JP3031245B2 - Screw-in type steel pipe pile - Google Patents
Screw-in type steel pipe pileInfo
- Publication number
- JP3031245B2 JP3031245B2 JP8143895A JP14389596A JP3031245B2 JP 3031245 B2 JP3031245 B2 JP 3031245B2 JP 8143895 A JP8143895 A JP 8143895A JP 14389596 A JP14389596 A JP 14389596A JP 3031245 B2 JP3031245 B2 JP 3031245B2
- Authority
- JP
- Japan
- Prior art keywords
- steel pipe
- wing
- pipe pile
- screw
- wings
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- Piles And Underground Anchors (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ねじ込み式鋼管杭
に係り、さらに詳しくは、鋼管の先端部に複数の下段翼
を傾斜して取付けると共に、この下段翼の上方に上段翼
を取付けて鋼管杭を構成し、この鋼管杭に回転力を与え
てねじ作用によって地中に押し込み、無排土で地中に埋
設するようにしたねじ込み式鋼管杭に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw-in type steel pipe pile, and more particularly, to a steel pipe having a plurality of lower blades attached to the tip of a steel tube at an angle, and an upper blade mounted above the lower blade. The present invention relates to a screw-in type steel pipe pile which comprises a pile, applies a rotational force to the steel pipe pile, pushes it into the ground by a screw action, and buries the steel pipe pile in the ground without discharging.
【０００２】[0002]
【従来の技術】鋼管の先端部や側面に螺旋翼などを取付
けた鋼管杭に、地上に設置した駆動装置により回転力を
与えることにより、ねじの作用で地中に埋設するように
したねじ込み式鋼管杭は従来から多数提案されており、
その一部は小径の杭を対象としたものではあるが実用化
されている。以下、従来のこの種のねじ込み式鋼管杭の
一例について説明する。2. Description of the Related Art A screw-in type that is buried underground by the action of a screw by applying a rotating force to a steel pipe pile having a spiral wing or the like attached to the tip or side of the steel pipe by a driving device installed on the ground. Many steel pipe piles have been proposed,
Some of them are intended for small diameter piles, but they have been put into practical use. Hereinafter, an example of such a conventional screw-in type steel pipe pile will be described.
【０００３】特開平７−２９２６６６号公報に記載され
た鋼管杭は、一枚の長さが半巻きで、外径が杭本体の
１．５〜３倍程度である一対のラセン翼を、鋼管杭の下
端部外周面の同じ高さ位置でラセン方向を同じにして互
いに相対的に複数枚不連続に固定したものである（従来
技術１）。A steel pipe pile described in Japanese Patent Application Laid-Open No. 7-292666 has a pair of spiral wings, each of which has a half length and an outer diameter of about 1.5 to 3 times the main body of the pile, is made of steel pipe. A plurality of piles are fixed discontinuously relative to each other with the same helix direction at the same height position on the outer peripheral surface of the lower end of the pile (prior art 1).
【０００４】また、特開昭６１−９８８１８号公報に記
載された回転圧入式鋼管杭は、鋼製円筒体の下部に、上
下方向に延長する押込用傾斜前面を有する刃を設けると
共に、その傾斜前面の下端部から円筒体回転方向の後方
に向って斜めに上昇する傾斜ブレードを固定して環状の
ドリルヘッドを構成し、そのドリルヘッドの上端部に鋼
管杭の下端部を取付けたものである（従来技術２）。A rotary press-fit steel pipe pile described in Japanese Patent Application Laid-Open No. 61-98818 is provided with a blade having a push-in inclined front surface extending vertically and provided at the lower portion of a steel cylindrical body. An annular drill head is formed by fixing an inclined blade that rises obliquely from the lower end of the front surface toward the rear in the direction of rotation of the cylindrical body, thereby forming an annular drill head, and the lower end of a steel pipe pile is attached to the upper end of the drill head. (Prior art 2).
【０００５】さらに、特公平５−４２５２４号公報に記
載された杭は、先端を尖端に形成した杭体の先端部に螺
旋状の掘鑿羽根又は掘鑿螺子を設け、後端に先端部に設
けられた螺旋状の掘鑿羽根又は掘鑿螺子のねじピッチよ
りも間隔の狭いねじピッチに形成した填圧羽根又は填圧
螺子を設けたものである（従来技術３）。これら従来技
術１〜３に示す螺旋翼又は傾斜ブレード等は、施工に際
してねじとして機能すると共に、大きな地盤支持力を得
るための支持体として機能も備えている。Further, in the pile described in Japanese Patent Publication No. 5-42524, a helical excavator blade or excavator screw is provided at the tip of a pile having a tip formed at the tip, and the tip is formed at the tip at the rear end. The pressure fin or the pressure screw formed with a screw pitch smaller than the screw pitch of the spiral digging blade or the digging screw provided is provided (prior art 3). The spiral wings or the inclined blades shown in these prior arts 1 to 3 function not only as screws at the time of construction, but also as a support for obtaining a large ground support force.
【０００６】[0006]
【発明が解決しようとする課題】従来技術１の鋼管杭
は、工事完了後上載建造物の重量や地震により鉛直力が
作用すると、螺旋翼には翼面下の地盤から強い反力を受
ける。その結果、螺旋翼の付け根部分に大きな曲げモー
メントが生じ、螺旋翼が鋼管の外周面に強固に固着され
ているために、この曲げモーメントが鋼管に伝達されて
大きな曲げ応力が発生する。この曲げ応力は、従来技術
１の明細書に記載されているように、鋼管の外径が１０
０〜２００ｍｍ程度の小さい鋼管杭であれば実用上大き
な問題にはならない。しかし、広く使用されている外径
が５００〜６００ｍｍの鋼管杭では、設計上大きな問題
となる。When a vertical force acts on the steel pipe pile of the prior art 1 due to the weight of an overlying building or an earthquake after the construction is completed, the spiral wing receives a strong reaction force from the ground below the wing surface. As a result, a large bending moment is generated at the root portion of the spiral blade, and since the spiral blade is firmly fixed to the outer peripheral surface of the steel pipe, the bending moment is transmitted to the steel pipe to generate a large bending stress. This bending stress is, as described in the specification of the prior art 1, when the outer diameter of the steel pipe is 10 mm.
If it is a small steel pipe pile of about 0 to 200 mm, it does not pose a serious problem in practical use. However, a steel pipe pile having an outer diameter of 500 to 600 mm, which is widely used, poses a major design problem.
【０００７】螺旋翼の外径は、従来技術１においては、
施工上あるいは支持力上、鋼管径の２倍程度がよいとさ
れている。ここで、鋼管径２００ｍｍの鋼管杭と、６０
０ｍｍの鋼管杭とを比較する。いま、それぞれの螺旋翼
の外径を鋼管径の２倍である４００ｍｍ、１２００ｍｍ
とすると、螺旋翼の幅（（螺旋翼外径−鋼管外径）／
２）は、それぞれ１００ｍｍ、３００ｍｍとなる。螺旋
翼に作用する単位面積当りの地盤反力が同じとすると、
螺旋翼の付け根に作用する単位周長当りの曲げモーメン
トは、螺旋翼の幅のほぼ２乗に比例するので、外径６０
０ｍｍの鋼管杭では、外径２００ｍｍの鋼管杭に比べて
約９倍の大きさになり、このため、螺旋翼は大変厚い鋼
板が要求される。発明者の試算によれば、外径６００ｍ
ｍの鋼管杭の場合、設計上４０ｍｍ以上の厚さが必要に
なる。このように厚さが厚くなると、平鋼板を螺旋状に
曲げ加工するのがきわめて面倒であり、高価になる。[0007] In the prior art 1, the outer diameter of the spiral blade is
It is said that about twice the diameter of the steel pipe is preferable in terms of construction or supporting force. Here, a steel pipe pile having a steel pipe diameter of 200 mm,
Compare with 0mm steel pipe pile. Now, the outer diameter of each spiral blade is 400 mm, 1200 mm, which is twice the diameter of the steel pipe.
Then, the spiral blade width ((spiral blade outer diameter-steel pipe outer diameter) /
2) is 100 mm and 300 mm, respectively. Assuming that the ground reaction force per unit area acting on the spiral wing is the same,
Since the bending moment per unit circumference acting on the root of the spiral blade is proportional to almost the square of the width of the spiral blade, the outer diameter is 60 mm.
A 0 mm steel pipe pile is about nine times as large as a 200 mm outer diameter steel pipe pile, and therefore, a very thick steel plate is required for the spiral blade. According to the inventor's calculation, the outer diameter is 600m.
In the case of a steel pipe pile of m, a thickness of 40 mm or more is required by design. When the thickness is increased in such a manner, it is extremely troublesome and expensive to flatly bend a flat steel plate.
【０００８】また、螺旋翼で大きな地盤支持力を得るた
めには、鋼管と螺旋翼の結合部は螺旋翼と同等以上の強
度が要求される。そのため、図１８に示すように、螺旋
翼２２に開先加工２３を施して全断面溶け込み溶接２４
により剛接合することが必要であり、厚さが大きくなる
と溶接費用が非常に高くなる。Further, in order to obtain a large ground support force with the spiral blade, the joint between the steel pipe and the spiral blade must have a strength equal to or higher than that of the spiral blade. For this reason, as shown in FIG.
Therefore, it is necessary to perform a more rigid connection, and as the thickness increases, the welding cost becomes very high.
【０００９】一方、鋼管の螺旋翼の付け根付近には、前
述のように螺旋翼から曲げモーメントが伝達され、曲げ
応力が発生する。鋼管に伝達される曲げモーメントは外
径寸法によって異なるが、螺旋翼の付け根部の曲げモー
メントの５〜１０割程度の値になる。例えば、外径６０
０ｍｍの鋼管の場合、設計上４０ｍｍ以上の厚さが必要
な螺旋翼の曲げモーメント値の５〜１０割の曲げモーメ
ントが付け根付近の鋼管に発生する。外径６００ｍｍの
鋼管杭の場合、一般に使用されている肉厚は９〜１２ｍ
ｍ程度であり、螺旋翼の曲げモーメントによって生ずる
鋼管の曲げ応力は、設計許容曲げ応力を大きく超過する
ことになる。これに対処するため、螺旋翼の付け根付近
の鋼管の厚さを、一般の厚さの２〜３倍に増やすことも
考えられるが、そのためにはコストが著しく増加し、実
用上設計不可能にならざるを得ない。On the other hand, a bending moment is transmitted from the spiral blade near the root of the spiral blade of the steel pipe as described above, and a bending stress is generated. The bending moment transmitted to the steel pipe varies depending on the outer diameter, but is about 50 to 100% of the bending moment at the root of the spiral blade. For example, outer diameter 60
In the case of a 0 mm steel pipe, a bending moment of 50 to 100% of the bending moment value of the spiral blade, which requires a thickness of 40 mm or more in design, occurs in the steel pipe near the root. In the case of a steel pipe pile with an outer diameter of 600 mm, the generally used wall thickness is 9 to 12 m.
m, and the bending stress of the steel pipe caused by the bending moment of the spiral blade greatly exceeds the design allowable bending stress. To cope with this, it is conceivable to increase the thickness of the steel pipe near the root of the spiral wing to two to three times the general thickness, but this significantly increases the cost and makes practical design impossible. I have to be.
【００１０】また、従来技術１は、大きな地盤支持力を
得るために、鋼管の先端部に底板を取付ける必要があ
り、そのためには、鋼管の先端部と底板を強固に溶接結
合しなければならず、そのコストも少なくない。Further, in the prior art 1, it is necessary to attach a bottom plate to the tip of the steel pipe in order to obtain a large ground support force, and for that purpose, the tip of the steel pipe and the bottom plate must be firmly welded to each other. And the cost is not small.
【００１１】従来技術２は、鋼製円筒体の先端部に蓋が
ないため大きな地盤支持力を得ることができない。ま
た、傾斜ブレードの幅が狭く、鋼製円筒体の先端部の内
外に僅かに突出する構造のため、傾斜ブレードを大きな
地盤支持力の支持体として期待することはできない。さ
らに、従来技術２は、傾斜ブレード付き鋼製円筒体を製
作してからこれを鋼管の先端部に固着するため、コスト
の増嵩は避けられない。In the prior art 2, since the steel cylindrical body has no lid at the tip, a large ground support force cannot be obtained. Further, since the width of the inclined blade is small and the structure slightly projects inside and outside the tip of the steel cylinder, the inclined blade cannot be expected as a support having a large ground support force. Furthermore, in the prior art 2, since a steel cylinder with an inclined blade is manufactured and then fixed to the tip of the steel pipe, an increase in cost cannot be avoided.
【００１２】さらに、従来技術１及び２においては、螺
旋翼又は傾斜ブレードが鋼管の下端部に１か所だけしか
設けられていない、いわゆる一段翼であるため、鋼管杭
のねじ込み施工時において、鋼管杭を下方に押し込む力
が比較的弱い。このため、鋼管杭の先端部が硬い地層に
達すると、から廻りすることがある。Furthermore, in the prior arts 1 and 2, the spiral wing or the inclined blade is a so-called single-stage wing in which only one portion is provided at the lower end of the steel pipe. The force to push the pile down is relatively weak. For this reason, when the tip of the steel pipe pile reaches a hard stratum, it may turn around.
【００１３】また、従来技術３においては、この技術を
外径が比較的大きい鋼管杭に適用する場合は、従来技術
１の場合と同様に、鋼管に過大な曲げ応力が発生すると
いう問題がある。さらに、上段の掘鑿羽根等のピッチは
下段の掘鑿羽根等のピッチより小さいために、鋼管杭の
ねじ込み施工時において、上段の掘鑿羽根等には鋼管杭
を下方に押し込む力は発生せず、上方に引く抜く力が発
生してしまう。このため、硬い地盤に到達すると一段翼
の場合よりもさらにから廻りしてしまい、深くねじ込む
ことができない。なお、鋼管外周面の下方から上方まで
連続した螺旋翼を取付けた鋼管杭も提案されているが、
このような構造では、螺旋翼に挾まれた土砂を上方に押
し上げて螺旋翼の上下に空隙が発生するため、大きな周
面摩擦力を得ることができない。Further, in the prior art 3, when this technique is applied to a steel pipe pile having a relatively large outer diameter, as in the case of the prior art 1, there is a problem that an excessive bending stress is generated in the steel pipe. . Furthermore, since the pitch of the upper excavator blades is smaller than the pitch of the lower excavator blades, when the steel pipe pile is screwed in, there is no force to push the steel pipe pile down on the upper excavator blades. Instead, an upward pulling force is generated. For this reason, when it reaches the hard ground, it turns further from the case of the single-stage wing and cannot be screwed deeply. In addition, a steel pipe pile with a spiral wing that is continuous from the bottom to the top of the steel pipe outer peripheral surface has been proposed,
In such a structure, since the earth and sand sandwiched between the spiral blades is pushed upward to form a gap above and below the spiral blade, a large circumferential friction force cannot be obtained.
【００１４】本発明は、上記従来技術の問題に鑑みて、
以下の課題を解決することを目的としたものである。 （１）下段翼及び上段翼を利用して大きな地盤支持力が
得られること。 （２）下段翼及び上段翼から伝達される曲げモーメント
により、鋼管に過大な曲げ応力を発生させないこと。 （３）下段翼を含めた鋼管杭先端部近傍の加工が容易
で、加工費が安いこと。 （４）下段翼と上段翼により鋼管杭を強固な地層までね
じ込んで埋設できること。The present invention has been made in view of the above-mentioned problems of the prior art,
It is intended to solve the following problems. (1) A large ground support force can be obtained by using the lower wing and the upper wing. (2) Do not generate excessive bending stress in the steel pipe due to the bending moment transmitted from the lower and upper blades. (3) The processing near the tip of the steel pipe pile including the lower wing is easy and the processing cost is low. (4) The steel pipe pile can be screwed down to the strong stratum and buried by the lower and upper wings.
【００１５】[0015]
（１）本発明に係るねじ込み式鋼管杭は、先端部を円周
方向に複数に分割し、この分割された個々の部分に同方
向に向ってそれぞれレ字状の取付部が形成された鋼管
と、直径が鋼管の直径より大きい円形鋼板又は楕円形鋼
板を複数に分割したほぼ半円状又は扇形状の下段翼と、
ドーナツ状の鋼板を１か所若しくは数個所で切断して螺
旋状に曲げ加工し、又はドーナツ状の鋼板を複数個に分
割した上段翼とを有し、下段翼を鋼管の先端部のほぼ中
心部からレ字状の取付部の下面に沿ってそれぞれ取付け
ると共に、下段翼の上方において鋼管の外周面に上段翼
を取付けたものである。(1) The screw-in type steel pipe pile according to the present invention has a distal end portion divided into a plurality in the circumferential direction, and each of the divided individual portions is formed with a R-shaped mounting portion in the same direction. And a substantially semicircular or fan-shaped lower wing in which a circular steel plate or an elliptical steel plate whose diameter is larger than the diameter of the steel pipe is divided into a plurality of pieces,
Donut-shaped steel plate is cut at one or several places and spirally bent, or has an upper stage wing obtained by dividing a donut-shaped steel plate into a plurality of parts, and the lower stage wing is substantially at the center of the tip of the steel pipe. The upper stage blade is attached to the outer peripheral surface of the steel pipe above the lower stage blade, while being attached along the lower surface of the R-shaped mounting portion from the portion.
【００１６】（２）上記（１）のねじ込み式鋼管杭にお
いて、隣接する下段翼と鋼管との間に形成された開口部
を閉塞部材によって閉塞した。(2) In the screw-in type steel pipe pile of the above (1), the opening formed between the adjacent lower wing and the steel pipe is closed by a closing member.
【００１７】（３）上記（１）又は（２）のねじ込み式
鋼管杭において、鋼管の先端部に設けたレ字状の取付部
に、低強度溶接手段又はヒンジ手段により下段翼を取付
けた。 （４）また、上記（１），（２）又は（３）のねじ込み
式鋼管杭において、鋼管の外周面に低強度溶接手段によ
り上段翼を取付けた。 （５）上記（１），（２），（３）又は（４）のねじ込
み式鋼管杭において、下段翼を平坦面又は螺旋面に形成
した。(3) In the screw-in type steel pipe pile of the above (1) or (2), the lower wing is attached to the L-shaped attachment portion provided at the tip of the steel pipe by low-strength welding means or hinge means. (4) In the screw-in type steel pipe pile of (1), (2) or (3), the upper wing was attached to the outer peripheral surface of the steel pipe by low-strength welding means. (5) In the threaded steel pipe pile of (1), (2), (3) or (4), the lower wing is formed on a flat surface or a spiral surface.
【００１８】[0018]
実施形態１ 図１は本発明に係るねじ込み式鋼管杭の実施形態１の斜
視図、図２はそのＡ−Ａ断面図である。図において、１
はねじ込み式鋼管杭（以下単に鋼管杭という）、２はこ
の鋼管杭１を構成する鋼管、１０ａ，１０ｂは鋼管２の
先端部に互いに反対方向に傾斜して取付けられた下段翼
で、２０ａ，２０ｂは下段翼１０ａ，１０ｂの上方にお
いて、鋼管２の外周に取付けられた上段翼である。Embodiment 1 FIG. 1 is a perspective view of a screw-in type steel pipe pile according to Embodiment 1 of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. In the figure, 1
Is a screw-in type steel pipe pile (hereinafter simply referred to as a steel pipe pile), 2 is a steel pipe constituting this steel pipe pile 1, 10a and 10b are lower wings which are attached to the tip of the steel pipe 2 at an angle in opposite directions to each other. 20b is an upper blade attached to the outer periphery of the steel pipe 2 above the lower blades 10a and 10b.
【００１９】鋼管２の先端部は、図３に示すように（図
３では、説明を容易にするため、鋼管２の上下を逆にし
てある）、円周方向に２等分して段部３ａ，３ｂにより
２部分に分割し、一方の部分は、一方の段部３ａの下端
部から他方の段部３ｂの上端部に連続する傾斜面４ａと
し、他方の部分は、前記一方の段部３ａの上端部から他
方の段部３ｂの下端部に連続する傾斜面４ｂとして、互
いに同方向に向うレ字状の下段翼１０ａ，１０ｂの取付
部５ａ，５ｂを形成したものである。なお、傾斜面４
ａ，４ｂを形成する段部の高さｈは、鋼管杭１を埋設す
る地盤の状態、鋼管２の外径及び下段翼１０ａ，１０ｂ
の数などによって異なるが、一般にｈ＝０．１〜０．５
Ｄ（Ｄは鋼管２の外径）程度であることが望ましい。As shown in FIG. 3 (in FIG. 3, the top and bottom of the steel pipe 2 is inverted for ease of explanation), the tip of the steel pipe 2 is divided into two steps in the circumferential direction. 3a and 3b, one of which is an inclined surface 4a continuous from the lower end of one step 3a to the upper end of the other step 3b, and the other part is the one step The attachment portions 5a and 5b of the lower wings 10a and 10b facing in the same direction are formed as an inclined surface 4b that is continuous from the upper end of 3a to the lower end of the other step 3b. In addition, the slope 4
The height h of the steps forming the a and 4b is determined by the state of the ground in which the steel pipe pile 1 is buried, the outer diameter of the steel pipe 2 and the lower blades 10a and 10b.
, But generally h = 0.1-0.5
It is desirable to be about D (D is the outer diameter of the steel pipe 2).
【００２０】下段翼１０ａ，１０ｂは、図４に示すよう
に、鋼管２の外径Ｄより大きい外径Ｄ1 （例えば、Ｄ1
＝２Ｄ）の円形鋼板を又は楕円形鋼板中心部から２分割
してほぼ半円状又は扇形状に構成したものである。な
お、下段翼１０ａ，１０ｂを曲げ又は反らせ加工して螺
旋面に形成してもよい。この下段翼１０ａ，１０ｂの大
きさは、鋼管杭１を埋設する地盤の状態、鋼管２の外径
及び下段翼１０ａ，１０ｂの数などによって異なるが、
一般に鋼管２の外径の１．５〜３倍程度が望ましい。こ
のような下段翼１０ａ，１０ｂは、鋼管２の先端部のほ
ぼ中心部からレ字状の取付部５ａ，５ｂの下面（図３で
は上面）に沿ってその内部を塞ぐように載置し、溶接等
により鋼管２に傾斜して取付けられる。As shown in FIG. 4, the lower blades 10a and 10b have an outer diameter D 1 (for example, D 1) larger than the outer diameter D of the steel pipe 2.
= 2D) or a semi-circular or sector shape by dividing the circular steel plate into two parts from the center of the elliptical steel plate. The lower blades 10a and 10b may be formed on the spiral surface by bending or warping. The size of the lower wings 10a and 10b varies depending on the state of the ground in which the steel pipe pile 1 is embedded, the outer diameter of the steel pipe 2, the number of the lower wings 10a and 10b, and the like.
Generally, it is desirable that the outer diameter of the steel pipe 2 is about 1.5 to 3 times. The lower wings 10a and 10b are placed so as to cover the inside of the steel pipe 2 along the lower surface (the upper surface in FIG. 3) of the R-shaped mounting portions 5a and 5b from substantially the center of the tip of the steel pipe 2. It is attached to the steel pipe 2 at an angle by welding or the like.
【００２１】上段翼２０ａ，２０ｂは、図５に示すよう
に、下段翼１０ａ，１０ｂの外径Ｄより大きいか、ほぼ
等しいか、又は若干小さい外径のドーナツ状の鋼板を中
心部から２等分し、直線側を、下段翼１０ａ，１０ｂの
傾斜に対応した鋼管外周面の形状に整合させて切除し、
ほぼ半ドーナツ状に構成したものである。そして、下段
翼１０ａ，１０ｂの上方において、下段翼１０ａ，１０
ｂの傾斜線の延長線、つまり、仮想ピッチ上の鋼管２の
外周面に、溶接により取付けたものである。この場合、
下段翼１０ａ，１０ｂと上段翼２０ａ，２０ｂとの間隔
は、０．５〜５Ｄ（但し、Ｄは鋼管２の外径）程度が望
ましい。As shown in FIG. 5, the upper wings 20a and 20b each have a donut-shaped steel plate having an outer diameter larger than, substantially equal to, or slightly smaller than the outer diameter D of the lower wings 10a and 10b. Then, the straight side is cut out in accordance with the shape of the outer peripheral surface of the steel pipe corresponding to the inclination of the lower blades 10a, 10b.
It is configured in a substantially semi-donut shape. The lower wings 10a, 10b are located above the lower wings 10a, 10b.
It is attached by welding to an extension of the inclined line b, that is, the outer peripheral surface of the steel pipe 2 on the virtual pitch. in this case,
The distance between the lower blades 10a, 10b and the upper blades 20a, 20b is preferably about 0.5 to 5D (where D is the outer diameter of the steel pipe 2).
【００２２】なお、上段翼２０ａ，２０ｄは、上述のよ
うに、下段翼１０ａ，１０ｂと同様の状態で鋼管２に取
付けてもよいが、一方の端部を互に溶接して一体化して
もよく、あるいはドーナツ状の鋼板を１か所若しくは複
数か所で切断し前述の仮想ピッチに対応させて曲げ加工
し、又はドーナツ状の鋼板を複数個に分割して形成して
もよい。The upper wings 20a and 20d may be attached to the steel pipe 2 in the same manner as the lower wings 10a and 10b as described above, but may be integrated by welding one end to each other. Alternatively, the donut-shaped steel sheet may be cut at one or more places and bent in accordance with the above-mentioned virtual pitch, or the donut-shaped steel sheet may be divided into a plurality of pieces.
【００２３】上記のように構成した鋼管杭１は、例えば
図１７に示すように、ベースマシン３０に搭載したオー
ガー３１に連結され、オーガー３１によって回転されて
下段翼１０ａ，１０ｂと上段翼２０ａ，２０ｂのねじ作
用により地中にねじ込まれ、埋設される。このとき、下
段翼１０ａ，１０ｂの食い違い部の間に形成された開口
部１１が小さいため、鋼管２内には土砂はほとんど侵入
しない。The steel pipe pile 1 constructed as described above is connected to an auger 31 mounted on a base machine 30 and rotated by the auger 31, as shown in FIG. 17, for example, and the lower wings 10a, 10b and the upper wing 20a, It is screwed into the ground by the screw action of 20b and buried. At this time, since the opening 11 formed between the staggered portions of the lower wings 10a and 10b is small, sediment hardly enters the steel pipe 2.
【００２４】実施形態２ 本実施形態は、図６に示すように、ドーナツ状の鋼板か
らなり１か所が切断された１枚の上段翼２０を、下段翼
１０ａ，１０ｂの傾斜に合わせて曲げ加工して構成し、
下段翼１０ａ，１０ｂの仮想ピッチ上において鋼管２の
外周面に溶接により取付けたものである。本実施形態に
係る鋼管杭１の施工方法及び作用、効果は実施形態１の
場合と同様である。Embodiment 2 In this embodiment, as shown in FIG. 6, a single upper wing 20 made of a donut-shaped steel plate and having one section cut is bent in accordance with the inclination of the lower wings 10a and 10b. Process and configure,
It is attached to the outer peripheral surface of the steel pipe 2 by welding on the virtual pitch of the lower blades 10a and 10b. The construction method, operation, and effects of the steel pipe pile 1 according to the present embodiment are the same as those in the first embodiment.
【００２５】実施形態３ 図７は本発明の実施形態３の斜視図、図８は図７のＢ−
Ｂ断面図である。本実施形態においては、図９に示すよ
うに、鋼管２の先端部を円周方向に４等分して段部３
ａ，３ｂ，３ｃ，３ｄにより４部分に分割し、各部分に
それぞれ隣接する段部３ａ〜３ｄの下端部から上端部に
連続する傾斜面４ａ，４ｂ，４ｃ，４ｄを形成し、これ
により、互いに同方向に向うレ字状の取付部５ａ，５
ｂ，５ｃ，５ｄを形成する。Third Embodiment FIG. 7 is a perspective view of a third embodiment of the present invention, and FIG.
It is B sectional drawing. In the present embodiment, as shown in FIG. 9, the distal end of the steel pipe 2 is divided into four equal parts in the circumferential direction, and the step part 3 is formed.
a, 3b, 3c, and 3d, which are divided into four parts, and inclined surfaces 4a, 4b, 4c, and 4d that are continuous from the lower end to the upper end of the steps 3a to 3d that are adjacent to the respective parts are formed. Le-shaped mounting portions 5a, 5 facing in the same direction
b, 5c and 5d are formed.
【００２６】そして、上記のように構成した鋼管２の取
付部５ａ〜５ｄに、鋼管２の外径より大きい外形の円形
鋼板又は楕円形鋼板を４等分した扇形状の下段翼１０
ａ，１０ｂ，１０ｃ，１０ｄを溶接等により傾斜して取
付けると共に、その上方に、実施例２の上段翼２０に準
じた構造の上段翼２０を溶接により鋼管２の外周面に取
付けて、鋼管杭１を構成したもである。なお、上記の上
段翼２０に代えて、実施形態１の上段翼２０ａ，２０ｂ
に準じてドーナツ状の鋼板を４等分した扇形状の上段翼
を、下段１０ａ〜１０ｄの仮想ピッチに合わせて、鋼管
２の外周面に傾斜して取付けてもよい。本実施形態に係
る鋼管杭１も、実施形態１，２の場合と同様にして地中
にねじ込まれ、埋設される。The fan-shaped lower wing 10 in which a circular steel plate or an elliptical steel plate having an outer diameter larger than the outer diameter of the steel pipe 2 is divided into four equal parts is attached to the mounting portions 5a to 5d of the steel pipe 2 configured as described above.
a, 10b, 10c, and 10d are attached by inclining by welding or the like, and an upper stage wing 20 having a structure similar to the upper stage wing 20 of the second embodiment is attached to the outer peripheral surface of the steel pipe 2 by welding above the upper end. 1 is constituted. Note that, instead of the above-described upper wing 20, the upper wings 20a and 20b of the first embodiment are used.
In accordance with the above, a fan-shaped upper wing obtained by dividing a donut-shaped steel plate into four equal parts may be inclinedly attached to the outer peripheral surface of the steel pipe 2 in accordance with the virtual pitch of the lower tiers 10a to 10d. The steel pipe pile 1 according to the present embodiment is also screwed into the ground and buried in the same manner as in the first and second embodiments.
【００２７】実施形態４ 本実施形態は、実施形態１〜３において、鋼管２と隣接
する下段翼１０ａ，１０ｂ又は１０ａ〜１０ｄ（以下特
別の場合を除き、下段翼１０ａ，１０ｂと記す）との間
に形成された小さい開口部１１を、図１０（ａ），
（ｂ）に示すように、鋼板等からなる閉塞部材１２によ
って閉塞し、併せて下段翼１０ａ，１０ｂ同志を相互に
剛接合したものである。Embodiment 4 This embodiment is different from Embodiments 1 to 3 in that the steel pipe 2 and the adjacent lower wings 10a, 10b or 10a to 10d (hereinafter referred to as lower wings 10a, 10b except in special cases) are used. The small opening 11 formed between them is formed as shown in FIG.
As shown in (b), the lower blades 10a and 10b are rigidly connected to each other by being closed by a closing member 12 made of a steel plate or the like.
【００２８】上記のように構成した実施形態１〜３に係
る鋼管杭１は、下段翼１０ａ，１０ｂが鋼管１の下部開
口部の大部分を閉塞すると共に、下段翼１０ａ，１０ｂ
及び上段翼２０又は２０ａ，２０ｂ（以下特別の場合を
除き、上段翼２０ａ，２０ｂと記す）は鋼管２の外周面
から大きく突出しているため、地中へのねじ込み施工時
においては、下段翼１０ａ，１０ｂは、その下方の地盤
へ食い込んで鋼管杭１をねじ込む機能と、鋼管杭１の下
方の土砂を食い違い部で掘削して鋼管２の周囲に押出
し、かつこれを圧縮する機能を有し、上段翼２０ａ，２
０ｂは、鋼管杭１を下方に押込む機能を有する。In the steel pipe pile 1 according to Embodiments 1 to 3 configured as described above, the lower wings 10a and 10b close most of the lower opening of the steel pipe 1 and the lower wings 10a and 10b.
And the upper wing 20 or 20a, 20b (hereinafter, referred to as the upper wing 20a, 20b unless otherwise specified) protrudes greatly from the outer peripheral surface of the steel pipe 2, so that the lower wing 10a , 10b have a function of cutting into the ground below and screwing the steel pipe pile 1 and a function of excavating earth and sand below the steel pipe pile 1 at the staggered portion, extruding it around the steel pipe 2, and compressing it. Upper wing 20a, 2
0b has a function of pushing the steel pipe pile 1 downward.
【００２９】また、施工後において、上載建造物等によ
る鉛直荷重を支持する杭として機能するときは、下段翼
１０ａ，１０ｂは、鋼管２の下端開口部を閉塞する底板
としての部分と、鋼管２の外周から突出した部分とを合
わせた全面積が支持体として機能し、さらに、鋼管２の
外周面から突出した上段翼２０ａ，２０ｂも地盤支持力
を得ることができる。Further, after the construction, when functioning as a pile for supporting a vertical load by an overlying building or the like, the lower wings 10a and 10b are provided with a portion as a bottom plate for closing a lower end opening of the steel pipe 2, and The entire area including the portion protruding from the outer periphery of the steel pipe 2 functions as a support, and the upper wings 20a and 20b protruding from the outer peripheral surface of the steel pipe 2 can also obtain the ground support force.
【００３０】このように、半円状又は扇形状の下段翼１
０ａ，１０ｂは、鋼管２の外周に突出して地盤へ食い込
む機能と、鋼管先端部の開口部を閉塞する底板としての
機能との両機能を備えており、先端部を閉塞した鋼管杭
の地盤支持力は、閉塞面積に比例することが知られてい
る。よって、例えば、下段翼１０ａ，１０ｂの外径を鋼
管２の外径の２倍にすると、下段翼の面積は、これがな
い場合の４倍の面積となり、非常に大きな地盤支持力が
得られる。Thus, the semi-circular or fan-shaped lower wing 1
Reference numerals 0a and 10b have both a function of projecting to the outer periphery of the steel pipe 2 to cut into the ground and a function as a bottom plate for closing the opening of the tip of the steel pipe, and support the ground of the steel pipe pile having the closed tip. It is known that the force is proportional to the occluded area. Therefore, for example, when the outer diameter of the lower wings 10a and 10b is twice as large as the outer diameter of the steel pipe 2, the area of the lower wing becomes four times as large as the case without the lower wing, and a very large ground support force can be obtained.
【００３１】また、実施形態４に示すように、鋼管２
と、隣接する下段翼１０ａ，１０ｂとの間に形成される
小さい開口部１１を、閉塞板１２で閉塞することによ
り、鋼管２内への土砂の侵入を防止できるので、鋼管杭
１の先端部の下方にあるすべての土砂は、鋼管杭１の側
方に押し出しされ、圧縮されて密度の高い土砂になるた
め、鋼管杭１の周面摩擦による地盤支持力を大きくする
ことができる。Further, as shown in Embodiment 4, the steel pipe 2
And the small opening 11 formed between the adjacent lower wings 10a and 10b is closed by the closing plate 12, so that intrusion of earth and sand into the steel pipe 2 can be prevented. Is extruded to the side of the steel pipe pile 1 and is compressed into high-density soil, so that the ground bearing force due to the peripheral friction of the steel pipe pile 1 can be increased.
【００３２】ところで、下段翼１０ａ，１０ｂによって
大きな地盤反力を受けるためには、下段翼１０ａ，１０
ｂは高い剛性が要求される。例えば、鋼管２の外径が５
００ｍｍ、下段翼１０ａ，１０ｂの外径が１０００ｍｍ
の場合、下段翼１０ａ，１０ｂには、地盤反力により大
きな曲げモーメントが発生するため、設計上、厚さ４０
ｍｍ程度の鋼板を用いることが要求され、この曲げモー
メントは鋼管２に伝達されて鋼管２に大きな曲げ応力が
生ずることになる。By the way, in order to receive a large ground reaction force by the lower wings 10a, 10b, the lower wings 10a, 10b are required.
b requires high rigidity. For example, if the outer diameter of the steel pipe 2 is 5
00mm, outer diameter of lower stage wings 10a, 10b is 1000mm
, A large bending moment is generated in the lower wings 10a and 10b due to the ground reaction force.
It is required to use a steel plate of about mm, and this bending moment is transmitted to the steel pipe 2 and a large bending stress is generated in the steel pipe 2.
【００３３】しかしながら、下段翼１０ａ，１０ｂは、
図１１（ａ）に示すように、鋼管２の先端部の内側から
外側に亘って連続しているため、下段翼１０ａ，１０ｂ
の鋼管２の外側の部分に対する地盤反力による曲げモー
メントＭ1 ，Ｍ4 と、内側の部分に対する曲げモーメン
トＭ2 ，Ｍ3 が、鋼管２と下段翼１０ａ，１０ｂとの結
合部において互いに打消し合い、結果として、鋼管２の
下段翼１０ａ，１０ｂの結合部近傍には、両者の差の小
さい曲げモーメントＭ1 −Ｍ2 及びＭ4 −Ｍ3が伝達さ
れるだけなので、鋼管２には過大な曲げ応力は生じな
い。また、実施形態４に示すように、下段翼１０ａ，１
０ｂ同志を剛接合した場合は、図９（ｂ）に示すよう
に、対向する外側の部分同志及び内側の部分同志で互い
に曲げモーメントを打消し合ってバランスするため、鋼
管２との接合部には曲げモーメントはほとんど作用しな
い。However, the lower wings 10a, 10b
As shown in FIG. 11A, since the steel pipe 2 is continuous from the inside to the outside of the distal end, the lower blades 10 a and 10 b
The bending moments M 1 and M 4 due to the ground reaction force on the outer portion of the steel pipe 2 and the bending moments M 2 and M 3 on the inner portion of the steel pipe 2 cancel each other at the joint between the steel pipe 2 and the lower blades 10a and 10b. As a result, only the bending moments M 1 -M 2 and M 4 -M 3 with a small difference between the two are transmitted to the vicinity of the joint between the lower wings 10 a and 10 b of the steel pipe 2. No severe bending stress occurs. Further, as shown in Embodiment 4, the lower wings 10a, 1
In the case of rigidly connecting the 0b members, as shown in FIG. 9 (b), the outer and inner portions oppose each other to cancel the bending moment and balance each other. Has almost no bending moment.
【００３４】このように、鋼管の外周面に螺旋翼などを
取付ける従来技術１，２で問題になった鋼管に生じる過
大な曲げ応力を、本発明は下段翼１０ａ，１０ｂにより
大幅に軽減することができる。一方、上段翼２０ａ，２
０ｂには下段翼１０ａ，１０ｂほど大きな地盤支持力は
期待できず、限られた地盤支持力しか得られない。しか
し、上段翼２０ａ，２０ｂは下段翼１０ａ，１０ｂほど
厚くないため（例えば、２５ｍｍ程度）、上段翼２０
ａ，２０ｂから鋼管２に伝達される曲げモーメントは小
さく、大きな問題にはならない。As described above, according to the present invention, the excessive bending stress generated in the steel pipe, which is a problem in the prior arts 1 and 2 in which the spiral wing is attached to the outer peripheral surface of the steel pipe, is greatly reduced by the lower wings 10a and 10b. Can be. On the other hand, the upper wing 20a, 2
0b cannot expect a ground support force as large as the lower wings 10a and 10b, and can obtain only a limited ground support force. However, since the upper wings 20a and 20b are not as thick as the lower wings 10a and 10b (for example, about 25 mm),
The bending moment transmitted from the a and 20b to the steel pipe 2 is small and does not cause a serious problem.
【００３５】また、鋼管２の外径と下段翼１０ａ，１０
ｂの外径との関係や地盤反力の分布状態によっては、下
段翼１０ａ，１０ｂの鋼管２の内側と外側に加えられる
曲げモーメントに大きなアンバランスが生じ、この曲げ
モーメントの差の曲げモーメントが鋼管２に加えられ、
鋼管２に大きな曲げ応力が発生することも考えられる。
さらに、鋼管２に剛接合された下段翼１０ａ，１０ｂに
加えられる曲げモーメントが前述のように打消し合った
場合でも、下段翼１０ａ，１０ｂが比較的薄肉のとき
は、全体が曲げ変形することも考えられる。このような
場合は、鋼管２の下段翼１０ａ，１０ｂの接合部には二
次的な曲げモーメントが作用する。The outer diameter of the steel pipe 2 and the lower blades 10a, 10a
Depending on the relationship with the outer diameter of b and the distribution state of the ground reaction force, a large imbalance occurs in the bending moment applied to the inside and outside of the steel pipe 2 of the lower blades 10a and 10b, and the bending moment of the difference between the bending moments is Added to steel pipe 2,
It is conceivable that a large bending stress is generated in the steel pipe 2.
Furthermore, even if the bending moments applied to the lower wings 10a, 10b rigidly connected to the steel pipe 2 cancel each other as described above, if the lower wings 10a, 10b are relatively thin, the whole will bend and deform. Is also conceivable. In such a case, a secondary bending moment acts on the joint between the lower wings 10a and 10b of the steel pipe 2.
【００３６】このような場合、図１８に示すように、鋼
管２の先端部と下段翼１０ａ，１０ｂとを剛接合する
と、従来技術１，２と同様の問題が生じるので、図１２
に示すように、鋼管２の先端部（取付部５ａ，５ｂ）
に、例えば隅肉溶接の如く全断面に溶け込まない簡略な
溶接１３、あるいは鋼管２の材質よりも降伏強度の小さ
い溶接材料を用いた全断面溶け込み溶接（以下両者を合
わせて低強度溶接手段という）により下段翼１０ａ，１
０ｂを取付け、鋼管２の曲げ応力が許容値に達する前に
故意に溶接部を降伏（塑性化）させてしまい、鋼管２に
それ以上の曲げモーメントが伝達されないようにしても
よい。In such a case, as shown in FIG. 18, if the distal end portion of the steel pipe 2 is rigidly connected to the lower blades 10a and 10b, the same problems as those of the prior arts 1 and 2 occur.
As shown in the figure, the distal end portion of the steel pipe 2 (the mounting portions 5a and 5b).
In addition, for example, simple welding 13 that does not melt into the entire cross section as in fillet welding, or full cross section penetration welding using a welding material having a lower yield strength than the material of the steel pipe 2 (hereinafter, both are referred to as low-strength welding means) Lower wing 10a, 1
0b may be attached so that the welded portion is intentionally yielded (plasticized) before the bending stress of the steel pipe 2 reaches an allowable value, so that no further bending moment is transmitted to the steel pipe 2.
【００３７】溶接材料などの鋼材は、図１３に示すよう
に、降伏後も相当変形するまで破壊を生じないという性
質があり、そのため、下段翼１０ａ，１０ｂは、溶接部
の降伏後においても鋼管２の先端部から脱落することは
ない。また、溶接部が降伏しても、下段翼１０ａ，１０
ｂは、地盤反力を受ける支持体として健全に機能するこ
とができる。As shown in FIG. 13, a steel material such as a welding material has a property that it does not break until it is considerably deformed even after yielding. Therefore, the lower stage wings 10a and 10b maintain the steel pipe even after yielding of the welded portion. 2 does not fall off the tip. Further, even if the welded portion yields, the lower wings 10a, 10a
b can function soundly as a support receiving the ground reaction force.
【００３８】また、上述の溶接に代えて、図１４に示す
ように、鋼管２の外周面の下端部に、ブロック状の複数
の鋼片１５を溶接して取付けると共に、下段翼１０ａ，
１０ｂの上面に、これら各鋼片１５に対向し、かつその
周囲を取り囲むようにコ字状の鋼板１６を溶接して配置
し、鋼板１６を鋼片１５にそれぞれ嵌合して（以下ヒン
ジ手段１４という）、下段翼１０ａ，１０ｂを鋼管２の
先端部に取付けるようにしてもよい。In place of the above welding, a plurality of block-shaped steel pieces 15 are welded to the lower end of the outer peripheral surface of the steel pipe 2 as shown in FIG.
A U-shaped steel plate 16 is welded and arranged on the upper surface of 10b so as to face each of the steel slabs 15 and surround the periphery thereof, and the steel plates 16 are fitted to the steel slabs 15 respectively (hereinafter hinge means). 14), the lower blades 10a, 10b may be attached to the tip of the steel pipe 2.
【００３９】このようにして下段翼１０ａ，１０ｂが取
付けられた鋼管杭１は、鉛直力とせん断力は伝達できる
構造であるため、ねじ込みによる鋼管杭１の埋設施工性
及び上載建造物完成後の支持機能上なんら問題はない。
また、下段翼１０ａ，１０ｂに生じた曲げモーメント
は、鋼管２には伝達されないので、鋼管２に曲げ応力が
発生することはない。Since the steel pipe pile 1 to which the lower wings 10a and 10b are attached in this manner has a structure capable of transmitting a vertical force and a shearing force, the workability of the steel pipe pile 1 to be embedded by screwing and after completion of the upper building. There is no problem in support function.
Further, since the bending moment generated in the lower blades 10a and 10b is not transmitted to the steel pipe 2, no bending stress is generated in the steel pipe 2.
【００４０】一方、上段翼２０ａ，２０ｂには、通常、
大きな曲げモーメントは作用しない。しかし、地中への
ねじ込み時に、大きな押し込み力を得るために上段翼２
０ａ，２０ｂの外径を、下段翼１０ａ，１０ｂのそれよ
り大きくすることがある。こように場合には、鋼管杭１
に上載建造物などによる鉛直荷重により、下段翼１０
ａ，１０ｂと同様に大きな曲げモーメントを受けること
がある。このような場合は、上段翼２０ａ，２０ｂを鋼
管２に前述の簡略な溶接手段により結合して、上段翼２
０ａ，２０ｂに一定以上の曲げモーメントが加えられる
と降伏（塑性化）するようにすれば、上段翼２０ａ，２
０ｂから鋼管２に伝達される曲げモーメントを抑えるこ
とができる。On the other hand, the upper wings 20a and 20b usually have
No large bending moment acts. However, when screwing into the ground, the upper wing 2
The outer diameter of 0a, 20b may be larger than that of the lower blades 10a, 10b. In this case, the steel pipe pile 1
Due to the vertical load from the building above the lower wing 10
As in the case of a and 10b, a large bending moment may be received. In such a case, the upper wings 20a and 20b are connected to the steel pipe 2 by the above-described simple welding means.
If a bending moment greater than a certain level is applied to the upper wings 20a, 20b, the upper wings 20a, 2b can be yielded.
0b to the steel pipe 2 can be suppressed.
【００４１】図１５は、鋼管杭１を地中にねじ込んで埋
設する際、下段翼１０ａ，１０ｂの端部が変形するのを
防止するため、下段翼１０ａ，１０ｂの回転方向側の端
部に、補強用鋼板１７を取付けたものである。また、図
１６は、鋼管杭１のねじ込み効率を向上するために、下
段翼１０ａ，１０ｂの回転方向側の端部に、下段翼１０
ａ，１０ｂの掘削を補助するための掘削刃１８を取付け
たものである。なお、これら補強用鋼板１７及び掘削刃
１８は、本発明に必須のものではない。FIG. 15 shows that when the steel pipe pile 1 is screwed and buried in the ground, the ends of the lower wings 10a and 10b are prevented from being deformed by rotating the lower wings 10a and 10b. And a reinforcing steel plate 17 attached thereto. FIG. 16 shows that the lower wings 10a, 10b are provided with lower wings 10a and 10b at their ends in the rotation direction in order to improve the screwing efficiency of the steel pipe pile 1.
Excavation blade 18 for assisting excavation of a and 10b is attached. The reinforcing steel plate 17 and the excavating blade 18 are not essential to the present invention.
【００４２】図１７は本発明に係る鋼管杭１を地中に埋
設する場合の施工試験の一例を示すもので、鋼管杭１を
構成する鋼管２の寸法は、外径：５００ｍｍ、肉厚：１
４ｍｍ、長さ：２１ｍであり、先端部に設けた取付部５
ａ，５ｂの傾斜面４ａ，４ｂの段部の高さｈを０．２５
Ｄとした。また、下段翼１０ａ，１０ｂは外径：１００
０ｍｍ、厚さ：４０ｍｍの円形鋼板を２分割し、上段翼
２０ａ，２０ｂは外径：１０００ｍｍ、厚さ２５ｍｍの
ドーナツ状の鋼板を２分割したものを用い、鋼管２の取
付部５ａ，５ｂへの結合は、いずれも低強度溶接手段に
よった。鋼管杭１の回転力は、ベースマシン３０に搭載
したオーガー３１により杭頭に伝達した。試験場所の地
盤は、地表から深さ１９ｍまでがＮ値５〜３０の砂とシ
ルトの互層、それ以深はＮ値６０以上の礫層で非常に硬
い地盤である。この施工試験の結果、鋼管杭１は短時間
でスムーズに所定の深さまで埋設することができた。FIG. 17 shows an example of a construction test when the steel pipe pile 1 according to the present invention is buried in the ground. The dimensions of the steel pipe 2 constituting the steel pipe pile 1 are: outer diameter: 500 mm, wall thickness: 1
4 mm, length: 21 m, mounting part 5 provided at the tip
The height h of the step portion of the inclined surfaces 4a, 4b of a, 5b is 0.25.
D. The outer diameter of the lower wings 10a, 10b is 100.
A circular steel plate having a thickness of 0 mm and a thickness of 40 mm is divided into two, and upper wings 20a and 20b are obtained by dividing a donut-shaped steel plate having an outer diameter of 1000 mm and a thickness of 25 mm into two parts. Were joined by low-strength welding means. The torque of the steel pipe pile 1 was transmitted to the pile head by the auger 31 mounted on the base machine 30. The ground at the test site is an alternate layer of sand and silt with an N value of 5 to 30 from the surface to a depth of 19 m, and a very hard ground with a gravel layer with an N value of 60 or more from the depth. As a result of this construction test, the steel pipe pile 1 was able to be buried to a predetermined depth smoothly in a short time.
【００４３】このように、本発明に係る鋼管杭は、鋼管
杭１に回転力を与えてねじ込みにより地中に埋設する
際、複数の下段翼１０ａ，１０ｂの鋼管２の外周面より
外側の部分及び上段翼２０ａ，２０ｂは、ねじの作用と
同様に周囲の地盤からの反力により、鋼管杭１を下方へ
推進させる機能を備えている。また、鋼管の内側の部分
は、従来技術に示された底板と異なり下段翼１０ａ，１
０ｂが互いに食い違って配置されているため、鋼管先端
部の下方の地盤を掘削する効果を有する。そして、下段
翼１０ａ，１０ｂは２個又は４個に分割されているた
め、１個の場合に比べて地盤に食い込む力が大きい。な
お、実施形態１〜４及び上述の説明では、下段翼１０
ａ，１０ｂを２個又は４個とした場合を示したが、円形
鋼板を３等分した扇形状の３個の鋼製板を用いてもよ
い。しかし、下段翼が５個以上になると、鋼管２に取付
けた各下段翼の傾斜が急になる。As described above, when the steel pipe pile according to the present invention is buried in the ground by applying a rotational force to the steel pipe pile 1 and screwing the same, portions of the plurality of lower wings 10a and 10b outside the outer peripheral surface of the steel pipe 2 are provided. The upper wings 20a and 20b have a function of propelling the steel pipe pile 1 downward by a reaction force from the surrounding ground similarly to the action of the screw. Further, unlike the bottom plate shown in the prior art, the inner part of the steel pipe has lower wings 10a, 1a.
0b are staggered from each other, which has the effect of excavating the ground below the steel pipe tip. Further, since the lower wings 10a and 10b are divided into two or four pieces, the force of digging into the ground is greater than that of one piece. In the first to fourth embodiments and the above description, the lower wing 10
Although the case where a or 10b is set to two or four is shown, three fan-shaped steel plates obtained by dividing a circular steel plate into three equal parts may be used. However, when the number of lower wings is five or more, the inclination of each lower wing attached to the steel pipe 2 becomes steep.
【００４４】以上の説明から明らかなように、本発明に
よれば、以下に記載する理由により、鋼管杭先端部の加
工費、したがって、鋼管杭の製造費を大幅に低減するこ
とができる。 （１）下段翼１０ａ，１０ｂは、鋼管杭１を推進させる
ためのねじとしての機能と、底板としての機能の両機能
を備えているので、従来のようにこれらを別々に設ける
必要がなく、このため、材料費及び取付費を低減するこ
とができる。 （２）鋼管先端部と下段翼１０ａ，１０ｂ及び上段翼２
０〜２０ｂとの結合は、隅肉溶接の如き部分溶接でも行
えるので、コストの大きな部分を占めていた溶接費用を
大幅に低減することができる。As is apparent from the above description, according to the present invention, the processing cost of the tip portion of the steel pipe pile, and therefore, the manufacturing cost of the steel pipe pile can be significantly reduced for the following reasons. (1) Since the lower wings 10a and 10b have both a function as a screw for propelling the steel pipe pile 1 and a function as a bottom plate, there is no need to separately provide them as in the related art. For this reason, material costs and mounting costs can be reduced. (2) Tip of steel pipe, lower blades 10a, 10b and upper blade 2
Joining with 0 to 20b can also be performed by partial welding such as fillet welding, so that the welding cost, which occupies a large part of the cost, can be greatly reduced.
【００４５】（３）レ字状の取付部５ａ，５ｂを直線状
に形成すれば、平坦面の下段翼１０ａ，１０ｂを用いる
ことができる。これは、下段翼１０ａ，１０ｂを複数に
分割したためで、下段翼の曲げ加工に要する費用が不要
になる。(3) If the V-shaped mounting portions 5a and 5b are formed in a straight line, the lower wings 10a and 10b of a flat surface can be used. This is because the lower wings 10a and 10b are divided into a plurality of parts, so that the cost required for bending the lower wings becomes unnecessary.
【００４６】また、以下の理由により、鋼管杭１を強固
な地層までねじ込むことができる。 （１）上段翼２０ａ，２０ｂにより鋼管杭１を下方に押
し込む力が強いために、下段翼１０ａ，１０ｂが硬い地
層に入ってもから回りを防止し、又は軽減する。 （２）下段翼１０ａ，１０ｂは、鋼管２の側方に食い込
むだけでなく、鋼管杭１の下方の地盤まで掘削して側方
に押出す作用を行う。 （３）下段翼１０ａ，１０ｂは複数個に分割されてお
り、鋼管杭１の下方の地盤に食い込む部分が分割数だけ
確保できるので、食い込み力が大きくなる。Further, for the following reason, the steel pipe pile 1 can be screwed into a solid stratum. (1) Since the force for pushing the steel pipe pile 1 downward by the upper wings 20a and 20b is strong, even if the lower wings 10a and 10b enter the hard stratum, the rotation is prevented or reduced. (2) The lower wings 10a and 10b not only cut into the side of the steel pipe 2 but also excavate to the ground below the steel pipe pile 1 and push it to the side. (3) The lower wings 10a and 10b are divided into a plurality of parts, and a portion that digs into the ground below the steel pipe pile 1 can be secured by the number of divisions, so that the digging force is increased.
【００４７】[0047]
【発明の効果】本発明に係るねじ込み式鋼管杭によれ
ば、次のような効果を得ることができる。 （１）先端部を円周方向に複数に分割し、この分割され
た個々の部分に同方向に向ってそれぞれレ字状の取付部
が形成された鋼管と、直径が鋼管の直径より大きい円形
鋼板又は楕円形鋼板を複数に分割したほぼ半円状又は扇
形状の下段翼と、ドーナツ状の鋼板を１か所又は複数か
所で切断して螺旋状に曲げ加工し、又はドーナツ状の鋼
板を複数個に分割した上段翼とを有し、下段翼を鋼管の
先端部のほぼ中心部からレ字状の取付部の下面に沿って
それぞれ取付けると共に、下段翼の上方において鋼管の
外周面に上段翼を取付けたので、以下のような効果が得
られる。According to the screw type steel pipe pile according to the present invention, the following effects can be obtained. (1) A steel pipe in which the tip is divided into a plurality of pieces in the circumferential direction, and each of the divided parts is provided with a letter-shaped mounting portion in the same direction, and a circle having a diameter larger than the diameter of the steel pipe. A substantially semicircular or fan-shaped lower wing obtained by dividing a steel plate or an elliptical steel plate into a plurality of pieces, and a donut-shaped steel sheet cut at one or more places and spirally bent, or a donut-shaped steel sheet The upper stage blade is divided into a plurality of parts, and the lower stage blade is attached along the lower surface of the R-shaped mounting portion from substantially the center of the tip of the steel pipe, and is attached to the outer peripheral surface of the steel pipe above the lower stage blade. Since the upper stage wing is attached, the following effects can be obtained.
【００４８】地盤への下段翼のねじ込み作用及び上段翼
の押し込み作用により、非常に硬い地盤でも下段翼がか
ら廻りすることなく貫入することができる。また、複数
に分割された下段翼は、鋼管杭先端部の地盤に食い込む
部分が複数のため、非常に硬い地盤にも適用することが
できる。また、下段翼に作用する曲げモーメントは互い
に打消されて、鋼管には両者の差の小さい曲げモーメン
トが伝達されるだけなので、鋼管に過大な曲げ応力が発
生することはない。Due to the screwing action of the lower wing and the pushing action of the upper wing into the ground, the lower wing can penetrate the very hard ground without turning around. Further, since the lower wing divided into a plurality of portions has a plurality of portions that bite into the ground at the tip of the steel pipe pile, the lower wing can be applied to very hard ground. Further, since the bending moments acting on the lower stage blades are canceled each other and only the bending moment having a small difference between the two is transmitted to the steel pipe, excessive bending stress is not generated in the steel pipe.
【００４９】下段翼は硬い支持層に貫入されて広い面積
で地盤反力を受け、これに上段翼の支持機能が付加され
るため、大きな鉛直支持力を得ることができる。また、
下段翼は底板の機能を備えているため別に底板を設ける
必要がないこと、下段翼は半円状又は扇形状の鋼板を用
いているため曲げ加工が不要であることなどから、鋼管
杭の製造費を低減することができる。The lower wing penetrates into the hard support layer and receives a ground reaction force in a wide area, and the support function of the upper wing is added thereto, so that a large vertical support force can be obtained. Also,
Manufacture of steel pipe piles because the lower wing has the function of a bottom plate, so there is no need to provide a separate bottom plate.Because the lower wing uses a semicircular or fan-shaped steel plate, it does not require bending. Costs can be reduced.
【００５０】（２）上記（１）の隣接する下段翼と鋼管
との間に形成された開口部を閉塞部材で閉塞したので、
鋼管杭のねじ込みに際して土砂が鋼管内に侵入すること
がなく、無排土で地中に埋設することができる。また、
鋼管杭の先端部下方にある地盤は下段翼で掘削され、鋼
管杭の側方に押し出され圧縮されて密度の高い土砂にな
るため、鋼管杭の周面摩擦による地盤支持力を大きくす
ることができる。(2) Since the opening formed between the lower blade and the steel pipe adjacent to each other in (1) above is closed by the closing member,
When the steel pipe pile is screwed in, earth and sand do not enter the steel pipe, and can be buried underground without soil removal. Also,
The ground below the tip of the steel pipe pile is excavated by the lower wing, extruded to the side of the steel pipe pile and compressed into dense soil, so it is necessary to increase the ground bearing capacity due to the friction of the peripheral surface of the steel pipe pile. it can.
【００５１】（３）上記（１）又は（２）の鋼管の先端
部に設けたレ字状の取付部に、低強度溶接手段若しくは
ヒンジ手段によって下段翼を取付け、又上段翼を低強度
溶接手段により鋼管外周面に取付けるようにしたので、
下段翼及び上段翼から鋼管に伝達される曲げモーメント
を抑制することができ、これにより、鋼管に過大な曲げ
応力が発生するのを防止することができる。このため、
大径（例えば６００ｍｍ）の鋼管からなるねじ込み式鋼
管杭にも本発明を実施することができる。(3) The lower wing is attached to the R-shaped attachment portion provided at the tip of the steel pipe of (1) or (2) by low-strength welding means or hinge means, and the upper wing is welded by low-strength welding. Since it was attached to the outer surface of the steel pipe by means,
The bending moment transmitted from the lower wing and the upper wing to the steel pipe can be suppressed, thereby preventing generation of excessive bending stress in the steel pipe. For this reason,
The present invention can be applied to a screw-in type steel pipe pile formed of a steel pipe having a large diameter (for example, 600 mm).
【００５２】（４）上記（１），（２）又は（３）の下
段翼を平坦面又は螺旋面に形成したので、鋼管への接合
が容易である。(4) Since the lower stage wing of (1), (2) or (3) is formed on a flat surface or a spiral surface, it can be easily joined to a steel pipe.
【図１】本発明の実施形態１の斜視図である。FIG. 1 is a perspective view of Embodiment 1 of the present invention.
【図２】図１のＡ−Ａ断面図である。FIG. 2 is a sectional view taken along line AA of FIG.
【図３】図１の鋼管の先端部を示す斜視図である。FIG. 3 is a perspective view showing a tip portion of the steel pipe of FIG. 1;
【図４】図１の下段翼の説明図である。FIG. 4 is an explanatory diagram of a lower wing of FIG. 1;
【図５】図１の上段翼の説明図である。FIG. 5 is an explanatory diagram of an upper stage wing in FIG. 1;
【図６】本発明の実施形態２の斜視図である。FIG. 6 is a perspective view of Embodiment 2 of the present invention.
【図７】本発明の実施形態３の説明図である。FIG. 7 is an explanatory diagram of Embodiment 3 of the present invention.
【図８】図７のＢ−Ｂ断面図である。FIG. 8 is a sectional view taken along the line BB of FIG. 7;
【図９】図７の鋼管の先端部を示す斜視図である。FIG. 9 is a perspective view showing a tip portion of the steel pipe of FIG. 7;
【図１０】本発明の実施形態４の斜視図である。FIG. 10 is a perspective view of Embodiment 4 of the present invention.
【図１１】鋼製板に加わる地盤反力の説明図である。FIG. 11 is an explanatory diagram of a ground reaction force applied to a steel plate.
【図１２】鋼製板の鋼管への結合例を示す説明図であ
る。FIG. 12 is an explanatory view showing an example of joining a steel plate to a steel pipe.
【図１３】溶接材料などの鋼材の性質を示す線図であ
る。FIG. 13 is a diagram showing properties of a steel material such as a welding material.
【図１４】鋼製板の鋼管への他の結合例を示す説明図で
ある。FIG. 14 is an explanatory view showing another example of joining a steel plate to a steel pipe.
【図１５】鋼製板に補強用鋼板を取付けた状態を示す斜
視図である。FIG. 15 is a perspective view showing a state in which a reinforcing steel plate is attached to a steel plate.
【図１６】鋼製板に掘削刃を取付けた状態を示す斜視図
である。FIG. 16 is a perspective view showing a state in which a digging blade is attached to a steel plate.
【図１７】本発明に係るねじ込み式鋼管杭の施工例を示
す説明図である。FIG. 17 is an explanatory view showing a construction example of a screw-in type steel pipe pile according to the present invention.
【図１８】従来の螺旋翼の鋼管への結合状態を示す説明
図である。FIG. 18 is an explanatory view showing a state in which a conventional spiral blade is connected to a steel pipe.
１ 鋼管杭 ２ 鋼管 ５ａ，５ｂ 取付部 １０ａ〜１０ｄ 下段翼 １１ 開口部 １２ 閉塞部材 １３ 低強度溶接（隅肉溶接） １４ ヒンジ手段 ２０，２０ａ，２０ｂ 上段翼 DESCRIPTION OF SYMBOLS 1 Steel pipe pile 2 Steel pipe 5a, 5b Attachment part 10a-10d Lower wing 11 Opening 12 Closure member 13 Low strength welding (fillet welding) 14 Hinge means 20, 20a, 20b Upper wing
───────────────────────────────────────────────────── フロントページの続き (72)発明者 林 正宏 東京都千代田区丸の内一丁目１番２号 日本鋼管株式会社内 (56)参考文献 特開 平８−326053（ＪＰ，Ａ) 特開 平７−292666（ＪＰ，Ａ) 特開 昭61−98818（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) E02D 5/56 E02D 5/28 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masahiro Hayashi 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (56) References JP-A-8-326053 (JP, A) JP-A-7 -292666 (JP, A) JP-A-61-98818 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) E02D 5/56 E02D 5/28
Claims (5)
分割された個々の部分に同方向に向ってそれぞれレ字状
の取付部が形成された鋼管と、 直径が前記鋼管の直径より大きい円形鋼板又は楕円形鋼
板を複数に分割したほぼ半円状又は扇形状の下段翼と、 ドーナツ状の鋼板を１か所若しくは複数か所で切断して
螺旋状に曲げ加工し、又はドーナツ状の鋼板を複数個に
分割した上段翼とを有し、 前記下段翼を前記鋼管先端部のほぼ中心部から前記レ字
状の取付部の下面に沿ってそれぞれ取付けると共に、該
下段翼の上方において前記鋼管の外周面に前記上段翼を
取付けたことを特徴とするねじ込み式鋼管杭。1. A steel pipe having a distal end portion divided into a plurality of pieces in the circumferential direction, and each of the divided portions having a letter-shaped mounting portion formed in the same direction, and having a diameter of the steel pipe. A substantially semicircular or fan-shaped lower wing obtained by dividing a larger circular or elliptical steel plate into a plurality of pieces, and a donut-shaped steel sheet cut at one or more places and spirally bent, or a donut An upper stage wing obtained by dividing a steel plate into a plurality of pieces, wherein the lower stage wing is attached along a lower surface of the R-shaped attachment portion from a substantially central portion of the tip end of the steel pipe, and is mounted above the lower stage wing. 3. The screw-in type steel pipe pile according to claim 1, wherein the upper wing is attached to an outer peripheral surface of the steel pipe.
た開口部を閉塞部材で閉塞したことを特徴とする請求項
１記載のねじ込み式鋼管杭。2. The screw-in type steel pipe pile according to claim 1, wherein an opening formed between the adjacent lower wing and the steel pipe is closed by a closing member.
に、低強度溶接手段又はヒンジ手段により下段翼を取付
けたことを特徴とする請求項１又は２記載のねじ込み式
鋼管杭。3. The screw-in type steel pipe pile according to claim 1, wherein the lower wing is attached to the R-shaped attachment portion provided at the tip of the steel pipe by low-strength welding means or hinge means.
段翼を取付けたことを特徴とする請求項１，２又は３記
載のねじ込み式鋼管杭。4. The screw-in type steel pipe pile according to claim 1, wherein an upper wing is attached to an outer peripheral surface of the steel pipe by low-strength welding means.
１，２，３又は４記載のねじ込み式鋼管杭。5. The screw-in type steel pipe pile according to claim 1, wherein the lower wing is a flat surface or a spiral surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8143895A JP3031245B2 (en) | 1996-06-06 | 1996-06-06 | Screw-in type steel pipe pile |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8143895A JP3031245B2 (en) | 1996-06-06 | 1996-06-06 | Screw-in type steel pipe pile |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09324425A JPH09324425A (en) | 1997-12-16 |
| JP3031245B2 true JP3031245B2 (en) | 2000-04-10 |
Family
ID=15349555
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8143895A Expired - Lifetime JP3031245B2 (en) | 1996-06-06 | 1996-06-06 | Screw-in type steel pipe pile |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3031245B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7910622B2 (en) | 2007-03-19 | 2011-03-22 | Wisconsin Alumni Research Foundation | Modulation of bacterial quorum sensing with synthetic ligands |
| US8269024B2 (en) | 2005-02-04 | 2012-09-18 | Wisconsin Alumni Research Foundation | Compounds and methods for modulating communication and virulence in quorum sensing bacteria |
| US8624063B2 (en) | 2009-06-30 | 2014-01-07 | Wisconsin Alumni Research Foundation | Non-lactone carbocyclic and heterocyclic antagonists and agonists of bacterial quorum sensing |
-
1996
- 1996-06-06 JP JP8143895A patent/JP3031245B2/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8269024B2 (en) | 2005-02-04 | 2012-09-18 | Wisconsin Alumni Research Foundation | Compounds and methods for modulating communication and virulence in quorum sensing bacteria |
| US7910622B2 (en) | 2007-03-19 | 2011-03-22 | Wisconsin Alumni Research Foundation | Modulation of bacterial quorum sensing with synthetic ligands |
| US8815943B2 (en) | 2007-03-19 | 2014-08-26 | Wisconsin Alumni Research Foundation | Modulation of bacterial quorum sensing with synthetic ligands |
| US9796694B2 (en) | 2007-03-19 | 2017-10-24 | Wisconsin Alumni Research Foundation | Modulation of bacterial quorum sensing with synthetic ligands |
| US8624063B2 (en) | 2009-06-30 | 2014-01-07 | Wisconsin Alumni Research Foundation | Non-lactone carbocyclic and heterocyclic antagonists and agonists of bacterial quorum sensing |
| US9758472B2 (en) | 2009-06-30 | 2017-09-12 | Wisconsin Alumni Research Foundation | Non-lactone carbocyclic and heterocyclic antagonists and agonists of bacterial quorum sensing |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09324425A (en) | 1997-12-16 |
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