JP4856483B2 - Steel slit dam - Google Patents

Description

  The present invention is intended to ensure that the sediment with a relatively small particle size contained in normal small and medium water discharge is actively permeated to flow downstream to secure the sand storage capacity upstream of the dam until debris flow occurs. It is related to a steel slit dam with a permeable structure for capturing large boulders, driftwood and large amounts of earth and sand to prevent outflow to downstream rivers.

  Conventionally, as a steel slit dam equipped with steel column members, by tilting the steel column members, a part of the impact force acting on the column members due to the flowing wood and rock is used as the component force to the basic concrete There is known a steel sabo dam that is acted to increase the structural strength (see, for example, Patent Document 1).

  FIG. 6 is a partially longitudinal side view showing an example of a conventional steel slit dam. As shown in FIG. 6, a three-dimensional frame structure 5 having a truncated pyramid shape having a horizontal member 2 that connects between the steel pipe column members 1 of the upstream side steel pipe column member 1 and the downstream side steel pipe column member 4 is used. In addition, a steel slit dam 15 is also known in which the steel pipe column member 1 on the upstream side and the steel pipe column member 4 on the downstream side in the three-dimensional frame structure 5 are inclined at the same inclination angle (for example, Patent Documents). 2).

JP 2002-327424 A JP 2001-303538 A

  However, in the embodiment shown in FIG. 6, the steel pipe column member 1 on the upstream side is a steel pipe column member having a thickness greater than the plate thickness of the steel pipe column member 4 on the downstream side. When constructing such a steel slit dam 15 in which the steel pipe column member 1 on the upstream side and the steel pipe column member 4 on the downstream side are inclined at the same inclination angle, the steel pipe column members on the upstream side and the downstream side in the field work. 1 and 4 are comparatively long similar dimensions, and it is difficult to visually check their planar shapes, and the plate thickness of the steel pipe column members 1 and 4 cannot be confirmed from the outside. There is a possibility that the thin steel pipe column member 4 is installed on the upstream side, or the thick steel pipe column member 1 to be arranged on the upstream side may be installed on the downstream side. There is a problem that it is difficult to distinguish.

  Further, since the steel pipe column member 1 on the upstream side and the steel pipe column member 4 on the downstream side are made of the steel slit dam 15 that is inclined at the same inclination angle that is relatively gentle, the steel pipe column member 4 on the downstream side is provided. As the column member size becomes longer, the foundation width from the upstream direction to the downstream direction becomes wider and the amount of the foundation concrete increases, so that the steel slit dam 15 with a high construction cost is obtained. Moreover, when the steel pipe column member 4 on the downstream side has the same gentle inclination angle as that of the steel pipe column member 1 on the upstream side, the probability that the debris that has overcome the steel slit dam 15 will directly hit the steel pipe column member 4 on the downstream side. Is a high steel slit dam 15. Therefore, it is desired to make the steel slit dam more economical, and it is also desired to make the steel slit dam with a low probability that the overturned earth and stone will directly hit the steel pipe column member 4 on the downstream side.

  In the present invention, even if the upstream and downstream steel pipe column members have relatively long and similar dimensions, it is difficult to visually check these planar shapes, and the plate thickness of the steel pipe column members is also viewed from the outside. Even if it cannot be confirmed, the steel pipe column member to be arranged on the downstream side can be reliably arranged on the downstream side, the steel pipe column member to be arranged on the upstream side can be reliably arranged on the upstream side, and the misplacement can be easily found. An object is to provide a steel slit dam. In addition, the foundation width from the upstream direction to the downstream direction is narrow, and it is a more economical steel slit dam, and the steel slit dam with a low probability that the overturned earth and stone will directly hit the steel pipe column member on the downstream side. The purpose is to provide.

In order to advantageously solve the above-described conventional problems, in the steel slit dam according to the present invention, the upstream steel pipe column member and the downstream steel pipe column member are brought close to each other at the upper part of each steel pipe column member. In the steel slit dam having a frame structure having a horizontal member for connecting the steel pipe column members to each other, the lower portions of the steel pipe column members are inclined so as to be separated from each other. The gradient and the normal gradient of the downstream steel pipe column member are different from each other, and when the vertical length is 1, the horizontal length of the normal gradient of the downstream steel pipe column member is 0. 2 and the horizontal length of the normal gradient of the upstream steel pipe column member is 0.3 to 0.4, and the upstream steel pipe column member and the downstream steel pipe column member are Are spaced apart from each other, and the horizontal member Together provided for several, distal mounting flange mutual and between the horizontal member overhanging from the tubular columns member, and characterized in that the intermediate horizontal member distal mounting flange disposed between the horizontal member is connected To do.

  According to the present invention, the steel pipe column member on the upstream side and the steel pipe column member on the downstream side are inclined so that the upper part of each steel pipe column member approaches each other and the lower part of each steel pipe column member is separated from each other, In a steel slit dam with a frame structure having a horizontal member that connects between steel pipe column members, the inclination angle of the downstream steel pipe column member is set to be steeper than the inclination angle of the upstream steel pipe column member. Since the slope of the steel pipe column member on the upstream side and the steel pipe column member on the downstream side was changed, the length of the steel pipe column member on the upstream side and the downstream side of the steel pipe column member of the same height is the Because the dimensions are different, they can be easily distinguished, and even if the upstream side and the downstream side are misplaced by mistake, the horizontal or verticality of the horizontal member or mounting flange will not be obtained, making it easy for field workers You can notice. Therefore, even if the thickness of the steel pipe column member on the upstream side is thicker than the plate thickness of the downstream steel pipe member and the rigidity is high on the upstream side, the plate thickness cannot be confirmed from the outside. The steel pipe column member to be arranged on the side can be reliably arranged on the downstream side, the steel pipe column member to be arranged on the upstream side can be reliably arranged on the upstream side, and the misplacement can be easily found. Further, in the present invention, since the inclination angle of the downstream steel pipe column member is set to be steeper than the inclination angle of the upstream steel tube column member, the length dimension of the column member of the downstream steel tube column member Becomes shorter and more economical, and the foundation width from the upstream direction to the downstream direction becomes narrower, and the amount of bar arrangement and the amount of foundation concrete are also reduced, resulting in a steel slit dam with a low construction cost. Moreover, since the steel pipe column member on the downstream side has a steeper angle than the steel tube column member on the upstream side, the probability that the debris that has climbed over the steel slit dam will directly hit the steel tube column member on the downstream side is low. It is a steel slit dam lower than the slit dam.According to the present invention, since the steel pipe column member and the horizontal member are cross-section circular steel pipes, a commercially available steel pipe is used, and an inexpensive steel slit dam is provided. can do.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a front view showing a steel slit dam according to an embodiment of the present invention, and FIG. 2 is a partially longitudinal side view of the steel slit dam shown in FIG. 3 is a rear view of the three-dimensional frame structure viewed from the upstream side, and FIG. 4 is a front view of the three-dimensional frame structure viewed from the downstream side. Furthermore, FIG. 5 is explanatory drawing which shows the normal gradient of the steel pipe column member of an upstream side and a downstream side. As shown in FIGS. 1 to 4, the steel pipe column members 1 arranged upstream in the left-right direction are mutually connected, and the mounting flanges 3 at the distal ends of the horizontal members 2 projecting in the left-right direction attached thereto are mutually connected. The steel pipe column members 4 which are fixedly connected by bolts and nuts and arranged at intervals in the left-right direction are mutually connected, and the horizontal flanges 2 attached to these are extended in the left-right direction. The steel pipe column member 1 in the upstream side and the steel pipe column member 4 in the downstream side, which are fixedly connected to each other by bolts and nuts and spaced in the front-rear direction, are arranged in the front-rear direction. The mounting flange 3 at the tip of the horizontal member 2 that protrudes from each other or the mounting flange 3 at the tip of the intermediate horizontal member 2a arranged between them is fixed by bolts and nuts to form a truncated pyramid three-dimensional frame structure 5, a plurality of three-dimensional frame structures 5 are arranged with gaps (slits) 10 in the left-right direction (width direction), and the lower portions of the three-dimensional frame structures 5 are embedded and fixed in the concrete foundation 12. A steel slit dam 14 having the three-dimensional frame structure 5 as a main element is configured.

  Steel seat plates 6 and 7 are fixed in a horizontal state to the lower end portion of each upstream steel pipe column member 1 and the lower end portion of each downstream steel tube column member 4 by welding, respectively, and the steel Reinforced by a large number of circumferential reinforcing ribs 8 fixed to the seat plates 6 and 7 and the steel pipe column members 1 and 4 by welding. Each of the steel seat plates 6 and 7 is fixed to the concrete foundation 12 by anchor bolts (not shown) and embedded and fixed together with the lower portion of each steel pipe column member 1.

  Each mounting flange 3 is reinforced by a large number of circumferential reinforcing ribs 9 fixed to the mounting flange 3 and the steel pipe horizontal member 2 or the steel pipe intermediate horizontal member 2a by welding in the same manner as the reinforcing ribs 8. Yes.

  Further, the upstream steel pipe column member 1 and the downstream steel pipe column member 4 which are arranged so that the central axes are located on the same vertical plane are made close to each other with their upper portions spaced apart from each other. A steel slit having a frame structure composed of a three-dimensional frame structure 5 having a horizontal member 2 provided with a horizontal member 2 that is arranged so as to incline the lower parts of the column members 1 and 4 away from each other. It is said to be a dam 14.

  Moreover, the inclination angle A of the steel pipe column member 4 on the downstream side is set to be an inclination angle steeper than the inclination angle B of the steel pipe column member 1 on the upstream side, and the steel pipe column member 1 on the upstream side and the steel pipe column member on the downstream side are arranged. 4 is a steel slit dam 14 in which the normal gradient is changed.

  The impact force received by the upstream steel pipe column member 1 due to driftwood and rocks flowing from the upstream side is large in the case of the upstream steel pipe column member 1 erected vertically, but it is upstream as in the present invention. The impact force can be reduced at the inclination angle B of the steel tube column member 1 on the side, and the inclination angle A of the steel tube column member 4 on the downstream side can be made smaller than the inclination angle B of the steel tube column member 1 on the upstream side as in the present invention. The steep inclination angle also reduces the length of the column member of the steel pipe column member 4 on the downstream side and the width of the foundation from the upstream direction to the downstream direction. Therefore, it becomes a steel slit dam 14 with a low construction cost. Further, since the steel pipe column member 4 on the downstream side has a steeper angle than the steel pipe column member 1 on the upstream side, there is a probability that the debris that has overcome the steel slit dam 14 will directly hit the steel pipe column member 4 on the downstream side. A lower steel slit dam 14. Therefore, the steel slit dam can be made more economical than before, and the steel slit dam has a low probability that the overturned earth and stone will directly hit the steel pipe column member 4 on the downstream side.

  If the steel pipe column member 4 on the downstream side is perpendicular to the horizontal plane, the size of the member is shortened and it is economical. If the driftwood or rock that has passed over the slit dam rolls down, the impact will occur. In order to receive force, it is better that it is vertical, but if it is steep so that the lower part is located on the downstream side, there is resistance to support the impact force received by the steel pipe column member 1 on the upstream side. It is structurally advantageous.

  Considering these things, for example, as shown in FIG. 5, the normal gradient of the steel pipe column members on the upstream side and the downstream side has a horizontal length of 0.2 when the vertical length is set to 1. -0.4 to 1: 0.2 to 0.4, preferably 1: 0.2 to 0.3. Therefore, for example, the downstream steel pipe column member 4 may have a combination form in which the normal gradient of the steel pipe column member 4 is 1: 0.2 and the upstream steel pipe column member 4 has a normal gradient of 1: 0.3. This form is shown.

  The upper end of the steel pipe column member 1 on the upstream side and the steel pipe column member 4 on the downstream side are advantageous in terms of strength, and it is advantageous to shorten the base interval and the amount of foundation concrete. Then, it is appropriately set to about 1.5 to 2.5 m.

  Further, as described above, even if the inclination angle A of the downstream steel pipe column member 4 is set to be the same height by making the inclination angle B steeper than the inclination angle B of the upstream steel pipe column member 1, Since the length dimension of the steel pipe column member 4 on the downstream side is shorter than the length dimension of the steel pipe column member 1 on the upstream side, the steel pipe column member 1 on the upstream side even in a state where it is placed horizontally in the yard near the construction site. Can be easily distinguished by the difference in length between the steel pipe column members 4 on the downstream side and when the steel pipe column member 1 on the upstream side is arranged at the downstream side at an inclination angle A, each horizontal member in the front-rear direction Since 2 becomes non-horizontal and the mounting flange 3 fixed to the horizontal member 2 becomes non-vertical, the operator can easily notice an error in the installation member at the time of installation work.

  Similarly, when the steel pipe column member 4 on the downstream side is arranged at the upstream side and at the inclination angle B on the upstream side, the horizontal members 2 in the front-rear direction are not horizontal and the mounting flange 3 fixed to the horizontal member 2 is vertical. Therefore, at the time of installation work, the operator can easily notice the error of the installation member.

  Further, even if the upstream steel pipe column member 1 is mistakenly arranged at the downstream side at the inclination angle A on the downstream side, the upstream side steel pipe column member 1 is mistakenly arranged, and the downstream inclination is erroneously arranged on the downstream side. Since the flange 3 at the tip of the horizontal member 2 with the steel pipe column member 1 to be arranged on the upstream side arranged at the angle A is displaced up and down or separated, the case where the three-dimensional frame structure 5 is assembled in advance However, since it cannot be assembled, the operator can easily notice it.

  Similarly, even if the steel pipe column member 4 on the downstream side is mistakenly arranged at the upstream side at the inclination angle B on the upstream side, the steel pipe column member 4 that is correctly arranged and the upstream side on the upstream side are mistakenly arranged. Since the flange 3 at the front end of the horizontal member 2 with the steel pipe column member 4 to be arranged at the downstream side arranged at the inclination angle B is shifted vertically or separated, it is assembled in advance to the three-dimensional frame structure 5. Even in this case, the worker cannot easily assemble it, so that the worker can easily notice it.

  Further, the downstream steel pipe column member 4 is mistakenly arranged at the upstream side at the upstream inclination angle B, and the upstream steel pipe column member 1 is mistakenly arranged at the downstream side at the downstream inclination angle A. Even in the same manner, the flange 3 at the tip of the horizontal member 2 is displaced up and down or separated, so that even if it is assembled in advance to the three-dimensional frame structure 5, it cannot be assembled. You can notice.

  Accordingly, when the steel pipe column members 1 and 4 are misplaced, the operator can easily notice them, so that the upstream side steel pipe column member 1 is located upstream and the downstream side steel pipe. The column member 4 can be reliably arranged downstream.

  Further, it is rational and preferable in terms of structure that the plate thickness of the steel pipe column member 1 on the upstream side is larger than the plate thickness of the steel tube column member 4 on the downstream side.

  If the steel pipe column member 1 and the horizontal member 2 are circular steel pipes in cross-section, commercially available inexpensive steel pipes can be used, resulting in an economical steel slit dam.

  When the present invention is carried out, the steel column member 1 may be a steel pipe column member other than a circular cross section, and the lower portion of the steel column member 1 is filled with concrete, and the lower portion of the steel column member 1 is rigid. The steel pillar member 1 may be filled with sand.

It is a front view which shows the steel slit dam which concerns on one Embodiment of this invention. It is a partial vertical side view of the steel slit dam of FIG. It is a rear view of the solid frame structure seen from the upstream side. It is a front view of the solid framework structure seen from the downstream side. It is explanatory drawing which shows the normal gradient of the steel pipe column member of an upstream side and a downstream side. It is a partially vertical side view which shows an example of the conventional steel slit dam.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upstream steel pipe pillar member 2 Horizontal member 3 Mounting flange 4 Downstream steel pipe pillar member 5 Three-dimensional frame structure 6, 7 Steel seat board 8, 9 Reinforcement rib 10 Slit 12 Concrete foundation 14, 15 Steel slit dam

Claims (1)

The steel pipe column member on the upstream side and the steel pipe column member on the downstream side are tilted so that the upper part of each steel pipe column member approaches each other and the lower part of each steel pipe column member is separated from each other, and the steel pipe column members are connected. In a steel slit dam provided with a frame structure having a horizontal member to
The legal gradient of the steel pipe column member on the upstream side and the legal gradient of the steel pipe column member on the downstream side are different from each other,
When the length in the vertical direction is 1, the horizontal length of the normal gradient of the steel pipe column member on the downstream side is 0.2, and the horizontal length of the normal gradient of the steel pipe column member on the upstream side is Is 0.3 to 0.4,
The upper steel pipe pillar member and the downstream steel pipe pillar member are spaced apart from each other at their upper ends,
The horizontal members are provided across a plurality of steel pipe column members vertically spaced apart from each other, and between the mounting flanges at the ends of the horizontal members protruding from the steel tube column members and between the horizontal members A steel slit dam, characterized in that the mounting flange at the tip of the horizontal member is connected.

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