibility that falling wood, such as driftwood, will be caught by the columnar structure, and that the accumulation of falling material during floods may damage the bridge or flood the river. Can be reduced.

  Further, by providing a force receiving portion that receives the force of the water flow on the surface of the rotating body and rotates the rotating body in one direction, the rotating body can be easily rotated by the water flow obtained from the river during a flood.

  In addition, by providing the blade portion as the force receiving portion, it is easy to receive the force of the water flow, the rotation speed of the rotating body can be increased, and the possibility that the falling objects are accumulated can be further reduced.

  Furthermore, if the rotating body has a bearing structure composed of a base, a ball part, and a moving part, the resistance during rotation can be made extremely small, and the rotating body can be reliably rotated by a water flow.

  In addition, by configuring the rotating body from the sprocket portion and the endless track belt that rotates while meshing with the sprocket section, the rotating body can be formed in columnar structures having various cross sections.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG.1 and FIG.2 is a figure explaining schematic structure of the pier 1 as a columnar structure of this Embodiment.

  First, in terms of configuration, the pier 1 according to the present embodiment is erected on a river 4 as a water area, and abutments 1c and 1c and piers 1 provided on both banks as shown in FIG. A bridge girder 1b is bridged over the head of the frame 10 to form a bridge 10.

  The river 4 has a normal low water level 4b and a flood high water level 4a so that the river 4 will not be flooded to the high water level 4a even if the water level increases due to heavy rain. Is planned.

  As shown in FIG. 1, the bridge pier 1 of the present embodiment rotates around the outer periphery of the main body 1a as a support member of the bridge 10 and at least a part of the outer periphery of the main body 1a in the circumferential direction. The rotating body 2 is mainly composed of a rotating body 2 and a blade section 3 as a force receiving section that receives a force of a water flow provided on the surface of the rotating body 2.

  The rotating body 2 is disposed so as to cover the main body 1a from slightly above the high water level 4a to near the bottom of the water.

  Further, the blade portion 3 receives a force from the upstream side to the downstream side (in the S direction in FIG. 1), and the rotating body 2 is rotated in one direction (clockwise, T direction in FIG. 1) around the main body 1a. It is formed to rotate.

  Although the rotation direction with respect to the S direction may be counterclockwise, a case where the rotating body 2 is rotated clockwise will be described here.

  That is, when a plurality of fan-shaped columnar blade portions 3 having a fan-shaped cross section are provided on the surface of the rotator 2 at intervals in the circumferential direction of the rotator 2, as shown in FIGS. When viewed, the blade 3 on the left bank side receives the flow in the plane portion 3a having a large resistance to the flow in the S direction, and the blade 3 on the right bank resists the flow in the S direction. The flow is received by the small curved surface portion 3b.

  If a plurality of blade portions 3,... Having an asymmetric shape in plan view are attached to the surface of the rotator 2, the rotator 2 rotates in one direction (T direction) according to the same principle as the Robinson anemometer. It will be.

  When the rotating body 2 is rotated only during a flood, it is only necessary to provide the blade portions 3,... Only above the low water level 4b and below the high water level 4a as shown in FIG.

  Moreover, since the magnitude | size of the force which the blade | wing part 3 receives from a water flow changes by changing the length of the blade | wing part 3, in order to rotate the rotary body 2 with the desired flow velocity, the length and shape of the blade | wing part 3 are appropriate. Adjust to things.

  As such a configuration of the rotating body 2, for example, a bearing structure as shown in FIG. 3 can be adopted.

  As shown in the sectional view of FIG. 3 (a), the rotating body 2 includes a cylindrical base portion 2a that surrounds the outer periphery of a columnar main body portion 1a in the circumferential direction, and a radial interval from the base portion 2a. It is mainly comprised from the cylindrical moving part 2b arrange | positioned so that the base part 2a may be covered, and the some ball | bowl part 2c arrange | positioned at the groove part 2d between the base part 2a and the moving part 2b.

  The base portion 2a is fixed to the main body portion 1a with an anchor bolt 2e and the like, and a groove portion extending in the circumferential direction is formed on the outer peripheral surface side, and formed on the inner peripheral surface side of the moving portion 2b facing the groove portion. A groove portion 2d for accommodating the ball portions 2c,... Is formed together with the groove portion.

  As shown in FIG. 3B (cross-sectional view taken along the line BB in FIG. 3A), a plurality of the groove portions 2d are formed at intervals in the vertical direction, and each groove portion 2d,. Is provided with a plurality of ball portions 2c.

  And when the force of the clockwise direction T acts on the moving part 2b in the plane part 3a of the blade | wing part 3 when the water flow S acts on the base part in the state which receives the restrictions with respect to the movement of T direction via the ball | bowl part 3c, ... The moving part 2b supported by 2a moves around the base part 2a and rotates.

  Next, the effect | action of the pier 1 of this Embodiment is demonstrated.

  The bridge pier 1 of the present invention configured as described above is provided with a rotating body 2 that rotates along the outer periphery of the main body 1a, and the blade portion 3 as a force receiving portion formed on the surface of the rotating body 2 has a water flow. The rotating body 2 is rotated in one direction by the force received from.

  And if the rotating body 2 is rotating, there is a low possibility that a fallen thing such as a driftwood 5 will be caught on the pier 1, and the fallen girder 1b and the pier 1 will be damaged due to accumulation of the fallen thing during a flood, or the river will be flooded. Can be reduced.

  Further, by providing the blade portion 3 as the force receiving portion, it is easy to receive the force of the water flow, and the rotational speed of the rotating body 2 can be increased. As a result, the possibility of accumulation of the falling material can be further reduced.

  Furthermore, if the rotating body 2 has a bearing structure composed of the base 2a, the ball portion 2c,... And the moving portion 2b, the resistance during rotation can be made extremely small, and the rotating body 2 can be moved by water flow. It can be rotated reliably.

  In addition, such a bearing structure can be installed simply by fixing the base 2a to the outer periphery of the main body 1a with an anchor bolt 2e and the like, and attaching the ball 2c,... And the moving part 2b to the base 2a. Even if the bridge 10 is built and shared, the rotating body 2 can be easily attached to take measures to suppress driftwood capture.

  Hereinafter, Example 1 of the above-described embodiment will be described.

  In Example 1, the results of experiments conducted to confirm the operational effects of the pier 1 of the above embodiment will be described.

  This experiment was conducted using the experimental apparatus shown in FIG. Here, FIG. 4A shows a plan view of the experimental water channel 24, and FIG. 4B shows a side view of the experimental water channel 24.

  This experiment was conducted by forming a one-way water flow from the pump toward the weir in the experimental water channel 24 having a length of 560 cm, a width of 50 cm, and a depth of 57 cm.

  In this experimental water channel 24, a pier 21 modeled as a columnar structure is erected in the vicinity of the center of the water channel, and a bridge girder portion 21b having a thickness of 1 cm is installed thereon.

  The bridge pier 21 is covered with a cylindrical tube as a rotating body 22 over the substantially entire length of a cylindrical main body 21a having a diameter of 5 cm and a height of 12 cm so that the rotating body 22 rotates with the main body 21a as a shaft member. It is configured.

  Further, five fan-shaped columnar blade portions 23 formed by dividing a circular column having a radius of 1 cm into four equal parts are attached to the surface of the rotating body 22 over the entire length of the rotating body 22.

  In addition, the driftwood model used in the experiment was a cylindrical timber with a diameter of 8 mm and had three lengths (L = 13.5, 18.0, 27.0 mm). The drifting of the driftwood was performed by a method of floating gently in the direction perpendicular to the flow at a position 50 cm upstream of the pier 21 (25 cm from the side wall).

  The experimental conditions are shown in Table 1 below.

  Here, the flow velocity U is a cross-sectional average flow velocity, and the angular velocity ω is a value indicating the rotation speed of the rotating body 22 measured in flowing water not flowing through driftwood.

  In addition, the determination as to whether or not driftwood was captured considered that the driftwood that had been in contact with the pier 21 for 10 seconds or more after colliding with the pier 21 was captured.

  When driftwood was captured, the next driftwood was allowed to flow after removing it, and 50 drop experiments were repeated under the same conditions. For comparison, the same experiment was performed on a cylinder without a rotating body.

  FIG. 5A is a diagram showing that the flow of the driftwood is promoted by the rotation of the rotating body 22.

  Here, the evaluation value R indicates a value obtained by dividing (number of times driftwood is captured by a rotating body) by (number of times driftwood is captured by a cylinder without a rotating body). It can be said that the closer the value is to 0, the greater the effect of suppressing the drifting of the rotating body 22 is, and the closer the value is to 1, the smaller the effect.

  In FIG. 5 (a), when the length of the driftwood is 13.5 cm and 27 cm, the evaluation value R approaches 0 as the flow velocity U increases, and the average flow velocity U is 25 cm / sec. From the above, it can be seen that the evaluation value R is very small, approximately 0.2 or less.

  From this result, it can be said that when the flow velocity is high as in a flood, the flow of the driftwood is promoted by the rotation of the rotating body 22, so that it is possible to effectively suppress the pier 21 from capturing the driftwood. .

  Moreover, in FIG.5 (b), the result of having examined the influence of the driftwood length L and the flow velocity U which has on the driftwood capture suppression effect of the rotary body 22 was shown. In FIG. 5B, the horizontal axis is the driftwood length (L / D) obtained by making the cylinder diameter dimensionless, and the vertical axis is the evaluation value R.

  From FIG. 5B, when the flow velocity U is fast (= 42 cm / sec), it can be said that all driftwood can flow down regardless of the driftwood length L, but when the flow velocity U becomes slow (= 25,34 cm / sec). ) And the length of the driftwood length L, it can be seen that the effect of promoting the flow-down is reduced.

  However, even in such a case, if the driftwood length (L / D) exceeds about 3.5, the drifting promotion effect will not be reduced further. It can be said that there is enough.

  Hereinafter, Example 2 which changed the structure of the rotary body 2 of the said embodiment is demonstrated.

  The pier 31 as the columnar structure according to the second embodiment is a pier 31 constructed of, for example, reinforced concrete having a main body 31a having an oval shape in cross section as shown in FIG.

  In FIG. 6, a cross-sectional view of the pier 31 is shown in the left half of the figure, and a plan view of the pier 31 is shown in the right half.

  The rotating body 32 according to the second embodiment mainly includes a sprocket portion 32a that is rotatably arranged on the main body portion 31a, an endless track band 32b that is rotated by meshing with the sprocket portion 32a, and an auxiliary roller 32c. Has been.

  The sprocket portion 32a is a disc-shaped gear having substantially the same curvature as the curved surface portion 31a1 of the main body portion 31a, and the tooth portion 32a1 is disposed so as to protrude outward from the curved surface portion 31a1 of the main body portion 31a.

  Further, the endless track band 32b is a crawler provided with protrusions 32b1,... On the inner surface of the sprocket portion 32a where the teeth 32a1,... Mesh with the teeth 32a1,. Between the sprocket portions 32a and 32a provided on the curved surface.

  Further, auxiliary rollers 32c,... Are arranged on the outer periphery of the flat surface portion 31a2 of the main body portion 31a between the sprocket portions 32a, 32a, and are configured to promote the rotation of the endless track band 32b.

  On the outer peripheral surface of the endless track band 32b, a plurality of blade portions 33,... As force receiving portions are provided at intervals in the continuous track direction of the endless track band 32b.

  The blade portion 33 is a columnar asymmetric member having a fan shape in cross section, and is formed so that rotation in the T direction occurs when a flow in the S direction is received.

  The bridge pier 31 according to the second embodiment configured as described above includes a rotating body 32 including a sprocket portion 32a and an endless track band 32b that rotates while meshing with the sprocket portion 32a.

  For this reason, the rotator 32 can be arranged in a columnar structure having various cross sections such as an ellipse in cross section and an ellipse.

  Other configurations and functions and effects are substantially the same as those in the above-described embodiment, and thus description thereof is omitted.

  Example 3 will be described below.

  In the third embodiment, a rotating body 42 constituted by an endless track different from the endless track of the second embodiment will be described.

  As shown in FIG. 7, the pier 41 as the columnar structure of the third embodiment has an oval body portion 41a in cross-sectional view, and a rotating body 42 is provided on the outer periphery thereof.

  The rotating body 42 is mainly composed of a sprocket portion 42a that is rotatably arranged on the main body portion 41a, an endless track band 42b that is rotated by meshing with the sprocket portion 42a, and an auxiliary roller 42c.

  The sprocket portion 42a is a small disk-shaped gear disposed on, for example, the curved surface portion 41a1 of the main body portion 41a. The sprocket portion 42a is disposed such that the tooth portion 42a1 protrudes outside the main body portion 41a.

  The sprocket part 42a can be installed, for example, by cutting a side surface of the existing main body part 41a into a semi-disc shape and providing a cutout part that can accommodate about half of the sprocket part 42a. Further, when newly constructing the main body portion 41a, a notch portion that can accommodate the sprocket portion 42a may be formed in advance.

  Further, the endless track band 42b is a crawler provided with protrusions 42b1,... On the inner surface of the sprocket portion 42a that meshes with the teeth 42a1,. .. Of the sprocket portions 42a... And the outer periphery of the main body portion 41a.

  Further, auxiliary rollers 42c,... Are arranged on the outer periphery of the flat surface portion 41a2 of the main body portion 41a between the sprocket portions 42a,... To promote the rotation of the endless track band 42b.

  In addition, a plurality of blade portions 43,... As force receiving portions are provided on the outer peripheral surface of the endless track band 42b at intervals in the continuous track direction of the endless track band 42b.

  The vane portion 43 is a columnar asymmetric member having a fan shape in cross section, and is formed so that rotation in the T direction occurs when a flow in the S direction is received.

  The bridge pier 41 of the third embodiment configured in this manner includes a rotating body 42 composed of a plurality of small sprocket portions 42a,.

  For this reason, the rotating body 42 can be arranged on a columnar structure having various cross sections such as an ellipse or an ellipse in cross section, and the sprocket portions 42a,. By forming the body 42, it is possible to take measures to suppress driftwood capture.

  Other configurations and functions and effects are substantially the same as those in the above-described embodiment or example, and thus description thereof is omitted.

  Although the best embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment or example, and the design does not depart from the gist of the present invention. Such modifications are included in the present invention.

  For example, in the above-described embodiments and examples, the configuration in which the force receiving portion is provided has been described. However, the configuration is not limited thereto, and the configuration may be only a rotating body that does not have the force receiving portion. In this case, the rotating body may be rotated by a power source such as a drive motor.

  Further, even when the force receiving portion is provided, it is not limited to the blade portion, and any member that can rotate the rotating body in one direction by receiving the force of the water flow, for example, is asymmetric in the circumferential direction. A concave portion or a convex portion having a simple shape may be provided on the surface of the rotating body.

  Further, even when the force receiving portion is provided, if the rotating body cannot be set to a desired rotation speed only by the water flow, a configuration in which the rotating body is rotated by using a drive motor as an auxiliary may be used.

  In addition, the shape of the blade is not limited to the fan-shaped columnar section in section view. For example, the blade section in the section view arc shape in which the flat surface portion 3a side is depressed, or a flat plate-shaped blade section supported on one side. It may be configured such that the stopper works to form a resistance surface only when a water flow is received from the side.

It is a perspective view explaining the bridge pier of the best embodiment of this invention. It is a side view explaining the schematic structure of the pier of the best embodiment of this invention. It is a figure explaining the structure of a rotary body, Comprising: (a) is the sectional view on the AA line of FIG. 2, (b) is the sectional view on the BB line of (a). (A) is a top view explaining the structure of the experimental apparatus of Example 1, (b) is the side view. It is a graph which shows the experimental result of Example 1, Comprising: (a) is the figure which showed the relationship between the evaluation value which shows a flow-down promotion effect, and the flow velocity, (b) is the figure which showed the relationship between driftwood length and an evaluation value. is there. It is explanatory drawing explaining the structure of the rotary body of Example 2. FIG. It is explanatory drawing explaining the structure of the rotary body of Example 3. FIG.

Explanation of symbols

1 Pier (columnar structure)
DESCRIPTION OF SYMBOLS 1a Main body part 2 Rotating body 2a Base part 2b Moving part 2c Ball part 3 Blade | wing part (power receiving part)
4 rivers (water bodies)
21, 31, 41 Pier (columnar structure)
21a, 31a, 41a Main body parts 22, 32, 42 Rotating bodies 32a, 42a Sprocket parts 32b, 42b Endless track zones 23, 33, 43 Blade parts (power receiving parts)

Claims (5)

  A columnar structure standing in the water area, wherein a rotating body is formed that surrounds at least a part of the outer periphery of the main body portion in the circumferential direction and rotates along the outer periphery. Columnar structure.   2. The water columnar structure according to claim 1, wherein a force receiving portion for rotating the rotating body in one direction by receiving a force of a water flow is formed on a surface of the rotating body.   The water columnar structure according to claim 2, wherein a plurality of blade portions protruding from the surface of the rotating body are provided as the force receiving portions at intervals in the circumferential direction.   The rotating body surrounds the outer periphery of the main body portion in the circumferential direction, is fixed to the main body portion, and is disposed in the groove portion having a groove portion formed on the outer peripheral surface side and extending in the circumferential direction. 4. The apparatus according to claim 1, comprising a plurality of ball portions and the moving portion that moves around the base portion by contacting an inner peripheral surface side with the ball portions. 5. The columnar structure of the water area as described in 2. 4. The rotary body according to any one of claims 1 to 3, wherein the rotary body includes a sprocket portion that is rotatably arranged on the main body portion, and an endless track belt that meshes with the sprocket portion and rotates. The water columnar structure according to claim 1.

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