JP2018024982A - Reinforcement method and reinforcement structure of existing pile foundation - Google Patents

Reinforcement method and reinforcement structure of existing pile foundation Download PDF

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JP2018024982A
JP2018024982A JP2016155356A JP2016155356A JP2018024982A JP 2018024982 A JP2018024982 A JP 2018024982A JP 2016155356 A JP2016155356 A JP 2016155356A JP 2016155356 A JP2016155356 A JP 2016155356A JP 2018024982 A JP2018024982 A JP 2018024982A
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pile
reinforcement
footing
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existing pile
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JP6762800B2 (en
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▲靖▼ 岩本
Yasushi Iwamoto
▲靖▼ 岩本
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オリエンタル白石株式会社
Oriental Shiraishi Corp
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Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement method and a reinforcement structure of existing pile foundation that can reinforce an existing foundation footing without widening and that can reduce the range of earth retaining work and temporary cofferdam construction work as much as possible without the need for a large-sized heavy machine.SOLUTION: A reinforcement method of an existing pile foundation for supporting a lower structure of a bridge such as a bridge pier P1 comprises: a footing drilling step of drilling until a pile head 20 of an existing pile 2 is exposed from the top face of a footing 3 of a pile foundation; a pile upper part drilling step of drilling the upper part of the existing pile 2 with the exposed pile head 20; a reinforcement material inserting step of inserting a reinforcement material 4 for reinforcing the existing pile 2 in holes h1 and h2 drilled in the previous step; and a concrete placing step of placing concrete in the holes h1 and h2 for back-filling with the reinforcement material 4 to the top face of the footing.SELECTED DRAWING: Figure 3

Description

本発明は、既設杭基礎の補強工法及び補強構造に関し、詳しくは、橋脚などの橋梁の下部構造体を支持する既設杭基礎の補強工法及び補強構造に関する。   The present invention relates to a reinforcing method and a reinforcing structure of an existing pile foundation, and more particularly to a reinforcing method and a reinforcing structure of an existing pile foundation that supports a lower structure of a bridge such as a bridge pier.
従来、このような橋梁の下部構造体を支持する既設杭基礎の補強工法及び補強構造としては、既設杭の脇に増し杭をして既設のフーチングを拡幅する工法や、橋脚の基礎フーチングが洗掘されて露出した場合に既設フーチングの周囲の地盤に地中壁を構築し、その内部の地盤に固化材を混ぜて地盤改良する工法など、が知られている。   Conventionally, as the reinforcement method and structure of the existing pile foundation that supports such a substructure of the bridge, a method of widening the existing footing by adding an additional pile to the side of the existing pile, and the foundation footing of the bridge pier are washed. A construction method is known in which an underground wall is constructed on the ground around the existing footing when it is dug and exposed, and the ground is improved by mixing solidified material with the ground inside.
例えば、特許文献1には、既設パイルベント橋脚に対し、河積阻害率を大きく増加させることなく、支持力及び地震時水平耐力の向上を図ることを目的として、河床に設置されたパイルベント橋脚12の上流側近傍及び下流側近傍に、小口径鋼管杭14を少なくとも一対設置することで、仮締め切りを不要とし、施工中及び施工後のいずれにおいても、小口径鋼管杭14を設置することに起因する河積阻害率の増大を、可能な限り小さく抑えた既設パイルベント橋脚の補強工法が開示されている(特許文献1の請求項1、明細書の段落[0006]〜[0023]、図面の図1、図6等参照)。   For example, Patent Document 1 discloses a pile vent pier installed on the riverbed for the purpose of improving the bearing capacity and the horizontal strength during earthquakes without significantly increasing the rate of hindrance to the existing pile vent pier. By installing at least one pair of small-diameter steel pipe piles 14 in the vicinity of the upstream side and the downstream side of 12, the provisional deadline is unnecessary, and the small-diameter steel pipe piles 14 are installed both during and after construction. A method of reinforcing an existing pile vent pier in which the increase in the river volume inhibition rate due to the above is suppressed as little as possible is disclosed (claim 1 of patent document 1, paragraphs [0006] to [0023] of the specification, drawings) 1 and 6).
また、特許文献2には、航路の障害とならずに、十分な支持強度を保証することを目的として、既設フーチングの周囲の地盤8が水流の影響により洗掘を受けた水上構造物の修復補強構造において、洗掘を受けた地盤8の内部に、既設フーチングの下方に位置させ且つ既設杭12に支持を取って新設フーチング21を構築し、新設フーチングと既設橋脚の下端との間に新設橋脚22を構築し、新設フーチング及び新設橋脚を構築する際にそれらに含まれる部分以外の既設杭の上端と既設フーチングの張り出し部とを撤去すると共に、既設橋脚の断面を橋脚長さの増大に応じて補強(補強部分23)した水上構造物の修復補強構造及び施工方法が開示されている(特許文献2の請求項1、明細書の段落[0017]〜[0030]、図面の図1〜図8等参照)。   In addition, Patent Document 2 describes the restoration of a floating structure in which the ground 8 around the existing footing has been scoured by the influence of water flow for the purpose of ensuring sufficient support strength without hindering the channel. In the reinforced structure, a new footing 21 is constructed in the ground 8 that has been scoured, located below the existing footing and supported by the existing pile 12, and newly installed between the new footing and the lower end of the existing pier. When the pier 22 is constructed and the new footing and the new pier are constructed, the upper ends of the existing piles and the overhanging portion of the existing footing are removed, and the cross section of the existing pier is increased in length. A repair reinforcement structure and construction method for a water structure reinforced (reinforcing portion 23) accordingly is disclosed (claim 1 of patent document 2, paragraphs [0017] to [0030] of the specification, FIG. 1 of the drawings). See Fig. 8, etc.).
しかし、特許文献1に記載された既設パイルベント橋脚の補強工法や、特許文献2に記載された水上構造物の修復補強構造及び施工方法は、これらの工事を行う際には、大規模な土留め工事や仮締切り工事を行う必要があった。そのため、大きな重機を使用することのできない橋梁下の狭隘な桁下空間では、土留め工事や仮締切り工事は、施工性が悪く、工期が長くなり、結果的に工費が嵩むという問題があった。   However, the existing pile vent pier reinforcement method described in Patent Document 1 and the repair structure and construction method for floating structures described in Patent Document 2 are not suitable for large-scale soils. It was necessary to perform fastening work and temporary closing work. For this reason, in a narrow girder space under a bridge where large heavy machinery cannot be used, earth retaining work and temporary cut-off work have the problem that workability is poor, the work period becomes long, and the work cost increases as a result. .
また、河川内や海中の基礎では、ドライな作業空間を確保するために仮締切り工事を行う必要があるが、必要な仮締切りの根入れ深さを確保できない場合は、地盤改良をしなければならないという問題もあった。その上、仮締切り工事を行う場合の止水処理も問題となっていた。   In addition, it is necessary to perform temporary closing work to ensure a dry working space in rivers and underwater foundations. However, if the necessary depth of temporary closing cannot be secured, ground improvement must be made. There was also a problem of not becoming. In addition, water stoppage treatment in the case of temporary closing work was also a problem.
それに加え、硬質な地盤では、増し杭の施工性が悪いだけでなく、土留め工事や仮締切り工事の施工性も悪く、工期が長くなり、結果的に工費が嵩むという問題があった。   In addition, the hard ground has not only poor workability for additional piles, but also poor workability for earth retaining work and temporary cut-off work, resulting in a longer construction period and higher construction costs.
また、特許文献3には、既存の杭を健全性にかかわらずに再利用することを目的として、中空部を有し、地中に埋設された杭と、前記杭の前記中空部に挿入された補強材と、前記補強材を挿入した前記中空部に充填されたセメント組成物と、前記杭の杭頭部を埋設して形成された基礎と、を備え、前記補強材は、前記中空部に配置されて前記杭を補強する補強部と、前記杭頭部から突出して前記基礎に定着される定着部と、を有する杭基礎構造及びその構築方法が開示されている(特許文献3の請求項1、明細書の段落[0016]〜[0030]、図面の図1、図2等参照)。   Moreover, in patent document 3, it has a hollow part for the purpose of reusing the existing pile irrespective of soundness, and it is inserted in the said hollow part of the pile embedded in the ground, and the said pile. A reinforcing material, a cement composition filled in the hollow portion into which the reinforcing material is inserted, and a foundation formed by burying a pile head portion of the pile, and the reinforcing material includes the hollow portion A pile foundation structure having a reinforcing part arranged to reinforce the pile and a fixing part that protrudes from the pile head and is fixed to the foundation and a construction method thereof are disclosed (Patent Document 3 claim). Item 1, paragraphs [0016] to [0030] of the specification, FIG. 1 and FIG.
しかし、特許文献3に記載の杭基礎構造及び構築方法は、既存の建築物を解体撤去する際に、既存の杭を再利用する発明であり、中空部を有した杭、即ちPC杭やPHC杭などの中空のプレキャストコンクリート杭等にしか適用できないという問題があった。このため、橋梁の下部構造体を支持する既設杭基礎の補強工法には、適用することができなった。   However, the pile foundation structure and construction method described in Patent Document 3 is an invention that reuses an existing pile when dismantling and removing an existing building. A pile having a hollow portion, that is, a PC pile or PHC There is a problem that it can be applied only to hollow precast concrete piles such as piles. For this reason, it could not be applied to the reinforcement method of the existing pile foundation that supports the substructure of the bridge.
特開2009−280956号公報JP 2009-280956 A 特開2009−114721号公報JP 2009-114721 A 特開2014−227735号公報JP 2014-227735 A
そこで、本発明は、前述した問題に鑑みて案出されたものであり、その目的とするところは、既設の基礎フーチングを拡幅することなく補強することができ、土留め工事や仮締切り工事の範囲を極力小さくすることができるとともに、大型の重機も不要である既設杭基礎の補強工法及び補強構造を提供することにある。   Therefore, the present invention has been devised in view of the above-described problems, and the object of the present invention is to reinforce an existing foundation footing without widening, and for earth retaining work or temporary fastening work. An object of the present invention is to provide a reinforcing method and a reinforcing structure for an existing pile foundation that can reduce the range as much as possible and that do not require a large heavy machine.
第1発明に係る既設杭基礎の補強工法は、橋脚などの橋梁の下部構造体を支持する既設杭基礎の補強工法であって、前記杭基礎のフーチングの上面から既設杭の杭頭が露出するまで削孔するフーチング削孔工程と、杭頭が露出した前記既設杭の上部を削孔する杭上部削孔工程と、前記既設杭を補強する補強材を前工程で削孔した孔に挿置する補強材挿置工程と、前記孔にコンクリートを打設して前記補強材ごと前記フーチングの上面まで埋め戻すコンクリート打設工程と、を備えることを特徴とする。   The existing pile foundation reinforcing method according to the first invention is a reinforcing method of an existing pile foundation that supports a lower structure of a bridge such as a bridge pier, and the pile head of the existing pile is exposed from the upper surface of the footing of the pile foundation. A footing drilling process that drills up to the top, a pile upper drilling process that drills the upper part of the existing pile where the pile head is exposed, and a reinforcing material that reinforces the existing pile is inserted into the hole drilled in the previous process. A reinforcing material inserting step, and a concrete placing step of placing concrete in the hole and filling the reinforcing material back to the upper surface of the footing.
第2発明に係る既設杭基礎の補強工法は、第1発明において、前記フーチングの上面鉄筋を切断するフーチング鉄筋切断工程を有することを特徴とする。   The reinforcing method for an existing pile foundation according to the second invention is characterized in that, in the first invention, a footing reinforcing bar cutting step of cutting the upper surface reinforcing bar of the footing is provided.
第3発明に係る既設杭基礎の補強工法は、第1発明又は第2発明において、前記コンクリート打設工程で打設するコンクリートの底面型枠を設置する型枠設置工程を有することを特徴とする。   The reinforcement method for an existing pile foundation according to the third invention is characterized in that in the first invention or the second invention, there is a formwork installation step of installing a bottom formwork of concrete to be placed in the concrete placement step. .
第4発明に係る既設杭基礎の補強構造は、橋脚などの橋梁の下部構造体を支持する既設杭基礎の補強構造であって、前記杭基礎のフーチング及び既設杭に削孔された孔に前記既設杭を補強する補強材が挿置されて補強されていることを特徴とする。   The reinforcement structure of the existing pile foundation according to the fourth invention is a reinforcement structure of an existing pile foundation that supports a lower structure of a bridge such as a bridge pier, and includes the footing of the pile foundation and the hole drilled in the existing pile. The reinforcing material which reinforces the existing pile is inserted and reinforced.
第5発明に係る既設杭基礎の補強構造は、第4発明において、前記既設杭は、鋼管杭又は鉄筋コンクリート杭であることを特徴とする。   The reinforcing structure of an existing pile foundation according to a fifth invention is characterized in that, in the fourth invention, the existing pile is a steel pipe pile or a reinforced concrete pile.
第1発明〜第3発明によれば、杭基礎のフーチングの上面から削孔して削孔した孔に補強材を挿置するので、既設の基礎フーチングを拡幅することなく補強することができる。このため、土留め工事や仮締切り工事の範囲を極力小さくすることができる。また、大型の重機も不要であり、杭頭制限のある橋梁下の狭隘な桁下空間でも容易に既設杭基礎の補強を行うことができる。   According to the 1st invention-the 3rd invention, since a reinforcing material is inserted in the hole drilled from the upper surface of the footing of the pile foundation, the existing foundation footing can be reinforced without widening. For this reason, the range of earth retaining work and temporary closing work can be made as small as possible. In addition, large heavy machinery is not required, and existing pile foundations can be easily reinforced even in a narrow under-girder space under a bridge with pile head restrictions.
特に、第2発明によれば、フーチング鉄筋切断工程を有するので、その後のフーチング削孔工程や杭上部削孔工程でコンクリートを斫って削孔することが容易となり、工期を短縮して工費を削減することができる。   In particular, according to the second invention, since it has a footing rebar cutting process, it becomes easy to drill concrete in the subsequent footing drilling process and pile upper drilling process, shortening the construction period and reducing the construction cost. Can be reduced.
特に、第3発明によれば、コンクリートの底面型枠を設置する型枠設置工程を有するので、既設杭が鋼管杭などの中空杭であり、杭の上部にしかコンクリートが打設されていない場合であっても、本発明を適用することができ、土壌とコンクリートが混ざってしまい新たに打設するコンクリートに強度的な弱点部ができてしまうおそれを低減することができる。   In particular, according to the third aspect of the present invention, since there is a formwork installation step of installing a concrete bottom formwork, the existing pile is a hollow pile such as a steel pipe pile, and the concrete is cast only on the top of the pile Even so, the present invention can be applied, and the possibility that the soil and concrete are mixed and a newly weakly placed concrete has a weak point can be reduced.
第4発明及び第5発明によれば、既設杭基礎のフーチング及び既設杭に削孔された孔に補強材が挿置されて補強されているので、既設の基礎フーチングを拡幅することなく補強することができる。このため、土留め工事や仮締切り工事の範囲を極力小さくすることができる。また、大型の重機も不要であり、杭頭制限のある橋梁下の狭隘な桁下空間でも容易に既設杭基礎の補強を行うことができる。   According to the 4th invention and the 5th invention, since the reinforcing material is inserted and reinforced by the footing of the existing pile foundation and the hole drilled in the existing pile, the existing foundation footing is reinforced without widening. be able to. For this reason, the range of earth retaining work and temporary closing work can be made as small as possible. In addition, large heavy machinery is not required, and existing pile foundations can be easily reinforced even in a narrow under-girder space under a bridge with pile head restrictions.
本発明の実施形態に係る既設杭基礎の補強構造を示す断面図である。It is sectional drawing which shows the reinforcement structure of the existing pile foundation which concerns on embodiment of this invention. 同上の既設杭基礎の補強構造を示す平面図であり、一部補強する既設杭を拡大して示している。It is a top view which shows the reinforcement structure of the existing pile foundation same as the above, and has expanded and has shown the existing pile to partly reinforce. 本発明の実施形態に係る既設杭基礎の補強工法を示すフローチャートである。It is a flowchart which shows the reinforcement construction method of the existing pile foundation which concerns on embodiment of this invention. 同上の既設杭基礎の補強工法のフーチング上面斫り工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。It is process explanatory drawing which shows the footing upper surface turning process of the reinforcement construction method of the existing pile foundation same as the above, (a) is a top view, (b) is a vertical sectional view. 同上の既設杭基礎の補強工法のフーチング鉄筋切断工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。It is process explanatory drawing which shows the footing rebar cutting process of the reinforcement construction method of the existing pile foundation same as the above, (a) is a top view, (b) is a vertical sectional view. 同上の既設杭基礎の補強工法のフーチング削孔工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。It is process explanatory drawing which shows the footing drilling process of the reinforcement construction method of the existing pile foundation same as the above, (a) is a top view, (b) is a vertical sectional view. 同上の既設杭基礎の補強工法の杭上部削孔工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。It is process explanatory drawing which shows the pile top drilling process of the reinforcement construction method of the existing pile foundation same as the above, (a) is a top view, (b) is a vertical sectional view. 同上の既設杭基礎の補強工法の型枠設置工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。It is process explanatory drawing which shows the form installation process of the reinforcement construction method of the existing pile foundation same as the above, (a) is a top view, (b) is a vertical sectional view. 同上の既設杭基礎の補強工法の補強材挿置工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。It is process explanatory drawing which shows the reinforcing material insertion process of the reinforcement construction method of the existing pile foundation same as the above, (a) is a top view, (b) is a vertical sectional view. 同上の既設杭基礎の補強工法のフーチング鉄筋復旧工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。It is process explanatory drawing which shows the footing reinforcement restoration process of the reinforcement construction method of the existing pile foundation same as the above, (a) is a top view, (b) is a vertical sectional view. 同上の既設杭基礎の補強工法のコンクリート打設工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。It is process explanatory drawing which shows the concrete placement process of the reinforcement construction method of the existing pile foundation same as the above, (a) is a top view, (b) is a vertical sectional view.
以下、本発明に係る既設杭基礎の補強工法を実施するための一実施形態について、図面を参照しながら詳細に説明する。   Hereinafter, an embodiment for carrying out the reinforcement method for an existing pile foundation according to the present invention will be described in detail with reference to the drawings.
先ず、図1及び図2を用いて、本発明の実施形態に係る既設杭基礎の補強構造について説明する。本実施形態に係る既設杭基礎の補強構造1は、既存の橋梁の橋桁G1を支持する橋脚P1の杭基礎を耐震補強のために、橋軸方向の前列、後列に位置する6本の杭の杭頭周辺を補強する場合を例示して説明する。図1は、本発明の実施形態に係る既設杭基礎の補強構造を示す断面図であり、図2は、図1の既設杭基礎の補強構造の橋脚下を示す平面図であり、一部補強する既設杭の補強部分のみを拡大して示している。   First, the reinforcement structure of the existing pile foundation which concerns on embodiment of this invention is demonstrated using FIG.1 and FIG.2. The reinforcement structure 1 of the existing pile foundation according to this embodiment includes six piles located in the front row and the rear row in the bridge axis direction for seismic reinforcement of the pile foundation of the pier P1 that supports the bridge girder G1 of the existing bridge. The case where the periphery of a pile head is reinforced is illustrated and demonstrated. 1 is a cross-sectional view showing a reinforcing structure of an existing pile foundation according to an embodiment of the present invention, and FIG. 2 is a plan view showing a pier under the reinforcing structure of the existing pile foundation of FIG. Only the reinforced part of the existing pile to be enlarged is shown.
図1、図2に示すように、本実施形態に係る既設杭基礎の補強構造1は、既設杭2と、この既設杭2と一体化した既設杭基礎のフーチング3と、これらのフーチング3及び既設杭2に削孔された孔h1,h2に挿置された補強材4など、から構成されている。   As shown in FIGS. 1 and 2, an existing pile foundation reinforcing structure 1 according to this embodiment includes an existing pile 2, an existing pile foundation footing 3 integrated with the existing pile 2, and these footings 3 and It is comprised from the reinforcing material 4 etc. which were inserted in the holes h1 and h2 drilled in the existing pile 2.
なお、図1、図2に示すように、橋脚P1の杭基礎は、河川の水面下にある水中構造物であり、作業空間としてドライエリアを構築するため、仮締切り鋼板S1が設置され、その支保工として腹起しH1、切梁H2がキリンジャッキK1を介して組み立てられている。但し、図2では、見えにくくなるので腹起しH1、切梁H2は省略している。   In addition, as shown in FIG. 1, FIG. 2, the pile foundation of the pier P1 is an underwater structure under the water surface of a river, and in order to construct a dry area as a work space, the temporary cutoff steel plate S1 is installed, As a support work, the upset H1 and the cut beam H2 are assembled via the giraffe jack K1. However, in FIG. 2, since it becomes difficult to see, the upset H1 and the cut beam H2 are omitted.
既設杭2は、図2の拡大図に示すように既設の円形筒状の鋼管杭であり、複数の円形筒状の鋼管が溶接で接合されて一体化したものである。勿論、この既設杭2は、鋼管杭に限られず、遠心力成形のプレストレストコンクリート杭(PC杭)や遠心力成形の高強度プレストレストコンクリート杭(PHC杭)、現場打ちの鉄筋コンクリート杭など、であっても本発明を適用することは可能である。   As shown in the enlarged view of FIG. 2, the existing pile 2 is an existing circular cylindrical steel pipe pile, and a plurality of circular cylindrical steel pipes are joined and integrated by welding. Of course, the existing pile 2 is not limited to a steel pipe pile, and is a prestressed concrete pile formed by centrifugal force (PC pile), a high-strength prestressed concrete pile formed by centrifugal force (PHC pile), a reinforced concrete pile made in the field, etc. It is also possible to apply the present invention.
フーチング3は、基礎の一部で橋脚P1を支え、地盤又は杭基礎へ荷重を伝える機能を有した鉄筋コンクリート製のフーチングである。このフーチング3には、図1に示すように、曲げ応力に対抗するため、異形鋼棒が平面視で井桁に組み合わされた上面鉄筋31及び下面鉄筋32が上面及び下面の表面から所定のかぶり厚さを取ってそれぞれ配筋されている。   The footing 3 is a reinforced concrete footing having a function of supporting a pier P1 with a part of the foundation and transmitting a load to the ground or the pile foundation. As shown in FIG. 1, the footing 3 has upper and lower surface reinforcing bars 31 and 32 in which deformed steel bars are combined in a cross-beam in a plan view so as to resist bending stress. Each bar is arranged.
そして、既設杭2とフーチング3とは、既設杭2の中空部内の上部に打設された杭頭部コンクリート21(図4等参照)で接合されて一体化されている。   And the existing pile 2 and the footing 3 are joined and integrated by the pile head concrete 21 (refer FIG. 4 etc.) cast in the upper part in the hollow part of the existing pile 2. As shown in FIG.
補強材4は、図2に示すように、既設杭2より径が小さい円形筒状の鋼管であり、複数の円形筒状の鋼管が溶接で接合されて一体化されたものである。勿論、この補強材4は、補強工事の現場において溶接されてもよいし、予め別の場所で溶接されていてもよい。また、補強材4の長さが短い場合などは、複数の鋼管から構成されたものではなく、シームレスパイプ等の1つの鋼管から構成されたものであってもよいことは云うまでもない。   As shown in FIG. 2, the reinforcing material 4 is a circular cylindrical steel pipe having a diameter smaller than that of the existing pile 2, and a plurality of circular cylindrical steel pipes are joined and integrated by welding. Of course, the reinforcing material 4 may be welded at the site of the reinforcement work, or may be welded in advance in another place. Moreover, when the length of the reinforcing material 4 is short, it is needless to say that the reinforcing material 4 may not be composed of a plurality of steel pipes but may be composed of one steel pipe such as a seamless pipe.
なお、この補強材4は、フーチング3と既設杭2との接合部分(杭頭部コンクリート21)も補強するため、既設杭2より高い位置に上端が位置するように設置されている。   In addition, this reinforcing material 4 is installed so that an upper end may be located in a position higher than the existing pile 2 in order to reinforce the joint part (pile head concrete 21) of the footing 3 and the existing pile 2.
以上説明した本発明の実施形態に係る既設杭基礎の補強構造によれば、既設杭基礎のフーチング及び既設杭に削孔された孔h1,h2に補強材4が挿置されて補強されているので、既設のフーチング3を拡幅することなく補強することができる。このため、土留め工事や仮締切り工事の範囲を極力小さくすることができる。また、大型の重機も不要であり、杭頭制限のある橋梁下の狭隘な桁下空間でも容易に既設杭基礎の補強を行うことができる。   According to the reinforcement structure of the existing pile foundation which concerns on embodiment of this invention demonstrated above, the reinforcing material 4 is inserted and reinforced by the footing of the existing pile foundation and the hole h1, h2 drilled by the existing pile. Therefore, the existing footing 3 can be reinforced without widening. For this reason, the range of earth retaining work and temporary closing work can be made as small as possible. In addition, large heavy machinery is not required, and existing pile foundations can be easily reinforced even in a narrow under-girder space under a bridge with pile head restrictions.
次に、図3〜図11を用いて、本発明の実施形態に係る既設杭基礎の補強工法について説明する。図3は、本実施形態に係る既設杭基礎の補強工法の各工程を示すフローチャートである。   Next, the reinforcement construction method of the existing pile foundation which concerns on embodiment of this invention is demonstrated using FIGS. FIG. 3 is a flowchart showing each step of the reinforcement method for the existing pile foundation according to the present embodiment.
(事前準備)
本実施形態に係る既設杭基礎の補強工法では、先ず、事前準備として、設計図や杭の施工図等から補強する既設杭2の正確な位置を割り出して、測量等により既設杭基礎のフーチング3にマーキング等を施して位置出しを行う。
(Advance preparation)
In the reinforcement method for the existing pile foundation according to the present embodiment, first, as an advance preparation, the exact position of the existing pile 2 to be reinforced is determined from a design drawing or a construction drawing of the pile, and the footing 3 of the existing pile foundation is determined by surveying or the like. Marking is performed to mark the position.
(1)フーチング上面斫り工程
次に、本実施形態に係る既設杭基礎の補強工法では、図3、図4に示すように、フーチング3の上面鉄筋31が露出するまでフーチング3の上面付近のコンクリートを斫り取って矩形状の孔h1を形成するフーチング上面斫り工程を行う。図4は、既設杭基礎の補強工法のフーチング上面斫り工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。
(1) Footing upper surface turning step Next, in the reinforcement method for the existing pile foundation according to the present embodiment, as shown in FIGS. 3 and 4, the upper surface of the footing 3 is exposed until the upper surface reinforcing bar 31 is exposed. A footing upper surface curling process is performed in which the concrete is scraped to form a rectangular hole h1. FIG. 4 is a process explanatory view showing the footing upper surface turning process of the reinforcing method of the existing pile foundation, wherein (a) is a plan view and (b) is a vertical sectional view.
具体的には、本工程では、コールピックハンマーなどの斫り機で、補強する既設杭2の直上となるフーチング3の上面付近の所定範囲のコンクリートを、上面鉄筋31の下端が浮き上がるまで斫り取って矩形状の孔h1を削孔する。なお、斫り取ったコンクリートの瓦礫は、搬出するか又は杭基礎の埋め戻しの際に利用する。勿論、孔h1は、矩形状に限らず、既設杭2より径の大きな円形の孔であっても構わない。但し、上面鉄筋の復旧を考えると継手作業が直線状となって容易となる矩形の孔の方が好ましい。   Specifically, in this process, a concrete machine in a predetermined range near the upper surface of the footing 3 that is directly above the existing pile 2 to be reinforced is beaten with a punching machine such as a call pick hammer until the lower end of the upper reinforcing bar 31 is lifted. Then, a rectangular hole h1 is drilled. The concrete rubble that has been scraped off is taken out or used for backfilling pile foundations. Of course, the hole h1 is not limited to a rectangular shape, and may be a circular hole having a diameter larger than that of the existing pile 2. However, in view of restoration of the upper surface reinforcing bar, a rectangular hole that facilitates the joint operation in a straight line is preferable.
(2)フーチング鉄筋切断工程
次に、本実施形態に係る既設杭基礎の補強工法では、図3、図5に示すように、フーチング3の上面鉄筋31を切断するフーチング鉄筋切断工程を行う。図5は、本実施形態に係る既設杭基礎の補強工法のフーチング鉄筋切断工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。
(2) Footing rebar cutting process Next, in the reinforcement method of the existing pile foundation concerning this embodiment, as shown in FIG. 3, FIG. 5, the footing rebar cutting process which cut | disconnects the upper surface reinforcing bar 31 of the footing 3 is performed. Drawing 5 is a process explanatory view showing the footing rebar cutting process of the reinforcement method of the existing pile foundation concerning this embodiment, (a) is a top view and (b) is a vertical sectional view.
具体的には、本工程では、回転切断砥石(ディスクサンダー)等を用いて、後工程であるフーチング鉄筋復旧工程において継手に必要な所定距離を確保できるように、コンクリートを斫って形成した矩形状の孔h1から一定距離離れた位置において前工程で浮き上がった上面鉄筋31を切断する。勿論、回転切断砥石を用いず、ガス切断器を用いて溶断することも可能である。   Specifically, in this process, a rectangular machine formed with concrete is used to secure a predetermined distance necessary for the joint in the footing rebar restoration process, which is a subsequent process, using a rotary cutting grindstone (disk sander) or the like. The top rebar 31 that has been lifted up in the previous step is cut at a position away from the shape hole h1 by a certain distance. Of course, it is also possible to melt with a gas cutter without using a rotary cutting grindstone.
このように、本工程を行うことにより、後述のフーチング削孔工程や杭上部削孔工程でコンクリートを斫って削孔することが容易となる。このため、実施形態に係る既設杭基礎の補強工法の作業時間を短縮して工費を削減することができる。   In this way, by performing this step, it becomes easy to punch and drill concrete in the footing drilling step and the pile upper hole drilling step described later. For this reason, the work time of the reinforcement construction method of the existing pile foundation which concerns on embodiment can be shortened, and a construction cost can be reduced.
(3)フーチング削孔工程
次に、本実施形態に係る既設杭基礎の補強工法では、図3、図6に示すように、フーチング3の上面から既設杭2の杭頭20が露出するまで削孔するフーチング削孔工程を行う。図6は、本実施形態に係る既設杭基礎の補強工法のフーチング削孔工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。
(3) Footing drilling step Next, in the reinforcement method for the existing pile foundation according to the present embodiment, as shown in FIGS. 3 and 6, the pile head 20 of the existing pile 2 is exposed from the upper surface of the footing 3. A footing drilling step for drilling is performed. FIG. 6 is a process explanatory view showing a footing drilling process of the reinforcing method of the existing pile foundation according to the present embodiment, wherein (a) is a plan view and (b) is a vertical sectional view.
具体的には、本工程では、フーチング上面斫り工程と同様に、コールピックハンマーなどの斫り機を用いて、フーチング3のコンクリート部分を斫り取ってフーチング上面斫り工程で形成した矩形状の孔h1を掘り下げて削孔して行く。そして、既設杭2の杭頭20が露出するまで矩形状の孔h1を掘り進めれば本工程が終了する。   Specifically, in this process, a rectangular shape formed by scraping the concrete portion of the footing 3 by using a punching machine such as a call pick hammer in the same way as the footing top face turning process and forming the footing top face turning process. The hole h1 is dug down and drilled. And if the rectangular hole h1 is dug until the pile head 20 of the existing pile 2 is exposed, this process will be complete | finished.
(4)杭上部削孔工程
次に、本実施形態に係る既設杭基礎の補強工法では、図3、図7に示すように、前工程で杭頭20が露出した既設杭2の上部を削孔する杭上部削孔工程を行う。図7は、本実施形態に係る既設杭基礎の補強工法の杭上部削孔工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。
(4) Pile upper hole drilling step Next, in the reinforcement method for the existing pile foundation according to this embodiment, as shown in FIGS. 3 and 7, the upper portion of the existing pile 2 where the pile head 20 is exposed in the previous step is cut. Pile top drilling process to drill. Drawing 7 is a process explanatory view showing the pile upper part drilling process of the reinforcement construction method of the existing pile foundation concerning this embodiment, (a) is a top view and (b) is a vertical sectional view.
具体的には、本工程では、図7に示すように、コアカッターなどの削孔機を用いて、補強する既設杭2の杭芯周りの中央部分を削孔して円形状の孔h2を削孔する。勿論、既設の杭基礎の設計によるが、一般的には、鋼管杭(既設杭2)とフーチング3とを一体化するため、鋼管杭(既設杭2)の上部部分のみ杭頭部コンクリート21が打設されている。このため、本工程では、既設杭2の杭頭部コンクリート21を貫通するまで削孔する。なお、円形状の孔h2の径は、補強材4を挿置できるように補強材4の径に応じて決定される。   Specifically, in this step, as shown in FIG. 7, a circular hole h2 is formed by drilling the central portion around the pile core of the existing pile 2 to be reinforced using a drilling machine such as a core cutter. Drill holes. Of course, depending on the design of the existing pile foundation, generally, the pile head concrete 21 is formed only in the upper part of the steel pipe pile (existing pile 2) in order to integrate the steel pipe pile (existing pile 2) and the footing 3. It has been cast. For this reason, in this process, it drills until it penetrates the pile head concrete 21 of the existing pile 2. The diameter of the circular hole h2 is determined according to the diameter of the reinforcing material 4 so that the reinforcing material 4 can be inserted.
(5)型枠設置工程
次に、本実施形態に係る既設杭基礎の補強工法では、図3、図8に示すように、後工程で打設するコンクリートの底面型枠を設置する型枠設置工程を行う。図8は、本実施形態に係る既設杭基礎の補強工法の型枠設置工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。
(5) Formwork installation process Next, in the reinforcement method for the existing pile foundation according to the present embodiment, as shown in FIGS. 3 and 8, the formwork installation for installing the bottom formwork of concrete to be placed in the subsequent process is performed. Perform the process. Drawing 8 is a process explanatory view showing the form installation process of the reinforcement construction method of the existing pile foundation concerning this embodiment, (a) is a top view and (b) is a vertical sectional view.
具体的には、本工程では、後工程で打設するコンクリートが流出してしまわないように、底面型枠5を前工程で形成した円形状の孔h2(杭頭部コンクリート21)の下方に設置する。底面型枠5の支持は、円形状の孔h2の周りの杭頭部コンクリート21に吊るし止めるか、又は、既設杭2内の空洞を土砂等で埋め戻することにより支える。   Specifically, in this step, the bottom mold 5 is placed below the circular hole h2 (pile head concrete 21) formed in the previous step so that the concrete to be placed in the subsequent step does not flow out. Install. The bottom formwork 5 is supported by hanging it on the pile head concrete 21 around the circular hole h2 or by filling the cavity in the existing pile 2 with earth or sand.
なお、本工程は、必須ではなく、フーチング3と一体化させる既設杭2の杭頭部コンクリート21の厚さが厚く、挿置する補強材4の下端まで達している場合は、行う必要がない。また、既設杭2が現場打ちの鉄筋コンクリート杭の場合も同様である。   In addition, this process is not essential, and when the thickness of the pile head concrete 21 of the existing pile 2 integrated with the footing 3 is thick and has reached the lower end of the reinforcing material 4 to be inserted, it is not necessary to perform this step. . The same applies to the case where the existing pile 2 is a reinforced concrete pile made in the field.
但し、本工程を行うことにより、既設杭2が鋼管杭などの中空杭であり、杭の上部にしかコンクリートが打設されていない場合であっても、本発明を適用することができ、土壌とコンクリートが混ざってしまい新たに打設するコンクリートに強度的な弱点部ができてしまうおそれを低減することができるため好ましい。   However, by performing this process, the present invention can be applied even if the existing pile 2 is a hollow pile such as a steel pipe pile and concrete is cast only on the top of the pile. This is preferable because it can reduce the possibility that a weak point will be formed in the concrete to be newly placed due to mixing with concrete.
(6)補強材挿置工程
次に、本実施形態に係る既設杭基礎の補強工法では、図3、図9に示すように、円形鋼管からなる補強材4を既設杭2内に形成された円形状の孔h2に挿置する補強材挿置工程を行う。図9は、本実施形態に係る既設杭基礎の補強工法の補強材挿置工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。
(6) Reinforcing Material Inserting Step Next, in the reinforcing method for the existing pile foundation according to the present embodiment, the reinforcing material 4 made of a circular steel pipe is formed in the existing pile 2 as shown in FIGS. A reinforcing material insertion step of inserting into the circular hole h2 is performed. FIGS. 9A and 9B are process explanatory views showing a reinforcing material insertion process of the reinforcing method of the existing pile foundation according to the present embodiment, where FIG. 9A is a plan view and FIG. 9B is a vertical sectional view.
具体的には、本工程では、複数の円形筒状の鋼管からなる補強材4を前述の円形状の孔h2内に吊り降ろす工程と、その鋼管の上に補強材4を構成する円形筒状の鋼管を積み重ねて溶接する工程を、順次繰り返して構造設計に応じた長さの補強材4を構築して設置する。   Specifically, in this step, a step of suspending the reinforcing material 4 made of a plurality of circular cylindrical steel pipes in the aforementioned circular hole h2, and a circular cylindrical shape constituting the reinforcing material 4 on the steel pipe The steps of stacking and welding the steel pipes are sequentially repeated to construct and install the reinforcing material 4 having a length corresponding to the structural design.
勿論、橋桁G1の桁下空間が広く、補強材4を分割して挿入する必要がない場合など、現場において溶接する必要がない場合は、単純に完成した補強材4を円形状の孔h2内に吊り降ろして挿置するだけでよいことは云うまでもない。   Of course, when the space under the bridge girder G1 is wide and there is no need to weld the reinforcing material 4 separately, such as when there is no need to weld on-site, the simply completed reinforcing material 4 is placed in the circular hole h2. It goes without saying that it is only necessary to hang it down and insert it.
(7)フーチング鉄筋復旧工程
次に、本実施形態に係る既設杭基礎の補強工法では、図3、図10に示すように、前工程(フーチング鉄筋切断工程)で切断したフーチング3の上面鉄筋31を復旧するフーチング鉄筋復旧工程を行う。図10は、本実施形態に係る既設杭基礎の補強工法のフーチング鉄筋復旧工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。
(7) Footing Rebar Restoration Step Next, in the reinforcement method for the existing pile foundation according to the present embodiment, as shown in FIGS. 3 and 10, the upper surface reinforcement 31 of the footing 3 cut in the previous step (footing rebar cutting step). The footing rebar restoration process to restore the Drawing 10 is a process explanatory view showing the footing reinforcement restoration process of the reinforcement method of the existing pile foundation concerning this embodiment, (a) is a top view and (b) is a vertical sectional view.
具体的には、本工程では、フーチング鉄筋切断工程で切断した上面鉄筋31を、矩形状の孔h1の側方から突出している上面鉄筋31の残置部分に溶接継手で接合して復旧する。勿論、溶接継手に限られず、重ね継手や機械式継手、圧接継手など、既知の種々の継手を用いて復旧しても良いことは云うまでもない。ここで、復旧とは、新たな異形鋼棒を用いて上面鉄筋31を再構成することを含むものである。   Specifically, in this step, the upper surface reinforcing bar 31 cut in the footing reinforcing bar cutting step is recovered by joining the remaining portion of the upper surface reinforcing bar 31 protruding from the side of the rectangular hole h1 with a welded joint. Of course, it is not limited to the welded joint, and needless to say, it may be restored by using various known joints such as a lap joint, a mechanical joint, and a pressure welding joint. Here, the recovery includes reconstructing the upper surface reinforcing bar 31 using a new deformed steel bar.
(8)コンクリート打設工程
最後に、本実施形態に係る既設杭基礎の補強工法では、図3、図11に示すように、円形状の孔h2及び矩形状の孔h1にコンクリートを打設して補強材4ごとフーチング3の上面まで埋め戻すコンクリート打設工程を行う。図11は、本実施形態に係る既設杭基礎の補強工法のコンクリート打設工程を示す工程説明図であり、(a)が平面図、(b)が鉛直断面図である。
(8) Concrete placing process Finally, in the reinforcement method for the existing pile foundation according to this embodiment, concrete is placed in the circular hole h2 and the rectangular hole h1 as shown in FIGS. Then, a concrete placing process is performed for filling the reinforcing material 4 back to the upper surface of the footing 3. FIG. 11 is a process explanatory view showing the concrete placing process of the reinforcing method of the existing pile foundation according to the present embodiment, where (a) is a plan view and (b) is a vertical sectional view.
具体的には、本工程では、設計基準強度に応じて配合されたコンクリートをポンプ車等で圧送し、空気等が抜けず空洞ができないようにバイブレータ等で振動を与えながら打設して、フーチング3の天端まで円形状の孔h2及び矩形状の孔h1を補強材4ごと埋めてフーチング3を復旧する。   Specifically, in this process, the concrete blended according to the design standard strength is pumped with a pump car, etc., and is placed while giving vibration with a vibrator etc. so that air does not escape and a cavity is not formed, and footing The footing 3 is restored by filling the circular hole h2 and the rectangular hole h1 together with the reinforcing material 4 up to the top of 3.
その後、適切な養生期間をとってコンクリートが硬化することにより、本実施形態に係る既設杭基礎の補強工法の全工程が終了する。   Thereafter, the concrete is cured with an appropriate curing period, whereby all the steps of the reinforcing method for the existing pile foundation according to the present embodiment are completed.
以上説明した本実施形態に係る既設杭基礎の補強工法によれば、杭基礎のフーチング3の上面から削孔して削孔した孔h1,h2に補強材4を挿置するので、既設のフーチング3を拡幅することなく補強することができる。このため、土留め工事や仮締切り工事の範囲を極力小さくすることができる。また、大型の重機も不要であり、杭頭制限のある橋梁下の狭隘な桁下空間でも容易に既設杭基礎の補強を行うことができる。   According to the reinforcing method of the existing pile foundation according to the present embodiment described above, the reinforcing material 4 is inserted into the holes h1 and h2 drilled from the upper surface of the footing 3 of the pile foundation. 3 can be reinforced without widening. For this reason, the range of earth retaining work and temporary closing work can be made as small as possible. In addition, large heavy machinery is not required, and existing pile foundations can be easily reinforced even in a narrow under-girder space under a bridge with pile head restrictions.
なお、本発明は、フーチングの上面から削孔するため、橋脚の真下にある杭の補強には適用することができない。しかし、杭基礎の耐震補強は、杭基礎の降伏に達しないことを照査するものである。また、杭基礎の降伏の定義は、(1)全ての杭において塑性化する。(2)一列の杭頭反力が押込支持力の上限値に達する。のいずれかである。したがって、橋脚の真下にある杭を補強しなくとも外周に位置する杭の杭上部について補強を行えば、杭基礎の耐震補強がOKとなる場合が殆どである。よって、本発明は、殆どの杭基礎の耐震補強に適用可能と云える。   In addition, since this invention drills from the upper surface of a footing, it cannot be applied to the reinforcement of the pile directly under a bridge pier. However, the seismic reinforcement of the pile foundation is to check that the yield of the pile foundation is not reached. Moreover, the definition of the yield of a pile foundation is (1) plasticizing in all the piles. (2) One row of pile head reaction forces reaches the upper limit of indentation support force. One of them. Therefore, if the pile upper part of the pile located on the outer periphery is reinforced without reinforcing the pile just below the pier, the earthquake-proof reinforcement of the pile foundation is often OK. Therefore, the present invention can be applied to the seismic reinforcement of most pile foundations.
以上、本実施形態に係る既設杭基礎の補強構造及び補強工法について詳細に説明したが、前述した又は図示した実施形態は、いずれも本発明を実施するにあたって具体化した一実施形態を示したものに過ぎず、これらによって本発明の技術的範囲が限定的に解釈されてはならないものである。   As mentioned above, although the reinforcement structure and reinforcement construction method of the existing pile foundation concerning this embodiment were demonstrated in detail, all the embodiment mentioned above or illustrated showed one embodiment in implementing this invention. Therefore, the technical scope of the present invention should not be construed in a limited manner.
特に、本実施形態に係る既設杭基礎の補強構造の補強材として円形鋼管を例示して説明したが、本発明に係る補強材は、H形鋼やI形鋼などの形鋼や杭頭補強筋などの異形鋼棒などの鋼材であっても構わない。要するに、本発明に係る補強材は、耐震補強において所定の強度を補強することができ、コンクリートとの付着や熱膨張の相性がよい素材であれば用いることができる。   In particular, the circular steel pipe is exemplified as the reinforcing material of the reinforcing structure of the existing pile foundation according to the present embodiment, but the reinforcing material according to the present invention is a shape steel such as H-shaped steel or I-shaped steel, or pile head reinforcement. Steel materials such as deformed steel bars such as streaks may be used. In short, the reinforcing material according to the present invention can reinforce a predetermined strength in seismic reinforcement, and can be used as long as it is a material having good compatibility with concrete and thermal expansion.
1 :既設杭基礎の補強構造
2 :既設杭(既設杭基礎)
20 :杭頭
h2 :円形状の孔(孔)
3 :フーチング(既設杭基礎)
31 :上面鉄筋
32 :下面鉄筋
h1 :矩形状の孔(孔)
4 :補強材
5 :底面型枠(型枠)
G1 :橋桁
P1 :橋脚(橋梁の下部構造)
H1 :腹起し
H2 :切梁
K1 :キリンジャッキ
S1 :仮締切り鋼板
1: Reinforced structure of existing pile foundation 2: Existing pile (existing pile foundation)
20: Pile head h2: Circular hole (hole)
3: Footing (existing pile foundation)
31: Top bar 32: Bottom bar h1: Rectangular hole (hole)
4: Reinforcement material 5: Bottom formwork (formwork)
G1: Bridge girder P1: Bridge pier (bridge substructure)
H1: Raised H2: Cut beam K1: Kirin jack S1: Temporary cut steel plate

Claims (5)

  1. 橋脚などの橋梁の下部構造体を支持する既設杭基礎の補強工法であって、
    前記杭基礎のフーチングの上面から既設杭の杭頭が露出するまで削孔するフーチング削孔工程と、
    杭頭が露出した前記既設杭の上部を削孔する杭上部削孔工程と、
    前記既設杭を補強する補強材を前工程で削孔した孔に挿置する補強材挿置工程と、
    前記孔にコンクリートを打設して前記補強材ごと前記フーチングの上面まで埋め戻すコンクリート打設工程と、を備えること
    を特徴とする既設杭基礎の補強工法。
    It is a reinforcement method for existing pile foundations that support the substructure of bridges such as piers,
    A footing drilling step for drilling until the pile head of the existing pile is exposed from the upper surface of the footing of the pile foundation;
    Pile upper drilling process for drilling the upper part of the existing pile with the pile head exposed;
    Reinforcing material insertion step of inserting the reinforcing material for reinforcing the existing pile into the hole drilled in the previous step;
    A concrete placing step in which concrete is placed in the hole and the entire reinforcing material is backfilled up to the upper surface of the footing.
  2. 前記フーチングの上面鉄筋を切断するフーチング鉄筋切断工程を有すること
    を特徴とする請求項1に記載の既設杭基礎の補強工法。
    The reinforcing method for an existing pile foundation according to claim 1, further comprising a footing rebar cutting step of cutting a top rebar of the footing.
  3. 前記コンクリート打設工程で打設するコンクリートの底面型枠を設置する型枠設置工程を有すること
    を特徴とする請求項1又は2に記載の既設杭基礎の補強工法。
    The reinforcement method for an existing pile foundation according to claim 1 or 2, further comprising a formwork installation step of installing a bottom formwork of concrete to be placed in the concrete placement step.
  4. 橋脚などの橋梁の下部構造体を支持する既設杭基礎の補強構造であって、
    前記杭基礎のフーチング及び既設杭に削孔された孔に前記既設杭を補強する補強材が挿置されて補強されていること
    を特徴とする既設杭基礎の補強構造。
    It is a reinforcement structure of the existing pile foundation that supports the substructure of the bridge such as the pier,
    A reinforcing structure for an existing pile foundation, wherein a reinforcing material for reinforcing the existing pile is inserted and reinforced in a footing of the pile foundation and a hole drilled in the existing pile.
  5. 前記既設杭は、鋼管杭であること
    を特徴とする請求項4に記載の既設杭基礎の補強構造。
    The said existing pile is a steel pipe pile, The reinforcement structure of the existing pile foundation of Claim 4 characterized by the above-mentioned.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109653233A (en) * 2018-11-14 2019-04-19 中交公局桥隧工程有限公司 Cushion cap single wall steel jacket box recoverable construction of bottom plates method
CN110258607A (en) * 2019-06-28 2019-09-20 王义东 A kind of convenient construction method of bridge construction that mass concrete Pile-supported stand foundation is set
KR102065743B1 (en) * 2019-05-28 2020-01-13 대한기초엔지니어링(주) Foundation slab removal method for bearing capacity measurment of pile
CN110983999A (en) * 2019-12-31 2020-04-10 浙江大学城市学院 Construction method for reinforcing bridge pile foundation pier stud
CN111980020A (en) * 2020-09-16 2020-11-24 中铁四局集团有限公司 Construction method of double-wall steel suspension box cofferdam of main bridge bearing platform of super-large bridge

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109653233A (en) * 2018-11-14 2019-04-19 中交公局桥隧工程有限公司 Cushion cap single wall steel jacket box recoverable construction of bottom plates method
CN109653233B (en) * 2018-11-14 2021-05-25 中交一公局桥隧工程有限公司 Construction method for recyclable bottom plate of large-volume bearing platform single-wall steel sleeve box
KR102065743B1 (en) * 2019-05-28 2020-01-13 대한기초엔지니어링(주) Foundation slab removal method for bearing capacity measurment of pile
CN110258607A (en) * 2019-06-28 2019-09-20 王义东 A kind of convenient construction method of bridge construction that mass concrete Pile-supported stand foundation is set
CN110983999A (en) * 2019-12-31 2020-04-10 浙江大学城市学院 Construction method for reinforcing bridge pile foundation pier stud
CN110983999B (en) * 2019-12-31 2021-03-12 浙江大学城市学院 Construction method for reinforcing bridge pile foundation pier stud
CN111980020A (en) * 2020-09-16 2020-11-24 中铁四局集团有限公司 Construction method of double-wall steel suspension box cofferdam of main bridge bearing platform of super-large bridge

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