JP2004316261A

JP2004316261A - Steel-made slit dam

Info

Publication number: JP2004316261A
Application number: JP2003111985A
Authority: JP
Inventors: Akihiro Morita; 昭宏森田; Keiichi Iwatsuri; 敬一岩釣; Hisashi Osumi; 久大隅
Original assignee: Nippon Steel Metal Products Co Ltd
Current assignee: Nippon Steel Metal Products Co Ltd
Priority date: 2003-04-16
Filing date: 2003-04-16
Publication date: 2004-11-11
Anticipated expiration: 2023-04-16
Also published as: JP4226377B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an economical steel-made slit dam capable of surely placing a steel pipe column member required to be placed to a down-stream side to the down-stream side and surely placing the steel pipe column member required to be placed to an up-stream side to the up-stream side. <P>SOLUTION: The steel pipe column member 1 on the up-stream side and the steel pipe column member 4 on the down-stream side are so inclined that the upper parts of the steel pipe column members 1 and 4 are relatively approached to each other and, at the same time, the lower parts of the steel pipe column members 1 and 4 are relatively separated from each other, and in the steel-made slit dam 14 equipped with a framing structural body having a horizontal member 2 connected between the steel pipe column members, an inclination angle A of the steel pipe column member 1 on the down-stream side is made as a steeper dip angle than an inclination angle B of the steel pipe column member 4 on the up-stream side, and the slop gradients of the steel pipe column member 1 on the up-stream side and the steel pipe column member 4 on the down-stream side are set different from each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、通常の中小出水に含まれる比較的粒径の細かい掃流土砂は、積極的に透過させて下流に流し土石流発生までのダム上流の貯砂容量を確保し、土石流発生時には、土石流中の巨礫・流木や多量の土砂を捕捉して河川下流への流出を防止するための透過型構造の鋼製スリットダムに関する。
【０００２】
【従来の技術】
従来、鋼製柱部材を備えた鋼製スリットダムとして、鋼製柱部材を傾斜させることにより、流されてくる木や岩石による柱部材に作用する衝撃力の一部を基礎コンクリートに分力として作用させ、構造上の強度を高めた鋼製砂防ダムが知られている（例えば、特許文献１参照）。
【０００３】
また、図５に示すように、上流側の鋼管柱部材１と下流側の鋼管柱部材４との鋼管柱部材間を結合する水平部材２を備えた截頭角錐状の立体骨組構造体５を使用し、かつ立体骨組構造体５における上流側の鋼管柱部材１と下流側の鋼管柱部材４とを、同じ傾斜角で傾斜するようにした鋼製スリットダム１５も知られている（例えば、特許文献２参照）。
【０００４】
また、図５に示す形態では、さらに上流側の鋼管柱部材１を下流側の鋼管柱部材４の板厚よりも、板厚の厚い鋼管柱部材としていた。このような上流側の鋼管柱部材１と下流側の鋼管柱部材４とを同じ傾斜角で傾斜させた鋼製スリットダム１５を構築する場合、現場作業において、上流側および下流側の鋼管柱部材１，４が比較的長尺の同様な寸法であり、これらの平面形状を目視しずらく、また、鋼管柱部材１，４の板厚について外側から確認できないため、下流側に配置すべき板厚の薄い鋼管柱部材４を上流側に設置したり、上流側に配置すべき板厚の厚い鋼管柱部材１を下流側に設置したりする恐れもあり、その確認作業も外観上からでは、判別しずらいという問題がある。
【０００５】
また、上流側の鋼管柱部材１と下流側の鋼管柱部材４とを、比較的緩傾斜の同じ傾斜角で傾斜するようにした鋼製スリットダム１５としていたので、下流側の鋼管柱部材４の柱部材寸法が長くなると共に、上流方向から下流方向への基礎幅が広くなり基礎コンクリート量も多くなるので、施工コストの高い鋼製スリットダム１５になる。また、下流側の鋼管柱部材４は、上流側の鋼管柱部材１と同じ緩傾斜の角度であると、鋼製スリットダム１５を乗り越えてきた土石が下流側の鋼管柱部材４に直撃する確率が高い鋼製スリットダム１５である。したがって、より経済的な鋼製スリットダムとすることが望まれると共に、また、乗り越えてきた土石が下流側の鋼管柱部材４に直撃する確率が低い鋼製スリットダムとすることが望まれる。
【０００６】
【特許文献１】
特開昭２００２−３２７４２４号公報
【特許文献２】
特開２００１−３０３５３８号公報
【０００７】
【発明が解決しようとする課題】
本発明は、上流側および下流側の鋼管柱部材が比較的長尺の同様な寸法であっても、これらの平面形状を目視しずらくても、また、鋼管柱部材の板厚について外側から確認できなくても、下流側に配置すべき鋼管柱部材を確実に下流側に配置でき、上流側に配置すべき鋼管柱部材を確実に上流側に配置でき、その誤配置も容易に発見できる鋼製スリットダムを提供することを目的とする。また、上流方向から下流方向への基礎幅が狭くてすみ、より経済的な鋼製スリットダムであると共に、乗り越えてきた土石が下流側の鋼管柱部材に直撃する確率の低い鋼製スリットダムを提供することを目的とする。
【０００８】
【課題を解決するための手段】
前記の従来の問題点を有利に解決するために、第１発明の鋼製スリットダムにおいては、上流側の鋼管柱部材と下流側の鋼管柱部材とを、各鋼管柱部材の上部を相互に接近させると共に各鋼管柱部材の下部を相互に離反させるように傾斜させ、鋼管柱部材間を結合する水平部材を有する骨組構造体を備えた鋼製スリットダムにおいて、下流側の鋼管柱部材の傾斜角度を、上流側の鋼管柱部材の傾斜角度よりも急傾斜の傾斜角度とし、上流側の鋼管柱部材と下流側の鋼管柱部材の法勾配を変えたことを特徴とする。
【０００９】
また、第２発明では、第１発明の鋼製スリットダムにおいて、上流側の鋼管柱部材の板厚を、下流側の鋼管柱部材の板厚よりも厚くしたことを特徴とする。
【００１０】
また、第３発明では、第１または第２発明の鋼製スリットダムにおいて、鋼管柱部材と水平部材が断面円形鋼管であることを特徴とする。
【００１１】
【発明の実施の形態】
次に、本発明を図示の実施形態に基づいて詳細に説明する。
【００１２】
図１〜図４は本発明の一実施形態を示すものであって、左右方向に間隔をおいて配置された上流側配置の鋼管柱部材１相互が、これらに取付けられた左右方向に張り出す水平部材２先端の取付フランジ３相互がボルト・ナットにより固定されて連結され、左右方向に間隔をおいて配置された下流側配置の鋼管柱部材４相互が、これらに取付けられた左右方向に張り出す水平部材２先端の取付フランジ３相互がボルト・ナットにより固定されて連結され、前後方向に間隔をおいて配置された上流側配置の前記鋼管柱部材１と下流側配置の前記鋼管柱部材４とは、これらに取付けられた前後方向に張り出す水平部材２先端の取付フランジ３相互またはその間に配置される中間水平部材２ａ先端の取付フランジ３がボルト・ナットにより固定されて、截頭角錐状の立体骨組み構造体５が構成され、複数の立体骨組み構造体５が左右方向（幅方向）に間隙（スリット）１０をおいて配置されると共に各立体骨組み構造体５の下部がコンクリート基礎部１２に埋め込み固定されて、立体骨組み構造体５を主要素とする鋼製スリットダム１４が構成されている。
【００１３】
また、上流側の各鋼管柱部材１の下端部および下流側の各鋼管柱部材４の下端部には、それぞれ水平状態で鋼製座板６，７が溶接により固定されていると共に、前記鋼製座板６，７と鋼管柱部材１，４に溶接により固着された周方向の多数の補強リブ８により補強されている。前記各鋼製座板６，７は、図示省略のアンカーボルトによりコンクリート基礎部１２に固定され、各鋼管柱部材１の下部と共に埋め込み固定されている。
【００１４】
また前記各取付けフランジ３は、前記補強リブ８と同様に取付けフランジ３と鋼管製水平部材２または鋼管製の中間水平部材２ａに溶接により固着された周方向の多数の補強リブ９により補強されている。
【００１５】
また、中心軸線が同じ垂直面に位置するように配置された上流側の鋼管柱部材１と下流側の鋼管柱部材４とは、これらの上部が間隔をおいて相互に接近させると共に前記各鋼管柱部材１，４の下部を相互に離反させるように傾斜させて配置され、鋼管柱部材間を結合する水平部材２を備えた立体骨組構造体５からなる骨組構造を主要素とする鋼製スリットダム１４とされている。
【００１６】
また、下流側の鋼管柱部材４の傾斜角度Ａを、上流側の鋼管柱部材１の傾斜角度Ｂよりも急傾斜の傾斜角度とされ、上流側の鋼管柱部材１と下流側の鋼管柱部材４の法勾配を変えている鋼製スリットダム１４とされている。
【００１７】
上流側から流れてくる流木や岩石による上流側の鋼管柱部材１が受ける衝撃力は、垂直に立設された上流側の鋼管柱部材１の場合は大になるが、本発明のように上流側の鋼管柱部材１の傾斜角度Ｂではその衝撃力を小さくでき、さらに本発明のように、下流側の鋼管柱部材４の傾斜角度Ａを、上流側の鋼管柱部材１の傾斜角度Ｂよりも急傾斜の傾斜角度とすることにより、下流側の鋼管柱部材４の柱部材の長さ寸法が短くなると共に、上流方向から下流方向への基礎幅が狭くなり、配筋量および基礎コンクリート量も少なくなるので、施工コストの安い鋼製スリットダム１４になる。また、下流側の鋼管柱部材４は、上流側の鋼管柱部材１より急傾斜の角度であるので、鋼製スリットダム１４を乗り越えてきた土石が下流側の鋼管柱部材４に直撃する確率がより低い鋼製スリットダム１４である。したがって、従来より経済的な鋼製スリットダムとすることができると共に、また、乗り越えてきた土石が下流側の鋼管柱部材４に直撃する確率が低い鋼製スリットダムとされている。
【００１８】
下流側の鋼管柱部材４は、水平面に対して直角な鉛直であると部材寸法が短くなり経済的であり、スリットダムを乗り越えてきた流木や岩石が転げ落ちる場合に緩傾斜しているとその衝撃力を受けるようになるため、鉛直であるほどよいが、下部が下流側に位置するように急傾斜しているほうが、上流側の鋼管柱部材１が受ける衝撃力に対し支承する抵抗力があり、構造上有利である。
【００１９】
これらのことを考えると、例えば、上流側および下流側の鋼管柱部材の法勾配は、図６に示すように、鉛直方向の長さを１とした場合、水平方向の長さを０．２〜０．４とする１：０．２〜０．４、好ましくは、１：０．２〜０．３とするとよい。したがって、例えば、下流側の鋼管柱部材４の法勾配を１：０．２とし、上流側の鋼管柱部材４の法勾配を１：０．３とした組み合わせ形態とするとよく、図示例では、この形態が示されている。
【００２０】
上流側の鋼管柱部材１と下流側の鋼管柱部材４の上端外間隔は、強度上は短いほうが有利で、ベース間隔も短くなり、基礎コンクリート量も減らすことができるため、組立施工性を考慮して１．５〜２．５ｍ程度に適宜設定される。
【００２１】
また、前記のように、下流側の鋼管柱部材４の傾斜角度Ａを、上流側の鋼管柱部材１の傾斜角度Ｂよりも急傾斜の傾斜角度とすることにより、同じ高さとした場合でも、下流側の鋼管柱部材４の長さ寸法が、上流側の鋼管柱部材１の長さ寸法よりも短くなるので、施工現場付近のヤードに横置きされた状態でも、上流側の鋼管柱部材１と下流側の鋼管柱部材４の長さ寸法差により容易に区別でき、また、上流側の鋼管柱部材１を下流側に、下流側の傾斜角度Ａで配置した場合、前後方向の各水平部材２が水平でなくなると共にその水平部材２に固定の取付けフランジ３は垂直でなくなるので、設置作業の時点において、作業者が容易に設置部材の誤りに気づくことができる。
【００２２】
同様に、下流側の鋼管柱部材４を上流側に、上流側の傾斜角度Ｂで配置した場合、前後方向の各水平部材２が水平でなくなると共にその水平部材２に固定の取付けフランジ３は垂直でなくなるので、設置作業の時点において、作業者が容易に設置部材の誤りに気づくことができる。
【００２３】
また、誤って上流側の鋼管柱部材１を下流側に、下流側の傾斜角度Ａで配置しても、正しく配置された上流側の鋼管柱部材１と、誤って下流側に下流側の傾斜角度Ａで配置された上流側に配置すべき鋼管柱部材１との、水平部材２先端のフランジ３が上下に位置ずれしたり、離反した状態になるので、予め立体骨組み構造体５に組み立てる場合でも、その組み立てができないので、作業者は容易に気づくことができる。
【００２４】
同様に、誤って下流側の鋼管柱部材４を上流側に、上流側の傾斜角度Ｂで配置しても、正しく配置された下流側の鋼管柱部材４と、誤って上流側に上流側の傾斜角度Ｂで配置された下流側に配置すべき鋼管柱部材４との、水平部材２先端のフランジ３が上下に位置ずれしたり、離反した状態になるので、予め立体骨組み構造体５に組み立てる場合でも、その組み立てができないので、作業者は容易に気づくことができる。
【００２５】
さらに、誤って下流側の鋼管柱部材４を上流側に、上流側の傾斜角度Ｂで配置し、かつ、誤って上流側の鋼管柱部材１を下流側に、下流側の傾斜角度Ａで配置しても同様に、水平部材２先端のフランジ３が上下に位置ずれしたり、離反した状態になるので、予め立体骨組み構造体５に組み立てる場合でも、その組み立てができないので、作業者は容易に気づくことができる。
【００２６】
したがって、鋼管柱部材１，４を誤った配置した場合には、作業者が容易に気づくことができる構成とされているので、上流側の鋼管柱部材１を上流側に、また下流側の鋼管柱部材４を下流側に確実に配置することができる。
【００２７】
また、上流側の鋼管柱部材１の板厚は、下流側の鋼管柱部材４の板厚よりも厚くするのが、構造上合理的で好ましい。
【００２８】
鋼管柱部材１と水平部材２として、断面円形鋼管であると、市販の安価な鋼管を使用でき、経済的な鋼製スリットダムとなる。
【００２９】
本発明を実施する場合、鋼製柱部材１は、横断面円形以外の鋼管製柱部材としてもよく、鋼製柱部材１内の下部にコンクリートを充填し、鋼製柱部材１の下部の剛性を高めてもよく、鋼製柱部材１内に砂を充填してもよい。
【００３０】
【発明の効果】
本発明は以上の構成であるので次のような効果を有している。
本発明によると、上流側の鋼管柱部材と下流側の鋼管柱部材とを、各鋼管柱部材の上部を相互に接近させると共に各鋼管柱部材の下部を相互に離反させるように傾斜させ、鋼管柱部材間を結合する水平部材を有する骨組構造を備えた鋼製スリットダムにおいて、下流側の鋼管柱部材の傾斜角度を、上流側の鋼管柱部材の傾斜角度よりも急傾斜の傾斜角度とし、上流側の鋼管柱部材と下流側の鋼管柱部材の法勾配を変えたので、同じ高さ寸法の上流側の鋼管柱部材と下流側の鋼管柱部材であっても、横倒し状態では長さ寸法が異なるため容易に区別でき、また、誤って上流側と下流側とを誤配置した場合でも、水平部材あるいは取付けフランジの水平度あるいは垂直度が出ない状態となるので、現場作業者が容易に気づくことができる。
したがって、上流側の鋼管柱部材の板厚を下流側の鋼管部材の板厚よりも厚くした剛性の大きい鋼管柱部材を上流側に使用して、板厚が外側から確認できなくても、下流側に配置すべき鋼管柱部材を確実に下流側に配置でき、上流側に配置すべき鋼管柱部材を確実に上流側に配置でき、その誤配置も容易に発見できる。
【００３１】
また、本発明では、下流側の鋼管柱部材の傾斜角度を、上流側の鋼管柱部材の傾斜角度よりも急傾斜の傾斜角度としたので、下流側の鋼管柱部材の柱部材の長さ寸法が短くなり経済的になると共に、上流方向から下流方向への基礎幅が狭くなり、配筋量および基礎コンクリート量も少なくなるので、施工コストの安い鋼製スリットダムになる。また、下流側の鋼管柱部材は、上流側の鋼管柱部材より急傾斜の角度であるので、鋼製スリットダムを乗り越えてきた土石が下流側の鋼管柱部材に直撃する確率が従来の鋼製スリットダムより低い鋼製スリットダムである。
【００３２】
また、本発明によると、鋼管柱部材と水平部材が断面円形鋼管であるので、市販の鋼管を使用して、施工の容易な安価な鋼製スリットダムとすることができる。
【図面の簡単な説明】
【図１】本発明の一実施形態に係る鋼製スリットダムを示す正面図である。
【図２】図１の鋼製スリットダムの一部縦断側面図である。
【図３】上流側から見た立体骨組み構造体の背面図である。
【図４】下流側から見た立体骨組み構造体の正面図である。
【図５】従来の鋼製スリットダムの一例を示す一部縦断側面図である。
【図６】上流側および下流側の鋼管柱部材の法勾配を示す説明図である。
【符号の説明】
１上流側の鋼管柱部材
２水平部材
３取付フランジ
４下流側の鋼管柱部材
５立体骨組み構造体
６鋼製座板
７鋼製座板
８補強リブ
９補強リブ
１０スリット
１２コンクリート基礎部
１４鋼製スリットダム
１５鋼製スリットダム[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, the bedload with relatively small particle size contained in ordinary small and medium-sized water is positively permeated and flows downstream to secure a sand storage capacity upstream of the dam until debris flow occurs. The present invention relates to a transmission type steel slit dam for catching boulders, driftwood and a large amount of sediment, and preventing runoff to the river downstream.
[0002]
[Prior art]
Conventionally, as a steel slit dam with steel column members, by inclining the steel column members, a part of the impact force acting on the column members due to flowing wood and rock is converted to basic concrete as a component force 2. Description of the Related Art A steel sabo dam having an increased structural strength by acting is known (for example, see Patent Document 1).
[0003]
As shown in FIG. 5, a truncated pyramid-shaped three-dimensional frame structure 5 having a horizontal member 2 for connecting between the steel pipe column members 1 on the upstream side and the steel pipe column member 4 on the downstream side is provided. There is also known a steel slit dam 15 that is used and in which the upstream steel pipe column member 1 and the downstream steel pipe column member 4 in the three-dimensional frame structure 5 are inclined at the same inclination angle (for example, Patent Document 2).
[0004]
In the embodiment shown in FIG. 5, the steel pipe column member 1 on the upstream side is a steel pipe column member thicker than the steel tube column member 4 on the downstream side. When constructing such a steel slit dam 15 in which the upstream steel pipe column member 1 and the downstream steel pipe column member 4 are inclined at the same inclination angle, in the field work, the upstream and downstream steel pipe column members are used. 1 and 4 are comparatively long and have similar dimensions, and it is difficult to visually confirm the planar shape thereof. Further, since the thickness of the steel pipe column members 1 and 4 cannot be confirmed from the outside, the plate to be disposed on the downstream side There is a risk that the thin steel pipe column member 4 may be installed on the upstream side, or the thick steel pipe column member 1 to be disposed on the upstream side may be installed on the downstream side. There is a problem that it is difficult to determine.
[0005]
Further, since the steel pipe column member 1 on the upstream side and the steel tube column member 4 on the downstream side are steel slit dams 15 inclined at the same inclination angle, which is relatively gentle, the steel pipe column member 4 on the downstream side is formed. As the column member size becomes longer, the base width from the upstream direction to the downstream direction becomes wider and the amount of foundation concrete increases, so that the steel slit dam 15 having a high construction cost is obtained. When the downstream steel pipe column member 4 has the same gentle inclination angle as that of the upstream steel pipe column member 1, the probability that debris that has passed over the steel slit dam 15 directly hits the downstream steel pipe column member 4 will be described. Is a steel slit dam 15 having a high height. Therefore, it is desired to provide a more economical steel slit dam, and a steel slit dam having a low probability that surplus debris directly hits the steel pipe column member 4 on the downstream side.
[0006]
[Patent Document 1]
JP-A-2002-327424 [Patent Document 2]
JP 2001-303538 A
[Problems to be solved by the invention]
The present invention provides a steel pipe column member on the upstream side and the downstream side that has a relatively long and similar size, makes it difficult to visually recognize the planar shape of the column member, and also determines the thickness of the steel pipe column member from the outside. Even if it cannot be confirmed, the steel pipe column member to be arranged on the downstream side can be securely arranged on the downstream side, the steel pipe column member to be arranged on the upstream side can be securely arranged on the upstream side, and the misplacement can be easily found. An object of the present invention is to provide a steel slit dam. In addition, a steel slit dam with a smaller base width from the upstream direction to the downstream direction, which is more economical, and a steel slit dam with a low probability that debris that has climbed over directly hits the steel pipe column member on the downstream side. The purpose is to provide.
[0008]
[Means for Solving the Problems]
In order to advantageously solve the above-mentioned conventional problems, in the steel slit dam of the first invention, the upstream steel pipe column member and the downstream steel pipe column member are connected to each other by the upper portion of each steel pipe column member. In the steel slit dam provided with a framed structure having a horizontal member for bringing the lower portions of the steel pipe column members closer to each other and moving away from each other and connecting the steel column members, the inclination of the downstream steel column members is reduced. The angle is set to an inclination angle steeper than the inclination angle of the steel pipe column member on the upstream side, and a normal gradient of the steel pipe column member on the upstream side and the steel pipe column member on the downstream side is changed.
[0009]
The second invention is characterized in that, in the steel slit dam of the first invention, the plate thickness of the steel pipe column member on the upstream side is larger than the plate thickness of the steel pipe column member on the downstream side.
[0010]
According to a third aspect of the present invention, in the steel slit dam according to the first or second aspect, the steel pipe column member and the horizontal member are circular cross-section steel pipes.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the present invention will be described in detail based on the illustrated embodiment.
[0012]
FIGS. 1 to 4 show an embodiment of the present invention, in which steel pipe column members 1 arranged on the upstream side arranged at intervals in the left and right direction project in the left and right direction attached thereto. The mounting flanges 3 at the ends of the horizontal members 2 are fixed and connected to each other by bolts and nuts, and the steel pipe column members 4 disposed downstream and disposed at intervals in the left-right direction are attached to each other in the left-right direction. The mounting flange 3 at the tip of the horizontal member 2 to be ejected is fixed and connected to each other by bolts and nuts, and the steel pipe column member 1 arranged upstream and the steel pipe column member 4 arranged downstream are spaced apart in the front-rear direction. The mounting flanges 3 at the tips of the horizontal members 2 protruding in the front-rear direction attached to these components are fixed to each other or between the mounting flanges 3 at the tips of the intermediate horizontal members 2a by bolts and nuts. A truncated pyramid-shaped three-dimensional frame structure 5 is formed, a plurality of three-dimensional frame structures 5 are arranged with a gap (slit) 10 in the left-right direction (width direction), and the lower part of each three-dimensional frame structure 5 is formed. A steel slit dam 14 having the three-dimensional frame structure 5 as a main element is embedded and fixed in the concrete foundation 12.
[0013]
Further, steel seat plates 6 and 7 are fixed to the lower end of each of the steel pipe column members 1 on the upstream side and the lower end of each of the steel pipe column members 4 on the downstream side by welding in a horizontal state. It is reinforced by a large number of circumferential reinforcing ribs 8 fixed to the seat plates 6, 7 and the steel pipe column members 1, 4 by welding. The steel seat plates 6 and 7 are fixed to the concrete foundation 12 by anchor bolts (not shown), and are embedded and fixed together with the lower portions of the steel pipe column members 1.
[0014]
Each of the mounting flanges 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 intermediate horizontal member 2a made of steel pipe by welding in the same manner as the reinforcing ribs 8. I have.
[0015]
Also, the upstream steel pipe column member 1 and the downstream steel pipe column member 4 arranged so that their central axes are located on the same vertical plane are arranged such that their upper parts are close to each other with a space therebetween and the respective steel pipe columns A steel slit whose main element is a framed structure composed of a three-dimensional framed structure 5 having a horizontal member 2 provided with a horizontal member 2 for connecting lower portions of the column members 1 and 4 with each other so as to separate the column members from each other. It is a dam 14.
[0016]
In addition, 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. 4 is a steel slit dam 14 having a different slope.
[0017]
The impact force applied to the upstream steel pipe column member 1 by the driftwood or rocks flowing from the upstream side is large in the case of the vertically installed upstream steel pipe column member 1, but as in the present invention, the upstream steel tube column member 1 is large. The impact force can be reduced at the inclination angle B of the steel pipe column member 1 on the side, and the inclination angle A of the steel pipe column member 4 on the downstream side is made larger than the inclination angle B of the steel pipe column member 1 on the upstream side as in the present invention. Also, by making the inclination angle steep, the length of the column member of the steel pipe column member 4 on the downstream side is shortened, and the base width from the upstream direction to the downstream direction is reduced, so that the amount of reinforcement and the amount of foundation concrete are reduced. Therefore, the steel slit dam 14 having a low construction cost is obtained. In addition, since the downstream steel pipe column member 4 has a steeper angle than the upstream steel pipe column member 1, the probability that debris that has climbed over the steel slit dam 14 directly hits the downstream steel pipe column member 4 is low. A lower steel slit dam 14. Therefore, the steel slit dam can be made more economical than the conventional one, and the steel slit dam is less likely to directly hit the steel pipe column member 4 on the downstream side.
[0018]
The steel pipe column member 4 on the downstream side is economical because the member size is short if it is perpendicular to the horizontal plane, and if the driftwood or rock that has passed over the slit dam falls down, the impact may occur if it is slightly inclined. It is better to be vertical because it receives the force, but it is better to be steeply inclined so that the lower part is located on the downstream side, there is a resistance force to support the impact force received by the steel pipe column member 1 on the upstream side This is structurally advantageous.
[0019]
Considering these facts, for example, the normal gradient of the steel pipe column members on the upstream side and the downstream side is, as shown in FIG. The ratio should be 1: 0.2 to 0.4, preferably 1: 0.2 to 0.3. Therefore, for example, it is preferable to adopt a combination form in which the normal gradient of the downstream steel pipe column member 4 is 1: 0.2 and the normal gradient of the upstream steel pipe column member 4 is 1: 0.3. This form is shown.
[0020]
As for the outer space between 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, it is advantageous that the shorter the distance, the shorter the base space and the amount of foundation concrete can be reduced. The distance is appropriately set to about 1.5 to 2.5 m.
[0021]
In addition, as described above, even when the inclination angle A of the downstream steel pipe column member 4 is set to be the same as that of the upstream steel pipe column member 1, the inclination angle A is 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, even if the steel pipe column member 1 on the upstream side is placed horizontally in the yard near the construction site, When the upstream steel pipe column member 1 is arranged at the downstream side at an inclination angle A of the downstream side, each horizontal member in the front-rear direction can be easily distinguished from each other by the length dimension difference of the steel pipe column member 4 at the downstream side. Since the mounting flange 3 is not horizontal and the mounting flange 3 fixed to the horizontal member 2 is not vertical, an operator can easily notice an error in the installation member at the time of the installation work.
[0022]
Similarly, when the downstream steel pipe column member 4 is arranged on the upstream side at an inclination angle B on the upstream side, each horizontal member 2 in the front-rear direction is not horizontal, and the mounting flange 3 fixed to the horizontal member 2 is vertical. Therefore, at the time of the installation work, the operator can easily notice an error in the installation member.
[0023]
Further, even if the upstream steel pipe column member 1 is erroneously arranged on the downstream side at the downstream inclination angle A, the upstream steel pipe column member 1 correctly arranged and the downstream steel tube column member 1 are mistakenly placed on the downstream side. When the flange 3 at the tip of the horizontal member 2 with respect to the steel pipe column member 1 to be disposed on the upstream side disposed at the angle A is vertically displaced or separated from each other. However, since the assembly cannot be performed, the operator can easily notice.
[0024]
Similarly, even if the downstream steel pipe column member 4 is erroneously arranged on the upstream side at the inclination angle B on the upstream side, the downstream steel pipe column member 4 correctly arranged and the upstream steel pipe column member 4 are erroneously arranged on the upstream side. Since the flange 3 at the tip of the horizontal member 2 is vertically displaced or separated from the steel pipe column member 4 to be disposed on the downstream side disposed at the inclination angle B, the three-dimensional frame structure 5 is assembled in advance. Even in such a case, the worker cannot easily assemble it, so that the worker can easily notice it.
[0025]
Further, the steel pipe column member 4 on the downstream side is erroneously arranged on the upstream side at the inclination angle B on the upstream side, and the steel pipe column member 1 on the upstream side is erroneously arranged at the inclination angle A on the downstream side. Similarly, the flange 3 at the tip of the horizontal member 2 is displaced up and down or separated from each other. Therefore, even if the three-dimensional frame structure 5 is assembled in advance, the assembly cannot be performed. You can notice.
[0026]
Therefore, when the steel pipe column members 1 and 4 are erroneously arranged, the configuration is such that the operator can easily notice. Therefore, the steel pipe column member 1 on the upstream side is placed on the upstream side, and the steel pipe column on the downstream side is made. The column member 4 can be reliably arranged on the downstream side.
[0027]
The thickness of the steel pipe column member 1 on the upstream side is preferably thicker than the thickness of the steel pipe column member 4 on the downstream side in terms of structure.
[0028]
When the steel pipe column member 1 and the horizontal member 2 are circular steel pipes having a circular cross section, commercially available inexpensive steel pipes can be used, and an economical steel slit dam can be obtained.
[0029]
In practicing the present invention, the steel column member 1 may be a steel tube 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. May be increased, and the steel column member 1 may be filled with sand.
[0030]
【The invention's effect】
The present invention having the above configuration has the following effects.
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 portions of the respective steel tube column members are brought closer to each other and the lower portions of the respective steel tube column members are separated from each other. In a steel slit dam having a skeleton structure having a horizontal member coupling between the column members, the inclination angle of the steel pipe column member on the downstream side is a steeper inclination angle than the inclination angle of the steel pipe column member on the upstream side, Because the gradient of the upstream steel pipe column member and the downstream steel pipe column member has been changed, even if the upstream steel pipe column member and the downstream steel pipe column member with the same height dimensions are sideways, the length dimension Can be easily distinguished, and even if the upstream side and the downstream side are misplaced by mistake, the horizontal member or the mounting flange will not be level or vertical, making it easier for field workers. You can notice.
Therefore, by using a steel pipe column member having a large rigidity in which the thickness of the steel pipe column member on the upstream side is made larger than the plate thickness of the steel pipe member on the downstream side, and the plate thickness cannot be confirmed from the outside, The steel pipe column member to be disposed on the side can be reliably disposed on the downstream side, the steel pipe column member to be disposed on the upstream side can be reliably disposed on the upstream side, and misplacement thereof can be easily found.
[0031]
Further, in the present invention, since the inclination angle of the steel pipe column member on the downstream side is set to an inclination angle that is steeper than the inclination angle of the steel pipe column member on the upstream side, the length dimension of the column member of the steel pipe column member on the downstream side is set. As a result, the width of the foundation from the upstream direction to the downstream direction is reduced, and the amount of reinforcement and the amount of foundation concrete are reduced, so that a steel slit dam having a low construction cost is obtained. In addition, since the downstream steel pipe column member has a steeper angle than the upstream steel pipe column member, the probability that debris that has climbed over the steel slit dam directly hits the downstream steel pipe column member is lower than that of the conventional steel pipe column member. This is a steel slit dam lower than the slit dam.
[0032]
Further, according to the present invention, since the steel pipe column member and the horizontal member are circular steel pipes in cross section, a commercially available steel pipe can be used to provide an inexpensive steel slit dam that can be easily constructed.
[Brief description of the drawings]
FIG. 1 is a front view showing a steel slit dam according to one embodiment of the present invention.
FIG. 2 is a partial longitudinal side view of the steel slit dam of FIG.
FIG. 3 is a rear view of the three-dimensional frame structure viewed from the upstream side.
FIG. 4 is a front view of the three-dimensional frame structure viewed from a downstream side.
FIG. 5 is a partially longitudinal side view showing an example of a conventional steel slit dam.
FIG. 6 is an explanatory diagram showing a normal gradient of the steel pipe column members on the upstream side and the downstream side.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Upstream steel pipe column member 2 Horizontal member 3 Mounting flange 4 Downstream steel pipe column member 5 Three-dimensional framed structure 6 Steel seat plate 7 Steel seat plate 8 Reinforcement rib 9 Reinforcement rib 10 Slit 12 Concrete foundation 14 Steel Slit dam 15 Steel slit dam

Claims

The steel pipe column members on the upstream side and the steel tube column members on the downstream side are inclined so that the upper parts of the steel pipe column members are close to each other and the lower parts of the steel pipe column members are separated from each other, and the steel pipe column members are connected. In a steel slit dam provided with a skeleton structure having a horizontal member to be formed, an inclination angle of a steel pipe column member on the downstream side is set to an inclination angle steeper than an inclination angle of the steel pipe column member on the upstream side, and an upstream steel pipe is provided. A steel slit dam characterized by changing the gradient of the column member and the steel tube column member on the downstream side.

The steel slit dam according to claim 1, wherein the thickness of the steel pipe column member on the upstream side is larger than the plate thickness of the steel pipe column member on the downstream side.

The steel slit dam according to claim 1 or 2, wherein the steel pipe column member and the horizontal member are circular steel pipes having a circular cross section.