JP2010048019A

JP2010048019A - Erection bar

Info

Publication number: JP2010048019A
Application number: JP2008214236A
Authority: JP
Inventors: Yasuhiro Saito; 安宏斉藤
Original assignee: Kiso Koji Kk Saitogumi
Current assignee: Kiso Koji Kk Saitogumi
Priority date: 2008-08-22
Filing date: 2008-08-22
Publication date: 2010-03-04
Anticipated expiration: 2028-08-22
Also published as: JP5237726B2

Abstract

PROBLEM TO BE SOLVED: To provide an erection bar allowing two upper and lower stages of enlarged diameter part bars and shear-reinforcing bars to be easily arranged at the enlarged diameter part of a bottom part of a pile hole. SOLUTION: The erection bar 1 is constituted by mounting the upper stage side enlarged diameter part bar 31 and lower stage side enlarged diameter part bar 32 turnably to a narrow diameter part bar 2, mounting the shear-reinforcing bars 33 turnably between the upper stage side enlarged diameter part bar 31 and the lower stage side enlarged diameter part bar 32, and connecting a sliding member 4 to an anchor part 31a of the upper stage side enlarged diameter part bar 31 through connecting members 5. When the erection bar 1 is lifted, the upper stage side enlarged diameter part bar 31 and the lower stage side enlarged diameter part bar 32 are turned upward by the load of the sliding member 4. When the erection bar 1 is arranged in the pipe hole H, the upper stage side enlarged diameter part bar 31 and the lower stage side enlarged diameter part bar 32 are horizontally arranged at an enlarged diameter part Hb of the pipe hole H, and the shear-reinforcing bars 33 are arranged at predetermined spaces between the upper stage side enlarged diameter part bar 31 and the lower stage side enlarged diameter part bar 32. COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、先端部が拡径された杭の構築に適した組立鉄筋に関する。 The present invention relates to an assembling reinforcing bar suitable for construction of a pile whose tip is expanded in diameter.

先端部が拡径された場所打ち杭の構築に用いる組立鉄筋（「鉄筋籠」ともいう。）として、本出願人は、例えば特許文献１に、円筒状の狭径部鉄筋に、拡径部に配置する拡径部鉄筋を回動自在に取り付け、この拡径部鉄筋の定着部側に連結部材を介してスライド部材を取り付けたものを開示している。 As an assembly reinforcing bar (also referred to as a “rebar bar”) used for construction of a cast-in-place pile whose tip is expanded in diameter, the present applicant, for example, in Patent Document 1, in a cylindrical narrow-diameter part reinforcing bar, An enlarged-diameter portion reinforcing bar disposed in a rotating manner is rotatably attached, and a slide member is attached to a fixing portion side of the enlarged-diameter portion reinforcing bar via a connecting member.

特許文献１に記載の組立鉄筋は、クレーンなどで組立鉄筋を吊り下げた状態では、スライド部材は、狭径部鉄筋の下端よりも突出しており、拡径部鉄筋は、スライド部材の重量によって先端側が上方に回動した状態となっている。そして、スライド部材が杭穴の底面に当接すると、狭径部鉄筋の定着部側を下方に引っ張っていた力が弛み、拡径部鉄筋の先端側が下方に回動して、狭径部鉄筋の設置が完了した状態で、拡径部鉄筋が略水平に配置されるようになっている。
特開２００６−２５７８５６号公報（図１４） In the assembly rebar described in Patent Document 1, in a state where the assembly rebar is suspended by a crane or the like, the slide member protrudes from the lower end of the narrow-diameter portion rebar, and the enlarged-diameter rebar is at the tip due to the weight of the slide member. The side is turned upward. Then, when the slide member comes into contact with the bottom surface of the pile hole, the force pulling the fixing portion side of the narrow-diameter portion rebar is loosened, and the distal end side of the large-diameter portion rebar is rotated downward, and the narrow-diameter portion rebar In the state where the installation of is completed, the expanded-diameter rebars are arranged substantially horizontally.
JP 2006-257856 A (FIG. 14)

ところで、杭の頭部に作用する荷重と杭の底面に作用する地盤反力とを考慮すると、杭の拡径部は、杭から張り出した片持ち梁のように機能し、杭の拡径部の下端側に引張力が作用する。そのため、杭の拡径部の下端側に鉄筋を配筋する必要がある。
また、杭の拡径部と狭径部の境界付近には、大きなせん断力が作用する。そのため、杭の拡径部に上下２段に鉄筋を配筋し、両者の間にせん断補強筋を配筋する必要がある。
しかしながら、特許文献１に記載の組立鉄筋では、杭穴の拡径部に上下２段に拡径部鉄筋を配置すること、及び、せん断補強筋を配筋することができなかった。 By the way, considering the load acting on the head of the pile and the ground reaction force acting on the bottom surface of the pile, the enlarged portion of the pile functions like a cantilever beam protruding from the pile, and the enlarged portion of the pile Tensile force acts on the lower end side. Therefore, it is necessary to arrange reinforcing bars on the lower end side of the enlarged diameter portion of the pile.
In addition, a large shearing force acts near the boundary between the enlarged diameter portion and the narrow diameter portion of the pile. Therefore, it is necessary to arrange reinforcing bars in upper and lower two stages in the enlarged diameter portion of the pile, and arrange shear reinforcing bars between them.
However, in the assembled reinforcing bar described in Patent Document 1, it has been impossible to arrange the enlarged-diameter reinforcing bars in the upper and lower two stages in the enlarged diameter part of the pile hole and to arrange the shear reinforcing bars.

本発明はかかる問題を解決するためになされたものであり、杭穴の底部の拡径された部分に上下２段の拡径部鉄筋とせん断補強筋を容易に配筋することができる組立鉄筋を提供することを課題とする。 SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an assembled reinforcing bar capable of easily arranging the upper and lower two-stage expanded portion reinforcing bars and the shear reinforcing bars in the expanded portion of the bottom of the pile hole. It is an issue to provide.

本発明は、底部が拡径された杭穴に配置される組立鉄筋であって、前記杭穴の狭径部に配置される狭径部鉄筋と、前記狭径部鉄筋の下端から上方に離間した位置に回動可能に連結された複数の上段側拡径部鉄筋と、前記上段側拡径部鉄筋よりも、前記狭径部鉄筋の下端に近い位置に回動可能に連結された複数の下段側拡径部鉄筋と、一端側が前記上段側拡径部鉄筋に回動可能に連結され、他端側が前記下段側拡径部鉄筋に回動可能に連結された複数のせん断補強筋と、前記組立鉄筋が杭穴の底面に接触する前の状態において、前記狭径部鉄筋の下端から突出するように配置され、前記狭径部鉄筋に対して上下方向にスライド可能に構成されたスライド部材と、一端側が前記上段側拡径部鉄筋及び前記下段側拡径部鉄筋の少なくともいずれか一方に回動可能に連結され、他端側が前記スライド部材に回動可能に連結された連結部材と、を備え、前記上段側拡径部鉄筋及び前記下段側拡径部鉄筋は、前記狭径部鉄筋との連結位置よりも前記杭穴の中心寄りに位置する定着部をそれぞれ有し、前記スライド部材は、前記連結部材を介して前記上段側拡径部鉄筋及び前記下段側拡径部鉄筋の少なくともいずれか一方の前記定着部に連結され、前記上段側拡径部鉄筋及び前記下段側拡径部鉄筋は、前記狭径部鉄筋の前記杭穴への設置が完了した状態において、前記杭穴の拡径部に略水平に配置されることを特徴とする。 The present invention relates to an assembly reinforcing bar arranged in a pile hole whose bottom is enlarged in diameter, and is spaced upward from a narrow diameter part reinforcing bar arranged in a narrow diameter part of the pile hole and a lower end of the narrow diameter part reinforcing bar. A plurality of upper-stage enlarged-diameter rebars that are rotatably connected to the position, and a plurality of upper-stage enlarged-diameter rebars that are rotatably connected to positions closer to the lower end of the narrow-diameter part reinforcing bars A plurality of shear reinforcement bars, one end side of which is pivotally connected to the upper stage side enlarged section reinforcing bar and the other end side of which is pivotally connected to the lower stage side enlarged section reinforcing bar; A slide member that is arranged so as to protrude from the lower end of the narrow-diameter part reinforcing bar and is slidable in the vertical direction with respect to the narrow-diameter part reinforcing bar before the assembly reinforcing bar contacts the bottom surface of the pile hole. And one end side is at least one of the upper-stage enlarged-diameter reinforcing bar and the lower-stage enlarged-diameter reinforcing bar A connecting member rotatably connected to the slide member and having the other end side rotatably connected to the slide member, and the upper-stage enlarged-diameter rebar and the lower-stage enlarged-diameter rebar are the narrow-diameter part. Each of the fixing members is located closer to the center of the pile hole than the position of connection with the reinforcing bar, and the slide member includes the upper-stage enlarged-diameter part reinforcing bar and the lower-stage enlarged-diameter part reinforcing bar via the connecting member. The pile hole is connected to at least one of the fixing portions, and the upper-stage enlarged-diameter reinforcing bar and the lower-stage enlarged-diameter reinforcing bar are installed in the pile hole of the narrow-diameter part reinforcing bar. It is characterized by being disposed substantially horizontally in the enlarged diameter portion.

かかる構成によれば、例えば、スライド部材が上段側拡径部鉄筋の定着部に連結部材を介して連結されている場合、クレーンなどで組立鉄筋を吊り下げている状態では、スライド部材によって定着部が下向きに引っ張られ、上段側拡径部鉄筋の先端側が上向きに回動した状態になる。また、下段側拡径部鉄筋は、せん断補強筋を介して上段側拡径部鉄筋に引っ張られて上向きに回動した状態になる。これにより、組立鉄筋の径方向の寸法が小さくなり、杭穴の狭径部を通過することが可能となる。 According to such a configuration, for example, when the slide member is connected to the fixing portion of the upper-stage enlarged-diameter rebar through the connecting member, the fixing member is fixed by the slide member in a state where the assembly rebar is suspended by a crane or the like. Is pulled downward and the tip side of the upper-stage enlarged-diameter portion reinforcing bar is turned upward. Further, the lower-stage enlarged-diameter portion reinforcing bar is pulled by the upper-stage enlarged-diameter portion reinforcing bar via the shear reinforcement bar and is turned upward. Thereby, the dimension of the radial direction of an assembly reinforcing bar becomes small, and it becomes possible to pass the narrow diameter part of a pile hole.

そして、スライド部材が杭穴の底面に当接した後、さらに狭径部鉄筋が降下すると、上段側拡径部鉄筋を上向きに回動させていた力が弛み、上段側拡径部鉄筋が下向きに回動する。また、これに伴い、上段側拡径部鉄筋にせん断補強筋を介して連結された下段側拡径部鉄筋も下向きに回動する。そして、狭径部鉄筋の杭穴への配置が完了した状態において、上段側拡径部鉄筋及び下段側拡径部鉄筋は、杭穴の拡径部に略水平に配置されるとともに、上段側拡径部鉄筋と下段側拡径部鉄筋の間にせん断補強筋が配筋されることとなる。 Then, after the slide member comes into contact with the bottom surface of the pile hole, when the narrow-diameter rebar further descends, the force that has caused the upper-stage enlarged-diameter rebar to rotate upwards loosens, and the upper-stage enlarged-diameter rebar faces downward To turn. Accordingly, the lower-stage enlarged-diameter reinforcing bar connected to the upper-stage enlarged-diameter reinforcing bar via the shear reinforcing bar also rotates downward. Then, in the state where the arrangement of the narrow-diameter part reinforcing bars in the pile holes is completed, the upper-stage enlarged-diameter part reinforcing bars and the lower-stage enlarged-diameter part reinforcing bars are arranged substantially horizontally on the enlarged-diameter part of the pile hole, and the upper stage side A shear reinforcement bar is arranged between the enlarged diameter part reinforcing bar and the lower-stage enlarged diameter part reinforcing bar.

また、前記せん断補強筋は、枠状に形成されており、前記上段側拡径部鉄筋及び前記下段側拡径部鉄筋は、前記せん断補強筋の内側に配置されているのが好ましい。 Moreover, it is preferable that the said shear reinforcement is formed in frame shape, and the said upper stage side enlarged diameter part reinforcement and the said lower stage side enlarged diameter part reinforcement are arrange | positioned inside the said shear reinforcement.

かかる構成によれば、せん断補強筋が枠状に形成されているので、せん断強度を効果的に向上させることができる。
なお、一つのせん断補強筋の内側に、複数の上段側拡径部鉄筋と、複数の下段側拡径部鉄筋が配筋されるのが好ましい。 According to this configuration, since the shear reinforcement is formed in a frame shape, the shear strength can be effectively improved.
In addition, it is preferable that a plurality of upper-stage enlarged-diameter reinforcing bars and a plurality of lower-stage enlarged-diameter reinforcing bars are arranged inside one shear reinforcement.

また、前記狭径部鉄筋は、大径部と、大径部の下方に連続して形成され、当該大径部よりも径の小さい小径部と、を備え、前記上段側拡径部鉄筋及び前記下段側拡径部鉄筋は、前記小径部に回動可能に連結されているのが好ましい。 The narrow-diameter portion reinforcing bar includes a large-diameter portion and a small-diameter portion formed continuously below the large-diameter portion and having a smaller diameter than the large-diameter portion, It is preferable that the lower-stage enlarged-diameter portion reinforcing bar is rotatably connected to the small-diameter portion.

かかる構成によれば、上段側拡径部鉄筋及び下段側拡径部鉄筋は、狭径部鉄筋のうち、大径部よりも径の小さい小径部に回動可能に連結されているので、吊り下げた状態における組立鉄筋の径方向の寸法を一層小さくすることができる。そのため、杭穴の掘削量を削減することができる。 According to such a configuration, the upper-stage enlarged-diameter reinforcing bar and the lower-stage enlarged-diameter reinforcing bar are pivotally connected to the small-diameter part having a smaller diameter than the large-diameter part among the narrow-diameter part reinforcing bars. The dimension in the radial direction of the assembled reinforcing bar in the lowered state can be further reduced. Therefore, the amount of excavation of the pile hole can be reduced.

本発明によれば、杭穴の底部の拡径された部分に上下２段の拡径部鉄筋とせん断補強筋を容易に配筋可能な組立鉄筋を提供することができる。
その結果、底部拡径杭の先端支持力を確実に増大させることが可能となり、また、底部拡径杭の信頼性を向上させることができる。 ADVANTAGE OF THE INVENTION According to this invention, the assembly reinforcing bar which can arrange | position a diameter expansion part reinforcing bar and a shear reinforcement bar of two steps of upper and lower sides easily to the part by which the diameter of the bottom part of the pile hole was expanded can be provided.
As a result, it is possible to reliably increase the tip supporting force of the bottom enlarged-diameter pile and improve the reliability of the bottom enlarged pile.

＜第１実施形態＞
本発明の第１実施形態について図面を参照して詳細に説明する。説明において、同一の要素には同一の番号を付し、重複する説明は省略する。 <First Embodiment>
A first embodiment of the present invention will be described in detail with reference to the drawings. In the description, the same elements are denoted by the same reference numerals, and redundant description is omitted.

［組立鉄筋１の構造］
はじめに、組立鉄筋１の構造について説明する。
図１は、第１実施形態に係る組立鉄筋を示した側面図である。図２は、図１に示すＩ−Ｉ矢視平面図である。図３は、拡径部鉄筋の一部を拡大して示した斜視図である。 [Structure of assembled rebar 1]
First, the structure of the assembled reinforcing bar 1 will be described.
FIG. 1 is a side view showing an assembled reinforcing bar according to the first embodiment. FIG. 2 is a plan view taken along arrows I-I shown in FIG. FIG. 3 is an enlarged perspective view showing a part of the enlarged diameter portion reinforcing bar.

組立鉄筋１は、図１に示すように、杭穴Ｈの内部に配置される鉄筋であり、杭穴Ｈの径（幅）の狭い部分である狭径部Ｈａに主に配置される狭径部鉄筋２と、杭穴Ｈの径が拡径された部分である拡径部Ｈｂに配置される拡径部鉄筋３と、狭径部鉄筋２の内部に配置されるスライド部材４と、拡径部鉄筋３とスライド部材４とを連結する連結部材５と、から構成されている。
ここで、杭穴Ｈは、例えば、一定の直径で地盤を掘削して狭径部Ｈａを構築した後、専用の掘削装置（拡径装置）を用いて、その底部付近を拡径させることによって拡径部Ｈｂを構築することにより形成されている。なお、拡径部Ｈｂの上部には、テーパ部Ｈｅが形成されている。 As shown in FIG. 1, the assembly reinforcing bar 1 is a reinforcing bar arranged inside the pile hole H, and a narrow diameter mainly arranged in a narrow diameter part Ha that is a narrow part of the diameter (width) of the pile hole H. The rebar 2, the enlarged portion rebar 3 arranged in the enlarged portion Hb which is the portion where the diameter of the pile hole H is enlarged, the slide member 4 arranged inside the narrow portion rebar 2, and the expansion It is comprised from the connection member 5 which connects the diameter part reinforcement 3 and the slide member 4. As shown in FIG.
Here, the pile hole H is formed by, for example, excavating the ground with a constant diameter to construct the narrow-diameter portion Ha and then expanding the vicinity of the bottom using a dedicated excavating device (diameter expanding device). It is formed by constructing the enlarged diameter portion Hb. In addition, the taper part He is formed in the upper part of the enlarged diameter part Hb.

狭径部鉄筋２は、図１に示すように、複数の棒状の主筋２１，２１…と、複数のリング状のフープ筋２２，２２…とを組み合わせて全体として筒状に形成された鉄筋である。主筋２１，２１…は、その軸方向を杭の軸方向と平行にした状態で、杭の中心軸回りに環状に配筋されている。また、複数のフープ筋２２，２２…は、杭の軸方向に互いに離間された状態で、環状に配筋された主筋２１，２１…の外周に嵌め合わされている。狭径部鉄筋２は、主に、杭穴Ｈの狭径部Ｈａに配置されるとともに、その下端部２ａは、拡径部Ｈｂを通って杭穴Ｈの底面Ｈｃに達している。 As shown in FIG. 1, the narrow-diameter rebar 2 is a rebar formed in a tubular shape as a whole by combining a plurality of rod-shaped main bars 21, 21... And a plurality of ring-shaped hoop bars 22, 22. is there. The main bars 21, 21... Are arranged in an annular shape around the center axis of the pile in a state where the axial direction thereof is parallel to the axial direction of the pile. Further, the plurality of hoop bars 22, 22... Are fitted on the outer circumferences of the main bars 21, 21,. The narrow-diameter rebar 2 is mainly disposed in the narrow-diameter portion Ha of the pile hole H, and the lower end portion 2a reaches the bottom surface Hc of the pile hole H through the enlarged-diameter portion Hb.

拡径部鉄筋３は、図１に示すように、組立鉄筋１を杭穴Ｈに設置したときに、拡径部Ｈｂに配筋される鉄筋である。拡径部鉄筋３は、複数の上段側拡径部鉄筋３１と、複数の下段側拡径部鉄筋３２と、複数のせん断補強筋３３と、から構成されている。 As shown in FIG. 1, the enlarged-diameter reinforcing bar 3 is a reinforcing bar arranged in the enlarged-diameter part Hb when the assembled reinforcing bar 1 is installed in the pile hole H. The enlarged-diameter reinforcing bar 3 includes a plurality of upper-stage enlarged-diameter reinforcing bars 31, a plurality of lower-stage enlarged-diameter reinforcing bars 32, and a plurality of shear reinforcing bars 33.

上段側拡径部鉄筋３１は、図１に示すように、拡径部Ｈｂに略水平に配置される部材であり、狭径部鉄筋２の下端部２ａから上方に離間した位置に回動可能に固定されている。上段側拡径部鉄筋３１は、主筋２１との連結部７よりも杭穴Ｈの中心寄りの位置に定着部３１ａを有している。定着部３１ａは、中間部をＬ字状に折り曲げるとともに、端部をJ字状に折り曲げて形成されている。
上段側拡径部鉄筋３１は、図２、図３に示すように、平面視略Ｕ字状に形成されている。第１実施形態では、８個の上段側拡径部鉄筋３１が、狭径部鉄筋２の周囲に、放射状に取り付けられている。 As shown in FIG. 1, the upper-stage enlarged-diameter portion reinforcing bar 31 is a member disposed substantially horizontally on the enlarged-diameter portion Hb, and can be rotated to a position spaced upward from the lower end 2 a of the narrow-diameter portion reinforcing bar 2. It is fixed to. The upper-stage enlarged-diameter portion reinforcing bar 31 has a fixing portion 31 a at a position closer to the center of the pile hole H than the connecting portion 7 with the main reinforcing rod 21. The fixing portion 31a is formed by bending an intermediate portion into an L shape and bending an end portion into a J shape.
As shown in FIGS. 2 and 3, the upper-stage enlarged-diameter portion reinforcing bar 31 is formed in a substantially U shape in plan view. In the first embodiment, eight upper-stage enlarged-diameter reinforcing bars 31 are attached radially around the narrow-diameter part reinforcing bars 2.

下段側拡径部鉄筋３２は、図１に示すように、拡径部Ｈｂに略水平に配置される部材であり、上段側拡径部鉄筋３１よりも狭径部鉄筋２の下端部２ａに近い位置に回動可能に固定されている。下段側拡径部鉄筋３２は、主筋２１との連結部７よりも杭穴Ｈの中心寄りの位置に定着部３２ａを有している。定着部３２ａは、中間部をＬ字状に折り曲げるとともに、端部をJ字状に折り曲げて形成されている。
下段側拡径部鉄筋３２は、図３に示すように、上段側拡径部鉄筋３１と同一の形状を呈しており、平面視で上段側拡径部鉄筋３１と重なる位置に、放射状に設置されている。 As shown in FIG. 1, the lower-stage enlarged-diameter reinforcing bar 32 is a member that is disposed substantially horizontally on the enlarged-diameter part Hb, and is located on the lower end 2 a of the narrow-diameter part reinforcing bar 2 than the upper-stage enlarged-diameter part reinforcing bar 31. It is fixed to a close position so that it can rotate. The lower-stage enlarged-diameter portion reinforcing bar 32 has a fixing portion 32 a at a position closer to the center of the pile hole H than the connecting portion 7 with the main reinforcing bar 21. The fixing portion 32a is formed by bending an intermediate portion into an L shape and bending an end portion into a J shape.
As shown in FIG. 3, the lower-stage enlarged-diameter reinforcing bar 32 has the same shape as the upper-stage enlarged-diameter reinforcing bar 31, and is radially installed at a position overlapping the upper-stage enlarged-diameter reinforcing bar 31 in a plan view. Has been.

図４（ａ）は狭径部鉄筋と上段側拡径部鉄筋の連結部の拡大斜視図であり、（ｂ）は（ａ）のＡ−Ａ矢視側面図である。
上段側拡径部鉄筋３１と狭径部鉄筋２との連結部７は、図４（ａ）に示すように、有底筒状の一対の筒状部材７１、７１と、軸部材７２とから構成されている。一対の筒状部材７１は、隣り合う主筋２１に溶接固定されており、互いに開口部を対向させた状態で配置されている。軸部材７２は、その両端部を各筒上部材７１の中空部に挿入することにより、回動自在になっている。上段側拡径部鉄筋３１は、この軸部材７２に溶接固定されることにより、狭径部鉄筋２に対して回動可能に連結されることとなる。
なお、下段側拡径部鉄筋３２と狭径部鉄筋２との連結部７も同様の構造であるので、詳細な説明を省略する。 Fig.4 (a) is an expansion perspective view of the connection part of a narrow diameter part reinforcement and an upper stage side enlarged diameter part reinforcement, (b) is an AA arrow side view of (a).
As shown in FIG. 4A, the connecting portion 7 between the upper-stage enlarged-diameter rebar 31 and the narrow-diameter rebar 2 includes a pair of cylindrical members 71 and 71 having a bottomed cylindrical shape, and a shaft member 72. It is configured. The pair of cylindrical members 71 are welded and fixed to the adjacent main reinforcing bars 21 and are arranged with the openings facing each other. The shaft member 72 is rotatable by inserting both end portions thereof into the hollow portions of the respective cylinder upper members 71. The upper-stage enlarged-diameter portion reinforcing bar 31 is connected to the narrow-diameter portion reinforcing bar 2 so as to be rotatable by being fixed to the shaft member 72 by welding.
In addition, since the connection part 7 of the lower diameter side enlarged diameter part reinforcement 32 and the narrow diameter part reinforcement 2 is also the same structure, detailed description is abbreviate | omitted.

上段側拡径部鉄筋３１は、図４（ａ），（ｂ）に示すように、略水平な状態のときに軸部材７２の下側に位置するように、軸部材７２に取り付けられている。
このように取り付けると、図４（ｂ）に仮想線（２点鎖線）で示すように、上段側拡径部鉄筋３１が回動したとき（畳まれたとき）に、上段側拡径部鉄筋３１を主筋２１と略平行な状態にすることができる。このとき、上段側拡径部鉄筋３１と主筋２１の間には、連結部７の幅寸法に応じた隙間ができるが、この隙間に後記するせん断補強筋３３の上端部３３ａを挿通する筒状部材３１ｂが納まることとなる。そのため、組立鉄筋１を吊り下げたときに、組立鉄筋１の径方向の寸法を小さくすることができる。
下段側拡径部鉄筋３２も同様である。 As shown in FIGS. 4A and 4B, the upper-stage enlarged-diameter portion reinforcing bar 31 is attached to the shaft member 72 so as to be positioned below the shaft member 72 in a substantially horizontal state. .
When attached in this manner, as shown by the phantom line (two-dot chain line) in FIG. 4B, when the upper-stage enlarged-diameter rebar 31 is rotated (when folded), the upper-stage enlarged-diameter reinforcing bar 31 can be made substantially parallel to the main muscle 21. At this time, a gap corresponding to the width dimension of the connecting portion 7 is formed between the upper-stage enlarged-diameter portion reinforcing bar 31 and the main reinforcing bar 21, but a cylindrical shape that passes through an upper end portion 33 a of a shear reinforcing bar 33 described later in this gap. The member 31b is accommodated. Therefore, when the assembled reinforcing bar 1 is suspended, the dimension of the assembled reinforcing bar 1 in the radial direction can be reduced.
The same applies to the lower-stage enlarged-diameter portion reinforcing bar 32.

せん断補強筋３３は、図１に示すように、上段側拡径部鉄筋３１と下段側拡径部鉄筋３２とを連結する部材である。
せん断補強筋３３は、図３に示すように、枠状に形成されており、この枠の中に、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２が配置されている。
せん断補強筋３３の上端部３３ａは、上段側拡径部鉄筋３１の上側に固定された筒状部材３１ｂに挿通されている。また、せん断補強筋３３の下端部３３ｂは、下段側拡径部鉄筋３２の下側に固定された筒状部材３２ｂに挿通されている。これにより、せん断補強筋３３は、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２に回動可能に連結されている。
せん断補強筋３３は、互いに所定の間隔を隔てて配置されている。杭の拡径部に作用するせん断力は、狭径部鉄筋２に近いほど大きくなるので、狭径部鉄筋２から遠い部分に配置されたせん断補強筋３３同士の間隔よりも、狭径部鉄筋２に近い部分に配置されたせん断補強筋３３同士の間隔を小さくするのが好ましい。
また、せん断補強筋３３は、図２に示すように、径方向外側に配置されているものほど、幅寸法が大きくなっている。このようにすれば、組立鉄筋１を吊り下げたときに、せん断補強筋３３同士が重ならず、径方向の寸法を小さくすることができる。 As shown in FIG. 1, the shear reinforcing bar 33 is a member that connects the upper-stage enlarged-diameter reinforcing bar 31 and the lower-stage enlarged-diameter reinforcing bar 32.
As shown in FIG. 3, the shear reinforcing bar 33 is formed in a frame shape, and the upper-stage enlarged-diameter reinforcing bar 31 and the lower-stage enlarged-diameter reinforcing bar 32 are arranged in the frame.
An upper end portion 33 a of the shear reinforcing bar 33 is inserted into a tubular member 31 b fixed on the upper side of the upper-stage enlarged-diameter portion reinforcing bar 31. Further, the lower end portion 33 b of the shear reinforcing bar 33 is inserted through a cylindrical member 32 b fixed to the lower side of the lower-stage enlarged-diameter portion reinforcing bar 32. Thereby, the shear reinforcement bar | burr 33 is connected with the upper stage enlarged diameter part reinforcement 31 and the lower stage enlarged diameter part reinforcement 32 so that rotation is possible.
The shear reinforcement bars 33 are arranged at a predetermined interval from each other. Since the shearing force acting on the enlarged diameter part of the pile becomes closer to the narrow-diameter part reinforcing bar 2, the narrow-diameter part reinforcing bar is larger than the interval between the shear reinforcing bars 33 arranged at a portion far from the narrow-diameter part reinforcing bar 2. It is preferable to reduce the interval between the shear reinforcement bars 33 arranged in a portion close to 2.
Further, as shown in FIG. 2, the width of the shear reinforcing bar 33 increases as it is arranged on the outer side in the radial direction. In this way, when the assembled reinforcing bar 1 is suspended, the shear reinforcing bars 33 do not overlap with each other, and the radial dimension can be reduced.

なお、最も先端側のせん断補強筋３３’は、図３に示すように、枠状ではなく棒状に形成されており、その両端部に筒状部材３３’ａが固定されている。そして、この筒状部材３３’ａに上段側拡径部鉄筋３１と下段側拡径部鉄筋３２とがそれぞれ挿通されている。ちなみに、この最も先端側のせん断補強筋３３’は、他のせん断補強筋３３と同様の構造にしてもよいし、省略してもかまわない。 As shown in FIG. 3, the most distal shear reinforcement bar 33 'is formed in a rod shape instead of a frame shape, and a cylindrical member 33'a is fixed to both ends thereof. The upper-stage enlarged-diameter reinforcing bar 31 and the lower-stage enlarged-diameter reinforcing bar 32 are inserted into the tubular member 33'a. Incidentally, the most distal shear reinforcement bar 33 ′ may have the same structure as the other shear reinforcement bars 33 or may be omitted.

スライド部材４は、上段側拡径部鉄筋３１を回動させる錘となる部材であり、狭径部鉄筋２に対して相対的にスライド可能に構成されている。
スライド部材４は、図１に示すように、複数の棒状の鉄筋４１を垂直に立てて環状に配列するとともに、その外側にリング状のフープ筋４２を嵌め合わせて全体として円筒状に形成された部材である。スライド部材４は、狭径部鉄筋２よりも小径に形成されており、狭径部鉄筋２の内側に同心で配置されている。また、スライド部材４は、複数の連結部材５と複数の上段側拡径部鉄筋３１とを介して狭径部鉄筋２に連結されている。 The slide member 4 is a member that serves as a weight for rotating the upper-stage enlarged-diameter portion reinforcing bar 31, and is configured to be slidable relative to the narrow-diameter portion reinforcing bar 2.
As shown in FIG. 1, the slide member 4 is formed in a cylindrical shape as a whole by vertically arranging a plurality of bar-shaped reinforcing bars 41 and fitting a ring-shaped hoop bar 42 on the outside thereof. It is a member. The slide member 4 is formed to have a smaller diameter than the narrow-diameter part reinforcing bar 2 and is disposed concentrically inside the narrow-diameter part reinforcing bar 2. The slide member 4 is connected to the narrow-diameter portion reinforcing bar 2 via a plurality of connecting members 5 and a plurality of upper-stage enlarged-diameter portion reinforcing bars 31.

連結部材５は、図１に示すように、上段側拡径部鉄筋３１とスライド部材４を連結する部材である。連結部材５は、図２に示すように、枠状に形成されている。連結部材５の上端側は、上段側拡径部鉄筋３１の定着部３１ａに固定された筒状部材に挿通されている。また、連結部材５の下端側は、スライド部材４の上端部に固定された筒状部材に挿通されている。連結部材５は、後記するように、狭径部鉄筋２の下端部２ａが杭穴Ｈの底面Ｈｃに着地したときに、拡径部鉄筋３が略水平に配置されるように、その長さが調節されている。 As shown in FIG. 1, the connecting member 5 is a member that connects the upper-stage enlarged-diameter portion reinforcing bar 31 and the slide member 4. As shown in FIG. 2, the connecting member 5 is formed in a frame shape. The upper end side of the connecting member 5 is inserted through a cylindrical member fixed to the fixing portion 31 a of the upper-stage enlarged-diameter portion reinforcing bar 31. Further, the lower end side of the connecting member 5 is inserted through a cylindrical member fixed to the upper end portion of the slide member 4. As will be described later, the connecting member 5 has a length such that when the lower end portion 2a of the narrow-diameter portion rebar 2 lands on the bottom surface Hc of the pile hole H, the enlarged-diameter portion rebar 3 is arranged substantially horizontally. Is adjusted.

図５は、補強部材の平面図である。
補強部材６は、隣り合う上段側拡径部鉄筋３１（あるいは下段側拡径部鉄筋３２）同士を連結して補強する部材であり、図５に示すように、２本の棒状部材６１、６２の一方の端部６１ｂ、６２ｂをピン接合して構成されている。また、２本の棒状部材６１，６２の他方の端部６１ａ，６２ａは、上段側拡径部鉄筋３１の先端部にプレート３１ｂを介してそれぞれピン接合されている。
これにより、補強部材６は、上段側拡径部鉄筋３１が広がっていない状態、すなわち、組立鉄筋１が杭穴Ｈの底面Ｈｃに着地していない状態では、図５に示すように折り畳まれた状態となっている。そして、上段側拡径部鉄筋３１が展開するにつれて棒状部材６１，６２の成す角度αが大きくなる。さらに、組立鉄筋１の設置が完了し、上段側拡径部鉄筋３１が放射状に展開すると、補強部材６は、図３に示すように、一直線状態となる。これにより、上段側拡径部鉄筋３１の先端部が環状に連結されることとなり、杭の支持力を一層向上させることができる。下段側拡径部鉄筋３２に連結されている補強部材６も同様である。 FIG. 5 is a plan view of the reinforcing member.
The reinforcing member 6 is a member that connects and reinforces adjacent upper-stage enlarged-diameter rebars 31 (or lower-stage enlarged-diameter reinforcing bars 32), and as shown in FIG. The one end portions 61b and 62b are pin-joined. The other end portions 61a and 62a of the two rod-shaped members 61 and 62 are respectively pin-bonded to the tip end portion of the upper-stage enlarged-diameter portion reinforcing bar 31 via the plate 31b.
As a result, the reinforcing member 6 is folded as shown in FIG. 5 in a state where the upper-stage enlarged-diameter rebar 31 is not expanded, that is, in a state where the assembled rebar 1 is not landed on the bottom surface Hc of the pile hole H. It is in a state. Then, as the upper-stage enlarged-diameter portion reinforcing bar 31 expands, the angle α formed by the rod-shaped members 61 and 62 increases. Further, when the installation of the assembly reinforcing bar 1 is completed and the upper-stage enlarged-diameter reinforcing bar 31 is radially expanded, the reinforcing member 6 is in a straight line state as shown in FIG. Thereby, the front-end | tip part of the upper stage side enlarged diameter part reinforcement 31 will be connected cyclically | annularly, and the support force of a pile can be improved further. The same applies to the reinforcing member 6 connected to the lower-stage enlarged-diameter portion reinforcing bar 32.

つづいて、組立鉄筋１の動作について説明する。
図６は、吊り下げた状態の組立鉄筋を示す側面図である。
組立鉄筋１は、図６に示すように、クレーンなどの揚重機で吊り下げられると、狭径部鉄筋２に対してスライド部材４が下方にスライドした状態となる。このとき、スライド部材４は、狭径部鉄筋２の下端部２ａよりも突出した状態となる。 Next, the operation of the assembled reinforcing bar 1 will be described.
FIG. 6 is a side view showing the assembled reinforcing bar in a suspended state.
As shown in FIG. 6, when the assembled rebar 1 is suspended by a lifting machine such as a crane, the slide member 4 is slid downward with respect to the narrow-diameter portion rebar 2. At this time, the slide member 4 protrudes from the lower end 2a of the narrow-diameter portion reinforcing bar 2.

また、スライド部材４は、連結部材５を介して上段側拡径部鉄筋３１の定着部３１ａにぶら下がった状態となっている。これにより、上段側拡径部鉄筋３１は、連結部７を中心に回動して、定着部３１ａが下向きとなり、先端側が上向きとなる。つまり、上段側拡径部鉄筋３１は、先端側を上方にして斜めに起立した状態になる。
また、下段側拡径部鉄筋３２は、上段側拡径部鉄筋３１の上方への回動に伴って、せん断補強筋３３に引っ張られて、先端側が上方に回動する。これにより、下段側拡径部鉄筋３２は、上段側拡径部鉄筋３１と同じく、先端側を上方にして斜めに起立した状態になる。 Further, the slide member 4 is in a state of being hung from the fixing portion 31 a of the upper-stage enlarged-diameter portion reinforcing bar 31 via the connecting member 5. Thereby, the upper-stage enlarged-diameter portion reinforcing bar 31 rotates around the connecting portion 7 so that the fixing portion 31a faces downward and the distal end side faces upward. That is, the upper-stage enlarged-diameter portion reinforcing bar 31 is in a state of standing obliquely with the distal end side upward.
Further, the lower-stage enlarged-diameter portion reinforcing bar 32 is pulled by the shear reinforcing bar 33 as the upper-stage enlarged-diameter portion reinforcing bar 31 is rotated upward, and the distal end side is rotated upward. Thereby, the lower stage side enlarged diameter part reinforcing bar 32 becomes the state which stood up diagonally like the upper stage side enlarged diameter part reinforcement 31 with the front end side upward.

このような状態となった組立鉄筋１を、揚重機を用いて杭穴Ｈの中に降ろしていくと、はじめに、スライド部材４の下端部が、杭穴Ｈの底面Ｈｃに着地する。そして、さらに組立鉄筋１を降下させると、スライド部材４に対して狭径部鉄筋２が近づくように移動する。これにより、上段側拡径部鉄筋３１の定着部３１ａを下方に引っ張っていた力が弛み、上段側拡径部鉄筋３１の先端側が下方に向かって回動する。また、これに伴い、下段側拡径部鉄筋３２の先端側も下方に向かって回動する。 When the assembled rebar 1 in such a state is lowered into the pile hole H using a lifting machine, first, the lower end portion of the slide member 4 is landed on the bottom surface Hc of the pile hole H. When the assembled rebar 1 is further lowered, the narrow-diameter portion rebar 2 moves so as to approach the slide member 4. As a result, the force pulling the fixing portion 31a of the upper-stage enlarged-diameter reinforcing bar 31 is loosened, and the tip side of the upper-stage enlarged-diameter reinforcing bar 31 is rotated downward. Further, along with this, the distal end side of the lower-stage enlarged-diameter portion reinforcing bar 32 also rotates downward.

そして、狭径部鉄筋２の下端部２ａが杭穴Ｈの底面Ｈｃに着地すると、図１に示すように、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２は、狭径部鉄筋２から略水平に張り出した状態となる。また、上段側拡径部鉄筋３１の定着部３１ａ及び下段側拡径部鉄筋３２の定着部３２ａは、狭径部鉄筋２の内側に略水平に張り出した状態となる。
また、せん断補強筋３３は、図１に示すように、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２の間に、所定の間隔で巻き回された状態となる。 And when the lower end part 2a of the narrow diameter part reinforcement 2 lands on the bottom face Hc of the pile hole H, as shown in FIG. 1, the upper stage side enlarged diameter part reinforcement 31 and the lower stage side enlarged diameter part reinforcement 32 are narrow diameter part reinforcement. 2 is in a state of projecting substantially horizontally. Further, the fixing portion 31 a of the upper-stage enlarged-diameter portion reinforcing bar 31 and the fixing portion 32 a of the lower-stage-side enlarged-diameter portion reinforcing bar 32 project substantially horizontally inside the narrow-diameter portion reinforcing bar 2.
Further, as shown in FIG. 1, the shear reinforcing bar 33 is wound between the upper-stage enlarged-diameter reinforcing bar 31 and the lower-stage enlarged-diameter reinforcing bar 32 at a predetermined interval.

その後、杭穴Ｈにトレミー管を挿入して、杭穴Ｈにコンクリートを充填することにより、底部が拡径された場所打ち杭（図示省略）が完成する。 Thereafter, a cast-in-place pile (not shown) with an expanded bottom is completed by inserting a tremely pipe into the pile hole H and filling the pile hole H with concrete.

第１実施形態に係る組立鉄筋１によれば、スライド部材４が上段側拡径部鉄筋３１の定着部３１ａに連結部材５を介して連結されているとともに、下段側拡径部鉄筋３２はせん断補強筋３３を介して上段側拡径部鉄筋３１に連結されているので、クレーンなどで組立鉄筋１を吊り下げている状態では、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２が起立して、組立鉄筋１の径方向の寸法が小さくなり、杭穴Ｈの狭径部Ｈａを通過することが可能となる。 According to the assembled reinforcing bar 1 according to the first embodiment, the slide member 4 is connected to the fixing portion 31a of the upper-stage enlarged-diameter portion reinforcing bar 31 via the connecting member 5, and the lower-stage enlarged-diameter portion reinforcing bar 32 is sheared. Since it is connected to the upper-stage enlarged-diameter reinforcing bar 31 via the reinforcing bar 33, the upper-stage enlarged-diameter reinforcing bar 31 and the lower-stage enlarged-diameter reinforcing bar 32 are in a state where the assembled reinforcing bar 1 is suspended by a crane or the like. Standing up, the dimension in the radial direction of the assembled reinforcing bar 1 is reduced, and it is possible to pass through the narrow-diameter portion Ha of the pile hole H.

また、杭穴Ｈに組立鉄筋１を配置するだけで、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２を、杭穴Ｈの拡径部Ｈｂに略水平に配置することができるとともに、上段側拡径部鉄筋３１と下段側拡径部鉄筋３２の間にせん断補強筋３３を配筋することができる。そのため、場所打ち杭の拡径部を片持ち梁として機能させることができる。 Moreover, while only arranging the assembly reinforcing bar 1 in the pile hole H, the upper-stage enlarged-diameter part reinforcing bar 31 and the lower-stage enlarged-diameter part reinforcing bar 32 can be arranged substantially horizontally in the enlarged-diameter part Hb of the pile hole H. Further, a shear reinforcement bar 33 can be arranged between the upper stage side enlarged part reinforcing bar 31 and the lower stage side enlarged part reinforcing bar 32. Therefore, the enlarged diameter part of a cast-in-place pile can be functioned as a cantilever.

また、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２は、上方から下方に回動するように構成されているところ、杭穴Ｈの拡径部Ｈｂの上部には、テーパ部Ｈｅが形成されているので、上段側拡径部鉄筋３１の回動が阻害されることがない。 In addition, the upper-stage enlarged-diameter portion reinforcing bar 31 and the lower-stage-side enlarged-diameter portion reinforcing bar 32 are configured to rotate downward from above, and the tapered portion He is formed above the enlarged-diameter portion Hb of the pile hole H. Therefore, the rotation of the upper-stage enlarged-diameter rebar 31 is not hindered.

＜第２実施形態＞
次に、本発明の第２実施形態について図７を参照して詳細に説明する。
図７は、第２実施形態に係る組立鉄筋の側面図である。なお、図７では、せん断補強筋３３を二点鎖線で描いている。
第２実施形態に係る組立鉄筋１’は、図７に示すように、狭径部鉄筋２が、大径部２Ａと、この大径部２Ａの下方に連続して形成され、大径部２Ａよりも径の小さい小径部２Ｂと、から構成されている点が、第１実施形態に係る組立鉄筋１と異なっている。 <Second Embodiment>
Next, a second embodiment of the present invention will be described in detail with reference to FIG.
FIG. 7 is a side view of the assembled reinforcing bar according to the second embodiment. In FIG. 7, the shear reinforcing bar 33 is drawn by a two-dot chain line.
As shown in FIG. 7, the assembled reinforcing bar 1 ′ according to the second embodiment includes a narrow-diameter part reinforcing bar 2 continuously formed below the large-diameter part 2 A and the large-diameter part 2 A. This is different from the assembled reinforcing bar 1 according to the first embodiment in that the small-diameter portion 2B having a smaller diameter is configured.

組立鉄筋１’の狭径部鉄筋２を構成する主筋２１は、下端側の所定位置において、径方向内側に折り曲げられている。このような主筋２１を環状に配列することにより、大径部２Ａと小径部２Ｂが形成されている。上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２は、小径部２Ｂに回動可能に連結されている。
なお、その他の構成については、第１実施形態と同一であるので、詳細な説明を省略する。 The main reinforcing bars 21 constituting the narrow-diameter rebar 2 of the assembled reinforcing bar 1 ′ are bent radially inward at a predetermined position on the lower end side. By arranging such main bars 21 in an annular shape, a large diameter portion 2A and a small diameter portion 2B are formed. The upper-stage enlarged-diameter reinforcing bar 31 and the lower-stage enlarged-diameter reinforcing bar 32 are rotatably connected to the small-diameter part 2B.
Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted.

かかる構成によれば、図７に示すように、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２が起立した状態となったときに、組立鉄筋１’の小径部２Ｂ付近の径方向の寸法を、大径部２Ａ付近の径方向の寸法と略同等にすることができる。 According to such a configuration, as shown in FIG. 7, when the upper-stage enlarged-diameter reinforcing bar 31 and the lower-stage enlarged-diameter reinforcing bar 32 are in an upright state, the radial direction in the vicinity of the small-diameter part 2B of the assembled reinforcing bar 1 ′. Can be made substantially equal to the radial dimension in the vicinity of the large diameter portion 2A.

以上、本発明を実施するための最良の形態について、図面を参照して詳細に説明したが、本発明はこれらの実施形態に限定されるものではなく、本発明の主旨を逸脱しない範囲で適宜変更が可能である。 The best mode for carrying out the present invention has been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be appropriately selected without departing from the gist of the present invention. It can be changed.

第１実施形態では、狭径部鉄筋２の下端部２ａが杭穴Ｈの底面Ｈｃに着地した状態で、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２が略水平となるように構成したが、本発明は、これに限定されるものではなく、例えば、狭径部鉄筋２の下端部２ａを杭穴Ｈの底面Ｈｃから所定間隔（例えば１０ｃｍ程度）だけ浮かせた状態で、上段側拡径部鉄筋３１及び下段側拡径部鉄筋３２が略水平となるように構成してもよい。
すなわち、場所打ち杭の施工においては、狭径部鉄筋２の下端部の腐食を防止するために、杭穴Ｈの底面Ｈｃから狭径部鉄筋２を浮かせた状態でコンクリートを打設する場合があるが、そのようなときでも拡径部鉄筋３を略水平に配置することができる。 In the first embodiment, in a state where the lower end portion 2a of the narrow-diameter portion reinforcing bar 2 has landed on the bottom surface Hc of the pile hole H, the upper-stage enlarged-diameter portion reinforcing bar 31 and the lower-stage-side enlarged-diameter portion reinforcing bar 32 are substantially horizontal. Although comprised, this invention is not limited to this, For example, in the state which floated the lower end part 2a of the narrow diameter part reinforcement 2 from the bottom face Hc of the pile hole H only by predetermined spacing (for example, about 10 cm), You may comprise so that the side enlarged diameter part reinforcement 31 and the lower stage side enlarged diameter part reinforcement 32 may become substantially horizontal.
That is, in the construction of cast-in-place piles, in order to prevent corrosion of the lower end portion of the narrow-diameter portion rebar 2, concrete may be placed with the narrow-diameter portion rebar 2 floating from the bottom surface Hc of the pile hole H. However, even in such a case, the enlarged diameter portion reinforcing bars 3 can be arranged substantially horizontally.

また、本実施形態では、上段側拡径部鉄筋３１の定着部３１ａに連結部材５を介してスライド部材４を連結したが、本発明はこれに限定されるものではなく、下段側拡径部鉄筋３２の定着部３２ａに連結部材５を介してスライド部材４を連結してもよいし、両方の定着部３１ａ，３２ａに連結部材５，５を介してスライド部材４を連結してもよい。 In the present embodiment, the slide member 4 is connected to the fixing portion 31a of the upper-stage enlarged-diameter portion reinforcing bar 31 via the connecting member 5. However, the present invention is not limited to this, and the lower-stage enlarged-diameter portion. The slide member 4 may be connected to the fixing portion 32a of the reinforcing bar 32 via the connecting member 5, or the slide member 4 may be connected to both the fixing portions 31a and 32a via the connecting members 5 and 5.

また、本実施形態では、鉄筋を組み合わせてスライド部材４を構成したが、本発明はこれに限定されるものではなく、狭径部鉄筋２の下端から突出するとともに、上段側拡径部鉄筋３１の定着部３１ａ（及び／又は下段側拡径部鉄筋３２の定着部３２ａ）を下方に回動させる部材であれば、どのようなものでも良く、例えば、短く切断した鋼管などをスライド部材４として用いてもよい。また、扁平な円筒状に形成した鉄筋コンクリートなどの重量物でスライド部材４を構成してもよい。 Moreover, in this embodiment, although the slide member 4 was comprised combining the reinforcing bar, this invention is not limited to this, While projecting from the lower end of the narrow diameter part reinforcing bar 2, the upper stage side enlarged diameter part reinforcing bar 31 Any member may be used as long as the fixing portion 31a (and / or the fixing portion 32a of the lower-diameter enlarged diameter portion reinforcing bar 32) is rotated downward. For example, a short cut steel pipe or the like is used as the slide member 4. It may be used. Moreover, you may comprise the slide member 4 with heavy objects, such as reinforced concrete formed in the flat cylindrical shape.

第１実施形態に係る組立鉄筋を示した側面図である。It is the side view which showed the assembly reinforcing bar which concerns on 1st Embodiment. 図１に示すＩ−Ｉ矢視平面図である。It is an II arrow top view shown in FIG. 拡径部鉄筋の一部を拡大して示した斜視図である。It is the perspective view which expanded and showed a part of enlarged diameter part reinforcement. （ａ）は狭径部鉄筋と上段側拡径部鉄筋の連結部の拡大斜視図であり、（ｂ）は（ａ）のＡ−Ａ矢視側面図である。(A) is an expansion perspective view of the connection part of a narrow diameter part reinforcement and an upper stage side enlarged diameter part reinforcement, (b) is an AA arrow side view of (a). 補強部材の平面図である。It is a top view of a reinforcing member. 吊り下げた状態の組立鉄筋を示す側面図である。It is a side view which shows the assembly reinforcing bar of the state suspended. 第２実施形態に係る組立鉄筋の側面図である。It is a side view of the assembly reinforcing bar which concerns on 2nd Embodiment.

Explanation of symbols

１，１’ 組立鉄筋
２狭径部鉄筋
３拡径部鉄筋
３１上段側拡径部鉄筋
３１ａ定着部
３２下段側拡径部鉄筋
３２ａ定着部
３３せん断補強筋
４スライド部材
５連結部材
６補強部材
Ｈ杭穴
Ｈａ狭径部
Ｈｂ拡径部
Ｈｃ底面 1,1 'Assembly Rebar 2 Narrow Diameter Reinforcing Bar 3 Wide Diameter Reinforcing Bar 31 Upper Stage Wide Diameter Reinforcing Bar 31a Anchoring Section 32 Lower Stage Large Diameter Reinforcing Bar 32a Anchoring Section 33 Shear Reinforcement Bar 4 Slide Member 5 Connecting Member 6 Reinforcing Member H Pile hole Ha Narrow part Hb Wide part Hc Bottom

Claims

An assembly rebar placed in a pile hole with an expanded bottom,
A narrow-diameter rebar disposed in the narrow-diameter portion of the pile hole;
A plurality of upper-stage enlarged-diameter rebars that are rotatably connected to positions spaced upward from the lower end of the narrow-diameter part reinforcing bars;
A plurality of lower-stage enlarged-diameter rebars that are rotatably connected to a position closer to the lower end of the narrow-diameter part reinforcing bars than the upper-stage enlarged-diameter reinforcing bars,
A plurality of shear reinforcement bars, one end side of which is rotatably connected to the upper-stage enlarged-diameter rebar, and the other end side of which is rotatably connected to the lower-stage enlarged-diameter reinforcing bar;
A slide member that is arranged so as to protrude from the lower end of the narrow-diameter part reinforcing bar and is slidable in the vertical direction with respect to the narrow-diameter part reinforcing bar before the assembly reinforcing bar contacts the bottom surface of the pile hole. When,
A connecting member having one end side rotatably connected to at least one of the upper-stage enlarged-diameter reinforcing bar and the lower-stage enlarged-diameter reinforcing bar, and the other end side rotatably connected to the slide member. ,
The upper-stage enlarged-diameter reinforcing bar and the lower-stage enlarged-diameter reinforcing bar each have a fixing part located closer to the center of the pile hole than the connection position with the narrow-diameter part reinforcing bar,
The slide member is connected to the fixing portion of at least one of the upper-stage enlarged-diameter rebar and the lower-stage enlarged-diameter rebar through the connecting member,
The upper-stage enlarged-diameter reinforcing bar and the lower-stage enlarged-diameter reinforcing bar are arranged substantially horizontally in the enlarged-diameter part of the pile hole in a state where the installation of the narrow-diameter part reinforcing bar to the pile hole is completed. Assembly rebar characterized by

The shear reinforcement is formed in a frame shape,
2. The assembled reinforcing bar according to claim 1, wherein the upper-stage enlarged-diameter reinforcing bar and the lower-stage enlarged-diameter reinforcing bar are arranged inside the shear reinforcing bar.

The narrow-diameter portion reinforcing bar includes a large-diameter portion and a small-diameter portion that is continuously formed below the large-diameter portion and has a smaller diameter than the large-diameter portion,
The assembled reinforcing bar according to claim 1 or 2, wherein the upper-stage enlarged-diameter reinforcing bar and the lower-stage enlarged-diameter reinforcing bar are rotatably connected to the small-diameter part.