JP2007191936A - Transmission type erosion control dam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely capture pebbles with a middle or a small diameter as well as pebbles with a large diameter which is predicted to cause disaster, minimize damage that an erosion control dam receives by impact at the time of collision, and further pass earth and sand, pebbles with a fine diameter or the like which do not influence the disaster through a lower part of the erosion control dam body in an ordinary time or in flooding on a small scale. <P>SOLUTION: The transmission type erosion control dam is provided with the erosion control dam body 1 which is assembled with supports 2 and horizontal beams 3 in the form of a tower, a middle or small pebble capturing member 6 for capturing the pebbles with a middle or a small diameter which is detachably attached to an upperstream surface of the erosion control dam body 1 through brackets 7. The middle or small pebble capturing member 6 is assembled with longitudinal bars 8 and cross bars 9 in a lattice shape, and the middle or small pebble capturing member 6 is installed with a space from the lower end of the erosion control dam body 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides a transmission type sabo dam, particularly a medium / small gravel trapping member that captures small / medium gravels on the upstream surface of the sabo dam main body. Can be reliably captured, and the impact of gravel collision can be absorbed by the medium-pebbles capture member, so that damage to the sabo dam body can be minimized, and the medium-pebbles capture member can be By detachably attaching to the sabo dam body, it is easy to replace the damaged medium pebbles catching member, and by attaching the medium pebbles catching member at a distance from the lower end of the sabo dam body, Further, the present invention relates to a transmission-type sabo dam that can pass sediments and gravel with a small diameter that does not affect disasters from the lower part of the sabo dam body during a small flood.

  In mountain streams and swamps, various sabo dams have been constructed to capture gravel that suddenly flows out with sediment during floods and to minimize various disasters caused by debris flows that occur downstream.

  Conventionally, this type of sabo dam has been made of concrete. However, in this concrete sabo dam, the gravels and sediments of small diameter that flow down during normal times and small floods are blocked. When large and medium-scale floods occurred, sedimentation proceeded rapidly, and the function as a sabo dam was lost early. Therefore, various types of transmission-type sabo dams have been developed and implemented in the normal and small-scale floods, which have the function of flowing down small-diameter gravel and earth and capturing large-diameter and medium- and small-diameter gravel only during large- and medium-scale floods. ing.

  One of such transmission-type sabo dams is disclosed in Patent Document 1 (Japanese Patent No. 3186910). Hereinafter, this transmission type sabo dam is called a conventional dam 1 and will be described with reference to the drawings.

  FIG. 6 is a view showing the conventional dam 1, (a) is a side view, and (b) is a front view as seen from the downstream side. As shown in FIGS. 6 (a) and 6 (b), the conventional dam 1 is composed of struts 11 and cross beams 12 assembled in a bowl shape, and the distance between the struts 11 is 1.5 to 2 times the diameter of the boulder. And the size of the grid-like mesh composed of the columns 11 and the cross beams 12 is large at the bottom of the dam, that is, two to three times the diameter of the boulder, and small at the top, that is, below the diameter of the boulder It is what.

  Patent Document 2 (Japanese Patent Laid-Open No. 2005-201019) discloses another transmission type sabo dam. Hereinafter, this transmission type sabo dam is called a conventional dam 2 and will be described with reference to the drawings.

  FIG. 7 is a perspective view showing the conventional dam 2. As shown in FIG. 7, the conventional dam 2 includes a sabo dam body 15 in which struts 13 and cross beams 14 are assembled in a bowl shape, and a gap forming member 16 made of a ring net or the like attached to the upstream surface of the sabo dam body 15. The gravel capturing member 17 is attached to the lower part of the sabo dam main body 15.

Japanese Patent No. 3186910 Japanese Patent Laying-Open No. 2005-201019

  According to the conventional dam 1, boulders can be captured by the pillars 11, small and medium-diameter gravel can be captured at the upper part of the dam with a small grid-shaped grid, and the grid-shaped grid at the lower part of the dam is Because of its large size, small-diameter gravel and earth and sand during normal times and small-scale floods can flow down as they are. Therefore, the problem that the function as a sabo dam is lost early is solved.

  However, when the dam is damaged by the impact at the time of collision of medium- and small-diameter gravels as well as large-diameter gravels, the conventional dam 1 is rebuilt, or the damaged part is melted and replaced with new members. In any case, a great deal of labor and time are required.

  Further, according to the conventional dam 2, the space forming member 16 and the gravel capturing member 17 have the advantages of the conventional dam 1 as described above, and the space forming member 16 made of a ring net or the like. Since it can be removed from the sabo dam main body 15, it has an advantage that it can be easily replaced when the space forming member 16 is damaged by the collision of gravel.

  However, damage to the dam body 15 when gravel collides directly with the sabo dam body 15 is inevitable, and in this case, the same problem as in the conventional dam 1 described above occurs.

  Therefore, the object of the present invention is to reliably capture not only large-diameter gravel that is expected to cause a disaster, but also small-and-medium-diameter gravel on the upstream surface of the sabo dam body. Moreover, as a result of absorbing the impact at the time of gravel collision by the medium-pebbles catching member, damage to the sabo dam body can be minimized, and the medium-pebbles catching member can be attached to the sabo dam body. It is easy to replace the damaged medium-pebbles catching member by attaching it to the detachable, and the medium-pebbles catching member is installed at a distance from the lower end of the sabo dam body, so that it can be used for normal and small-scale floods. In some cases, it is an object to provide a transmission type sabo dam that can pass sediments and gravel with a small diameter that does not affect disasters from the bottom of the sabo dam body.

  The present invention has been made to achieve the above-described object, and is characterized by the following.

  The invention according to claim 1 is a sabo dam body composed of a column and a cross beam assembled in a bowl shape, and a medium pebbles capturing member that is attached to the upstream surface of the sabo dam body and captures small and medium diameter gravel. The medium and small gravel capturing member is characterized by comprising a plurality of horizontal bars, a plurality of vertical bars, or a combination of a plurality of vertical bars and horizontal bars in a grid pattern. is there.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, when the medium and small gravel capturing member is composed of a horizontal beam, the interval between the horizontal beams is less than the interval between the columns. It is.

  The invention according to claim 3 is characterized in that, in the invention according to claim 1, when the medium and small gravel capturing member is composed of vertical bars, the interval between the vertical bars is less than the interval between the columns. It is.

  According to a fourth aspect of the present invention, in the first aspect of the invention, in the case where the medium and small gravel capturing members are each composed of a plurality of vertical bars and horizontal bars assembled in a lattice shape, the vertical bars and the The distance between at least one of the horizontal rails is less than the distance between the columns.

  According to a fifth aspect of the present invention, in the first or fourth aspect of the present invention, when the medium and small gravel capturing members are each composed of a plurality of vertical bars and horizontal bars assembled in a lattice shape, the vertical bars And the horizontal rail is characterized by being assembled by hinge connection.

  A sixth aspect of the invention is characterized in that, in the fifth aspect of the invention, the distance between at least one of the vertical beam and the horizontal beam is less than the distance between the columns.

  The invention described in claim 7 is characterized in that, in the invention described in any one of claims 1 to 6, the medium and small gravel capturing member is detachably attached to the sabo dam body. Is.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, characterized in that the medium and small gravel capturing member is attached at a distance from a lower end of the sabo dam body. It is what has.

  The invention according to claim 9 is characterized in that, in the invention according to claim 8, the interval is an interval equal to or greater than a water depth at the time of a small-scale flood.

  The invention according to claim 10 is the invention according to any one of claims 1 to 9, wherein the medium and small gravel capturing member is attached to an upstream surface of the sabo dam body via a spacing member. It has characteristics.

  The invention according to claim 11 is characterized in that, in the invention according to any one of claims 1 to 10, the interval between the struts for capturing large-diameter gravel is not more than 1 times the target gravel diameter. It is what you have.

  A twelfth aspect of the invention is characterized in that, in the invention according to any one of the first to eleventh aspects, the longitudinal beam is made of H-section steel.

  A thirteenth aspect of the invention is characterized in that, in the invention according to any one of the first to twelfth aspects, the cross rail is formed of a round steel pipe.

  According to the present invention, not only large-diameter gravel predicted to cause a disaster but also medium- and small-diameter gravel surely capture medium-small-diameter gravel on the upstream surface of the sabo dam body. Moreover, as a result of being able to absorb the impact at the time of gravel collision by the medium-pebbles catching member, damage to the sabo dam body can be minimized, and the medium-pebbles catching member can be attached to the sabo dam body. By attaching it detachably, it is easy to replace the damaged medium-pebbles catching member, and by attaching the medium-pebbles catching member at a distance from the lower end of the sabo dam body, Sediment and gravel with a small diameter that does not affect disasters can be passed from the bottom of the sabo dam body.

  Next, one embodiment of the transmission type sabo dam of this invention will be described with reference to the drawings.

  1 is a perspective view showing a transmission type sabo dam according to the present invention, FIG. 2 is a side view showing the transmission type sabo dam according to the present invention, and FIG. 3 is a view in the direction of arrow A in FIG. FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, and FIG. 5 is a plan view showing a transmission type sabo dam according to the present invention.

  In FIG. 1 to FIG. 5, reference numeral 1 denotes a sabo dam body composed of a column 2 and a cross beam 3 assembled in a bowl shape, and is constructed on a concrete foundation 5 between sleeves 4. The column 2 is composed of an upstream side (arrow side in FIG. 2) column 2A and a downstream column 2B assembled in an inverted V shape. The horizontal beam 3 is disposed between the upstream horizontal beam 3A disposed between the upstream columns 2A, the downstream horizontal beam 3B disposed between the downstream columns 2B, and the upstream column 2A and the downstream column 2B. It consists of the side beam 3C and the inclined beam 3D arranged between the upstream column 2A and the foundation 3.

  The interval between the upstream struts 2A for capturing the large-diameter gravel is less than or equal to the target gravel diameter. Here, the target gravel diameter is a diameter corresponding to the diameter of the gravel that is expected to flow down with a debris flow during a flood and cause a disaster. The definition of the target gravel diameter is, for example, the survey of 100 gravel diameters and the 80th gravel diameter counted from the smallest diameter. The survey target is the gravel diameter from the vicinity of the dam site to the top and bottom terrain change points.

  Reference numeral 6 denotes a medium / small gravel capturing member that captures medium / small diameter gravel, and is detachably attached to the upstream surface of the sabo dam main body 1 by a bolt and a nut via a bracket 7 as a spacing member. The medium and small gravel capturing member 6 may be directly and detachably attached to the upstream surface of the sabo dam main body 1, but by attaching the bracket via the bracket 7, an impact buffering effect is further increased. The medium and small gravel capturing member 6 is composed of a vertical beam 8 and a horizontal beam 9 assembled in a lattice pattern. For example, a vertical beam 8 made of an H-shaped steel and a horizontal beam 9 made of a round steel pipe that passes through the H-shaped steel web and is fixed at right angles thereto, and the vertical beam 8 passes through a bracket 7. The sabo dam main body 1 is detachably attached to the upstream column 2A. The vertical distance (L1) of the horizontal rails 9 is less than the distance between the upstream struts 2A, for example, half the distance (L2) between the upstream struts 2A. Can be captured. The large-diameter boulders are captured by the sabo dam body 1 after colliding with the medium-and-small pebbles capturing member 6. In the medium and small gravel capturing member 6, if the distance between at least one of the vertical beam 8 and the horizontal beam 9 is less than the distance between the upstream columns 2A, medium and small diameter gravel can be captured. If the vertical beam 8 and the horizontal beam 9 are hinge-coupled, the buffering effect is further improved.

  In addition, the medium and small gravel capturing member 6 may be composed of a plurality of horizontal beams or a plurality of vertical beams. In this case, the interval between the horizontal rails or the vertical rails is set to be less than the interval between the upstream columns 2A.

  The medium and small gravel capturing member 6 is attached with a space (L3) from the lower end of the sabo dam body 1 (see FIG. 3 for L1, L2, and L3). The interval (L3) is an interval greater than the water depth during a small flood. Thus, by attaching the medium / small gravel capturing member 6 to the sabo dam body 1 with a space (L3) from the lower end of the sabo dam body 1, the lower part of the sabo dam body 1 is only the upstream column 2A. During normal times and small-scale floods, sediments and gravels with a small diameter that do not affect disasters pass freely through the sabo dam body 1.

  The medium / small gravel capturing member 6 has an effect of absorbing damage energy of the gravel and minimizing damage to the sabo dam body 1. That is, when a gravel collides with the horizontal beam 9 fixed between the vertical beams 8 during a flood, the absorbed energy (E1) due to the elastic deformation of the horizontal beam 9 and the absorption due to the local dent deformation of the steel pipe constituting the horizontal beam 9. The energy (E2) and the absorbed energy (E3) due to plastic deformation of the crosspiece 9 absorb the impact energy of gravel, and as a result, damage to the sabo dam body 1 can be minimized.

  The horizontal beam 9 of the medium and small gravel capturing member 6 is not a structural member for maintaining the sabo dam main body 1 but only requires a function of capturing the medium and small gravel. It is possible to consider up to a large deformation that allows the plastic state of the crosspiece 9. Therefore, greater energy absorption is possible.

  Since the medium / pebbles catching member 6 is detachably attached to the upstream column 2A by means of bolts and nuts via the bracket 7, if the medium / pebbles catching member 6 is damaged due to the impact of gravel, it can be easily replaced with a new one. Can be replaced.

As explained above, according to the transmission type sabo dam of this invention, the following effects are brought about.
(1) By attaching the medium and small gravel capturing member 6 to the upstream surface of the sabo dam main body 1, not only large diameter gravel predicted to cause a disaster but also medium and small diameter gravel can be reliably captured.
(2) As a result of the impact at the time of gravel collision being absorbed by the medium and small gravel capturing member 6, damage to the sabo dam body 1 can be minimized.
(3) By attaching the medium and small gravel trapping member 6 at a distance from the lower end of the sabo dam main body 1, during normal times and small-scale floods, the bottom of the sabo dam main body 1 does not affect the sediment or disaster. Small diameter gravel can be passed freely.
(4) By attaching the medium and small gravel capturing member 6 to the sabo dam main body 1 so as to be detachable, replacement can be easily performed when the medium and small gravel capturing member 6 is damaged by the collision of gravel.

It is a perspective view which shows the transmission type sabo dam of this invention. It is a side view which shows the transmission type sabo dam of this invention. It is an A direction arrow directional view of FIG. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is a top view which shows the transmission type sabo dam of this invention. It is a figure which shows the conventional dam 1, (a) is a side view, (b) is the front view seen from the downstream. It is a perspective view which shows the conventional dam 2.

Explanation of symbols

1: Sabo dam main body 2: Column 2A: Upstream column 2B: Downstream column 3: Cross beam 3A: Upstream horizontal beam 3B: Downstream horizontal beam 3C: Side beam 3D: Inclined beam 4: Sleeve 5: Concrete foundation 6 : Medium and small gravel capturing member 7: Bracket 8: Vertical beam 9: Horizontal beam 11: Post 12: Horizontal beam 13: Post 14: Horizontal beam 15: Sabo dam body 16: Spacing forming member 17: Gravel capturing member

Claims (13)

  A sabo dam body composed of a column and a cross beam assembled in a bowl shape, and a medium pebbles capturing member attached to the upstream surface of the sabo dam body for capturing small and medium-diameter gravel, Is a transmission-type sabo dam characterized by comprising a plurality of horizontal rails, a plurality of vertical rails, or a plurality of vertical rails and horizontal rails each assembled in a grid pattern.   The transmission type sabo dam according to claim 1, wherein, when the medium and small gravel capturing member is composed of a horizontal beam, the interval between the horizontal beams is less than the interval between the columns.   The transmission type sabo dam according to claim 1, wherein when the medium and small gravel trapping member is composed of vertical bars, an interval between the vertical bars is less than an interval between the columns.   In the case where each of the medium and small gravel capturing members is composed of a plurality of vertical beams and horizontal beams assembled in a lattice shape, the interval between at least one of the vertical beam and the horizontal beam is less than the interval between the columns. The transmission type sabo dam according to claim 1, wherein   In the case where each of the medium and small gravel capturing members is composed of a plurality of vertical beams and horizontal beams assembled in a lattice shape, the vertical beam and the horizontal beam are assembled by hinge connection. The transmission type sabo dam according to claim 1.   The transmission type sabo dam according to claim 5, wherein a distance between at least one of the vertical beam and the horizontal beam is less than a distance between the columns.   The transmission type sabo dam according to any one of claims 1 to 6, wherein the medium and small gravel capturing member is detachably attached to the sabo dam body.   The transmission type sabo dam according to any one of claims 1 to 7, wherein the medium-pebbles capturing member is attached with a space from a lower end of the sabo dam body.   The transmission type sabo dam according to claim 8, wherein the interval is an interval equal to or greater than a water depth during a small flood.   The transmission type sabo dam according to any one of claims 1 to 9, wherein the medium and small gravel capturing member is attached to an upstream surface of the sabo dam main body via a spacing member.   The transmission type sabo dam according to any one of claims 1 to 10, wherein an interval between the struts for capturing a large-diameter gravel is equal to or less than a target gravel diameter.   The transmission type sabo dam according to any one of claims 1 to 11, wherein the vertical beam is made of H-shaped steel.   The transmission type sabo dam according to any one of claims 1 to 12, wherein the horizontal rail is made of a round steel pipe.

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