JP2000220139A - Steel pipe pile for inner digging - Google Patents
Steel pipe pile for inner diggingInfo
- Publication number
- JP2000220139A JP2000220139A JP11026083A JP2608399A JP2000220139A JP 2000220139 A JP2000220139 A JP 2000220139A JP 11026083 A JP11026083 A JP 11026083A JP 2608399 A JP2608399 A JP 2608399A JP 2000220139 A JP2000220139 A JP 2000220139A
- Authority
- JP
- Japan
- Prior art keywords
- steel pipe
- pipe pile
- pile
- protrusion
- tip
- 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.)
- Withdrawn
Links
Landscapes
- Piles And Underground Anchors (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、橋梁基礎杭、建築
基礎杭などの基礎杭に使用される中掘り工法用鋼管杭に
関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe pile for a middle digging method used for a foundation pile such as a bridge foundation pile and a building foundation pile.
【０００２】[0002]
【従来の技術】一般に、低公害工法の一つとして知られ
ている「中掘り工法」は、まず、図５（ａ）〜（ｄ）に
示すように、無限軌道式ベースマシン２２におけるリー
ダ２３に沿って配置される鋼管杭１内に鋼管杭１の内径
より小さな直径を有するオーガースクリュー２を配置
し、オーガー駆動装置３によりオーガースクリュー２を
回転させ鋼管杭１の先端の地盤４をゆるめながら油圧押
し込み装置により鋼管杭１を圧入し、次に図６（ａ）〜
（ｄ）に示すように、支持層５に到達したところでセメ
ントミルクをオーガースクリュー２の先端より杭先端の
地盤（支持層５）に注入し、ジェットあるいは機械撹拌
によりソイルセメント６を現場造成して先端根固めを行
う工法である。橋梁あるいは建築物等の上部構造物の荷
重は、鋼管杭１〜ずれ止め１０〜鋼管杭内ソイルセメン
ト６〜拡大球根部７〜支持地盤（支持層５）の順に円滑
に荷重が伝達されるよう、図４（ｂ）に示すように、ソ
イルセメント６は、ずれ止め部を含む鋼管８内にも造成
される。2. Description of the Related Art In general, as shown in FIGS. 5A to 5D, a "medium digging method", which is known as one of the low-pollution methods, first uses a leader 23 in an endless track type base machine 22. As shown in FIG. The auger screw 2 having a diameter smaller than the inner diameter of the steel pipe pile 1 is arranged in the steel pipe pile 1 arranged along the slab, and the auger screw 2 is rotated by the auger driving device 3 to loosen the ground 4 at the tip of the steel pipe pile 1. The steel pipe pile 1 is press-fitted by the hydraulic press-in device, and then FIG.
As shown in (d), when the soil reaches the support layer 5, the cement milk is injected from the tip of the auger screw 2 into the ground at the tip of the pile (support layer 5), and soil cement 6 is formed on site by jet or mechanical stirring. This is a method of solidifying the tip. The load of the upper structure such as a bridge or a building is smoothly transmitted in the order of the steel pipe pile 1, the stopper 10, the soil cement 6 in the steel pipe pile, the enlarged bulb 7, and the support ground (support layer 5). As shown in FIG. 4B, the soil cement 6 is also formed in the steel pipe 8 including the slip prevention portion.
【０００３】「中掘り工法」に適用される鋼管杭１の先
端部には、図４（ａ）に示す、フリクションカッターと
呼ばれる金具９とずれ止めと呼ばれる金具１０が、工場
などで施工前に事前に溶接により取り付けられる。フリ
クションカッター９は、杭先端部の鋼管杭１の外面に、
帯状の鋼板を巻き付け隅肉溶接などにより固定される金
具である。鋼管杭１の外表面より９〜２２ｍｍ程度突出
させているので、鋼管杭１の貫入時に鋼管杭１とその外
周面の土とに一時的に間隙が生じ、そのため鋼管杭１と
地盤４との摩擦力を低減させ、所定の圧入力で鋼管杭１
を貫入できるように設ける中掘り工法用鋼管杭に必須の
金具である。また、ずれ止め１０は、鋼管杭１の先端部
の内面に、平鋼あるいは丸鋼などの鋼材１１を鋼管８の
内周面に沿って円周状に配置すると共に上下方向に間隔
をおいて数段配置して、各鋼材１１を隅肉溶接あるいは
フレアー溶接などにより固定される金具である。ずれ止
め１０は、施工後、鋼管杭１が構造物の鉛直荷重を受け
た際、鋼管杭１の先端部より鋼管杭１内のソイルセメン
ト６、拡大球根部７を経由して支持地盤（支持層５）に
荷重が円滑に伝達できるよう設ける金具であり、鋼管杭
１内のソイルセメント６と拡大球根部７とにより先端根
固め１５を行う中掘り工法用鋼管杭にとって必須の金物
である。[0003] A metal fitting 9 called a friction cutter and a metal fitting 10 called a slip stopper shown in FIG. Installed by welding in advance. The friction cutter 9 is provided on the outer surface of the steel pipe pile 1 at the tip of the pile.
A metal fitting that is wound around a belt-shaped steel plate and fixed by fillet welding or the like. Since the steel pipe pile 1 protrudes by about 9 to 22 mm from the outer surface thereof, a temporary gap is formed between the steel pipe pile 1 and the soil on the outer peripheral surface thereof when the steel pipe pile 1 penetrates. Reduce the frictional force, and steel pipe pile 1
It is an indispensable metal fitting for the steel pipe pile for the inside digging method, which is provided so that it can penetrate. Further, the slip stopper 10 arranges a steel material 11 such as a flat steel or a round steel on the inner surface of the tip portion of the steel pipe pile 1 along the inner peripheral surface of the steel pipe 8 and is spaced apart in the vertical direction. It is a metal fitting in which several steels 11 are arranged and fixed by fillet welding or flare welding. When the steel pipe pile 1 receives the vertical load of the structure after construction, the slip stopper 10 is supported from the tip of the steel pipe pile 1 via the soil cement 6 in the steel pipe pile 1 and the expanded bulb part 7 to the supporting ground (supported ground). It is a metal fitting provided so that the load can be smoothly transmitted to the layer 5), and is an essential metal for the steel pipe pile for the middle digging method in which the tip cementing 15 is performed by the soil cement 6 and the expanded bulb part 7 in the steel pipe pile 1.
【０００４】[0004]
【発明が解決しようとする課題】前記従来のフリクショ
ンカッター９は施工時の摩擦力低減機能、またずれ止め
１０は完成時の鋼管杭から鋼管杭内ソイルセメント６を
経由した支持地盤（支持層５）への荷重伝達機能と、フ
リクションカッター９およびずれ止め１０それぞれが、
単一機能しか果たしておらず、中掘り工法は、常に２種
類の取り付け金具を必要とする。また、フリクションカ
ッター９およびずれ止め１０は、中掘り工法特有の金具
であり、一般の打撃工法で施工する杭には不要なこと、
また前記金具９，１０の仕様は、設計条件、地盤条件な
どにより１本１本異なることから、加工工程の自動化が
図りにくい。例えばフリクションカッター９において
は、地盤の硬軟によりその板厚が変わり、鋼管杭１の直
径に応じてその帯状の鋼板の長さが異なる。またずれ止
め１０においては、鋼管杭１の設計支持力および鋼管杭
１の直径に応じて鋼管杭１内に取り付けられる必要段数
が決められる。そのため、フリクションカッター９およ
びずれ止め１０の取り付け加工費が、非常に割高になっ
ている。フリクションカッター９およびずれ止め１０の
加工費は、たとえば２０〜３０ｍの杭では、鋼管杭１の
材料費の約１０〜１５％を占めており、中堀り工法で施
工する鋼管杭１の工事費を割高にしている原因の一つと
なっている。この発明は、前記従来のフリクションカッ
ター９およびずれ止め１０の機能を果たしながら、しか
も簡単な構造で低コストで製作することができる中掘り
工法用の鋼管杭を提供することを目的とするものであ
る。The conventional friction cutter 9 has a function of reducing frictional force at the time of construction, and the slip stopper 10 has a support ground (support layer 5) from a steel pipe pile at the time of completion via soil cement 6 in the steel pipe pile. ), The friction cutter 9 and the slip stopper 10
It only performs a single function and the digging method always requires two types of mounting hardware. In addition, the friction cutter 9 and the slip stopper 10 are metal fittings peculiar to the inside digging method, and are unnecessary for a pile constructed by a general impact method,
In addition, since the specifications of the metal fittings 9 and 10 differ one by one depending on design conditions, ground conditions, and the like, it is difficult to automate a processing step. For example, the thickness of the friction cutter 9 varies depending on the hardness of the ground, and the length of the strip-shaped steel plate varies depending on the diameter of the steel pipe pile 1. In the slip stopper 10, the required number of steps to be mounted in the steel pipe pile 1 is determined according to the design support force of the steel pipe pile 1 and the diameter of the steel pipe pile 1. For this reason, the cost of mounting the friction cutter 9 and the slip stopper 10 is extremely high. The processing cost of the friction cutter 9 and the slip stopper 10 occupies about 10 to 15% of the material cost of the steel pipe pile 1 for a pile of 20 to 30 m, for example. This is one of the reasons why it is expensive. An object of the present invention is to provide a steel pipe pile for a middle digging method that can be manufactured at a low cost with a simple structure while performing the functions of the conventional friction cutter 9 and the slip stopper 10. is there.
【０００５】[0005]
【課題を解決するための手段】前記の目的を達成するた
めに、請求項１の発明の中掘り工法用鋼管杭において
は、支持層に貫入させる鋼管杭先端部に、鋼管杭中心よ
り鋼管外周面方向に凸で、鋼管杭同一円周上で概ね同一
高さで突起させた突起部１２を、１段以上鋼管杭打設前
に設けたことを特徴とする。In order to achieve the above-mentioned object, in the steel pipe pile for the middle digging method according to the first aspect of the present invention, the outer periphery of the steel pipe pile is provided at the tip of the steel pipe pile penetrating the support layer from the center of the steel pipe pile. It is characterized in that one or more protruding portions 12 which are convex in the surface direction and protrude at substantially the same height on the same circumference of the steel pipe pile are provided before the steel pipe pile is cast.
【０００６】また請求項２の中掘り工法用鋼管杭におい
ては、鋼管杭外周面を基準にした突起高さＨが２２ｍｍ
以下である突起部１２を持つことを特徴とする。Further, in the steel pipe pile for the middle digging method according to claim 2, the projection height H based on the outer peripheral surface of the steel pipe pile is 22 mm.
It is characterized by having the following projections 12.
【０００７】また請求項３の中掘り工法用鋼管杭におい
ては、鋼管杭先端部を拡径変形して突起部１２が形成さ
れていることを特徴とする。According to a third aspect of the present invention, there is provided a steel pipe pile for a middle digging method, wherein a protrusion 12 is formed by expanding and deforming the tip of the steel pipe pile.
【０００８】[0008]
【作用】鋼管杭先端部に、鋼管杭中心より鋼管外面方向
に凸で、鋼管杭円周方向に概ね同一高さで突起させた突
起部１２を、１段以上設けているので、鋼管外周面より
突出した突起部は、（１）施工時においては、突起部１
２より上の鋼管外面と周面地盤との間に一時的に間隙を
生じさせるので、従来のフリクションカッター９と同じ
摩擦力低減の役割を果たし、（２）完成時においては、
鋼管杭１に軸力が作用した場合、突起部１２の内側の凸
状空間部１３に充填されたソイルセメント部が突出部１
４となり鋼管杭１の突起部１２から突出部１４を介して
これと一体の鋼管内ソイルセメント６に円滑に荷重を伝
達するずれ止めの役割を同時に果たすことができる。[Function] At the tip of the steel pipe pile, there is provided one or more projections 12 projecting from the center of the steel pipe pile toward the outer surface of the steel pipe and projecting at substantially the same height in the circumferential direction of the steel pipe pile. The more protruding protrusions are: (1) At the time of construction, the protrusions 1
Since a gap is temporarily generated between the outer surface of the steel pipe above 2 and the peripheral ground, the same role of reducing the frictional force as that of the conventional friction cutter 9 is achieved. (2) At the time of completion,
When an axial force is applied to the steel pipe pile 1, the soil cement portion filled in the convex space 13 inside the projection 12 becomes the projection 1.
4 and can simultaneously serve as a slip stopper for transmitting a load smoothly from the protrusion 12 of the steel pipe pile 1 to the soil cement 6 in the steel pipe via the protrusion 14 via the protrusion 14.
【０００９】鋼管杭外周面を基準に突起部１２の突起高
さＨをほぼ２２ｍｍ以下にすることにより、施工中は従
来のフリクションカッター９と同じ役割を発揮させ、同
時に施工後周辺地盤が鋼管杭１との間隙を埋めて周面摩
擦力が回復するので、完成時の杭としての周面摩擦力を
極端に低減させることなく、杭の支持力を発揮させるこ
とができる。By making the projection height H of the projection 12 approximately 22 mm or less based on the outer peripheral surface of the steel pipe pile, the same role as the conventional friction cutter 9 is exerted during the construction, and at the same time, the peripheral ground after the construction is formed. Since the peripheral frictional force is recovered by filling the gap with the pile 1, the pile supporting force can be exhibited without extremely reducing the peripheral frictional force as a pile at the time of completion.
【００１０】また、突出部１４によるずれ止めの機能
は、突起部１２の内側の凸状空間部１３に充満（充填）
されたソイルセメント部が突出部１４となり鋼管杭の突
起部１２からソイルセメント根固め部１５に円滑に荷重
を伝達することにより発揮するが、突起部１２の内側の
凸状空間部１３に充満されたソイルセメント部が閉鎖し
た円形断面の鋼管杭により周方向に強く拘束されている
ため、通常の拘束を受けないソイルセメントより大きな
支圧耐力、せん断耐力を発揮することができる。Further, the function of preventing the slippage by the protruding portion 14 is to fill (fill) the convex space portion 13 inside the protruding portion 12.
The soil cement portion thus formed becomes a protrusion 14 and is exerted by smoothly transmitting a load from the protrusion 12 of the steel pipe pile to the soil cement rooting portion 15, but is filled in the convex space 13 inside the protrusion 12. Since the soil cement portion is strongly restrained in the circumferential direction by the closed steel pipe pile having a closed circular section, it is possible to exhibit greater bearing capacity and shear strength than soil cement which is not normally restrained.
【００１１】なお、鋼管杭外周面を基準に突起部１２の
突起高さＨをほぼ９ｍｍ以上にすることが望ましい。突
起部１２の突起高さＨがほぼ９ｍｍ以上であれば、フリ
クションカッター９と同じ役割を発揮させることがで
き、また効果的な突出部１４を形成するための凸状空間
部１３を形成することができる。It is desirable that the projection height H of the projection 12 be approximately 9 mm or more based on the outer peripheral surface of the steel pipe pile. If the projection height H of the projection 12 is about 9 mm or more, the same role as the friction cutter 9 can be exhibited, and the convex space 13 for forming the effective projection 14 is formed. Can be.
【００１２】[0012]
【発明の実施の形態】次にこの発明の一実施形態を図を
参照しながら説明する。図１はこの発明を実施した一実
施形態を示すものであって、例えば一例として、直径８
００ｍｍ、板厚９ｍｍの鋼管杭１を示している。鋼管杭
１における支持層５に貫入させる先端部を上下方向に間
隔を置いて拡径変形して拡管し、鋼管杭外面からの突起
高さＨが２２ｍｍを目標量として、円周方向に概ね同一
高さで拡径変形して突出させて、左右両側部分の縦断面
が円弧状で、横断面が円環状に膨出した突起部１２を形
成し、その突起部１２の上下方向の突出幅Ｌを３００ｍ
ｍ、上下方向に隣り合う突起部１２の中心間隔Ｄを５０
０ｍｍ、鋼管杭１の先端部に上下方向に間隔を置いて突
起部１２を鋼管杭１の先端部に３段形成した実施形態で
ある。Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment embodying the present invention.
1 shows a steel pipe pile 1 having a thickness of 00 mm and a thickness of 9 mm. The distal end portion of the steel pipe pile 1 penetrating into the support layer 5 is expanded and deformed at an interval in the vertical direction to expand the pipe, and the projection height H from the outer surface of the steel pipe pile is set to 22 mm as a target amount and is substantially the same in the circumferential direction. The projection 12 is expanded and deformed at the height to form a projection 12 whose left and right portions have an arcuate vertical section and an annular cross section that bulges in an annular shape, and a projection width L of the projection 12 in the vertical direction. 300m
m, the center distance D between the vertically adjacent projections 12 is 50
In this embodiment, three protrusions 12 are formed at the tip of the steel pipe pile 1 at a distance of 0 mm from the tip of the steel pipe pile 1 in the vertical direction.
【００１３】鋼管杭１は、施工前に工場、中継地あるい
は施工場所付近のヤードで鋼管杭１の先端部（下端部）
を拡径変形して拡管する。鋼管杭１の拡管は、図３に示
すような、油圧発生装置（図示を省略した）により供給
される圧油により油圧ホース１７を介して作動する油圧
シリンダー１８ａ〜１８ｆから進退移動するロッド１９
ａ〜１９ｆの先端部に形成された拡径ブロック２０ａ〜
２０ｆを固定した油圧式等の拡径（拡管）装置１６によ
り行い、油圧発生装置（図示を省略した）により油圧ホ
ース１７を介して全ての油圧シリンダー１８ａ〜１８ｆ
内に圧油を供給して、各ロッド１９ａ〜１９ｆが鋼管杭
内面に向かって移動するように同時に作動させて、各ロ
ッド１９ａ〜１９ｆに取り付けられた全ての拡径ブロッ
ク２０ａ〜２０ｆを押し出し、鋼管杭の内部から強力な
押圧力（拡径力）を作用させ、実施する。挿入用支持杆
体２１により支持された拡管装置１６を鋼管杭１の開口
部先端から離れた所定の位置に挿入し、必要量拡径変形
して拡管し、間隔をおいてまた次の位置に移動させて拡
管し、これらの作業を必要回数繰り返し、所定の拡管作
業を終了させ、中掘り用鋼管杭を製作する。拡径により
形成する突起部１２の形状は、拡径ブロック２０ａ〜２
０ｆの外面形状に依存するので、円弧状あるいは半円状
等の適切な形状を選択することが必要である。Before the construction, the steel pipe pile 1 is placed at the tip (lower end) of the steel pipe pile 1 in a factory, a junction, or a yard near the construction place.
Is expanded and expanded. The expansion of the steel pipe pile 1 is performed by a rod 19 which moves forward and backward from hydraulic cylinders 18a to 18f operated via hydraulic hoses 17 by hydraulic oil supplied by a hydraulic generator (not shown) as shown in FIG.
a to 19f, the enlarged diameter blocks 20a to
All the hydraulic cylinders 18a to 18f are controlled by a hydraulic pressure generating device (not shown) through a hydraulic hose 17 using a hydraulic type expanding (tube expanding) device 16 such as a hydraulic type in which 20f is fixed.
The pressure oil is supplied to the inside, and each rod 19a to 19f is simultaneously operated so as to move toward the inner surface of the steel pipe pile, thereby extruding all the enlarged blocks 20a to 20f attached to each rod 19a to 19f, A strong pressing force (diameter expansion force) is applied from inside the steel pipe pile to carry out. The pipe expanding device 16 supported by the insertion support rod 21 is inserted into a predetermined position away from the opening end of the steel pipe pile 1, expanded by a necessary amount to expand the diameter, and moved to the next position at an interval. Then, these operations are repeated as many times as necessary, and the predetermined tube expansion operation is completed to manufacture a steel pipe pile for digging. The shape of the projecting portion 12 formed by the diameter expansion is the same as the diameter expansion blocks 20a to 20
Since it depends on the outer surface shape of 0f, it is necessary to select an appropriate shape such as an arc shape or a semicircle shape.
【００１４】図２は、前記実施形態の鋼管杭１を使用し
て、支持層５に中掘り工法により施工した後の実施形態
である。鋼管杭１の下端部が支持層５に貫入された後、
鋼管杭１の先端部は、セメントミルクを噴出させる前に
１５０ｋｇ／ｃｍ2 程度の高圧ジェット水で鋼管杭１の
内面を予備洗浄し、鋼管杭１の内面に付着した土砂を取
り除く。その後、オーガースクリュー２の先端をオーガ
ースクリュー２を駆動装置３により回転させながら鋼管
杭１の先端より先行して下げ、下端まで到達した後、セ
メントミルクを高圧ジェットにより噴射しながらオーガ
ースクリュー２を引き上げソイルセメント６を造成し、
拡大球根部７を形成させる。また突起部１２を含む鋼管
杭１内も引き続きオーガースクリュー２を引き上げなが
らソイルセメント６を造成する。３段目の突起部１２に
ソイルセメント６が充満（充填）した後、ソイルセメン
ト６の造成作業を終了し、オーガースクリュー２を引き
上げる。なお、この実施形態においては、支持層５に貫
入させる鋼管杭１の上端部に、現場溶接により直列に上
側の鋼管杭１Ａを一体に連結し、所要長の鋼管杭２４が
形成されている。FIG. 2 shows an embodiment after the steel pipe pile 1 of the above embodiment has been used and constructed on the support layer 5 by the middle digging method. After the lower end of the steel pipe pile 1 is penetrated into the support layer 5,
The inner surface of the steel pipe pile 1 is preliminarily washed with high-pressure jet water of about 150 kg / cm 2 before the cement milk is spouted to remove sediment attached to the inner surface of the steel pipe pile 1. Thereafter, the tip of the auger screw 2 is lowered ahead of the tip of the steel pipe pile 1 while rotating the auger screw 2 by the drive unit 3 and reaches the lower end. After reaching the lower end, the auger screw 2 is pulled up while injecting cement milk by a high-pressure jet. Create soil cement 6,
An enlarged bulb 7 is formed. The soil cement 6 is formed while the auger screw 2 is continuously pulled up in the steel pipe pile 1 including the protruding portion 12. After the soil cement 6 is filled (filled) in the third-stage protrusions 12, the creation of the soil cement 6 is completed, and the auger screw 2 is pulled up. In this embodiment, a steel pipe pile 24 having a required length is formed by integrally connecting an upper steel pipe pile 1A in series with an upper end portion of the steel pipe pile 1 penetrating into the support layer 5 by field welding.
【００１５】図４に示すような従来公知の直径１３ｍｍ
の鉄筋を溶接したずれ止め１０を使用した鋼管杭１の鋼
管杭内コンクリートの押しぬき試験によれば、上下方向
に隣り合うずれ止め１０を２５０ｍｍ以上離間しておれ
ば、一般にせん断破壊ではなく支圧破壊をすることが知
られており、この発明の実施形態のような突起部１２の
突起高さ２２ｍｍ、突起幅３００ｍｍの突起では、支圧
破壊による十分大きなずれ止め効果が期待できる。A conventionally known diameter of 13 mm as shown in FIG.
According to the push-out test of concrete in the steel pipe pile of the steel pipe pile 1 using the slip stopper 10 to which the reinforcing steel is welded, if the slip stoppers 10 adjacent to each other in the vertical direction are separated by 250 mm or more, it is generally not a shear failure but a support. It is known to cause pressure rupture, and a protrusion having a protrusion height of 22 mm and a protrusion width of 300 mm as in the embodiment of the present invention can be expected to have a sufficiently large effect of preventing displacement due to supporting pressure breakage.
【００１６】また、突起部１２の突起幅Ｌは、鋼管杭１
の局部座屈による急激な変形、荷重低下をさけるため、
鋼管杭１の局部座屈波長Ｓより大きくとる必要がある。
本実施形態では、「中低層鉄骨建物の耐震設計法（１９
７８、技報堂出版）」で紹介されている下記の式（１）
で算定される鋼管杭１の局部座屈波長Ｓである２１７ｍ
ｍより大きくとり、３００ｍｍとしたので、局部座屈に
よる急激な荷重低下が生じない。また突起部１２を設け
た中掘り用鋼管杭１の施工時の軸耐力は、降伏荷重の２
／３程度であり、本実施形態では、材質がＳＫＫ４００
材の場合には、３５００ＫＮ以上期待できるので、一般
の中掘り工法の圧入時軸荷重の約１０００ＫＮより十分
大きな耐力を持っており、施工時に局部座屈が発生する
ことがなく鋼管杭１の貫入が可能となる。 式（１） Ｓ＝２．５６（Ｄ・ｔ）0.5 The protrusion width L of the protrusion 12 is set to
To prevent sudden deformation and load reduction due to local buckling of
It is necessary to make the wavelength larger than the local buckling wavelength S of the steel pipe pile 1.
In the present embodiment, the seismic design method (19)
78, Gihodo Publishing)]
217m which is the local buckling wavelength S of the steel pipe pile 1 calculated by
Since it is larger than m and 300 mm, there is no sudden load drop due to local buckling. Also, the axial strength at the time of construction of the steel pipe pile for digging 1 provided with the projections 12 is 2% of the yield load.
/ 3, and in this embodiment, the material is SKK400
In the case of the material, since it can be expected to be 3500 KN or more, it has a proof strength sufficiently larger than the axial load of about 1000 KN at the time of press-fitting of the general middle digging method, and there is no local buckling during construction and the penetration of the steel pipe pile 1 Becomes possible. Equation (1) S = 2.56 (D · t) 0.5
【００１７】前記突起部１２の突起高さＨ、突起幅Ｌ、
突起間隔Ｄは、１実施形態であり、中掘り施工のソイル
セメント６の管理可能な一軸圧縮強度、完成時の鋼管杭
１の設計軸耐力により、これらの突起高さＨ、突起幅
Ｌ、突起間隔Ｄを適宜決定すればよい。また、拡管装置
１６も、前記実施形態のように拡径ブロック２０ａ〜２
０ｆを直接油圧力で押す方式に代えて、くさび状のコア
を油圧により引き込み、底部に前記コアと同じ角度のテ
ーパーを付けた拡径ブロックを押し広げる公知のくさび
式（図示を省略した）、なども使用するようにしてもよ
く、拡管（拡径）作業の効率性を高めるため、拡管装置
１６に自走機能を組み込み、挿入・引き抜き作業を自走
式あるいは遠隔制御等により簡略化するようにしてもよ
い。The protrusion height H, the protrusion width L of the protrusion 12,
The protrusion interval D is one embodiment, and is based on the manageable uniaxial compressive strength of the soil cement 6 for the middle digging work, the design axial strength of the steel pipe pile 1 at the time of completion, and the protrusion height H, the protrusion width L, and the protrusion. The interval D may be determined appropriately. In addition, as in the above-described embodiment, the pipe expanding device 16 is also provided with the diameter expanding blocks 20a to 20a.
A known wedge type (not shown) in which a wedge-shaped core is pulled in by hydraulic pressure and a widened block having a tapered bottom at the same angle as the core is spread out instead of directly pressing 0f by oil pressure. In order to enhance the efficiency of the pipe expansion (diameter expansion) work, a self-propelled function is incorporated in the pipe expansion device 16 so that the insertion / withdrawal work can be simplified by a self-propelled or remote control. It may be.
【００１８】前記実施形態においては、突起部１２を鋼
管杭１の前端部（下端部）に上下方向に間隔をおいて３
段拡径形成しているが、突起部１２を１段形成するよう
にしてもよく、あるいは２段以上の複数段設けるように
してもよく、また支持層５に貫入させる突起部１２の段
数も１段または２段以上であってもよい。In the above embodiment, the protrusion 12 is formed at the front end (lower end) of the steel pipe pile 1 at an interval in the vertical direction.
Although the step diameter is formed, the protrusions 12 may be formed in one step, or two or more steps may be provided, and the number of steps of the protrusions 12 penetrating into the support layer 5 may also be increased. One or two or more stages may be used.
【００１９】[0019]
【発明の効果】本発明によれば、下記のような効果を奏
することができる。 （１）本発明の中掘り用鋼管杭は、鋼管先端部に、拡管
装置により鋼管外面方向に凸で鋼管円周方向に概ね同一
高さで突起させた突起部１２を、１段以上設けているの
で、鋼管外周面より突出した突起部１２は、施工時にお
いては、突起部１２より上の鋼管杭外面と周面地盤４と
の間に一時的に間隙を生じさせる、従来のフリクション
カッター９と同じ摩擦力低減の役割を果たし、完成時に
おいては、鋼管杭１に軸力が作用した場合、突起部１２
の内側の凸状空間部１３に充満（充填）されたソイルセ
メント部が突出部（突起物）１４となり鋼管杭１の突起
部１２からソイルセメント根固め部７に円滑に荷重を伝
達するずれ止めの役割を同時に果たすので、これまで中
掘り工法で必須であったフリクションカッター９と、ず
れ止め１０を設けるための複雑な加工作業を大幅に簡素
化できる。 （２）本発明の中掘り工法用鋼管杭の突起部１２の加工
は、油圧式の拡管装置１６のみで行なうことができるの
で、所要の突起高さＨの突起部１２を適宜の段数設ける
ことにより、従来のフリクションカッター９の厚さの変
化への対応、ずれ止め１０の段数の変化への対応が容易
にできる。 （３）従来の中掘り工法用鋼管杭１では、加工の自動化
が図りにくいため、製管工程とは別の場所に鋼管杭１を
一端移動させオフライン作業により溶接加工を実施して
いたが、本発明の鋼管杭の加工は、油圧式の拡管装置の
みで行なうことができるので、製管工場の鋼管仮置き場
など製作工程の端末で簡単に加工作業が実施できる。 （４）上記の理由により、本発明の中掘り工法用鋼管杭
の場合は、従来の杭先端部のフリクションカッターおよ
びずれ止め作用を、それぞれ突起部１２の外側および突
起部１２の内側を利用することができるので、その突起
部１２の加工費用を、従来のフリクションカッター９お
よびずれ止め１０を設ける場合に比べて、概ね１／４以
下に低減することができる。According to the present invention, the following effects can be obtained. (1) The steel pipe pile for middle digging of the present invention is provided with one or more projections 12 at the tip of the steel pipe, the projections 12 being convex in the outer surface direction of the steel pipe and projecting at substantially the same height in the circumferential direction of the steel pipe by a pipe expanding device. Therefore, at the time of construction, the projection 12 protruding from the outer peripheral surface of the steel pipe temporarily forms a gap between the outer surface of the steel pipe pile above the projection 12 and the peripheral ground 4. When the steel pipe pile 1 is completed, when the axial force acts, the protrusion 12
The soil cement portion filled (filled) in the convex space portion 13 inside the protrusion becomes a projection (projection) 14 and a slip stopper for smoothly transmitting a load from the projection 12 of the steel pipe pile 1 to the soil cement rooting portion 7. At the same time, it is possible to greatly simplify complicated machining operations for providing the friction cutter 9 and the slip stopper 10 which have been indispensable in the middle digging method. (2) Since the processing of the projecting portion 12 of the steel pipe pile for the middle digging method of the present invention can be performed only by the hydraulic expansion device 16, the projecting portion 12 having the required projecting height H is provided in an appropriate number of steps. Accordingly, it is possible to easily cope with a change in the thickness of the conventional friction cutter 9 and a change in the number of stages of the slip stopper 10. (3) In the conventional steel pipe pile 1 for the middle digging method, since it is difficult to automate the processing, the steel pipe pile 1 is once moved to a place different from the pipe making process, and the welding process is performed by off-line work. Since the processing of the steel pipe pile of the present invention can be performed only by a hydraulic pipe expansion device, the processing operation can be easily performed at a terminal of a manufacturing process such as a temporary storage site of a steel pipe in a pipe factory. (4) For the above reason, in the case of the steel pipe pile for the inside digging method according to the present invention, the friction cutter and the slip preventing action of the conventional pile tip utilize the outside of the projection 12 and the inside of the projection 12 respectively. Therefore, the processing cost of the projection 12 can be reduced to approximately １ ／ or less as compared with the case where the conventional friction cutter 9 and the slip stopper 10 are provided.
【図１】本発明の一実施形態の中掘り工法用鋼管杭を示
す一部縦断正面図である。FIG. 1 is a partially longitudinal front view showing a steel pipe pile for a middle digging method according to an embodiment of the present invention.
【図２】図１に示す鋼管杭１を使用して、支持層に中掘
り工法により施工した後の状態を示す一部縦断正面図で
ある。FIG. 2 is a partially longitudinal front view showing a state after the steel pipe pile 1 shown in FIG. 1 is constructed on a support layer by a middle digging method.
【図３】拡径（拡管）装置を使用して、鋼管杭先端部に
突起部を形成する直前の状態を示すものであって、
（ａ）は一部縦断正面図であり、（ｂ）はそのＡ−Ａ線
断面図である。FIG. 3 shows a state immediately before forming a projection at the tip of a steel pipe pile by using a diameter expansion (expansion) device,
(A) is a partial longitudinal front view, and (b) is a cross-sectional view along the line AA.
【図４】（ａ）は従来の鋼管杭の先端部を示す一部縦断
正面図であり、（ｂ）は鋼管杭の下端部を支持地盤（支
持層）に貫入させると共に、拡大球根部および鋼管杭内
ソイルセメントを築造した状態を示す縦断正面図であ
る。FIG. 4 (a) is a partially longitudinal front view showing the tip of a conventional steel pipe pile, and FIG. 4 (b) shows the lower end of the steel pipe pile penetrating into a supporting ground (support layer), and the enlarged bulb part and It is a vertical front view which shows the state which built the soil cement in a steel pipe pile.
【図５】中掘り工法の施工工程順を示す概略説明図であ
る。FIG. 5 is a schematic explanatory view showing the order of construction steps of the middle digging method.
【図６】中掘り工法の施工工程順を示す概略説明図であ
る。FIG. 6 is a schematic explanatory view showing the order of construction steps of the middle digging method.
１ 鋼管杭 ２ オーガースクリュー ３ オーガー駆動装置 ４ 地盤 ５ 支持層 ６ ソイルセメント ７ 拡大球根部 ８ 鋼管 ９ フリクションカッター １０ ずれ止め １１ 鋼材 １２ 突起部 １３ 凸状空間部 １４ 突出部 １５ ソイルセメント根固め部 １６ 拡管（拡径）装置 １７ 油圧ホース １８ａ 油圧シリンダ １８ｂ 油圧シリンダ １８ｃ 油圧シリンダ １８ｄ 油圧シリンダ １８ｅ 油圧シリンダ １８ｆ 油圧シリンダ １９ａ ロッド １９ｂ ロッド １９ｃ ロッド １９ｄ ロッド １９ｅ ロッド １９ｆ ロッド ２０ａ 拡径ブロック ２０ｂ 拡径ブロック ２０ｃ 拡径ブロック ２０ｄ 拡径ブロック ２０ｅ 拡径ブロック ２０ｆ 拡径ブロック ２１ 挿入用支持杆体 ２２ 無限軌道式ベースマシン ２３ リーダー（縦型ガイド装置） ２４ 鋼管杭 REFERENCE SIGNS LIST 1 steel pipe pile 2 auger screw 3 auger driving device 4 ground 5 support layer 6 soil cement 7 enlarged bulb 8 steel pipe 9 friction cutter 10 stopper 11 steel material 12 protrusion 13 convex space part 14 protrusion 15 soil cement fixing part 16 Pipe expansion (diameter expansion) device 17 Hydraulic hose 18a Hydraulic cylinder 18b Hydraulic cylinder 18c Hydraulic cylinder 18d Hydraulic cylinder 18e Hydraulic cylinder 18f Hydraulic cylinder 19a Rod 19b Rod 19c Rod 19d Rod 19e Rod 19f Rod 20a Diameter enlarged block 20c Diameter enlarged block 20c Block 20d Large diameter block 20e Large diameter block 20f Large diameter block 21 Supporting rod for insertion 22 Endless track base machine 23 Leader (vertical guide device) 24 Steel pipe pile
───────────────────────────────────────────────────── フロントページの続き (72)発明者 木下 雅敬 千葉県富津市新富20−１ 新日本製鐵株式 会社技術開発本部内 Ｆターム(参考） 2D041 AA03 BA12 BA25 CA03 DA13 DB02 DB14 EC02 FA03 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masataka Kinoshita 20-1 Shintomi, Futtsu-shi, Chiba F-term in the Technology Development Division, Nippon Steel Corporation 2D041 AA03 BA12 BA25 CA03 DA13 DB02 DB14 EC02 FA03
Claims (3)
管杭中心より鋼管外周面方向に凸で、鋼管杭同一円周上
で概ね同一高さで突起させた突起部を、１段以上鋼管杭
打設前に設けた中掘り工法用鋼管杭。At least one step at the tip of a steel pipe pile penetrating into a support layer, the protrusion being convex from the center of the steel pipe pile toward the outer peripheral surface of the steel pipe and projecting at substantially the same height on the same circumference as the steel pipe pile. Steel pipe pile for medium digging method installed before steel pipe pile driving.
２ｍｍ以下である突起部を持つ請求項１に記載の中掘り
工法用鋼管杭。2. The projection height based on the outer peripheral surface of the steel pipe pile is 2
The steel pipe pile for middle digging method according to claim 1, wherein the pile has a protrusion that is 2 mm or less.
成されている請求項１または２のいずれかに記載の中掘
り工法用鋼管杭。3. The steel pipe pile for a middle digging method according to claim 1, wherein the protrusion is formed by expanding and deforming the tip of the steel pipe pile.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11026083A JP2000220139A (en) | 1999-02-03 | 1999-02-03 | Steel pipe pile for inner digging |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11026083A JP2000220139A (en) | 1999-02-03 | 1999-02-03 | Steel pipe pile for inner digging |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000220139A true JP2000220139A (en) | 2000-08-08 |
Family
ID=12183739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11026083A Withdrawn JP2000220139A (en) | 1999-02-03 | 1999-02-03 | Steel pipe pile for inner digging |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000220139A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015045872A1 (en) * | 2013-09-25 | 2015-04-02 | 新日鐵住金株式会社 | Composite structure |
| JP2018172962A (en) * | 2017-03-31 | 2018-11-08 | Ｊｆｅスチール株式会社 | Method for reinforcing existing steel pipe pile foundation, method for constructing steel pipe pile, and steel pipe pile |
| JP2020026708A (en) * | 2018-08-17 | 2020-02-20 | 株式会社横山基礎工事 | Steel pipe for inner excavation pile construction method |
| JP2021116661A (en) * | 2020-01-29 | 2021-08-10 | 日本製鉄株式会社 | Method of manufacturing steel pipe pile with protrusion on inner surface, construction method for steel pipe pile, and steel pipe pile with protrusion on inner surface |
| JP2021116655A (en) * | 2020-01-29 | 2021-08-10 | 日本製鉄株式会社 | Method of manufacturing steel pipe pile with protrusion on inner surface, construction method for steel pipe pile, and steel pipe pile with protrusion on inner surface |
| CN114277831A (en) * | 2022-01-11 | 2022-04-05 | 中国电建集团福建省电力勘测设计院有限公司 | Offshore pawl type concrete filled steel tube pile foundation, adaptive drill bit and foundation construction method |
-
1999
- 1999-02-03 JP JP11026083A patent/JP2000220139A/en not_active Withdrawn
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015045872A1 (en) * | 2013-09-25 | 2015-04-02 | 新日鐵住金株式会社 | Composite structure |
| AU2014325437B2 (en) * | 2013-09-25 | 2016-10-13 | Nippon Steel Corporation | Composite structure |
| JPWO2015045872A1 (en) * | 2013-09-25 | 2017-03-09 | 新日鐵住金株式会社 | Composite structure |
| JP2018172962A (en) * | 2017-03-31 | 2018-11-08 | Ｊｆｅスチール株式会社 | Method for reinforcing existing steel pipe pile foundation, method for constructing steel pipe pile, and steel pipe pile |
| JP2020026708A (en) * | 2018-08-17 | 2020-02-20 | 株式会社横山基礎工事 | Steel pipe for inner excavation pile construction method |
| JP2021116661A (en) * | 2020-01-29 | 2021-08-10 | 日本製鉄株式会社 | Method of manufacturing steel pipe pile with protrusion on inner surface, construction method for steel pipe pile, and steel pipe pile with protrusion on inner surface |
| JP2021116655A (en) * | 2020-01-29 | 2021-08-10 | 日本製鉄株式会社 | Method of manufacturing steel pipe pile with protrusion on inner surface, construction method for steel pipe pile, and steel pipe pile with protrusion on inner surface |
| JP7288199B2 (en) | 2020-01-29 | 2023-06-07 | 日本製鉄株式会社 | METHOD FOR MANUFACTURING STEEL PIPE PILE WITH INTERNAL PROJECTS, CONSTRUCTION METHOD OF STEEL PIPE PILE, AND STEEL PIPE PILE WITH INNER PROJECTIONS |
| JP7295436B2 (en) | 2020-01-29 | 2023-06-21 | 日本製鉄株式会社 | METHOD FOR MANUFACTURING STEEL PIPE PILE WITH INTERNAL PROJECTS, CONSTRUCTION METHOD OF STEEL PIPE PILE, AND STEEL PIPE PILE WITH INNER PROJECTIONS |
| CN114277831A (en) * | 2022-01-11 | 2022-04-05 | 中国电建集团福建省电力勘测设计院有限公司 | Offshore pawl type concrete filled steel tube pile foundation, adaptive drill bit and foundation construction method |
| CN114277831B (en) * | 2022-01-11 | 2023-09-22 | 中国电建集团福建省电力勘测设计院有限公司 | Offshore pawl type steel pipe concrete pile foundation, adaptive drill bit and foundation construction method |
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| Date | Code | Title | Description |
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| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20060404 |