JP3946525B2

JP3946525B2 - Construction method of steel pipe soil cement pile

Info

Publication number: JP3946525B2
Application number: JP2002002295A
Authority: JP
Inventors: 英樹木村
Original assignee: Tenox Corp
Current assignee: Tenox Corp
Priority date: 2002-01-09
Filing date: 2002-01-09
Publication date: 2007-07-18
Anticipated expiration: 2022-01-09
Also published as: JP2003206529A

Description

【０００１】
【発明の属する技術分野】
この発明は鋼管杭とソイルセメントからなる鋼管ソイルセメント杭を施工する方法に関するものである。
【０００２】
【従来の技術及び発明が解決しようとする課題】
鋼管杭とソイルセメントからなる鋼管ソイルセメント杭の施工は特許第 2731806号のようにソイルセメント柱を構築した後に鋼管杭を挿入することにより、または特許第 2866248号のようにソイルセメント柱を構築しながら、鋼管杭を挿入することにより行われる。
【０００３】
いずれの方法も地盤の掘削開始時から地中に固化材液を吐出し、掘削孔の全深度に亘ってソイルセメント柱を構築するため、掘進に伴い、固化材液の吐出によるソイルセメントの体積増加と鋼管杭の挿入により固化材を含む土砂が地上へ排出される可能性が高い。
【０００４】
固化材を含む土砂の量は吐出される固化材液の総量にほぼ比例することから、上記方法では地上へ排出される土砂の量が多量になる上、排出分が産業廃棄物扱いとなるため、処分場所を確保する必要がある。
【０００５】
この発明は上記背景より、排土量を低減し、固化材を含む土砂の排出を防止する施工方法を提案するものである。
【０００６】
【課題を解決するための手段】
本発明では先端部に少なくとも掘削攪拌翼と攪拌翼を持ち、先端付近と攪拌翼付近にそれぞれ下部吐出口と上部吐出口が形成された、周面にスパイラル状のスクリューのない掘削ロッドを回転させ、いずれの吐出口からも固化材液を吐出することなく掘進させることにより、掘削孔内に固化材を含まない掘削土を存在させ、そのまま固化材を含まない掘削土の重量により次の工程で構築されるソイルセメントに圧力を付与する。
【０００７】
掘削土の重量により後から構築されるソイルセメントに与えられる下向きの圧力により、掘削孔外への掘削土の溢れ出しを抑制する効果が発揮される深度に至るまで固化材液を吐出しない掘進を続行することで、排土量を低減しながら、ソイルセメント柱の構築時、もしくは鋼管杭挿入時のソイルセメントの横溢を回避し、地上へ排出される土砂を固化材を含まない普通残土とし、残土処理を容易にする。
【０００８】
固化材液を吐出しない掘進後に、掘削ロッドを回転させつつ下部吐出口から固化材液を吐出しながら掘削ロッドの先端部が後から挿入される鋼管杭の先端部付近に到達するまで掘進が行われることでソイルセメントが構築されるが、固化材を含まない掘削土の重量によるソイルセメントへの圧力が、掘削孔外への掘削土の溢れ出しを抑制する効果を発揮する深度に至るまで固化材液を吐出しない掘進を続行することで、ソイルセメントを構築する工程で固化材液の吐出に起因する掘削孔内の体積増加に伴う掘削土の溢れ出しが抑制され、その量が低減される。
【０００９】
掘削土の溢れ出しが抑制されるのは、固化材液を吐出しない掘進工程での掘削土の重量によりソイルセメントが加圧された状態で構築されることで、固化材液中の水分が地盤中に浸透し、形成されるソイルセメント自体の容積が小さくなるためと、地盤条件によってはソイルセメントが側方へ拡がるためであると考えられる。
【００１０】
掘削ロッドの先端部が後から挿入される鋼管杭の先端部付近に到達するまでの掘進によるソイルセメントの構築後、掘削ロッドを引き上げ、掘進時に下部吐出口から固化材液を吐出した深度の近傍に上部吐出口が達した時点で、上部吐出口から固化材液を吐出しながら掘削ロッドを回転させつつ引き抜いてソイルセメント柱を構築し、ソイルセメント柱中に先端が開放した鋼管杭を挿入することが行われる。
【００１１】
ソイルセメント柱の全長の内、特に根固め部の強度を増大させ、鋼管ソイルセメント杭としての先端支持力を向上させる場合には請求項２に記載のように掘削ロッドの先端部が後から挿入される鋼管杭の先端部が定着される根固め部に到達する深度付近において下部吐出口から根固め液を吐出して根固め部を構築することが行われる。
【００１２】
根固め液にはその上に構築されるソイルセメント柱の構築に使用される固化材液より富配合、及び／又は多量の固化材液が使用され、根固め部の構築後、掘削ロッドを引き上げ、掘進時に下部吐出口から固化材液を吐出した深度の近傍に上部吐出口が達した時点で、上部吐出口から根固め液より貧配合、及び／又は少量の固化材液を吐出しながら掘削ロッドを回転させつつ引き抜いてソイルセメント柱を構築し、ソイルセメント柱中に先端が開放した鋼管杭を挿入することが行われる。
【００１３】
請求項２では掘削ロッドの先端部が根固め部に到達する深度付近から根固め液の吐出を開始することで、根固め液の吐出開始位置の深度が請求項１において固化材液の吐出を開始する深度より大きいため、下部吐出口より上に存在する掘削土の重量が多くなる。このため、固化材液の吐出に起因する体積増加に伴う掘削土の掘削孔外への溢れ出し量が少なくなる請求項１の効果は請求項２においても維持される。
【００１４】
請求項３では請求項１、もしくは請求項２において、掘削ロッドの引き抜き時に、後から挿入される鋼管杭の頭部付近までソイルセメント柱を構築し、その上に前記ソイルセメント柱を構築した固化材液より貧配合、及び／又は少量の固化材液を上部吐出口から吐出しながら地盤面、もしくはその付近までソイルセメントを構築することにより、後から挿入される鋼管杭の頭部が地盤面以深に位置し、ヤットコを用いて鋼管杭の挿入を行う場合に対応する。
【００１５】
鋼管杭の頭部が地盤面以深に位置する場合に、鋼管杭頭部から地盤面までの区間を空掘りし、ソイルセメントを構築しないとすれば、鋼管杭挿入時にその先端が土砂から抵抗を受けることになるが、請求項３では地盤面から鋼管杭頭部の位置までソイルセメントが構築されていることで、鋼管杭挿入時の抵抗を低減することができる。また鋼管杭挿入時に鋼管杭周面への土砂の付着が防止されるため、ソイルセメント柱と鋼管杭との一体性が阻害されることがない。加えて地盤面からソイルセメントが構築されていることで、施工後の地表面でのトラフィカビリティーが改善される。
【００１６】
【発明の実施の形態】
図１に請求項１の方法の施工手順例を示す。請求項１は図２，図３に示すような掘削ロッド１を用いて根固め部８を含むソイルセメント柱９を構築した後、ソイルセメント柱９中に先端が開放した、図６〜図10に示すような鋼管杭10を挿入して鋼管ソイルセメント杭を施工する方法である。
【００１７】
掘削ロッド１の先端には先行掘削翼２が突設され、その上に掘削攪拌翼４と攪拌翼３が突設され、攪拌翼３の上には掘削土を地上へ排出しようとするスパイラル状のスクリューは突設されない。
【００１８】
図面では攪拌の効率を上げるために、掘削攪拌翼４の上に、掘削土が掘削攪拌翼４や攪拌翼３と共に回転することを防止する共回り防止翼５を掘削ロッド１の回転から絶縁させた状態で装着している。図２は掘削攪拌翼４の直上に装着した場合、図３は最上部の攪拌翼３の下に装着した場合を示す。
【００１９】
掘削ロッド１の、最下部に位置する掘削攪拌翼４の下方位置には掘削ロッド１の内部を通じ、掘進時に固化材液や根固め液、または清水や泥水等の掘削液を吐出する下部吐出口６が形成され、最上部の攪拌翼３の上方位置には引き抜き時に固化材液を吐出する上部吐出口７が形成される。
【００２０】
図１により請求項１の方法の施工手順を説明する。
(a) に示すように掘削ロッド１を回転させ、空掘りしながら、もしくは下部吐出口６から固化材を含まない掘削液を吐出しながら掘進させ、所定の深度まで固化材を混合しない掘進により掘削孔内に固化材を含まない掘削土を存在させる。
【００２１】
所定の深度とは、固化材を含まない掘削土の重量により次の工程で構築されるソイルセメントに圧力を付与し、その圧力により掘削孔外への掘削土の溢れ出しを抑制する効果が発揮される深度を言う。
【００２２】
所定の深度に至るまで固化材液を吐出しない掘進を続行することにより、(b) の下部吐出口６から固化材液を吐出しながら掘進させてソイルセメントを構築する工程において固化材液の吐出に起因する掘削孔内の体積増加に伴う掘削土の溢れ出し量が少なくなる。
【００２３】
所定の深度まで上記掘進を続行した後、それ以深において下部吐出口６からの固化材液の吐出を開始し、掘進を継続する。
【００２４】
下部吐出口６から吐出された固化材液と掘削土との攪拌・混合によるソイルセメントの体積増加に伴い、(a) ，(b) に示すように少ないながらも、上部の掘削土は地上へ押し上げられる。
【００２５】
下部吐出口６からの固化材液の吐出開始後、(b) ，(c) に示すように掘削ロッド１の先端部が後から挿入される鋼管杭10の先端部付近、すなわち根固め部８を形成すべき深度に到達するまで固化材液の吐出を継続し、掘削ロッド１を回転させながら掘進する。その後、根固め部８用の固化材液に切り替えて下部吐出口６から根固め部８用の固化材液を吐出しながら、掘削ロッド１の掘進を継続し、根固め部８を構築する。
【００２６】
根固め部８の構築後、(d) ，(e) に示すように掘削ロッド１を回転させつつ引き抜く。この際、下部吐出口６からの固化材液の吐出はしない。掘進の際に吐出した固化材液の量が少ない場合は、上部吐出口７から固化材液を吐出しながら、掘削ロッド１を引き上げることもある。
【００２７】
掘削ロッド１が(e) に示す位置、すなわち(a) に示す、固化材液を吐出することなく前記の所定の深度まで掘進し、下部吐出口６からの固化材液の吐出を開始したときの深度に達した時点で、上部吐出口７から固化材液を吐出しながら、掘削ロッド１を回転させつつ引き上げる。
【００２８】
上部吐出口７からの固化材液の吐出は(f) に示すように地表面まで続けることなく、地表面より幾らか下の位置で固化材液の吐出を中止することが好ましい。これは鋼管杭10の挿入に伴うソイルセメント９’の見かけの体積増加によりソイルセメント９’が地上へ排出されることを防止する、もしくは排出量を少なくするためである。鋼管杭10の挿入に伴う体積増加によるソイルセメント９’の上昇分は(g) と(h) のソイルセメント９’の上端位置の差に表れている。
【００２９】
上部吐出口７からの固化材液の吐出により、(f) 〜(h) に示すようにそれ以前に下部吐出口６から吐出した固化材液により構築されたソイルセメント柱９の上にソイルセメント９’が構築され、掘削孔全体にソイルセメント柱が構築されている。
【００３０】
掘削ロッド１の引き抜き後、(g) に示すようにソイルセメント柱９に先端が開放した鋼管杭10を圧入、または回転圧入させながら、(h) に示すように鋼管杭10の先端部が根固め部８中に埋設されるまで圧入、または回転圧入させることにより鋼管ソイルセメント杭が完成する。
【００３１】
図１は根固め部８の構築開始位置以浅において下部吐出口６からの固化材液の吐出を開始する場合を示すが、図４は根固め部８の構築開始位置から下部吐出口６からの固化材液として根固め液の吐出を開始する請求項２の方法の施工手順例を示す。
【００３２】
この図４の場合も下部吐出口６から根固め液を吐出するまでは(a) ，(b) に示すように空掘り、もしくは下部吐出口６から掘削液を吐出しながらの掘削が行われ、掘削ロッド１の先端部が後から挿入される鋼管杭10の先端部が定着される根固め部８に到達する深度付近において下部吐出口６からの根固め液の吐出が開始され、そのまま(c) に示すように掘削ロッド１の先端部を鋼管杭10の先端部付近まで到達させることにより根固め部８が構築される。
【００３３】
根固め部８の構築後、掘削ロッド１に供給される根固め液をそれより貧配合、及び／又は少量の固化材液に切り替えると共に、吐出位置を下部吐出口６から上部吐出口７に切り替え、(d) ，(e) に示すように上部吐出口７から固化材液を吐出しながら掘削ロッド１を回転させつつ引き抜くことによりソイルセメント柱９が構築される。
【００３４】
ソイルセメント柱９の構築後は図１と同様に(f) ，(g) に示すようにソイルセメント柱９に先端が開放した鋼管杭10を回転させながら、鋼管杭10の先端部が根固め部８中に埋設されるまで圧入することにより鋼管ソイルセメント杭が完成する。
【００３５】
図５は鋼管杭10の頭部を地表面以深に位置させる場合に、掘削ロッド１の引き抜き時に、後から挿入される鋼管杭10の頭部付近までソイルセメント柱９を構築し、その上にソイルセメント柱10を構築した固化材液より貧配合、及び／又は少量の固化材液を上部吐出口７から吐出しながら地盤面、もしくはその付近までソイルセメント11を構築する請求項３の方法の施工手順例を示す。
【００３６】
図５は図４−(a) 〜(d) に示す請求項２の方法で根固め部８と上層部を除くソイルセメント柱９を構築した後に、ソイルセメント柱９上にソイルセメント11を構築する様子を示しているが、図５−(d) までは図１−(a) 〜(d) の手順により根固め部８とソイルセメント柱９を構築することもある。
【００３７】
図５の場合、根固め部８の構築後、(d) ，(e) に示すように上部吐出口７から固化材液を吐出しながら掘削ロッド１を回転させつつ引き抜くことにより鋼管杭10の頭部が位置する地表面以深までソイルセメント柱９を構築し、引き続き、ソイルセメント柱９を構築した固化材液より貧配合、及び／又は少量の固化材液を上部吐出口７から吐出しながら地盤面、もしくはその付近までソイルセメント11を構築する。
【００３８】
ソイルセメント11の構築後、頭部をヤットコで保持しながら、(f) ，(g) に示すように鋼管杭10をソイルセメント柱９中に圧入することにより鋼管ソイルセメント杭が完成する。
【００３９】
図７〜図10は先端部外周に拡大翼10ａを突設した鋼管杭10の製作例を示す。図７はスクリュー状の拡大翼10ａを１ピッチ分形成し、その上に根固め部８のソイルセメントとの付着のためのリング状のリブ10ｂを多段に配置した場合、図８はスクリュー状の２枚の拡大翼10ａ，10ａを半ピッチ分、対称に配置した場合、図９は同じく拡大翼10ａ，10ａを１ピッチ分、対称に配置した場合、図10は図８の拡大翼10ａ，10ａを上下２段に配置した場合である。なお、図７のリング状のリブ10ｂは省略される場合もある。
【００４０】
図７〜図10では拡大翼10ａを曲面のスクリュー状に形成し、拡大翼10ａの先端を鋼管杭10の先端より突出させているが、拡大翼10ａは平坦な板を切断した形のまま溶接して形成される場合もあり、拡大翼10ａの先端が鋼管杭10の先端より突出しない場合、すなわち拡大翼10ａの先端が鋼管杭10の先端の位置、または鋼管杭10の先端より上に位置する場合もある。また図面では拡大翼10ａを鋼管杭10の周方向に１周、または半周の長さで形成しているが、これには限定されず、１／３周、１／４周等、更に細かく分割することもある。
【００４１】
【発明の効果】
先端部に少なくとも掘削攪拌翼と攪拌翼を持ち、先端付近と攪拌翼付近にそれぞれ下部吐出口と上部吐出口が形成された、周面にスパイラル状のスクリューのない掘削ロッドを回転させて掘進させるため、スパイラルスクリューを持つ掘削装置を使用する場合と異なり、掘削ロッドの掘進に伴う掘削土の地上への排出を抑制することができる。
【００４２】
またいずれの吐出口からも固化材液を吐出することなく掘進させることで、掘削孔内に固化材を含まない掘削土を存在させ、そのまま固化材を含まない掘削土の重量により次の工程で構築されるソイルセメントに圧力を付与し、掘削孔外への掘削土の溢れ出しを抑制する効果が発揮される深度に至るまで固化材液を吐出しない掘進を続行するため、掘削土の地上への排出量を削減することができ、仮に掘削土の排出が生じた場合にも固化材液を含む土砂の排出を回避することができる。
【００４３】
このように周面にスクリューがない掘削ロッドを使用することと、所定深度まで固化材液の吐出をしない掘進を続行することの二通りの手段を用いるため、それぞれの手段を単独で用いる場合より掘削土の地上へ排出量を一層削減することができる。
【００４４】
請求項２では所定深度まで固化材液の吐出をしない掘進を続行し、掘削ロッドの先端部が、後から挿入される鋼管杭先端部が位置する根固め部に到達する深度付近において初めて下部吐出口からの根固め液の吐出を開始して根固め部を構築することで、根固め液の吐出を開始する深度が請求項１において固化材液の吐出を開始する深度より大きいことから、下部吐出口より上に存在する掘削土の量が多くなるため、固化材液の吐出に起因する掘削孔内の体積増加に伴う掘削土の溢れ出しを抑制する請求項１の効果を一層高めることができる。
【００４５】
また請求項１と同様に周面にスパイラル状のスクリューがない掘削ロッドを使用するため、掘削ロッドの掘進に伴う掘削土の地上への排出も抑制することができる。
【００４６】
請求項３では掘削ロッドの引き抜き時に、後から挿入される鋼管杭の頭部付近までソイルセメント柱を構築し、その上に前記ソイルセメント柱を構築した固化材液より貧配合、及び／又は少量の固化材液を上部吐出口から吐出しながら地盤面、もしくはその付近までソイルセメントを構築するため、鋼管杭挿入時の抵抗を低減することができる。また鋼管杭挿入時に鋼管杭周面への土砂の付着が防止されるため、ソイルセメント柱と鋼管杭との一体性が阻害されない。加えて施工後の地表面でのトラフィカビリティーが改善される。
【図面の簡単な説明】
【図１】請求項１の鋼管ソイルセメント杭の施工手順を示した立面図である。
【図２】掘削ロッドの製作例を示した立面図である。
【図３】掘削ロッドの他の製作例を示した立面図である。
【図４】請求項２の鋼管ソイルセメント杭の施工手順を示した立面図である。
【図５】請求項３の鋼管ソイルセメント杭の施工手順を示した立面図である。
【図６】 (a) は鋼管杭を示した立面図、(b) は(a) の底面図である。
【図７】 (a) は先端部に拡大翼を形成した鋼管杭の製作例を示した立面図、(b) は(a) の底面図である。
【図８】 (a) は先端部に拡大翼を形成した鋼管杭の他の製作例を示した立面図、(b) は(a) の底面図である。
【図９】 (a) は先端部に拡大翼を形成した鋼管杭の他の製作例を示した立面図、(b) は(a) の底面図である。
【図１０】 (a) は先端部に拡大翼を形成した鋼管杭の他の製作例を示した立面図、(b) は(a) の底面図である。
【符号の説明】
１……掘削ロッド、２……先行掘削翼、３……攪拌翼、４……掘削攪拌翼、５……共回り防止翼、６……下部吐出口、７……上部吐出口、８……根固め部、９……ソイルセメント柱、９’……ソイルセメント、10……鋼管杭、10ａ……拡大翼、10ｂ……リブ、11……ソイルセメント。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing a steel pipe soil cement pile comprising a steel pipe pile and a soil cement.
[0002]
[Prior art and problems to be solved by the invention]
Construction of a steel pipe soil cement pile consisting of a steel pipe pile and soil cement can be done by inserting the steel pipe pile after constructing the soil cement pillar as in Patent No. 2731806 or by constructing the soil cement pillar as in Patent No. 2866248. However, this is done by inserting a steel pipe pile.
[0003]
Both methods discharge the solidified material liquid into the ground from the beginning of excavation of the ground and construct the soil cement pillar over the entire depth of the excavation hole. There is a high possibility that sediment containing solidified material will be discharged to the ground due to the increase and the insertion of steel pipe piles.
[0004]
Since the amount of earth and sand containing solidification material is almost proportional to the total amount of solidification material discharged, the above method increases the amount of earth and sand discharged to the ground, and the discharge is handled as industrial waste. It is necessary to secure a disposal place.
[0005]
This invention proposes the construction method which reduces the amount of soil discharge and prevents discharge | emission of the earth and sand containing a solidification material from the said background.
[0006]
[Means for Solving the Problems]
In the present invention, at least a drilling stirring blade and a stirring blade are provided at the tip, and a lower discharge port and an upper discharge port are formed near the tip and the stirring blade, respectively, and a drilling rod without a spiral screw is rotated on the peripheral surface. By excavating without discharging the solidified material liquid from any discharge port, the excavated soil not containing the solidified material is present in the excavation hole, and the weight of the excavated soil not including the solidified material is used in the next step. Apply pressure to the soil cement being constructed.
[0007]
Due to the downward pressure applied to the soil cement to be constructed later due to the weight of the excavated soil, the excavation without discharging the solidified liquid until reaching a depth where the effect of suppressing the overflow of the excavated soil outside the excavation hole is exhibited. By continuing, avoiding the overflow of soil cement when building soil cement pillars or inserting steel pipe piles while reducing the amount of soil discharged, the soil discharged to the ground will be ordinary residual soil that does not contain solidification material, Makes the remaining soil easier.
[0008]
After the excavation without discharging the solidified material liquid, the excavation continues until the tip of the excavating rod reaches the vicinity of the tip of the steel pipe pile to be inserted later while discharging the solidified liquid from the lower discharge port while rotating the excavating rod. Soil cement is built, but solidifies to a depth where the pressure on the soil cement due to the weight of the excavated soil that does not contain solidifying material exerts the effect of suppressing the overflow of the excavated soil outside the drilling hole By continuing the excavation without discharging the material liquid, the overflow of the excavated soil due to the increase in the volume in the excavation hole due to the discharge of the solidified material liquid is suppressed in the process of building the soil cement, and the amount is reduced .
[0009]
The overflow of the excavated soil is suppressed because the soil cement is pressurized with the weight of the excavated soil in the excavation process without discharging the solidified material liquid, so that the moisture in the solidified material liquid is grounded. It is considered that the soil cement permeates into the soil and the volume of the soil cement itself is reduced, and depending on the ground conditions, the soil cement spreads laterally.
[0010]
After constructing the soil cement by excavation until the tip of the excavation rod reaches the tip of the steel pipe pile to be inserted later, the excavation rod is pulled up, and the vicinity of the depth at which the solidified material liquid is discharged from the lower discharge port during excavation When the upper discharge port arrives, the soil cement column is constructed by pulling out the drilling rod while discharging the solidified material liquid from the upper discharge port, and the steel pipe pile with the open end is inserted into the soil cement column Is done.
[0011]
The tip of the excavating rod is inserted later as described in claim 2 in the case of increasing the strength of the solidified portion of the soil cement column, particularly the strength of the rooted portion, and improving the tip supporting force as a steel pipe soil cement pile. In the vicinity of the depth at which the tip portion of the steel pipe pile reaches the root consolidation portion to be fixed, the root consolidation portion is constructed by discharging the root solidification liquid from the lower discharge port.
[0012]
The root solidification liquid is richer than the solidification liquid used for the construction of the soil cement pillar built on it, and / or a larger amount of the solidification liquid is used. When the upper discharge port reaches the vicinity of the depth at which the solidified material liquid was discharged from the lower discharge port during excavation, excavation is performed while discharging a lower amount of the solidified liquid and / or a smaller amount of the solidified liquid from the upper discharge port. A soil cement column is constructed by pulling it out while rotating the rod, and a steel pipe pile having an open end is inserted into the soil cement column.
[0013]
According to a second aspect of the present invention, the discharge of the solidification liquid is started from the vicinity of the depth at which the tip of the excavation rod reaches the root consolidation part, so that the depth at the discharge start position of the root solidification liquid discharges the solidified liquid according to the first aspect. Since it is larger than the starting depth, the weight of the excavated soil existing above the lower discharge port increases. Therefore, the effect of claim 1 in which the amount of overflow of the excavated soil to the outside of the excavation hole due to the increase in volume due to the discharge of the solidifying material liquid is reduced is also maintained in claim 2.
[0014]
In claim 3, in claim 1 or claim 2, when the excavation rod is pulled out, the soil cement pillar is constructed up to the vicinity of the head of the steel pipe pile to be inserted later, and the soil cement pillar is constructed thereon. The head of the steel pipe pile to be inserted later is the ground surface by constructing the soil cement to the ground surface or its vicinity while discharging a poorly mixed material liquid and / or a small amount of solidified material liquid from the upper discharge port. It is located deeper and corresponds to the case where steel pipe piles are inserted using Yatco.
[0015]
If the head of the steel pipe pile is located deeper than the ground surface, if the section from the steel pipe pile head to the ground surface is dug and no soil cement is constructed, the tip of the steel pipe pile will resist from the earth and sand when the steel pipe pile is inserted. Although it will receive, in Claim 3, the resistance at the time of steel pipe pile insertion can be reduced because the soil cement is constructed from the ground surface to the position of the steel pipe pile head. Moreover, since adhesion of the earth and sand to a steel pipe pile peripheral surface is prevented at the time of steel pipe pile insertion, the integrity of a soil cement pillar and a steel pipe pile is not inhibited. In addition, since soil cement is constructed from the ground surface, trafficability on the ground surface after construction is improved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a construction procedure example of the method of claim 1. In the first aspect, after the soil cement pillar 9 including the root consolidation portion 8 is constructed using the excavating rod 1 as shown in FIGS. 2 and 3, the tip is opened in the soil cement pillar 9. This is a method of inserting a steel pipe pile 10 as shown in FIG.
[0017]
A leading excavation blade 2 protrudes from the tip of the excavation rod 1, and an excavation stirring blade 4 and an agitation blade 3 project on the leading excavation blade 2. A spiral shape is formed on the stirring blade 3 to discharge the excavated soil to the ground. The screw is not projected.
[0018]
In the drawing, in order to increase the efficiency of agitation, a co-rotation prevention blade 5 that prevents the excavation soil from rotating together with the excavation stirring blade 4 and the stirring blade 3 is insulated from the rotation of the excavation rod 1 on the excavation stirring blade 4. Wearing in the state. FIG. 2 shows a case where the excavator is installed immediately above the stirring blade 4, and FIG. 3 shows a case where the excavator is installed under the uppermost stirring blade 3.
[0019]
A lower discharge port for discharging a solidified material liquid, a root-solidifying liquid, or a drilling liquid such as fresh water or muddy water during excavation through the inside of the drilling rod 1 to the lower position of the drilling stirring blade 4 positioned at the bottom of the drilling rod 1 6 is formed, and an upper discharge port 7 for discharging the solidified material liquid at the time of drawing is formed above the uppermost stirring blade 3.
[0020]
The construction procedure of the method of claim 1 will be described with reference to FIG.
As shown in (a), the excavation rod 1 is rotated and excavated while being excavated or excavated while discharging the excavating liquid not containing the solidified material from the lower discharge port 6, and by excavating without mixing the solidified material to a predetermined depth. Excavation soil that does not contain solidification material is present in the excavation hole.
[0021]
Predetermined depth means that pressure is applied to the soil cement built in the next process based on the weight of the excavated soil that does not contain solidified material, and the pressure suppresses the overflow of the excavated soil outside the excavated hole. Say the depth to be.
[0022]
By continuing the excavation without discharging the solidified material liquid until reaching a predetermined depth, the solidified material liquid is discharged in the step of constructing the soil cement by excavating the solidified material liquid from the lower discharge port 6 of (b). The amount of overflow of excavated soil due to the increase in volume in the excavation hole due to the decrease is reduced.
[0023]
After the excavation is continued to a predetermined depth, the solidification material liquid starts to be discharged from the lower discharge port 6 at a deeper depth, and the excavation is continued.
[0024]
As shown in (a) and (b), the excavated soil in the upper part moves to the ground as the volume of soil cement increases due to the stirring and mixing of the solidified material liquid discharged from the lower discharge port 6 and the excavated soil. Pushed up.
[0025]
After the start of the discharge of the solidified material liquid from the lower discharge port 6, as shown in (b) and (c), the vicinity of the tip of the steel pipe pile 10 into which the tip of the excavation rod 1 is inserted later, that is, the root consolidation part 8 The solidified material liquid is continuously discharged until the depth to be formed is reached, and the excavation rod 1 is rotated and dug. After that, the excavation rod 1 is continuously advanced while the solidification liquid for the root hardening part 8 is switched to discharge the solidification liquid for the root hardening part 8 from the lower discharge port 6, thereby constructing the root hardening part 8.
[0026]
After the construction of the root hardening part 8, as shown in (d) and (e), the excavation rod 1 is rotated and pulled out. At this time, the solidifying material liquid is not discharged from the lower discharge port 6. When the amount of the solidifying material liquid discharged during the excavation is small, the excavating rod 1 may be pulled up while discharging the solidifying material liquid from the upper discharge port 7.
[0027]
When the excavating rod 1 digs up to the predetermined depth without discharging the solidified material liquid shown in (e), that is, (a), and starts discharging the solidified material liquid from the lower discharge port 6 When reaching this depth, the excavating rod 1 is pulled up while being rotated while discharging the solidified material liquid from the upper discharge port 7.
[0028]
The discharge of the solidifying material liquid from the upper discharge port 7 is preferably stopped at a position somewhat below the ground surface without continuing to the ground surface as shown in (f). This is to prevent the soil cement 9 'from being discharged to the ground due to the apparent increase in the volume of the soil cement 9' accompanying the insertion of the steel pipe pile 10, or to reduce the discharge amount. The rise of the soil cement 9 'due to the increase in volume accompanying the insertion of the steel pipe pile 10 is shown in the difference between the upper end positions of the soil cement 9' in (g) and (h).
[0029]
By discharging the solidified material liquid from the upper discharge port 7, as shown in (f) to (h), the soil cement is formed on the soil cement column 9 constructed by the solidified material liquid discharged from the lower discharge port 6 before that. 9 'is constructed, and a soil cement column is constructed throughout the borehole.
[0030]
After the excavation rod 1 is pulled out, as shown in (g), while the steel pipe pile 10 with the open end is press-fitted or rotationally pressed into the soil cement column 9, the tip of the steel pipe pile 10 is rooted as shown in (h). A steel pipe soil cement pile is completed by press-fitting or rotationally press-fitting until it is buried in the hardened portion 8.
[0031]
FIG. 1 shows a case where the discharge of the solidified material liquid from the lower discharge port 6 is started at a position shallower than the construction start position of the root consolidation portion 8, while FIG. An example of a construction procedure of the method according to claim 2 for starting discharge of a root hardening liquid as a solidifying liquid.
[0032]
In the case of FIG. 4 as well, until the root hardening liquid is discharged from the lower discharge port 6, excavation is performed as shown in (a) and (b), or while excavating liquid is discharged from the lower discharge port 6. In the vicinity of the depth at which the tip of the excavating rod 1 reaches the root-fixing portion 8 where the tip of the steel pipe pile 10 to be inserted later is fixed, discharge of the root-setting liquid from the lower discharge port 6 is started as it is ( As shown in c), the rooted portion 8 is constructed by reaching the tip of the excavating rod 1 to the vicinity of the tip of the steel pipe pile 10.
[0033]
After the root consolidation part 8 is constructed, the root consolidation liquid supplied to the drilling rod 1 is switched to a poorer mixture and / or a small amount of solidified material liquid, and the discharge position is switched from the lower discharge port 6 to the upper discharge port 7. (D), (e), the soil cement pillar 9 is constructed by pulling out the rotating rod 1 while rotating the excavating rod 1 while discharging the solidified material liquid from the upper discharge port 7.
[0034]
After the construction of the soil cement column 9, as shown in (f) and (g), as shown in Fig. 1, the tip of the steel pipe pile 10 is solidified while rotating the steel pipe pile 10 with the tip open to the soil cement column 9. The steel pipe soil cement pile is completed by press fitting until it is buried in the part 8.
[0035]
5 shows that when the head of the steel pipe pile 10 is positioned deeper than the ground surface, the soil cement pillar 9 is constructed up to the vicinity of the head of the steel pipe pile 10 to be inserted later when the excavation rod 1 is pulled out. 4. The method according to claim 3, wherein the soil cement 11 is constructed on the ground surface or in the vicinity thereof while discharging a small amount of the solidifying material liquid from the upper discharge port 7 and poorly mixed with the solidifying material liquid in which the soil cement pillar 10 is constructed. An example of construction procedure is shown.
[0036]
FIG. 5 shows the construction of the soil cement pillar 9 on the soil cement pillar 9 after the construction of the soil cement pillar 9 excluding the root hardening part 8 and the upper layer part by the method of claim 2 shown in FIGS. 4 (a) to (d). Although FIG. 5- (d) is shown, the root hardening part 8 and the soil cement pillar 9 may be constructed | assembled by the procedure of FIG. 1- (a)-(d).
[0037]
In the case of FIG. 5, after construction of the root hardening portion 8, as shown in (d) and (e), the steel pipe pile 10 is pulled out by rotating the excavating rod 1 while discharging the solidified material liquid from the upper discharge port 7. While constructing the soil cement column 9 deeper than the ground surface where the head is located, and continuously discharging a lower amount of the solidifying material liquid from the solidifying material liquid and / or a small amount of the solidifying material liquid from the upper discharge port 7 while constructing the soil cement column 9 Soil cement 11 is built up to the ground surface or its vicinity.
[0038]
After the construction of the soil cement 11, the steel pipe pile cement pile is completed by press-fitting the steel pipe pile 10 into the soil cement pillar 9 as shown in (f) and (g) while holding the head with a Yatco.
[0039]
7 to 10 show an example of manufacturing a steel pipe pile 10 in which an enlarged wing 10a protrudes from the outer periphery of the tip. FIG. 7 shows a case where a screw-shaped expansion wing 10a is formed for one pitch, and ring-shaped ribs 10b for adhering to the soil cement of the root consolidation part 8 are arranged in multiple stages on the screw-shaped expansion wing 10a. When two expansion blades 10a and 10a are arranged symmetrically by a half pitch, FIG. 9 shows a case where the expansion blades 10a and 10a are arranged symmetrically by one pitch and FIG. 10 shows the expansion blades 10a and 10a of FIG. Is arranged in two upper and lower stages. Note that the ring-shaped rib 10b in FIG. 7 may be omitted.
[0040]
7-10, the enlarged wing 10a is formed in a curved screw shape, and the tip of the enlarged wing 10a protrudes from the tip of the steel pipe pile 10. However, the enlarged wing 10a is welded in the form of a flat plate cut. The tip of the enlarged wing 10a does not protrude from the tip of the steel pipe pile 10, that is, the tip of the enlarged wing 10a is positioned at the tip of the steel pipe pile 10 or above the tip of the steel pipe pile 10. There is also a case. Further, in the drawing, the enlarged wing 10a is formed in the circumferential direction of the steel pipe pile 10 with a length of one or a half circumference, but is not limited to this, and is further divided into 1/3 circumference, 1/4 circumference, etc. Sometimes.
[0041]
【The invention's effect】
At least the excavation stirring blade and the stirring blade are provided at the tip, and the lower discharge port and the upper discharge port are formed near the tip and the stirring blade, respectively. Therefore, unlike the case of using a drilling device having a spiral screw, it is possible to suppress the discharge of excavated soil to the ground accompanying the excavation of the excavating rod.
[0042]
Moreover, by excavating without discharging the solidifying material liquid from any of the discharge ports, the excavated soil not including the solidified material is present in the excavation hole, and the weight of the excavated soil not including the solidified material is used in the next step. In order to continue the excavation without discharging the solidified material liquid to the depth where pressure is applied to the constructed soil cement and the effect of suppressing the overflow of the excavated soil outside the excavation hole is exhibited, Therefore, even when excavated soil is discharged, it is possible to avoid discharge of earth and sand containing the solidifying material liquid.
[0043]
In this way, since two means of using a drilling rod without a screw on the peripheral surface and continuing excavation without discharging the solidified material liquid to a predetermined depth are used, compared to the case where each means is used alone. The amount of discharged excavated soil can be further reduced.
[0044]
In claim 2, the excavation without discharging the solidified material liquid to a predetermined depth is continued, and the bottom discharge is not performed for the first time near the depth at which the tip of the excavation rod reaches the root consolidation where the tip of the steel pipe pile to be inserted later is located. Since the depth of starting the discharge of the solidifying liquid is larger than the depth of starting the discharge of the solidifying material liquid according to claim 1 by constructing the root consolidation part by starting the discharge of the root hardening liquid from the outlet, Since the amount of excavated soil existing above the discharge port increases, it is possible to further enhance the effect of claim 1 that suppresses excavation of the excavated soil due to an increase in the volume in the excavated hole due to the discharge of the solidified material liquid. it can.
[0045]
Moreover, since the excavation rod having no spiral screw on the peripheral surface is used as in the first aspect, the excavation of the excavated soil to the ground accompanying the excavation of the excavation rod can be suppressed.
[0046]
In claim 3, when the excavation rod is pulled out, a soil cement column is constructed up to the vicinity of the head of the steel pipe pile to be inserted later, and the mixture is poorer than the solidification material liquid on which the soil cement column is constructed, and / or a small amount. Since the soil cement is constructed to the ground surface or the vicinity thereof while discharging the solidified material liquid from the upper discharge port, the resistance at the time of steel pipe pile insertion can be reduced. Moreover, since adhesion of earth and sand to a steel pipe pile peripheral surface is prevented at the time of steel pipe pile insertion, the integrity of a soil cement pillar and a steel pipe pile is not inhibited. In addition, trafficability on the ground surface after construction is improved.
[Brief description of the drawings]
FIG. 1 is an elevational view showing a construction procedure of a steel pipe soil cement pile according to claim 1;
FIG. 2 is an elevational view showing an example of manufacturing a drilling rod.
FIG. 3 is an elevation view showing another example of manufacturing a drilling rod.
FIG. 4 is an elevational view showing a construction procedure of the steel pipe soil cement pile according to claim 2;
FIG. 5 is an elevation view showing a construction procedure of the steel pipe soil cement pile according to claim 3;
6A is an elevation view showing a steel pipe pile, and FIG. 6B is a bottom view of FIG. 6A.
7A is an elevation view showing an example of manufacturing a steel pipe pile with an enlarged wing formed at the tip, and FIG. 7B is a bottom view of FIG. 7A.
FIG. 8A is an elevation view showing another example of manufacturing a steel pipe pile in which an enlarged wing is formed at the tip, and FIG. 8B is a bottom view of FIG. 8A.
9A is an elevation view showing another example of manufacturing a steel pipe pile with an enlarged wing formed at the tip, and FIG. 9B is a bottom view of FIG. 9A.
FIG. 10A is an elevation view showing another example of manufacturing a steel pipe pile with an enlarged wing formed at the tip, and FIG. 10B is a bottom view of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Drilling rod, 2 ... Leading drilling blade, 3 ... Stirring blade, 4 ... Drilling stirring blade, 5 ... Co-rotation prevention blade, 6 ... Lower discharge port, 7 ... Upper discharge port, 8 ... ····································································································································

Claims

Hold at least the excavation stirring blade and the stirring blade at the tip, and rotate the drilling rod without spiral screw on the peripheral surface, where the lower discharge port and the upper discharge port are formed near the tip and the stirring blade, respectively. The soil cement is constructed in the next step by excavating without discharging the solidifying material liquid from the discharge port, making the excavated soil not containing the solidified material exist in the excavation hole, and the weight of the excavated soil not containing the solidified material as it is Pressure is applied, and the excavation without discharging the solidified material liquid is continued until reaching the depth where the pressure suppresses the overflow of the excavated soil outside the excavation hole, and then the excavation rod is rotated After excavating while discharging the solidified material liquid from the lower discharge port and the tip of the drilling rod reaches the vicinity of the tip of the steel pipe pile to be inserted later, the drilling rod is pulled up, and the lower discharge port is When the upper discharge port reaches the vicinity of the depth at which the solidifying material liquid was discharged, the drill rod was rotated while the solidifying material liquid was being discharged from the upper discharge port, and then the soil cement column was constructed by pulling it out while rotating the drilling rod. A steel pipe soil cement pile construction method, characterized in that a steel pipe pile whose tip is opened is inserted into the steel pipe pile.

Hold at least the excavation stirring blade and the stirring blade at the tip, and rotate the drilling rod without spiral screw on the peripheral surface, where the lower discharge port and the upper discharge port are formed near the tip and the stirring blade, respectively. The solidified material liquid is also excavated from the discharge port without discharging, and the root end of the drilling rod is solidified from the lower discharge port in the vicinity of the depth where the tip of the steel pipe pile reaches the root consolidation part where the tip is fixed. After the liquid has been discharged and the root has been built, the excavating rod is pulled up, and when the upper discharge reaches the depth where the solidified material liquid has been discharged from the lower discharge during the excavation, the rooting liquid is discharged from the upper discharge. It is characterized by constructing a soil cement column by rotating the drilling rod while discharging a poorer compound and / or discharging a small amount of solidified material liquid, and inserting a steel pipe pile with an open end into the soil cement column Construction methods of steel pipe soil cement piles to be.

When the excavation rod is pulled out, a soil cement column is constructed up to the vicinity of the head of the steel pipe pile to be inserted later, and a poorer composition and / or a small amount of a solidification material solution than the solidification material solution on which the soil cement column is constructed. The construction method of the steel pipe soil-cement pile of Claim 1 or Claim 2 which builds a soil cement to the ground surface or its vicinity, discharging a pipe | tube from an upper discharge port.