TW201207198A - Steel pipe pile and installation method thereof - Google Patents

Steel pipe pile and installation method thereof Download PDF

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Publication number
TW201207198A
TW201207198A TW100123493A TW100123493A TW201207198A TW 201207198 A TW201207198 A TW 201207198A TW 100123493 A TW100123493 A TW 100123493A TW 100123493 A TW100123493 A TW 100123493A TW 201207198 A TW201207198 A TW 201207198A
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Taiwan
Prior art keywords
steel pipe
pipe pile
pile
end portion
tapered
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TW100123493A
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Chinese (zh)
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TWI461589B (en
Inventor
Yoshiroh Ishihama
Masahide Takagi
Hisashi Hirata
Nobuyuki Matsui
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Nippon Steel Corp
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Publication of TW201207198A publication Critical patent/TW201207198A/en
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Publication of TWI461589B publication Critical patent/TWI461589B/en

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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
    • E02D5/66—Mould-pipes or other moulds
    • E02D5/665—Mould-pipes or other moulds for making piles

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  • Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Paleontology (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Piles And Underground Anchors (AREA)
  • Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)

Abstract

A steel pipe pile, which opens a front end of the drilling direction thereof and is hollow, including: a fixed diameter portion in which an outer diameter is fixed, and a distal end portion in which an inner diameter and the outer diameter become gradually smaller toward the front end portion; wherein projections which extend partly or wholly from the front end portion to the back end portion and project outward from the diameter direction of the distal end, are provided on the outer periphery.

Description

201207198 * J 六、發明說明： 【明片^ ·；：^_ 】 發明領域 本發明係有關於一種於港灣構造物或橋梁的基礎及建 物之基礎等土木、建築領域中使用之鋼管樁及其施工方法。 本案係依據2010年7月5曰於日本申請之特願 2010-153290號而主張優先權，此處並沿用其内容。 【先前J 發明背景 習知，作為摩擦樁，為了提高樁之周面摩擦力，使樁 之前端部的外周面作成錐狀外周面，或是將樁全長之外周 - 面作成錐狀外周面，且從樁之前端部之錐狀部起橫跨外徑 為一定的定徑部全長，將鋼筋纏繞成螺旋狀者係為人所知 . (例如參照專利文獻1)。對如此之摩擦樁是期待樁之外周面 的摩擦力。 又，於樁長度方向之中間部的外周面，於樁軸方向隔 著間隔設置複數螺旋翼，且在樁之前端部的錐體部分以與 螺旋翼之翼距(推進螺距)相同間隔，將帶鋼藉由熔接等以相 同推進螺距螺旋狀地固定於前述錐體部分者亦為人所知 (例如，參照專利文獻2)。 於使樁貫入至地盤的情況，錐狀之外周面部分的平面 投影面積大時，於樁貫入完成後，便成為發揮樁之支撐力 的部分。另一方面，於樁施工時，特別是必須穿透單軸壓 縮強度超過3N/mm2之所謂軟岩或中硬岩、硬岩之岩盤的中 201207198 間層時，及支撐層為岩盤且使樁貫入該處時，錐狀之外周 面部分便會成為大的貫入阻力。 為了埋設現場澆製鋼筋混凝土樁及既成混凝土樁，使 用將前端側作成錐狀之外周面及錐狀之内周面的套管者亦 為人所知（例如，參照專利文獻3)。 【先行技術文獻】 【專利文獻】 【專利文獻1】日本特開2003-3465號公報 【專利文獻2】日本特開平8-284160號公報 【專利文獻3】日本特開2〇05_248439號公報 【發明内容】 發明概要 【發明所欲解決的問題】 在藉由旋轉壓入施工將樁貫入地下時，由於隨著貫入 深度變大，會發生較大之管内閉塞土的阻力，而需要高壓 入力、旋轉力。此處，所謂壓入力是指為了將樁朝地下之 貫入方向壓入所施加的力。又，旋轉力是指為了使樁旋轉 所施加的力。 為了確保將樁旋轉壓入的壓入力，便需要反力，為了 確保反力，便須一面將配重設於旋轉壓入施工機，一面設 置固定錨等。因此便需要該等之輸送費及作業費、材料費 等，而增加樁之施工成本。又，為了確保壓入力，旋轉壓 入施工機也變得大能力化、大型化，所以也使得樁施工成 本更向上增加。 4 201207198 再者，為了獲得樁的推進力，將推進用之螺旋翼或葉 片等工具安裝於樁時，需耗費加工費及安裝費或材料費， 再者，於軟弱地盤之施工中，相反地，由於因螺旋翼或葉 片之間隔而限制了施工速度，因此導致施工速度的降低。 又，將既成樁貫入支撐層後，為了獲得更高支撐力， 而有確實地使既成樁之前端閉塞的工法。在該工法中，將 樁前端之土壤完全排除後，必須一面打設混凝土，一面將 水泥（cement milk)注入到樁前端以製造護基部。 又，前端開口且於該樁前端部設有掘削刀具之具刀具 開端樁在旋轉壓入施工時，伴隨開端樁朝地下之貫入量， 土壤會流入管内而堆積。藉此，樁之前端部的閉塞程度變 高，而會成為樁壓入時阻力的原因。前述樁前端之閉塞係 藉由構成所謂流入管内的砂或黏土或石礫之地盤的材料 (土壤)與樁内側之内周面的摩擦而產生。 特別是，樁旋轉壓入施工時會成為問題的是將樁朝地 下的貫入方向壓入之壓入力。此係於樁旋轉壓入施工時， 由於通常係以配重或施工用之機械本身的自重獲得反力， 為了使反力變大而需要很多配重，因此並不經濟。旋轉方 向的力由於係可以反力獲得用之棒狀工具等置於其他重機 等而取得反力，因此較少成為問題。 於外徑為一定之定徑部螺旋狀地設有突起之樁的情 況，將樁旋轉壓入進行施工時，設於定徑部之部分的螺旋 狀突起會擾動樁之外周面部分的周圍地盤。藉此，有降低 鋼管樁之周面與周圍地盤之樁周面摩擦阻力的可能性。因 201207198 此，即使是屬於支撐樁， 前端支撐力與定徑部之周面摩 也可藉由使不極力擾動定徑部之 外周側面的地盤，而期待樁 擦阻力。 於樁軸方向之全長具有錐狀外周面的樁之情況， 樁之製作成本變高且振 且捲施工裝置也特殊，施工變得繁雜。 於施工樁之錐狀外周面之周方向設置螺旋狀突起 以螺旋狀地橫跨數周而成為推制距時螺旋狀突起會導 引樁％轉壓人時錐狀外周面附近的土壤流動而使土壌流 % °狀突_極地使土壤剪力破壞，因 此要降低祕外周面與土壞之附著便會變得困難。 於此％口，錐狀之外周面部分的平面投影面積變得越 大壓入力便變得越大，又，土壤附著於錐狀之外周面部 分所產生之阻力也會變大。 本案申明人提申了只於樁之前端部設置錐狀外周面及 錐狀内周面之鋼管樁之發明，作為解除如前述橫跨捲全長 設置錐狀外周面之錐狀樁的缺點之技術。 如此’利用於鋼管樁之前端設置具有錐狀外周面及錐 狀内周面之錐狀部分’而減少管内土與樁内周面之摩擦所 產生之阻力。藉此，可降低因侵入到管内之土砂與鋼管之 内側的摩擦而發生之阻力，即所謂管内閉塞阻力。又，藉 由錐狀部分，增加樁底面之投影面積，由於對地盤抵抗而 可易於獲得高支#力。特別是，在地盤高拘束壓之深支樓 層或硬岩盤層’利用錐狀部分之底面投影面積的部分而可 負擔高壓縮荷重。又，可發揮高於前端開口之通常的直鋼 6 201207198 管樁之支撐力。 但是’在具有前端錐狀部分的鋼管樁中，其前端錐狀 部分於樁施工時，由於前述前端錐狀部分具有角度而直接 與地盤接觸，因此於錐狀部分會發生高荷重。在發生高荷 重下因旋轉具前鱗㈣突起之鋼轉，而會有前端錐狀 部分之鋼材的板厚因摩擦而減少，且會有產生變形之虞。 又’前端錐狀❹之荷重由於產生大的阻力，&了使施工 機械的能力更小而可施工，更希望降低阻力。 藉由旋轉壓入施工而將樁進行施工時，可以使將捲於 地下之貫人方向壓人之壓入力較小時’便可謀求每一根捲 之施工成本的降低。因此’為了將多數根樁旋轉壓入到地 盤，在顯著地降低全部施I成本之下，使每根樁之施工成 本降低便變得重要。 本發明係以提供一種可降低樁之壓入力的鋼管樁及其 施工方法為目的。 ' 【用以解決課題之手段】 本發明為了解決上述課題以達成如此目的，而採取以 下之手段。 亦即， (1)本發明之-態樣之鋼管㈣㈣方向的前端開口且 為中空者，其特徵在於：該鋼管樁包含外徑尺寸為一定的 定徑部及㈣尺寸及外形尺寸朝前述前端逐漸變小的前端 部’於前述前端部之外周面設有姨，前述突起係從前述 前端朝後端延伸在一部分或全體，且突出於前述前端部之 201207198 半徑方向外方。 (2) 上述（1)記載之鋼管樁係前述突起於前述前端部之 前述外周面的周方向隔著間隔設有複數個為佳。 (3) 在上述（1)或(2)記載之鋼管樁中，係以前述突起傾斜 成使前述突起之前述後端側成前述定徑部及前述前端部之 旋轉方向的後方者為佳。 (4) 在上述（1)或(2)記載之鋼管樁中，係以前述突起相對 前述前端部之中心軸線於周方向傾斜配置，且垂直於前述 中心軸線之面與前述突起之延伸方向的中心軸線所呈的角 度為20°〜70°者為佳。 (5) 在上述（1)或(2)記載之鋼管樁中，係以前述突起之高 度係規定成前述突起較前述定徑部之外形尺寸位於前述前 端部之前述半徑方向的内側者為佳。 (6) 在上述(2)記載之鋼管樁中，係以於前述前端之周方 向隔著間隔設有複數掘削刀者為佳。 (7) 在上述(6)記載之鋼管樁中，係以前述突起之下端係 位於前述掘削刀之上面的正上方者為佳。 (8) 在上述(6)記載之鋼管樁中，係以前述掘削刀較前述 定徑部之外形尺寸配置於前述前端部之前述半徑方向的内 側者為佳。 (9) 在上述（1)記載之鋼管樁中，係以前述前端部之長度 方向的高度尺寸相對於前述定徑部之外形尺寸的比為0.3 〜5.5者為佳。 (10) 在上述（1)記載之鋼管樁中，係以前述前端之外徑 8 201207198 尺寸相對於前述定徑部之外徑尺寸的比為0.60〜0.95者為 佳。 (11) 在上述（1)記載之鋼管樁中，係以於前述前端部設 有從前述前端突出且朝前述掘削方向尖銳之尖銳部者為 佳。 (12) —種使用上述（1)記載之鋼管樁之鋼管樁的施工方 法，其特徵在於：以藉由對前述鋼管樁附與旋轉力及壓入 力之旋轉壓入工法而壓入到地盤時，一面藉由前述突起剪 力破壞前述地盤一面壓入前述鋼管樁者為佳。 (13) 在上述（12)記載之鋼管樁的施工方法中，係以將前 述鋼管樁旋轉壓入到包含硬質地盤之地盤者為佳。 (14) 在上述（12)記載之鋼管樁的施工方法中，係以於施 工途中，一面在地下使前述鋼管格旋轉、或者是不加旋轉、 或組合其等，一面使上下動，藉以降低前述鋼管樁内之土 壤的高度者為佳。 (15) 在上述（12)記載之鋼管樁的施工方法中，係以於支 撐層内最後停止打設前述鋼管樁之前述前端部時，逆旋轉 前述鋼管樁，且藉由前述突起將前述前端部之外周面附近 的土壤壓入到下方者為佳。 【發明的效果】 首先，鋼管樁有其前端閉塞之閉端樁與前端開口之開 端樁，本發明係屬於前端開口之開端樁。 又，鋼管樁有不打入到支撐層而主要使周面摩擦力發 揮以期待支撐力之摩擦樁、與打入到支撐層而主要使在前 9 201207198 之支撐樁，本發明係屬於 前端部之支撐力以期待支 端部之支撐力發揮以期待支待为 將鋼管樁打入到支撐層而發揮在 撐力的支撐樁。 m儺上戟之鋼管樁， 寸逐漸變小之錐狀前端部，單^在内形尺寸及外形' 而可於藉衫祕樁施工到地^置聽的簡單構成 變形。 下時，抑制前端部之摩擦/ 且可控 小型化 又，降低鋼管樁施謂之施工荷重變成可能， 制施工機械之能力。並可獲得依情況而使施工機械 之施工成本便宜之鋼管樁等效果。 又，由於前端部係錐狀，所以本鋼管樁可降低因内周 面之摩擦所產生之阻力，謀求提升施工性。又由於藉由 錐狀别端部增加樁底面之投影面積，以對地盤進行阻抗， 所以可易於獲得高支撐力。又，在拘束壓高且支撐層深， 或是在岩盤層硬等之地盤中，由於可利用錐狀前端部（底面 投影面積的部分）來負擔高壓縮荷重，所以可發揮較通常具 有直的開口之鋼管樁（只具有定徑部之鋼管樁）高的支樓力。 通常，在打入樁等中’為了發揮在樁之前端的支樓力， 需要使樁之前端閉塞。例如，前端開口之打入樁的情況， 為了使樁前端閉塞，必須使樁貫入支撐層一定深度以上。 然而’本鋼管樁由於具有錐狀前端部’所以可提高樁前端 之支撐力。其結果，不須為了發現在樁前端之支撐力而使 樁前端面閉塞，且即使小貫入量，也可獲得支樓力，又， 獲得了可縮短施工時間等之效果。 10 201207198 依據上述(2)記載之鋼管樁，由於前述突起係隔著間隔 複數個設於前端部之周方向，所以可獲得藉由隔著間隔設 置之突起，而可謀求進一步抑制錐狀前端部之摩擦及變形 的效果。 依據上述(3)記載之鋼管樁，由於前述突起係傾斜以使 前述突起之後端側成為定徑部及前端部之旋轉方向的後 方，所以可獲得平順地沿著突起傾斜的方向，導引朝上流 動在掘削後之錐狀前端部之外周側面的掘削土（土渣），或是 藉由突起剪力破壞之土砂而流動等之效果。 依據上述(4)記載之鋼管樁，由於垂直於前端部之中心 軸線的面與前述突起之延伸方向之中心軸線所成之角度為 20Q〜70°，所以獲得可發揮突起所產生之適度的土壤剪力破 壞作用或是導引作用等之效果。 依據上述(5)記載之鋼管樁，由於突起之高度係被規定 以使突起較定徑部之外形尺寸位於前端部之半徑方向的内 側，所以藉由突起，擾動土擾的範圍變少。是故，獲得可 抑制外周面之摩擦降低等的效果。 依據上述(6)記載之鋼管樁，由於在前端部之前端具有 複數掘削刀，所以即使是地盤為硬質地盤，也可獲得易於 掘削、旋轉，以貫入地盤等之效果。 依據上述(7)記載之鋼管樁，由於突起之下端位於掘削 刀之上面的正上方，所以可獲得以突起確實地導引藉由掘 削刀而沿著錐狀前端部之外周面側流動的土壤（土渣）之效 果0 11 201207198 依據上述⑻記載之鋼管樁，由於掘削刀係相較定徑部 之外形尺寸配置於前端部之半徑方向的⑽，所以相較直 的鋼官樁’旋轉壓人之鋼管樁之平面外徑變小，所以可謀 求j里化·^者，掘削外徑變小的部分，掘削量少，而可 獲得提升施工性的效果。 依據上述(9)記载之鋼管格，由於前述前端部之長度方 向的高度尺寸對定徑部之外形尺寸的比為G3〜55，所以於 軟弱地盤’相對於直的鋼管樁（只有定徑部的鋼管格），可減 輕鋼管樁之内周面的摩擦所產生之阻力而課求提升施工 性。再者，於讀層獲得可崎少貫人量發揮高支樓力# 效果。 w 載之鋼官樁，由於前端之外徑尺寸對 徑部之外徑尺寸的比， ^ 亦即鋼管椿之縮徑率為0.60〜〇 的範圍，所以相較於尬τ 士 、 直的铜管樁時，可使旋轉壓入 工機之配重較少。又，~ 可谋求椿施工機械之小型化且謀 中間層之施工性的提升。 降低支樓層之貫入量—面:二’獲得了可:為可-面課 7 _ 9大支樓力之鋼管樁的效果。 依=上述(U)記載之鋼管捲之施工方法，由於在前端 设置從則端突出且朝掘削 ,, 万向尖銳之尖銳部，所以可獲」 一面掘削地盤一面可有q ’放率地施工之鋼管樁的效果。 上述(12)記載之鋼管樁之施工方法，由於藉由對' 鋼官樁給予旋轉力及壓 刀之旋轉壓入工法，將具有上 (:=前端部的鋼管樁壓八地下，所以可降低施工 本進灯施工。又，相較於 、直的鋼管樁（只有定徑部之鋼 12 201207198 樁）’即使相對支撐層之貫入量少，也可獲得施工性佳、低 成本施工具高支撐力之基礎樁的效果。再者，藉由使用例 如具有掘削刀之鋼管樁，而可更有效率施工鋼管樁。 依據上述（13)記載之鋼管樁之施工方法，由於將上述p) 之具有錐狀前端部之鋼管樁旋轉壓入到包含硬質地盤之地 盤，所以即使是包含硬質地盤之地盤，也可以低成本施工。 又，在使其貝入到硬質地盤之支撑層時，相較於直的樁， 即使是對支撐層之貫入量少，也獲得可施工具有高支撐力 的基礎樁等之效果。 依據上述（14)記載之鋼管樁之施工方法，於施工途中， 由於利用在地下使鋼管樁上下動，而降低鋼管樁内土壌的 尚度，所以獲得一面降低鋼管之内周面的摩擦一面可有效 率地施工等效果。 依據上述(15)記載之鋼管樁之施工方法，於支樓層内最 後停止打設鋼管樁之前端部時，將鋼管樁逆旋轉，而藉由 突起將錐狀外周面附近的土壤（包含碎石等土清)壓入至下 L藉此’利用突起將錐狀前端部之外周面附近的土壤壓 入至下方，可獲得使 樁等之效果。 則之支撐層密實而使支撐鋼管 圖式簡單說明 第1A圖係顯示本發明第 起之鋼管樁的前視圖。 1實施形態之於前端部具有突 第1B圖係前述鋼瞢板 捲之縱斷面前視圖。 第1C圖係自第iB圖之 圆之a-a箭頭所見之斷面圖 13 201207198 第ID圖係自第1B圖之b-b箭頭所見之斷面圖。 第2A圖係顯示本發明第2實施形態之於前端部具有突 起之鋼管樁的立體圖。 第2B圖係前述鋼管樁之前視圖。 第3A圖係顯示本發明第3實施形態之於前端部具有突 起之鋼管樁的前視圖。 第3B圖係前述鋼管樁之縱斷面前視圖。 第3C圖係自第3B圖之c-c箭頭所見之斷面圖。 第3D圖係自第3B圖之d-d箭頭所見的圖示。 第4A圖係顯示本發明第4實施形態之於前端部具有突 起之鋼管樁的立體圖。 第4B圖係前述鋼管樁之前視圖。 第5圖係顯示本發明第5實施形態之於前端部具有突起 之鋼管樁的前視圖。 第6A圖係顯示本發明第6實施形態之於前端部具有突 起之鋼管樁的前視圖。 第6B圖係前述鋼管樁之縱斷面前視圖。 第6C圖係自第6B圖之e-e箭頭所見之斷面圖。 第6D圖係自第6B圖之f-f箭頭所見的圖示。 第7 A圖係顯示設於本發明第7實施形態之鋼管樁之突 起的形狀及安裝範圍的側面圖。 第7 B圖係顯示設於本發明第7實施形態之鋼管樁之突 起的形狀及安裝範圍的斷面圖。 第8 A圖係顯示比較例的說明圖。 14 201207198 第8B圖係顯示比較例的說明圖。 第9圖係顯示藉由旋轉壓入施工機將鋼管樁旋轉壓入 到地盤之狀態的前視圖。 第10圖係顯示於錐狀前端部具有突起之本發明之鋼管 樁、與於錐狀前端部不具有突起之比較例的鋼管樁之施工 荷重、貫入量與壓入力之關係的圖表。 第11圖係比較施工本發明之於錐狀前端部具有突起之 鋼管樁的場合、與於錐狀前端部不具有突起之鋼管樁的場 合之前端部的平均磨耗量的圖示。 第12圖係比較將本發明之於錐狀之前端部具有突起之 鋼管樁的場合、與於錐狀之前端部不具有突起之鋼管樁施 工時之前端部的平均變形量的圖示。 第13A圖係顯示使用本發明之鋼管樁旋轉壓入到地盤 時之旋轉方向的圖示。 第13B圖係第13A圖之斷面圖，且係顯示土壤的流動之 說明圖。 第14圖係顯示將前述鋼管樁旋轉壓入到支撐層的狀態 之縱斷面前視圖。 第15圖係顯示使用前述鋼管樁旋轉壓入到地盤時之土 壤的流動之說明圖。 第16圖係顯示將前述鋼管樁朝支撐層壓入時之壓入深 度、管内土壤的高度、與前端部附近之尺寸的關係之縱斷 面前視圖。 第17圖係就有關前述鋼管樁與作為比較例之直樁，顯 15 201207198 示每一樁閉塞斷面積之壓入力與貫入量對樁徑之比的關係 之圖表。 第18圖係就有關前述鋼管樁與作為比較例之直樁，顯 示前端沉下量對樁徑之比、與樁之前端荷重度之關係的圖 表。 第19圖係顯示前端部之長度對前述鋼管樁之外徑的 比、及前述鋼管樁之必要壓入力與直樁之必要壓入力的之 比率的必要壓入力比率之關係的圖表。 第2 0圖係顯示前端部之縮徑率（D 2 /D1)與必要壓入力 比率之關係的圖表。 第21A圖係顯示鋼管樁之前端部側之阻力的圖示，且係 顯示比較例之直樁之場合的縱斷面前視圖。 第21B圖係顯示錐狀前端部之鋼管樁的場合之縱斷面 前視圖。 第22A圖係顯示作為比較例之鋼管樁的前視圖。 第22B圖係第22A圖之縱斷面前視圖。 第22C圖係自第22B圖之g-g箭頭所見之斷面圖。 I：實施方式3 較佳實施例之詳細說明 接著，依據圖示之實施形態來詳細說明本發明。 第1A圖〜第1D圖係顯示本發明第1實施形態之鋼管樁 (以下，也稱為具前端錐狀部突起之鋼管樁1A)1。 本發明之具前端錐狀部突起之鋼管樁1A係藉由旋轉壓 入工法來打設。該鋼管樁1A如第1圖所示，係掘削方向A1 16 201207198 的前頭端（前端)4a開口且為中空，並包含有定徑部9與錐狀 部（前端部)4。 定徑部9係外徑尺寸為一定。又，錐狀部4係錐狀且 於錐狀部4設有突起i6a。錐狀部4之内周面3係朝前端知内 形尺寸於長度方向逐漸縮徑之錐狀。又，錐狀部4之外周面 2係朝前端4a外形尺寸於長度方向逐漸縮徑之錐狀。 又，在錐狀部4之前端4a於周方向隔著等角度間隔設有 複數掘削刀6。於設置複數之偶數個掘削刀6時係相對包 含鋼管樁1A之中心減C之平面配置成對稱，秘配置複 ^之奇數個時，係隔著等角度間隔設置。_刀_透㈣ 當支持部（省略圖示）而固定於鋼管樁丨A之前端知。 如此’藉由將掘削刀6設於具前端錐狀部突起之鋼管樁 A:前端，即使地盤為硬質，於旋轉壓^法，也可一面 7 一面使鋼管輪貫入地盤。特別是，如第U圖所示， ^ 一面於箭頭x方向及箭頭γ方向旋轉並掘 C到由硬質地盤所構成之支軸。於此場 。吏用如第9圖所示之旋轉壓入施 管的樁施工機械。 &具打樁用之導 在本實施㈣之鋼管樁1Α巾，雖以 具有掘削用77 a + ;、隹狀°M之前端4a 、有掘削用刀6之形態為佳，然 形態。 J马不具掘削用刀6之 在第1A圖所示之形態中，於 刀6，且鋼管4#1A前端如之 狀。H之前端知具有掘則 係配置於錐狀部4之半徑方向：:徑部6之外形尺寸 側。错此’相較於在 17 201207198 如第22A圖〜第22C圖所示之直 管樁）ιο的錐狀部4設置掘削刀θ S樁（”有疋植部之鋼 管樁1A5之平面外徑尺寸較小。2合’可使具掘削刀之鋼 裝貨成複數段^進行貨車輪如、，在將複數鋼管樁1A 鋼管樁干涉。目此，即絲_ ^肖會對相鄰接之 態將複數鋼管樁1A裝貨.又，> 等’也可在安定狀 於在第22A圖〜第22C圖所示轉壓人至地盤時，相較 置掘削刀6的情;兄，可排除的鋼管樁10之錐狀部4設201207198 * J VI. Description of the invention: [Ming film ^ ·;: ^_] Field of the invention The present invention relates to a steel pipe pile used in the civil engineering and construction fields, such as the foundation of a harbor structure or a bridge and the foundation of a building. Construction method. This case claims priority based on the Japanese Patent Application No. 2010-153290, filed on July 5, 2010, and the content is hereby incorporated. [In the prior art, as a friction pile, in order to increase the circumferential frictional force of the pile, the outer peripheral surface of the front end portion of the pile is formed into a tapered outer peripheral surface, or the outer circumference of the pile is made into a tapered outer peripheral surface. Further, it is known that the entire length of the sizing portion is constant from the tapered portion at the end portion of the pile, and the reinforcing bar is wound into a spiral shape (see, for example, Patent Document 1). Such a friction pile is expected to have a frictional force on the outer peripheral surface of the pile. Further, the outer peripheral surface of the intermediate portion in the longitudinal direction of the pile is provided with a plurality of spiral wings at intervals in the pile axis direction, and the tapered portion at the end portion of the pile is spaced at the same distance from the wing pitch (propulsion pitch) of the spiral wing. It is also known that the steel strip is spirally fixed to the aforementioned conical portion by welding or the like with the same propulsive pitch (for example, refer to Patent Document 2). In the case where the pile is penetrated to the ground, when the plane projection area of the outer circumferential surface portion of the tapered shape is large, after the pile penetration is completed, the support force of the pile is exerted. On the other hand, in the pile construction, especially when it is necessary to penetrate the middle layer 201207198 of the so-called soft rock or medium hard rock or hard rock slab with a uniaxial compression strength exceeding 3 N/mm 2 , and the support layer is a rock disk and the pile penetrates At this point, the outer peripheral portion of the tapered shape becomes a large penetration resistance. In order to bury a cast-in-place reinforced concrete pile and an existing concrete pile, it is known to use a sleeve having a tapered outer peripheral surface and a tapered inner peripheral surface (for example, refer to Patent Document 3). [Patent Document 1] [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. Contents] Summary of the Invention [Problems to be Solved by the Invention] When the pile is penetrated into the ground by the rotary press-in construction, as the penetration depth becomes larger, the resistance of the larger closed soil within the tube occurs, and high-pressure input and rotation are required. force. Here, the press-in force refers to a force applied to press the pile in the penetration direction of the ground. Further, the rotational force refers to the force applied to rotate the pile. In order to ensure the pressing force for the pile to be pressed in, the reaction force is required. In order to ensure the reaction force, the weight must be placed on the rotary press machine while the fixed anchor is installed. Therefore, such transportation costs, operating costs, material costs, etc. are required, and the construction cost of the pile is increased. Further, in order to secure the press-fitting force, the rotary press-in construction machine is also increased in capacity and size, so that the pile construction cost is further increased. 4 201207198 Furthermore, in order to obtain the propulsive force of the pile, when the tools such as the propeller blades or blades for propulsion are installed on the pile, the processing fee and the installation fee or the material cost are required, and in the construction of the weak site, conversely Since the construction speed is limited due to the spacing of the spiral wings or the blades, the construction speed is lowered. Further, after the existing pile is inserted into the support layer, in order to obtain a higher supporting force, there is a method of reliably closing the front end of the existing pile. In this method, after the soil at the front end of the pile is completely removed, concrete must be placed on one side, and cement (cement milk) is injected into the front end of the pile to manufacture the base. Further, the tool having the cutting tool at the front end and the cutting tool is provided at the front end portion of the pile. At the time of the rotary press-in construction, the soil flows into the pipe and accumulates as the opening pile penetrates into the ground. Thereby, the degree of occlusion of the front end portion of the pile becomes high, which may cause the resistance at the time of pile press-in. The clogging of the front end of the pile is caused by friction between the material (soil) constituting the so-called sand or clay or gravel in the inside of the pipe and the inner peripheral surface of the pile inner side. In particular, a problem that becomes a problem when the pile is rotated into the construction is the pressing force that pushes the pile into the ground in the penetration direction. This is because during the construction of the pile rotary press-in, since the reaction force is usually obtained by the weight of the counterweight or the machine itself for construction, it is not economical to require a lot of counterweights in order to increase the reaction force. The force in the direction of rotation is less likely to be a problem because the rod-like tool that can be obtained by the reaction force is placed on another heavy machine or the like to obtain a reaction force. In the case where a pile having a raised diameter is provided in a fixed diameter portion, the pile is rotated and pushed into the construction, and the spiral protrusion provided in the portion of the sizing portion disturbs the surrounding ground portion of the outer peripheral portion of the pile. . Thereby, there is a possibility of reducing the frictional resistance of the circumferential surface of the steel pipe pile and the surrounding surface of the pile. According to 201207198, even if it belongs to the support pile, the circumferential surface friction of the front end support force and the sizing portion can be expected to cause the pile resistance by not disturbing the ground surface on the outer circumferential side of the sizing portion. In the case of a pile having a tapered outer peripheral surface in the direction of the pile axis, the production cost of the pile is high, and the vibration and the coil construction apparatus are also special, and the construction becomes complicated. A spiral protrusion is provided in a circumferential direction of the tapered outer peripheral surface of the construction pile to spirally span for several weeks, and when the pitch is pushed, the spiral protrusion guides the soil flowing near the tapered outer peripheral surface when the pile is rotated. The soil turbulence is caused by the % 状 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ At this % port, the larger the plane projection area of the outer peripheral portion of the tapered shape becomes, the larger the press-in force becomes, and the greater the resistance generated by the soil adhering to the tapered outer peripheral surface portion. In the case of the present invention, the invention of the steel pipe pile in which the tapered outer peripheral surface and the tapered inner peripheral surface are provided only at the front end of the pile is proposed as a technique for releasing the tapered pile having the tapered outer peripheral surface over the entire length of the pile. . Thus, the taper portion having the tapered outer peripheral surface and the tapered inner peripheral surface is provided at the front end of the steel pipe pile to reduce the friction generated by the friction between the soil inside the pipe and the inner peripheral surface of the pile. Thereby, the resistance generated by the friction between the soil sand invaded into the pipe and the inner side of the steel pipe can be reduced, that is, the so-called in-tube occlusion resistance. Further, by the tapered portion, the projected area of the bottom surface of the pile is increased, and the high support force can be easily obtained by resisting the ground. In particular, a high compression load can be afforded by the portion of the deep support floor or the hard rock layer where the ground is highly restrained by the projected area of the bottom surface of the tapered portion. Moreover, it can exert the supporting force of the normal straight steel 6 201207198 pipe pile which is higher than the front end opening. However, in the steel pipe pile having the tapered end portion, when the tapered portion of the tip end is applied to the pile, since the tapered portion of the front end is in direct contact with the ground plate, a high load occurs in the tapered portion. In the event of a high load, the steel of the front scale (four) of the rotating tool rotates, and the thickness of the steel having the tapered portion at the front end is reduced by friction, and there is a possibility of deformation. Moreover, the load on the front end of the tapered crucible is due to the generation of large resistance, and the construction machinery is less capable of being constructed, and it is desirable to reduce the resistance. When the pile is constructed by the rotary press-in construction, the pressing force for pressing the person in the direction of the underground can be reduced, and the construction cost per roll can be reduced. Therefore, in order to press a large number of piles into the floor, it is important to reduce the construction cost of each pile under the significant reduction of the total cost of the application. The present invention is directed to providing a steel pipe pile capable of reducing the pressing force of a pile and a construction method thereof. [Means for Solving the Problem] In order to achieve the above object, the present invention has been made in order to achieve the above object. That is, (1) the front end of the steel pipe (four) (four) direction of the present invention is open and hollow, and is characterized in that the steel pipe pile includes a sizing portion having a constant outer diameter and (iv) a size and an outer dimension toward the front end. The tapered front end portion is provided with a weir on the outer peripheral surface of the front end portion, and the projection extends from the front end toward the rear end in a part or the entirety, and protrudes outward in the radial direction of 201207198 of the front end portion. (2) The steel pipe pile system according to the above (1) is preferably provided with a plurality of the projections at intervals in the circumferential direction of the outer peripheral surface of the front end portion. (3) The steel pipe pile according to the above aspect (1) or (2), wherein the protrusion is inclined such that the rear end side of the protrusion is a rear side in a rotation direction of the sizing portion and the tip end portion. (4) The steel pipe pile according to (1) or (2), wherein the protrusion is inclined in a circumferential direction with respect to a central axis of the distal end portion, and a surface perpendicular to the central axis and a direction in which the protrusion extends It is preferred that the central axis exhibits an angle of 20° to 70°. (5) In the steel pipe pile according to the above aspect (1) or (2), preferably, the height of the protrusion is such that the protrusion is larger than the outer diameter of the sizing portion in the radial direction of the front end portion. . (6) In the steel pipe pile according to the above (2), it is preferable that a plurality of boring cutters are provided at intervals in the circumferential direction of the front end. (7) In the steel pipe pile according to the above (6), preferably, the lower end of the projection is located directly above the upper surface of the boring cutter. (8) In the steel pipe pile according to the above (6), it is preferable that the boring tool is disposed on the inner side in the radial direction of the front end portion in a shape other than the sizing portion. (9) In the steel pipe pile according to the above (1), the ratio of the height dimension of the distal end portion in the longitudinal direction to the outer dimension of the sizing portion is preferably 0.3 to 5.5. (10) In the steel pipe pile according to the above (1), the ratio of the outer diameter of the front end 8 201207198 to the outer diameter of the sizing portion is preferably 0.60 to 0.95. (11) In the steel pipe pile according to the above (1), it is preferable that the front end portion is provided with a sharp portion that protrudes from the front end and is sharp toward the boring direction. (12) A method of constructing a steel pipe pile using the steel pipe pile according to (1) above, wherein the steel pipe pile is pressed into the ground by a rotary press-fitting method for attaching a rotational force and a press-in force to the steel pipe pile It is preferable that one side of the above-mentioned ground plate is pressed into the steel pipe pile by the above-mentioned protruding shear force. (13) In the method of constructing a steel pipe pile according to the above (12), it is preferable that the steel pipe pile described above is rotated and pressed into a ground plate including a hard land. (14) In the method of constructing a steel pipe pile according to the above (12), the steel pipe is rotated in the ground while being rotated, or is rotated, or combined, and the like. The height of the soil in the aforementioned steel pipe pile is preferred. (15) In the method of constructing a steel pipe pile according to the above (12), when the front end portion of the steel pipe pile is finally stopped in the support layer, the steel pipe pile is reversely rotated, and the front end is raised by the protrusion It is better that the soil near the outer surface of the part is pressed into the lower part. [Effect of the Invention] First, the steel pipe pile has a closed end pile whose front end is closed and an open end pile whose front end is open, and the present invention belongs to the open end pile of the front end opening. In addition, the steel pipe pile has a friction pile that does not enter the support layer and mainly exerts a circumferential frictional force to exhibit a supporting force, and a support pile that is driven into the support layer and mainly causes the first 9 201207198, and the present invention belongs to the front end portion. The support force is exerted in anticipation of the supporting force of the end portion, and it is expected to support the support pile for driving the steel pipe pile into the support layer. The steel pipe pile on the top of the m傩, the tapered front end portion of the inch is gradually smaller, and the inner shape and shape of the inner part can be deformed by the simple construction of the piled pile to the ground. In the case of the lower part, the friction at the front end portion is suppressed and the size is controlled and reduced, and the construction load of the steel pipe pile is reduced, and the construction machinery is capable. It is also possible to obtain effects such as steel pipe piles where the construction cost of the construction machine is low depending on the situation. Further, since the front end portion has a tapered shape, the steel pipe pile can reduce the resistance caused by the friction of the inner circumferential surface and improve the workability. Further, since the projected area of the bottom surface of the pile is increased by the tapered end portion, the impedance is applied to the ground plate, so that high supporting force can be easily obtained. In addition, in the ground plate where the restraining pressure is high and the support layer is deep, or the rock disk layer is hard, the tapered front end portion (portion of the bottom surface projected area) can be used to bear the high compression load, so that it can be more straight. The open steel pipe pile (only the steel pipe pile with the sizing part) has a high branching force. Usually, in the pile or the like, in order to exert the branching force at the front end of the pile, it is necessary to close the front end of the pile. For example, in the case where the front end opening is driven into the pile, in order to close the pile front end, it is necessary to penetrate the pile into the support layer to a certain depth or more. However, since the steel pipe pile has a tapered front end portion, the supporting force of the pile front end can be improved. As a result, it is not necessary to close the front end surface of the pile in order to find the supporting force at the tip end of the pile, and even if the penetration amount is small, the branching force can be obtained, and the effect of shortening the construction time and the like can be obtained. In the steel pipe pile according to the above (2), since the projections are provided in a plurality of intervals in the circumferential direction of the distal end portion, the projections provided at intervals can be obtained, and the tapered distal end portion can be further suppressed. The effect of friction and deformation. According to the steel pipe pile according to the above (3), the projections are inclined such that the rear end side of the projection is rearward in the rotation direction of the sizing portion and the distal end portion, so that the direction in which the projection is inclined smoothly can be obtained. The effect of flowing the excavated soil (slag) on the outer peripheral side of the tapered tip end portion after the excavation or the soil sand destroyed by the protruding shear force. According to the steel pipe pile according to the above (4), since the angle perpendicular to the central axis of the front end portion and the central axis of the extending direction of the protrusion are 20Q to 70°, a moderate soil capable of exhibiting the protrusion is obtained. Shear damage or guiding effect. According to the steel pipe pile described in the above (5), since the height of the projection is set such that the projection is smaller than the fixed diameter portion in the radial direction of the distal end portion, the range of disturbance of the disturbance is reduced by the projection. Therefore, an effect of suppressing the reduction in friction of the outer peripheral surface or the like is obtained. According to the steel pipe pile described in the above (6), since the plurality of boring tools are provided at the front end of the front end portion, even if the ground plate is a hard ground plate, it is possible to obtain an effect of easy cutting, rotation, and penetration into the ground plate. According to the steel pipe pile described in the above (7), since the lower end of the projection is located directly above the upper surface of the boring cutter, it is possible to reliably guide the soil flowing along the outer peripheral surface side of the tapered front end portion by the boring cutter with the projection. (Essence of the slag) 0 11 201207198 The steel pipe pile according to the above (8) is arranged in the radial direction of the tip end portion (10) because the boring tool is smaller than the sizing portion. Since the outer diameter of the plane of the steel pipe pile of the human is small, it is possible to find a part where the outer diameter is small, and the amount of the outer diameter is small, and the effect of improving the workability can be obtained. According to the steel pipe according to the above (9), since the ratio of the height dimension of the distal end portion in the longitudinal direction to the dimension of the sizing portion is G3 to 55, the weak ground plate is opposed to the straight steel pipe pile (only the sizing The steel pipe of the department can reduce the resistance caused by the friction of the inner circumferential surface of the steel pipe pile and seek to improve the construction. In addition, in the reading layer, the effect of the high-rise building power is achieved. w The steel official pile, due to the ratio of the outer diameter of the front end to the outer diameter of the diameter, ^, that is, the reduction ratio of the steel pipe is 0.60~〇, so compared to the 尬τ士, straight copper When the pile is piled, the weight of the rotary press-in machine can be made less. In addition, it is possible to reduce the size of the construction machinery and improve the construction of the intermediate layer. Reduce the penetration of the support floor - the surface: the second 'obtained: can be - face class 7 _ 9 large branch strength of the steel pipe pile effect. According to the construction method of the steel pipe coil described in the above (U), since the tip end is provided at the front end and protrudes toward the boring, the sharp portion of the universal direction is sharpened, so that the construction of the site can be carried out with a q' rate. The effect of the steel pipe pile. In the construction method of the steel pipe pile described in the above (12), the steel pipe pile having the upper end (:= the front end portion is pressed eight times by the rotary pressing force method for the steel official pile, and the steel pipe pile can be lowered. Construction of the light into the construction. In addition, compared with the straight steel pipe pile (only the steel of the sizing part 12 201207198 pile), even if the penetration of the support layer is small, the construction can be obtained, and the low-cost tooling is supported. The effect of the foundation pile of the force. Further, the steel pipe pile can be more efficiently constructed by using, for example, a steel pipe pile having a boring cutter. According to the construction method of the steel pipe pile described in the above (13), since the above p) Since the steel pipe pile at the tapered front end portion is rotatably pressed into the ground including the hard land, it can be constructed at low cost even in a ground plate including a hard land. Further, when the shell is placed in the support layer of the hard land, the effect of constructing a foundation pile having a high supporting force or the like is obtained as compared with a straight pile, even if the amount of penetration into the support layer is small. According to the construction method of the steel pipe pile described in the above (14), since the steel pipe pile is moved up and down in the underground during construction, the degree of soiling in the steel pipe pile is reduced, so that the friction of the inner circumferential surface of the steel pipe can be reduced. Effective construction and other effects. According to the construction method of the steel pipe pile described in the above (15), when the front end portion of the steel pipe pile is finally stopped in the branch floor, the steel pipe pile is reversely rotated, and the soil near the tapered outer peripheral surface (including the gravel) is protruded by the protrusion. When the soil is pressed down to the lower side, the soil near the outer peripheral surface of the tapered tip end portion is pressed downward by the projections, and the effect of the pile or the like can be obtained. Then, the support layer is dense and the support steel pipe is simply illustrated. Fig. 1A is a front view showing the first steel pipe pile of the present invention. In the first embodiment, the front end portion has a projection. Fig. 1B is a longitudinal sectional front view of the steel slab coil. Fig. 1C is a cross-sectional view taken from the arrow a-a of the circle iB. 13 201207198 The ID diagram is a cross-sectional view taken from the arrow b-b of Fig. 1B. Fig. 2A is a perspective view showing a steel pipe pile having a protruding end portion in a second embodiment of the present invention. Figure 2B is a front view of the aforementioned steel pipe pile. Fig. 3A is a front elevational view showing a steel pipe pile having a protruding end portion in a third embodiment of the present invention. Figure 3B is a front elevational view of the longitudinal section of the steel pipe pile. Figure 3C is a cross-sectional view taken from the arrow c-c of Figure 3B. Figure 3D is a representation of the d-d arrow from Figure 3B. Fig. 4A is a perspective view showing a steel pipe pile having a protruding end portion in a fourth embodiment of the present invention. Figure 4B is a front view of the aforementioned steel pipe pile. Fig. 5 is a front elevational view showing a steel pipe pile having a projection at a front end portion according to a fifth embodiment of the present invention. Fig. 6A is a front elevational view showing a steel pipe pile having a protruding end portion at a tip end portion according to a sixth embodiment of the present invention. Figure 6B is a front elevational view of the longitudinal section of the steel pipe pile. Figure 6C is a cross-sectional view taken from the arrow e-e of Figure 6B. Figure 6D is a representation of the arrow f-f from Figure 6B. Fig. 7A is a side view showing the shape and mounting range of the steel pipe pile provided in the seventh embodiment of the present invention. Fig. 7B is a cross-sectional view showing the shape and mounting range of the steel pipe pile provided in the seventh embodiment of the present invention. Fig. 8A is an explanatory view showing a comparative example. 14 201207198 Fig. 8B is an explanatory diagram showing a comparative example. Fig. 9 is a front view showing a state in which a steel pipe pile is rotationally pressed into a ground plate by a rotary press-in construction machine. Fig. 10 is a graph showing the relationship between the construction load, the penetration amount, and the press-fitting force of the steel pipe pile of the present invention having a projection at the tapered tip end portion and the steel pipe pile having no projection at the tapered tip end portion. Fig. 11 is a view showing the comparison of the average wear amount of the end portion before the construction of the steel pipe pile having the projection at the tapered front end portion and the steel pipe pile having no projection at the tapered front end portion. Fig. 12 is a view for comparing the average deformation amount of the front end portion of the present invention in the case where the steel pipe pile having a projection at the tapered front end portion and the steel pipe pile having no projection at the tapered front end portion are used. Fig. 13A is a view showing the direction of rotation when the steel pipe pile of the present invention is rotationally pressed into the ground. Fig. 13B is a sectional view of Fig. 13A, and is an explanatory view showing the flow of soil. Fig. 14 is a longitudinal sectional front view showing a state in which the aforementioned steel pipe pile is rotationally pressed into the support layer. Fig. 15 is an explanatory view showing the flow of soil when the steel pipe pile is rotationally pressed into the ground. Fig. 16 is a longitudinal front view showing the relationship between the press-in depth when the steel pipe pile is laminated to the support, the height of the soil in the pipe, and the size of the vicinity of the front end portion. Figure 17 is a graph showing the relationship between the press-in force and the ratio of the penetration amount to the pile diameter for each of the above-mentioned steel pipe piles and the straight piles as a comparative example. Fig. 18 is a graph showing the relationship between the ratio of the amount of the front end sinking to the pile diameter and the load at the front end of the pile with respect to the aforementioned steel pipe pile and the straight pile as a comparative example. Fig. 19 is a graph showing the relationship between the ratio of the length of the front end portion to the outer diameter of the steel pipe pile, and the ratio of the required pressing force of the steel pipe pile to the required pressing force of the straight pile. Fig. 20 is a graph showing the relationship between the reduction ratio (D 2 /D1) of the front end portion and the required pressing force ratio. Fig. 21A is a view showing the resistance of the front end side of the steel pipe pile, and is a longitudinal sectional front view showing the straight pile of the comparative example. Fig. 21B is a front elevational view showing the longitudinal direction of the steel pipe pile at the tapered front end portion. Fig. 22A is a front view showing a steel pipe pile as a comparative example. Figure 22B is a front elevational view of the longitudinal section of Figure 22A. Figure 22C is a cross-sectional view taken from the g-g arrow of Figure 22B. I. Embodiment 3 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail based on the embodiments shown in the drawings. 1A to 1D are views showing a steel pipe pile according to a first embodiment of the present invention (hereinafter also referred to as a steel pipe pile 1A having a tip end tapered portion). The steel pipe pile 1A of the present invention having a front end tapered portion is formed by a rotary pressing method. As shown in Fig. 1, the steel pipe pile 1A is open at the front end (front end) 4a of the boring direction A1 16 201207198 and is hollow, and includes a sizing portion 9 and a tapered portion (front end portion) 4. The sizing portion 9 has a constant outer diameter. Further, the tapered portion 4 is tapered and the projection i6a is provided in the tapered portion 4. The inner peripheral surface 3 of the tapered portion 4 has a tapered shape in which the inner dimension is gradually reduced in the longitudinal direction toward the front end. Further, the outer peripheral surface 2 of the tapered portion 4 has a tapered shape in which the outer shape of the distal end 4a is gradually reduced in diameter in the longitudinal direction. Further, a plurality of boring cutters 6 are provided at equal angular intervals in the circumferential direction at the front end 4a of the tapered portion 4. When a plurality of even number of boring cutters 6 are provided, the planes which are opposite to the center of the steel pipe pile 1A minus C are arranged symmetrically, and when the odd number is complex, the interval is set at equal angular intervals. _刀_透(4) When the support part (not shown) is fixed to the front end of the steel pipe pile 丨A. Thus, by providing the boring blade 6 to the end of the steel pipe pile A having the tip tapered portion, even if the ground plate is rigid, the steel pipe can be penetrated into the ground surface on one side by the rotary pressing method. In particular, as shown in Fig. U, ^ rotates in the direction of the arrow x and the direction of the arrow γ and digs C to the fulcrum formed by the hard land. In this field. Use the pile construction machine that is rotated into the pipe as shown in Figure 9. & Guide for piling The steel pipe pile 1 of the present embodiment (4) is preferably in the form of 77 a + for excavation, 4 a at the front end of the M-shaped shape, and the blade 6 for excavation. J horse does not have a cutting knife 6 In the form shown in Fig. 1A, the knife 6 is formed, and the front end of the steel pipe 4#1A is in a shape. The front end of the H is arranged in the radial direction of the tapered portion 4: the outer side of the diameter portion 6. In this case, compared to the straight pipe pile shown in 17 201207198 as shown in Fig. 22A to Fig. 22C), the taper portion 4 of the ιο is provided with a boring cutter θ S pile ("the outer diameter of the steel pipe pile 1A5 with the planting portion" The size is small. 2 in 'can make the steel with the cutting knife into a plurality of sections ^ carry the cargo wheel, for example, in the multiple steel pipe pile 1A steel pipe pile interference. Therefore, the wire _ ^ Xiao will be adjacent The state will load the multiple steel pipe piles 1A. Also, > etc. can also be used to stabilize the shape of the cutting blade 6 when it is stabilized in the 22A to 22C drawings; The tapered portion 4 of the excluded steel pipe pile 10 is provided

之半徑方向外側之地盤的可能性。 ㈣綱41A 又’於前述錐狀部4之外周面2設有突起16a。該突起心 如第1A圖及第1B圖所示，係、從前端知朝後端9a延伸於一部 分或全體，且突出於錐狀部4之半徑方向外方。本實施形態 之突起16_設於錐狀部4之外周面2之—部分。再者，突起 16 a係隔著間隔複數個設於錐狀部4之外周面2的周方向。 前述突起16&係傾斜成其鋼管樁1A之中心軸線c方向 之上方於旋轉貫入時成為樁旋轉方向之後方。具體而言， 突起16a傾斜以使突起16a之後端％側成為定徑部9及錐狀 部4之旋轉方向的後方。如此，於中心軸線c方向突起16& 之上部係傾斜成相對下方成為鋼管樁1A之旋轉方向的後 方，藉以如在第1A圖之箭頭b 1所示般，可將藉由掘削刀6 所掘削之朝上流動在外周面2側的掘削土（土產），或是將藉 由突起16a剪力破壞之土砂導引至突起傾斜的方向。其結 果’可將掘削土及土砂平順地朝掘削方向A1之後方流動。 又，突起16a係相對錐狀部4之中心袖線C於周方向傾斜 201207198 配置。突起16a之中心軸線C2係成角度δ而相對錐狀部4之， 面4a傾斜。亦即，即使是突起16a之中心軸線C2與前面4a 之所成角度為90。亦可，然而在本實施形態中，角度5係小於 90°。有關角度δ之細節於後說明。 利用將錐狀部4設於鋼管樁1Α之前端4a’而可期待可大 幅削減鋼管樁1A内之閉塞所產生之地盤阻力的效果，而有 關錐狀部4，由於受到大阻力，所以發生錐狀部4之磨耗及 變形。因此，在本實施形態中，於貫入施工鋼管樁1A時最 受到阻力部分的錐狀部4之外周部2設置複數突起16a。 作為設置突起16a之形態，也可是藉由將鋼筋或是平鋼 等棒狀鋼材熔接於錐狀部4之外周面2而固定突起16a的形 態，又，雖省略圖示，也可於錐狀部4之外周面2施行堆焊 作為突起，也可為於形成錐狀部4時，設置軋延加工所產生 之突起的形態。作為軋延加工所產生之突起的形態，例如 將扇狀之具單面突起鋼板配置成突起部分成為樁之外側且 朝樁之中心軸線方向傾斜，並且彎曲加工成截頭圓錐狀且 藉由，熔接將端部閉合而為截頭圓錐狀體。利用將該截頭圓 錐狀體之大徑側的端部藉由熔接而固定於鋼管之下端部， 而作為具有錐狀部4之鋼管樁丨八。也可利用將掘削刀設於前 述截頭圓錐狀體之錐狀部4，而作為具有本實施形態之錐狀 部4之鋼管樁1A。 又’設置突起16a之形態，在第1A圖中，係將突起16a 從鋼管樁1A之前端4a朝後端9a作成直線狀，於周方向也將 突起16a作成直線狀，然而也可設成弧狀。突起16a之樁周 19 201207198 方向的寬度尺寸如第ΙΑ圖所示，係使鋼管樁1A之中心軸線 c方向的寬度尺寸為_定’然而也可設成突起16a之上部側 (後端9娜）變狹窄。錢構成中，突起16a之鋼管⑽之周 方向寬度尺寸，在土壤沿著突起他導引到維狀部4之外周 面2上部時’在從突⑹6a<上㈣朝上方_之瞬間，突 起16a之樁周方向之寬度&寸邹分會成為空間。藉此，而可 平順地流動土砂等。 «又置刖述大起16a的形態如第丨a圖所示，也可設置突起 16a之下端部以使連接於掘削刀6之上部安裝部。如此，設 成連接於掘削刀6時，藉由掘削刀6及與其連接之突起16a， 而可沿著錐狀部4之外周面2有效率地導引土壤而流動。 其次’就有關第2實施形態之鋼管樁1B進行說明。 如第2A圖及第2B圖所示，也可在從掘削刀6於鋼管樁 1B的周方向隔著間隔分離的狀態下設置突起16b。具體而 言’突起係從掘削刀6朝鋼管樁1之旋轉方向（正旋轉方向） 的後方，在掘削刀6之周方向之寬度尺寸左右的範圍，設於 從掘削刀6朝樁正轉方向之後方或樁軸方向離開的位置。即 使在此場合，與第1實施形態同樣地，如第2B圖之箭頭B1 所示，可將以掘削刀掘削之朝上流動在外周面2側的掘削土 (土渣）’或是將藉由突起16b剪力破壞之土砂導引到突起傾 斜的方向。其結果，可平順地將掘削土及土砂流動至掘削 方向A1的後方。 其次’就有關第3實施形態之鋼管樁1C進行説明。 在上述之第1、第2實施形態中，係就有關突起16a、16b 20 201207198 於鋼官樁1C之中心iiC方向及周方向之至少—者連續的構 成進行說m ’如第3A圖〜第3d圖所示，也可斷續地 配置X起16e #即’如苐3A圖及第3β圖所示，也可將2個 突起關㈣隔配私_方向Μ。㈣，在掘削方向 A1斷續地設置魏㈣，也可料__地直排配 置3個以上。 其次，就㈣第4實施形態之鋼管樁1D進行說明。 在上述各貫施形態中，係顯示了突起心〜16。相對中 心軸線C傾斜的構成’然而也可不傾斜。 突起_如第4A圖所示，係沿著鋼管樁1D之中心軸線C 延伸。又，突起16d之下端⑹如第4B圖係位於掘削加之上 面6a的正上;^在如此之場合，藉由突糾d，土壤係被導 引成沿著錐狀前端部4之外周面2朝鋼管格⑴之中心轴線C 方向机動。雖也可疋如此形態之突起16d，然而在考慮將鋼 &樁1D進订旋轉施卫時，如在上述各實施形態所示之突起 16a l6c^，使突起16a〜16c為朝鋼管樁1A〜丨匸之正旋轉 方向的後方傾斜的構成時，沿著錐狀部4之外周面2的土壤 之流動會變得平順。 如此，掘削刀6與突起16d連接時，可有效率地沿著錐 狀部4將藉由掘削刀6所掘削之土壌及藉由突起丨6 d所剪力 破壞之土壞（土渣）朝上部流動。 其次’就有關第5實施形態之鋼管樁1E進行說明。 如第5圖所示，在鋼管樁1E的錐狀部4設有從前端如突 出且朝掘削方向A1尖銳之尖銳部5。又，在錐狀部4之前端 21 201207198 4a設有凹部5a。該凹部5a並不必要一定要形成。 又，在本實施形態中，由於不具有掘削刀’所以突起 16e係從前端4a朝後端9a延伸於錐狀部4之外周面2全體。 其次，就有關第6實施形態之鋼管樁1F進行說明。 如第6A圖〜第6D圖所示，在第1A圖所示之掘削刀6間 之錐狀部4之前端4a也可設有朝掘削方向A1尖銳之尖銳部 5b。相較於第5圖所示之尖銳部5，尖銳部5b之前端變得平 坦。於本實施形態中，也可與第5實施形態同樣地使前面尖 銳’又，也可使第5實施形態之尖銳部5之前端為平坦。 其次，就有關第7實施形態之鋼管樁1G進行說明。 第7A圖及第7B圖係顯示設於鋼管樁1G之突起的形狀 及安裝範圍的說明圖。 犬起16g之從前端4a朝後端9a之方向的長度尺寸也可 是使橫跨錐狀部4之外周面2的大約全體設置。此時，為了 極力抑制鋼管樁1G之外周摩擦的降低，可設定突起16g的高 度。 例如’如第7B圖所示，突起16g之高度H2係被規定以 使犬起16g較定徑部9之外形尺寸位於錐狀部4之半徑方向 的内側°換言之’限制突起16g之高度及突起16g延伸方向 之中心轴線C2的上端部位置，以使突起16g較延伸於錐狀部 4側之疋從部9的外形延長線18位於鋼管樁1G之半徑方向的 内側°如此’設置突起16g時，使藉由突起16g而擾動土壞 的圍綠小 -j- . . 而可抑制鋼管樁1G之周面摩擦的降低。突起 16g之延伸方向的長度也可是在較定徑部9之外形延長線a 22 201207198 成為内側的範圍，使較上述實施形態的情況為短。 其次’就有關突起部16g之傾斜角度使用第7A圖及第 7B圖來說明。 在從垂直掘削方向A1的方向正面視鋼管樁1〇時，垂直 中心軸線C之橫線D(前面4a)與突起l6g之延伸方向之中心 軸線C2所成的角度（突起16g之中心軸線C2對橫線D交又的 傾斜角占）為20°〜90°的範圍，較佳為2〇。〜7〇。，更佳為配合 通常地盤之内部摩擦角0而設定成3〇。〜5〇。的範圍時可有 效地剪力破壞。 犬起16g之傾斜角0為9〇。時，在鋼管樁旋轉的情況， 藉由最短的突起16g而可有效將土壤剪力破壞。但是，由於 伴隨鋼管樁之正旋轉之土壤的導引作用小，所以有效地將 掘削後的土壞(土渣)從錐狀部4流動至其上側的作用降低。 突起响的傾斜角S小於2〇。時，由於將突起吻設於鋼管 樁之周方向的長度範m變長，並不經濟，又，因為土壤之 剪力破壞效率降低’在本實施形態中將突起响之傾 的下限設定為20。。又，使突起16g之傾斜角§為2〇。〜％左 右時，將土壤剪力麵時突起之每單位長度的諸相較於 90時顯者地變小。再者，也可確實發揮已掘削之土壤(土 的導引作用。又’突起16g之傾斜㈣獅。時 管播之正旋轉方向之施工，將藉由突起％剪力破壞之土 ： (土潰)朝下方壓下，土紅流動及突起^所產生之^ 壞效率也降低。藉此，如前述般，設定成考慮了 = 部摩擦角0之30。〜5〇。的範圍作為最佳範圍。 23 201207198 該傾斜角§的範圍於上述各實施形態皆相同。 其次，就有關突起16g之高度尺寸使用第7B圖進行說 明。 突起16g之鋼管樁1G半徑方向的高度尺寸H2，係設定 成外徑為一定之定徑部9之外徑尺寸D1的0.6%〜3.0%長度 尺寸。也就是，設定成高度尺寸H2 = 0.006D1〜0.03D1的尺 寸。 通常’因為鋼管樁之外徑為400mm〜2500mm左右，所 以突起16g之樁半徑方向之高度尺寸H2在外徑400mm之鋼 管樁中係最大12mm左右’在外徑2500ηΐιη之鋼管樁中為 15mm〜75mm左右。 該突起之高度尺寸H2於上述各實施形態也相同。 於鋼管樁之周方向相鄰之突起16g間的突起間隔雖無 特別規定’然而也可例如隔著與在鋼管樁之周方向相鄰之 掘削刀6相同等角度間隔設置，也可以是與掘削刀6相同位 相設置，也可是接近掘削刀6以相同等角度間隔之配置間隔 或相異之配置間隔設置。又，也可是將突起16g之下端部的 位置设成連接於掘削刀6之上端部。鋼管樁之正旋轉施工時 之錐狀部4的外周面2側中，掘削刀6與突起16g連接時，可 將藉由掘削刀6所掘削之土壌及藉由突起i 6 g所煎力破壞的 土讓（土渣）有效地沿著錐狀部流動到上部。 其次’就有關有無設於錐狀部4之突起16g所導致之施 工何重等的減輕作用，關於試驗的結果參照第7A圖〜第8B 圖、第11圖及第12圖進行說明。 24 201207198 試驗所用之鋼管樁之錐狀部的形態係就有關在第从圖 及第7B圖所示之第7實施形態之錐狀部4具有突起^之鋼 管樁1G、與作為比較例在第8A圖及第纽圖所示之錐狀部4 不具有突起形態之鋼管樁17進行試驗。試賴用之兩試驗 體之鋼管樁1G、17係隔著等角度間隔在錐狀部4具有4個掘 削用刀6。 試驗所用之兩試驗體之鋼管捲1G、㈣主要尺寸係該 鋼管樁1G、π之外徑為-定之心部9的外徑尺寸⑴任一 者皆為HiOOmm。錐狀部4之鋼管樁1G、17中心軸線c方向 的長度H1任-者皆為Hl=〇.5D1 ’且錐狀部4之外徑尺寸D2 與定徑部9之外形尺寸01的關係是D2=〇 9m。又，在錐狀 部4设置突起16g之本實施形態的鋼管樁1(}係將直徑⑽⑺ 之鋼筋配置成連接於掘削刀6之上端部以作為突起16g，並 藉由熔接而固定。突起l6g之高度尺寸H2^H2=〇〇16D1， 突起16g係鋼筋。以連接於掘削刀6之方式從掘削刀6之正上 方到錐狀部4之上端使突起16g之傾斜角5為45〇，且藉由熔 接將突起16g固定於錐狀部4，作為鋼管樁1G。 地盤係單軸壓縮強度為5N/min2之軟岩（泥岩），從該地 盤旋轉壓入到各鋼管樁1(}、17之外徑尺寸〇13倍距離的深 度。於施工時’計測—定之定徑部D丨外徑尺寸〇 1 (樁頭部側) 之樁頭部的每單位面積施工荷重（壓入力：kN/m2)、與相對 前述外徑尺寸D1之貫入量（貫入比），有關該等施工荷重與 貫入量（貫入比）的關係在第10圖顯示成圖表。 如第10圖所示’於錐狀部4不具突起16g之鋼管樁17的 25 201207198 情況，相對於壓入力最大為645kN/m2,於錐狀部4具有突起 16g之本實施形態的鋼管樁1(}的情況，係壓入力最大為363 kN/m2。亦即，了解到可降低約30%以上的施工荷重。 藉此，本發明之於錐狀部4具有突起16g之鋼管捲⑽ 情況，由於可降低施工荷重，所以可使配重較少。又，施 工荷重可降低約30%以上時，可使施卫機械之能力下降， 在現存之施工機械中，例如由於可使n級下之小型施工 機械施工，所以可顯著地地降低施工成本。 又’有關前述各試驗體之鋼管樁1G、17，將就有關錐’ 狀部4外周面之鋼管樁1G、l7之中心轴線C方向的平均磨耗 量W進行測錄之結果_錢科第n圖。 從第11圖，於錐狀部4具有突起16g之鋼管捲1〇中，相 管樁17，在錐狀部4之前 及其心㈣靴上糊表U5D1的位置） =:7:的位置)，平均磨耗量顯著地降低到-半 沒磨耗，在…起二乎 :產生2%弱的平均磨耗量’在錐狀部4之上端端 平均磨耗量。 產生3%強的 時的：)前:平量(難錐狀部4之原厚度作為丨 耗量平均後的值。均磨耗量(％)係將複數試驗体的磨 又 ’有關各試驗體鋼管細、17之相對於錐狀和外周 26 201207198 之半方向位置(原形狀)的半徑方向平均變形量(％)， 糸字第12圖之上圖中 7 圖矣is- 所不位置計測㈣結果之 "·'、不於第12圖之下圖。本發明之且右* 4之計_ # （、有犬起16g之錐狀部 科！點係沿者突起16g進行計測。將朝鋼管樁心17半 （内側）f曲而凹下方式變形的情況表示為 起方^V將_管樁1G、17半徑方向之外側彎曲而鼓 式變形的情況表示為_(負）變形。 ,"_在錐狀部4不具突起之鋼管樁17中，直錐狀 二广方向之前端側朝中心_下變形，在軸方向之基 :(大役側）呈鼓起。可以了解於㈣向，㈣於錐狀部4 之$反轉（凹下後鼓起），在本發明之鋼管樁1G中，錐狀 部4在捲軸方向只是產生微小鼓起。 從第11圖及第12圖之圖表可了解，於錐狀部4具有突起 峋之本發明鋼管樁1(}的情況，比起於錐狀部4不具突起峋 形態的鋼管樁17，顯著地改善錐狀部4之磨耗量及變形量。 於錐狀部4設置突起偷的情況，設置突起峋之部分的 板厚當然變厚剛性變高且也提升錐狀部4全體的剛性。 於錐狀部4外周面2設置如前述之突起16g的鋼管樁1(} 中可期待如下述(1)〜(4)的效果。 (1)樁旋轉壓入施工時，藉由突起16g而有效地且積極地 破壞(剪力破壞)錐狀部4外周面2附近的地盤（土壤），可易於 進行樁之旋轉插入。 (2)利用突起16g部分負擔原來在錐狀部4因地盤之阻力 所發生之摩擦及變形，而可抑制用以發揮樁支撐力性能之 27 201207198 重要構件之錐狀部4的磨耗、變形，並可使樁體之健全性(安 全性)大為提升。 (3) 利用連續於掘削刀6之正上面來設置突起16g ’由於 掘削刀6所掘削之土砂沿著突起16g朝上方流動而減少樁施 工之阻力。 (4) 藉由使突起16g具有安裝角度5而設置以使與鋼管 樁1G之中心線c方向之軸線交叉，在使樁旋轉施工之際， 可發現會使因突起16g剪力破壞之土壤藉由突起16g而朝上 方流動的效果。再者，可降低樁施工時之地盤阻力。 在本試驗中，雖是使用第7實施形態之鋼管樁1G進行說 明’然而使用其他實施形態之鋼管樁1A〜1F也可獲得相同 的效果。 於本發明中，所謂硬質地盤稱為岩盤，該岩盤雖可分 為軟岩系岩盤（單軸壓縮強度〜小於20MPa)與硬岩系岩盤 (單軸壓縮強度：20MPa以上）’然而本發明之前端錐狀部具 突起之鋼管樁1A〜1G在具有掘削刀6之形態中，可適用於 任一岩盤。 前述錐狀部4外周面2及錐狀部4内周面3之樁長度方向 的斷面形態，作為樁長度方向之單側的斷面形態，如第1Β 圖所示外側及内側可為直線狀，且雖省略圖示，也可為曲 線狀。錐狀部4外周面2及錐狀部4内周面3之樁長度方向之 斷面形態，可為從樁中心軸上在半徑方向朝内側凸出（在半 徑方向朝内側凹陷），也可為從樁中心轴在半徑方向朝内側 凸出（在半經方向朝外側凹陷）。設置突起16a〜16e、16g時， 28 201207198 直接設置於錐狀部4之外周面2。 其··人，就有關本發明之錐狀部4尺寸及作用進行說明。 此處，第13A圖及第13B圖係省略突起16a〜16e、16g之圖示。 如前述般，藉由設置將鋼管樁1A〜1G之前端4a側縮小 直徑之錐狀部4,如第13B圖之箭頭^及第15圖之箭頭以所 示各·，利用積極地將土壤流動至樁之外側，而可減少流入 到管内的土壤。又，利用減少錐狀部4之開口面積，如第13B 圖之箭頭Cl及第15圖之箭頭Cl所示般，可減少流入到管内 的土壤且可使其擴散到半徑方向。藉此，可抑制樁前端部 因管内土壤發生閉塞，減輕管内土與樁1A〜1G内周面3之 摩擦，並可謀求減輕樁壓入力。 利用於樁前端部設置錐狀部4,而增大作用於錐狀部4 内周面3之土壤的阻力，利用採取旋轉壓入施工之工法也可 產生抑制樁周面摩擦增大的利點。再者，利用設置突起 〜16e、l6g可促進使作用於錐狀部4内周面3之土壤移動至 内周面3之上方，而降低土壞之阻力。 錐狀部4前端4a之外徑尺寸D2與鋼管樁之外徑為一定 之定徑部之外徑尺寸D1的比率’即縮徑率，較小，且錐狀 部4之樁長度方向（軸方向）之長度尺寸Hi與外徑為—定之 定徑部之外徑尺寸D1之比率（H1/D1)變得過小時（換言之， 錐狀部4之錐狀角Θ (。）變得過大時），於旋轉壓入施工時， 作用於錐狀部4之面壓所產生之阻力便會變高。其結果，有 可能產生施工障礙。因此，在實施形態中，利用將該等比 率限制於預定之範圍内而可謀求良好之旋轉壓入施工性。 29 201207198 在本發明中，於前述錐狀部4之樁長度方向（與鋼管播之中 心轴線C方向相同）的長度m、錐狀部4前端之外根尺寸 D2、外徑為-定之定徑部的外徑尺寸⑴、與錐狀角0之間， 有著tan0 = (D1-D2)/2Hl的關係。又，於施工時，除了錐狀 部4相對地盤進行旋轉方向與貫入方向鉛直組合後的動 作，且具有與樁之貫入方向呈錐狀之錐狀角θ。藉此，使剪 力及壓縮力相對地盤同時仙，且發揮將地盤擴展到側方 的效果。 因此，可有效地擾動地盤，而使錐狀部4之施工時的阻 力變小。 利用設置錐狀部4,由於增加樁底面之投影面積，在貫 入到支撐層時，藉由錐狀部4而可獲得確實的支撐力。在前 端4a開口之開端樁為了確保支撐力，即使管内閉塞不充 分，也可發揮確實的支撐力。由於可以錐狀部4之底面投影 面積的部分負擔高壓縮荷重，所以鋼管樁1A〜1C^S較將通 常直的開端樁旋轉壓入施工而使其貫入的情況，可發揮高 支樓力。 再者，於地盤之拘束壓力充分之硬質地盤中，鋼管捲 1A〜1G確實地發揮高支撐力。因此，相較將前端4a閉塞之 直的鋼管樁藉由旋轉壓入施工而貫入的情況，可期待高支 撐力。 將鋼管樁1A〜1G旋轉壓入施工時，於其施工中，利用 在地下將鋼管樁1A〜1G交互地反覆上動及下動，而於上動 時，管内的土壤落下到管之下方，於下動時，落下之土壤 30 201207198 被推到管外。藉此，如第15圖及第16圖所示，可將管内的 土壤之高度降低’且可使定徑部9之内周面12與管内土壌14 之接觸面減少。其結果，由於減輕了内周面12與管内土壌 14之摩擦，所以可更降低施工荷重。 在本發明中，錐狀部4之樁長度方向的長度H1與外徑為 —定之定徑部9之外徑尺寸D1之比率（H1/D1)設定成〇.3〜 5·5 °亦即，H1/D1設定成0.3〜5.5。 又’外徑尺寸D2設定較外徑尺寸D1小，以使錐狀部前 端之外徑尺寸D2與鋼管樁之外徑為一定之定徑部9之外徑 尺寸D1的比率（D2/Dl)，即縮徑率(D2/D1)，成為0.60〜0.95 的範圍。 如前述般，有關將H1/D1設定成0.3〜5.5的理由及設定 鋼管樁1A〜1G之外徑尺寸D2的理由，參照第16圖〜第20 圖予以說明。此處，錐狀部4之形狀由於鋼管樁1A〜1G任 —者皆相同，所以參照鋼管樁1A予以說明。 首先，參照第19圖進行說明，在使縮徑率(D2/D1)為0.9 的場合，係藉由實驗調查錐狀部4之中心線C方向的長度H1 與外徑為一定之定徑部9之外徑尺寸D1的比率（H1/D1)、與 必要壓入力比率（具有錐狀部4之鋼管樁1A之必要壓入力、 與直的鋼管樁1〇之必要壓入力的比率）之關係後的圖表。 實驗所使用之鋼管樁1A，定徑部9之外徑尺寸(D1)為 iOOmm ’鋼管部分之厚度⑴為4.2mm，錐狀部4之前端4a的 外徑尺寸(D2)為90mm。又，橫跨全長外徑尺寸(D1)為一定 之直的鋼管樁10之外徑尺寸(D1)及鋼管部分之厚度⑴係與 31 201207198 前述鋼管樁1A相同。 從第19圖可了解，111/〇1為0.3時，必要壓入力比率為 〇·9，又，出/〇1為0.4時’必要壓入力比率為〇 6，又，H1/m 為1_35時’必要壓入力比率為0.6，又，111/〇1為5 5時，必 要壓入力比率為0.9。由此結果可了解，錐狀部4之中心袖 線C方向的長度H1與外徑為一定之定徑部9之外徑尺寸D1 的比率(H1/D1)為0.3〜5.5時，亦即，而〇1為〇 3〜5 5時， 必要壓入力比率成0.9以下，鋼管樁丨八相較第22A圖所示之 直的鋼管樁10至少可降低1成必要壓入力。 又，可了解H1/D1為0_40〜1·35時，必要壓入力的比率 成0.6以下，在鋼管樁1Α中相較直的鋼管樁1〇可降低4成之 必要壓入力。 而且，於第20圖，顯示將實驗值晝出並連結的曲線， 該圖係將前端4a之外徑尺寸D2與定徑部9之外徑尺寸D1的 比率’即縮徑率（D2/D1)取為橫軸，並就有關各種縮徑率之 鋼管樁1A藉由實驗調查且比較必要壓入力比率後的圖表。 如第20圖所示，縮徑率(D2/D1)為0.60時，必要壓入力 比率為0.9，縮徑率（D2/D1)為0.75時，必要壓入力比率為 0.6，縮徑率(D2/D1)為0.92時，必要壓入力比率為0.6，縮徑 率(D2/D1)為0.95時，必要壓入力比率為0.9。 該等第19圖及第20圖所示之下，從凸的圖表可了解， 於縮徑率（D2/D1)為0.60〜0.95的範圍，必要壓入力比率減 少至0.90以下，且可使必要壓入力至少減少10%。又，於 縮徑率（D2/D1)為0.75〜0.92的範圍，必要壓入力比率便成 32 201207198 0 06以下’且必要壓入力可減少40%。 因此，使H1/D1為0.3〜5.5,縮徑率（D2/D1)為0.60〜0.95 者為佳’更佳者係使H1/D1為0.3〜5.5，使縮徑率（D2/D1) 為0.75〜〇_92的範圍。 壓入力比率下降到〇.9以下時，可大幅減少配重（重 物）。例如’必要壓入力86t(噸）、反力重量66t(噸）、旋轉壓 入施工機械之重量20t(噸）的旋轉壓入施工設備的情況，必 要壓入力可減少10%時，則可減少8.6t(噸），且可使配重減 少 13% 〇 又’如第19圖所示，可了解到H1/D1為0·40〜1.35時， ;·、、要壓入力比率可為〇·6以下，可更減輕配重。如此， 使义要壓入力比率為〇 6以下時’由於旋轉壓入施工機可使 下層級之小型旋轉壓入施工機來將樁進行旋轉壓入施 工，所以是特別希望的。 有關將鋼管樁1續轉壓人到地盤時之阻力降低機構， 执、第21Α圖及第21Β圖予以說明。第2卿係顯示省略了 '又於鋼管樁1Α之突起⑹及掘削刀6的圖示。 於第21A圖之直的鋼管樁1〇及第2ib圖之鋼管樁认 :、將a及Μ乍為在前端閉塞部的阻力將b作為在前端外 二的阻力’將b作為錐狀部4所產生之阻力，將。及c，作為 总、口P4外周面2之摩擦所產生之阻力的情況，又將丁作為 官内土所產生之阻力。 此之“ ’於第21Α圖中，由於成為㈣，所以如第 圖’使H1/D1較小(換言之，使錐狀部*之錐狀角⑷較 33 201207198 大）時，前端4a所產生之阻力b，便增加。又，於第21B圖中， 使錐狀。卩4之縮徑率增加時，在前端閉塞部之陴力a，便減 ^錐狀部4所產生之阻力b，便增加，如第21A圖及第21B 圖所不，水平的部分(在縮徑率為70%左右〜80%左右的範 圍）因該等阻力之增減效果而為平衡的範圍。 本發明之鋼管樁1A之錐狀部4具有如前述之作用，更藉 由在錐狀部4具有突起16a，而可積極地剪力破壞接 觸於錐 狀部4之土壤而減輕錐狀部4與地盤之接觸所產生之阻力。 又，突起16a之傾斜角δ為30。〜50。時，利用配合於通常地盤 之内部摩擦角φ而可有效率地進行破碎。 朝前述掘削方向Α1尖銳之尖銳部5，使為朝掘削方向 Α1尖銳之尖銳部5即可。在前述的情況中，也可具有朝樁之 周方向尖銳的部分。 如該等形態般，於錐狀部4之前端4a設置朝掘削方向八( 尖銳之尖銳部5時，即使地盤為硬質，藉由掘削刀6與尖銳 部5，或是藉由錐狀部4之兼掘削刀6的尖銳部5，而於樁打 設施工時’可-面破壞或掘削前端部地盤，—面將鋼管捲 貫入到地盤。 將如前述之本發明鋼管樁1A〜1G或是不具突起支鋼 管樁17進行施工時，與習知同樣地，可藉由對鋼管樁賦予 旋轉力及壓人力之旋轉壓人卫法而壓人至地盤。藉由如第9 圖所示之旋轉壓入施工機7,把持具前端錐狀部之鋼管樁P 等之周側面而進行旋轉壓入施工的情況，相較於將習知之 鋼管樁10,亦即鋼管樁之外徑尺寸〇1及其厚度相同之直的 34 201207198 鋼官樁10進彳了施，了解到本發明之鋼管樁lA〜lG 在如第17圖所不之每單位壓入力之貫入量、士口第18圖所示 之前端荷重度(kN/m2)的點上是優異的。 再進一步說明，於第17圖顯示了使用第16圖所示外徑 尺寸D1、錐狀部4前端之外徑尺寸〇2的樁之施工時施工荷 重’即樁每單位閉塞斷面積之壓入力（kN/m2)貫入量/樁徑 (H2/D1)之關係。了解到在本發明之鋼管樁ιΑ〜ι(}，相較 於第22Αϋ所示之直的鋼管樁(在第17圖係表記為直播），貫 入量大。 又，於第18圖’顯示了將鋼管旋轉壓入施工外徑尺寸 D1之3倍I度份到硬質地盤中後施加靜力荷重時之前端荷 重度(kN/m )-前端下沉量/樁徑_的關係。從該第以圖可 以了解’在本發之銅管樁1A〜lG巾相較於直樁，前端荷 重度大，發揮高支持力。 在ic*工本發明之鋼管樁1A〜1G或不具突起之鋼管捲 17的％合’可-面貫人直到軟質地盤下之支撐層一面旋 轉壓入至包含硬質地盤的地盤。 於知工本發明之鋼管樁ia〜ig的場合，在施工途中， 利用在地τ使鋼f #lA〜1G上下動，而使鋼管樁内之土壤 (官内土壤)的尚度下降時，如第15圖及第16圖所示 ，鋼管樁 1A〜1G内之官内土壤與内周面以之附著面積變少。藉此， 附著面積變少的部分版力變少，而減輕施工機械之負擔， 以可更有效率進行施工。 作為使鋼管樁u〜1G上下動的機構，係在藉由旋轉壓 35 201207198 入施工機7把持前端錐狀部具突起之鋼管樁1A〜1G等的狀 態，使旋轉壓入施工機7之液壓式等之伸縮式千斤頂⑴申 縮。藉此’可易於使鋼管樁1A〜ig上下動。 又，於鋼管樁1A〜1G之施工法中，在支撲層内最後停 止打設鋼管樁1A〜1G的錐狀部4時，反旋_管格ia〜 1G’而藉由突起16a〜16e、16g將錐狀部4外周面附近的土 壤（包含碎石等之土潰)壓入到下方。其結果，以藉由突起⑹ 〜166、168而將錐狀部外周面附近的土壤（包含碎石等土逢) 壓入到下方，以使樁下面側的支樓層緊密，而可支持捲: 作為製作本發明㈣播1A〜1G等之鋼管本體部分之 方法的-例，係可製作成藉由冷.料㈣形成丨根鋼管樁之 ，狀口P X ’也可製作成藉由冷壓成形而形成雜狀部。或 疋將帶狀鋼板作成扇狀，且藉由冷彎將該扇狀之具突起的 鋼板加工成錐狀，並藉由炫接而接合兩側緣部。然後，可 ㈣與其外徑部應連接之鋼管大致相同外徑之錐狀的短 管藉由炫接將該錐狀之短管的上端部固定則根鋼管之錐 ，P而製作抑樁本體^又，也可塑性加工丨根鋼管之錐狀 P ^作具有錐狀部之鋼管樁本體。可將具有掘削刀之 ^持β固疋於如此之錢形態的錐狀部且藉由㈣等設置 犬=以製作前端錐狀部具突起之鋼f樁等。也可將單面 其犬起之帶狀鋼板作為扇狀之具突起鋼板，製作錐狀之短 e =藉㈣接將轉狀之短管的上卿㈣於1根鋼管之 作前端錐狀部具突起之鋼管樁等。 【圖武簡舉說明】 36 201207198 第1A圖係顯示本發明第丨實施形態之於前端部具有突 起之鋼管樁的前視圖。 第1B圖係前述鋼管樁之縱斷面前視圖。 苐1C圖係自第1B圖之a-a箭頭所見之斷面圖。 第1D圖係自第1B圖之b-b箭頭所見之斷面圖。 第2A圖係顯示本發明第2實施形態之於前端部具有突 起之鋼管樁的立體圖。 第2B圖係前述鋼管樁之前視圖。 第3A圖係顯示本發明第3實施形態之於前端部具有突 起之鋼管樁的前視圖。 第3B圖係前述鋼管樁之縱斷面前視圖。 第3C圖係自第3B圖之c-c箭頭所見之斷面圖。 第3D圖係自第3B圖之d-d箭頭所見的圖示。 第4 A圖係顯示本發明第4實施形態之於前端部具有突 起之鋼管樁的立體圖。 第4B圖係前述鋼管樁之前視圖。 第5圖係顯示本發明第5實施形態之於前端部具有突起 之鋼管樁的前視圖。 第6 A圖係顯示本發明第6實施形態之於前端部具有突 起之鋼管樁的前視圖。 第6B圖係前述鋼管樁之縱斷面前視圖。 第6C圖係自第6B圖之e-e箭頭所見之斷面圖。 第6D圖係自第6B圖之f-f箭頭所見的圖示。 第7A圖係顯示設於本發明第7實施形態之鋼管樁之突 37 201207198 起的形狀及安裝範圍的側面圖。 第7 B圖係顯示設於本發明第7實施形態之鋼管樁之突 起的形狀及安裝範圍的斷面圖。 第8A圖係顯示比較例的說明圖。 第8B圖係顯示比較例的說明圖。 第9圖係顯示藉由旋轉壓入施工機將鋼管樁旋轉壓入 到地盤之狀態的前視圖。 第10圖係顯示於錐狀前端部具有突起之本發明之鋼管 樁、與於錐狀前端部不具有突起之比較例的鋼管樁之施工 荷重、貫入量與壓入力之關係的圖表。 第11圖係比較施工本發明之於錐狀前端部具有突起之 鋼管樁的場合、與於錐狀前端部不具有突起之鋼管樁的場 合之前端部的平均磨耗量的圖示。 第12圖係比較將本發明之於錐狀之前端部具有突起之 鋼管樁的場合、與於錐狀之前端部不具有突起之鋼管樁施 工時之前端部的平均變形量的圖示。 第13A圖係顯示使用本發明之鋼管樁旋轉壓入到地盤 時之旋轉方向的圖示。 第13B圖係第13A圖之斷面圖，且係顯示土壤的流動之 說明圖。 第14圖係顯示將前述鋼管樁旋轉壓入到支撐層的狀態 之縱斷面前視圖。 第15圖係顯示使用前述鋼管樁旋轉壓入到地盤時之土 壤的流動之說明圖。 38 201207198 第16圖係顯示將前述鋼管樁朝支撐層壓入時之壓入深 度、管内土壤的高度、與前端部附近之尺寸的關係之縱斷 面前視圖。 第17圖係就有關前述鋼管樁與作為比較例之直樁，顯 示每一樁閉塞斷面積之壓入力與貫入量對樁徑之比的關係 之圖表。 第18圖係就有關刖述鋼管樁與作為比較例之直樁，顯 不前端沉下量對樁徑之比、與樁之前端荷重度之關係的圖 表。 第19圖係顯示前端部之長度對前述鋼管樁之外徑的 比、及前述鋼管樁之必要壓入力與直樁之必要壓入力的之 比率的必要壓入力比率之關係的圖表。 第20圖係顯示前端部之縮徑率（D2/D1)與必要壓入力 比率之關係的圖表。 第21A圖係顯示鋼管樁之前端部側之阻力的圖示，且係 顯示比較例之直樁之場合的縱斷面前視圖。 第21B圖係顯示錐狀前端部之鋼管樁的場合之縱斷面 前視圖。 第22A圖係顯示作為比較例之鋼管樁的前視圖。 第22B圖係第22A圖之縱斷面前視圖。 第22C圖係自第22B圖之g-g箭頭所見之斷面圖。 【主要元件符號說明】 1A…鋼管樁 1C...鋼管樁 1B··.鋼管樁 1D...鋼管樁 39 201207198 1E...鋼管樁 16g·.·突起 IF...鋼管樁 17...鋼管樁 1G...鋼管樁 18...延長線 2...外周面 a·..阻力 3...内周面 a’.. ·阻力 4...錐狀部 b·.·阻力 4a...前端 b’...阻力 5...尖銳部 C·.·阻力 5a...凹部 C’···阻力 5b...尖銳部 A1...掘削方向 6...掘削刀 B1...箭頭 7...旋轉壓入施工機 C...中心軸線 8...支撐層 C1...箭頭 9...定徑部 C2...中心軸線 9a...後端 D...橫線 10...直的鋼管樁 D1...外徑尺寸 12...内周面 D2...外徑尺寸 13...千斤頂 H1...長度 14…管内土壤 H2...高度 16a...突起 X...箭頭 16b...突起 Y...箭頭 16c...突起 τ...阻力 16d...突起 Θ...錐狀角 16e··.突起 δ...角度 40The possibility of a site on the outside in the radial direction. (4) The outline 41A is further provided with a projection 16a on the outer peripheral surface 2 of the tapered portion 4. As shown in Figs. 1A and 1B, the projections extend from the front end toward the rear end 9a to a part or the whole, and protrude outward in the radial direction of the tapered portion 4. The projection 16_ of the present embodiment is provided in a portion of the outer peripheral surface 2 of the tapered portion 4. Further, the projections 16a are provided in the circumferential direction of the outer peripheral surface 2 of the tapered portion 4 at a plurality of intervals. The projections 16& are inclined so that the upper direction of the center axis c of the steel pipe pile 1A becomes the direction after the rotation of the pile. Specifically, the projection 16a is inclined such that the rear end % side of the projection 16a becomes the rear side in the rotation direction of the fixed diameter portion 9 and the tapered portion 4. In this way, the upper portion of the projection 16& in the direction of the central axis c is inclined so as to be rearward in the direction of rotation of the steel pipe pile 1A, so that it can be cut by the boring cutter 6 as indicated by the arrow b1 in Fig. 1A. The excavation soil (indigenous product) flowing on the outer peripheral surface 2 side is directed upward, or the earth sand destroyed by the shearing force of the projection 16a is guided to the direction in which the projection is inclined. As a result, the excavated soil and the soil sand can flow smoothly toward the direction behind the excavation direction A1. Further, the projection 16a is disposed with respect to the center cuff line C of the tapered portion 4 in the circumferential direction of 201207198. The central axis C2 of the projection 16a is at an angle δ with respect to the tapered portion 4, and the surface 4a is inclined. That is, even the central axis C2 of the projection 16a and the front surface 4a are at an angle of 90. However, in the present embodiment, the angle 5 is less than 90°. The details of the angle δ are explained later. By providing the tapered portion 4 to the front end 4a' of the steel pipe pile 1Α, it is expected that the effect of the ground resistance caused by the clogging in the steel pipe pile 1A can be greatly reduced, and the tapered portion 4 is subjected to a large resistance, so that the cone is generated. Wear and deformation of the portion 4. Therefore, in the present embodiment, the plurality of projections 16a are provided in the outer peripheral portion 2 of the tapered portion 4 which is most subjected to the resistance portion when the steel pipe pile 1A is inserted. In the form of the projections 16a, the projections 16a may be fixed by welding a rod-shaped steel material such as steel bars or flat steel to the outer peripheral surface 2 of the tapered portion 4, and may be tapered as shown in the drawings. The outer peripheral surface 2 of the portion 4 is subjected to surfacing as a projection, and when the tapered portion 4 is formed, a form of a projection generated by the rolling process may be provided. As a form of the protrusion generated by the rolling process, for example, a fan-shaped single-sided projecting steel sheet is disposed such that the protruding portion becomes the outer side of the pile and is inclined toward the central axis direction of the pile, and is bent into a truncated cone shape by The fusion closes the end to be a truncated cone. The end portion on the large diameter side of the truncated cone is fixed to the lower end portion of the steel pipe by welding, and serves as a steel pipe pile having the tapered portion 4. The steel pipe pile 1A having the tapered portion 4 of the present embodiment can also be used as the tapered portion 4 of the frustoconical body of the present embodiment. Further, in the first embodiment, the projections 16a are formed linearly from the front end 4a of the steel pipe pile 1A toward the rear end 9a, and the projections 16a are linearly formed in the circumferential direction. However, the projections 16a may be formed as an arc. shape. The width of the pile 19 of the projection 16a is the width dimension of the direction of the center axis c of the steel pipe pile 1A. However, it can also be set to the upper side of the protrusion 16a (the rear end is 9A). ) becomes narrower. In the money configuration, the circumferential width dimension of the steel pipe (10) of the projection 16a is guided to the upper portion of the outer surface 2 of the outer portion 4 along the projections. <Upper (four) toward the top _, the width of the pile around the 16a direction & inch Zou will become a space. Thereby, soil sand and the like can be smoothly flowed. «The shape of the large 16a is also shown. As shown in Fig. a, the lower end of the projection 16a may be provided so as to be connected to the upper mounting portion of the boring cutter 6. As described above, when the boring cutter 6 is connected, the boring blade 6 and the projection 16a connected thereto can efficiently guide the soil along the outer peripheral surface 2 of the tapered portion 4 and flow. Next, the steel pipe pile 1B according to the second embodiment will be described. As shown in Figs. 2A and 2B, the projections 16b may be provided in a state where the boring cutter 6 is separated from each other in the circumferential direction of the steel pipe pile 1B. Specifically, the projections are provided from the boring cutter 6 toward the pile in the forward direction from the boring cutter 6 to the rear side in the circumferential direction of the boring cutter 6 from the boring cutter 6 toward the rotation direction (positive rotation direction) of the steel pipe pile 1 The position after the square or the pile axis direction. In this case, as shown in the arrow B1 of FIG. 2B, the excavation soil (slag) that flows on the outer peripheral surface 2 side with the boring tool can be borrowed or borrowed. The earth sand destroyed by the shearing force of the protrusion 16b is guided to the direction in which the protrusion is inclined. As a result, the excavated soil and the soil sand can be smoothly flowed to the rear of the excavation direction A1. Next, the steel pipe pile 1C according to the third embodiment will be described. In the first and second embodiments described above, the protrusions 16a and 16b 20 201207198 are at least in the center iiC direction and the circumferential direction of the steel official pile 1C. As shown in Fig. 3d, it is also possible to arrange X from 16e #''' as shown in Fig. 3A and Fig. 3β, and it is also possible to separate two protrusions (4) from each other. (4) In the direction of excavation, A1 is intermittently set to Wei (four), and it is also possible to arrange more than three in-line arrangement. Next, the steel pipe pile 1D of the fourth embodiment will be described. In each of the above-described embodiments, the protrusions ～16 are displayed. The configuration inclined with respect to the center axis C is 'but may not be inclined. The projections _ extend along the central axis C of the steel pipe pile 1D as shown in Fig. 4A. Further, the lower end (6) of the projection 16d is located on the upper side of the excavation plus the upper surface 6a as in Fig. 4B; in this case, the soil system is guided along the outer peripheral surface 2 of the tapered front end portion 4 by the sudden correction d Maneuvering towards the central axis C of the steel tube (1). Although the projections 16d of such a shape are also possible, in consideration of the rotation of the steel & 1D, the projections 16a to 16c are oriented toward the steel pipe pile 1A to 丨 as shown in the above embodiments. When the squat is configured to be inclined rearward in the direction of rotation, the flow of soil along the outer peripheral surface 2 of the tapered portion 4 is smooth. In this way, when the boring blade 6 is connected to the projection 16d, the soil boring by the boring cutter 6 and the soil damage (slag) which is destroyed by the shearing force of the projection 丨 6 d can be efficiently along the tapered portion 4 The upper part flows. Next, the steel pipe pile 1E according to the fifth embodiment will be described. As shown in Fig. 5, the tapered portion 4 of the steel pipe pile 1E is provided with a sharp portion 5 which is protruded from the front end and sharpened toward the boring direction A1. Further, a recess 5a is provided in the front end 21 201207198 4a of the tapered portion 4. This recess 5a does not have to be formed necessarily. Further, in the present embodiment, since the boring blade is not provided, the projection 16e extends from the distal end 4a toward the rear end 9a and extends over the entire outer peripheral surface 2 of the tapered portion 4. Next, the steel pipe pile 1F of the sixth embodiment will be described. As shown in Figs. 6A to 6D, the front end 4a of the tapered portion 4 between the boring cutters 6 shown in Fig. 1A may be provided with a sharp portion 5b which is sharp toward the boring direction A1. The front end of the sharp portion 5b becomes flat as compared with the sharp portion 5 shown in Fig. 5. In the present embodiment, the front end can be sharpened as in the fifth embodiment, and the front end of the sharp portion 5 of the fifth embodiment can be made flat. Next, the steel pipe pile 1G according to the seventh embodiment will be described. Fig. 7A and Fig. 7B are explanatory views showing the shape and mounting range of the projections provided in the steel pipe pile 1G. The length of the dog 16g from the front end 4a toward the rear end 9a may be set to be approximately the entire circumference of the outer peripheral surface 2 of the tapered portion 4. At this time, in order to suppress the decrease in the outer peripheral friction of the steel pipe pile 1G as much as possible, the height of the projection 16g can be set. For example, as shown in Fig. 7B, the height H2 of the projection 16g is defined such that the dog 16g is smaller than the sizing portion 9 in the radial direction of the tapered portion 4, in other words, the height and projection of the restriction projection 16g. The upper end portion of the central axis C2 of the extending direction of the 16g direction is such that the projection 16g extends from the side of the tapered portion 4 from the outer shape extension line 18 of the portion 9 in the radial direction of the steel pipe pile 1G. Thus, the projection 16g is provided. At this time, it is possible to suppress the decrease in the circumferential friction of the steel pipe pile 1G by disturbing the surrounding green small-j-. The length in the extending direction of the projections 16g may be a range in which the extension line a 22 201207198 is formed inside the fixed diameter portion 9 and is shorter than the case of the above embodiment. Next, the inclination angle of the projection 16g will be described using Figs. 7A and 7B. When the steel pipe pile 1 正面 is viewed from the direction of the vertical boring direction A1, the angle formed by the horizontal line D (front surface 4a) of the vertical center axis C and the central axis C2 of the extending direction of the protrusion 16g (the central axis C2 of the protrusion 16g) The angle of inclination of the horizontal line D is in the range of 20° to 90°, preferably 2 inches. ~7〇. More preferably, it is set to 3 配合 in accordance with the internal friction angle 0 of the usual ground. ~5〇. The range can be effectively sheared. The angle of inclination of the dog from 16g is 9〇. At the time of the rotation of the steel pipe pile, the soil shear force can be effectively broken by the shortest projection 16g. However, since the guiding effect of the soil accompanying the positive rotation of the steel pipe pile is small, the effect of effectively flowing the soil (slag) after the excavation from the tapered portion 4 to the upper side thereof is lowered. The inclination angle S of the protrusion sound is less than 2 〇. At this time, since the length m of the circumferential direction of the steel pipe pile is long, it is not economical, and the shearing efficiency of the soil is lowered. In the present embodiment, the lower limit of the inclination of the protrusion is set to 20 . . Further, the inclination angle § of the projection 16g is 2 〇. When ~% is left and right, the phase per unit length of the protrusion of the soil shearing surface is significantly smaller than that of 90. In addition, it is also possible to play the soil that has been excavated (the guiding effect of the soil. In addition, the 'slanting 16g of the slant (four) lion. The construction of the positive direction of rotation of the tube will destroy the soil by the protrusion % shear: (earth When the crushing is pressed downward, the flow efficiency of the soil red flow and the protrusions is also lowered. Therefore, as described above, the range of the friction angle of 0 = 30 。 is considered to be the best. 23 201207198 The range of the inclination angle § is the same in each of the above embodiments. Next, the height dimension of the projection 16g will be described with reference to Fig. 7B. The height dimension H2 in the radial direction of the steel pipe pile 1G of the projection 16g is set to The outer diameter is a length dimension of 0.6% to 3.0% of the outer diameter dimension D1 of the fixed diameter portion 9. That is, the dimension of the height dimension H2 = 0.006D1 to 0.03D1 is set. Usually, 'because the outer diameter of the steel pipe pile is 400 mm ～2500mm or so, the height dimension H2 of the pile 16g in the radial direction of the pile is about 12mm in the steel pipe pile having an outer diameter of 400mm, and is about 15mm to 75mm in the steel pipe pile of the outer diameter of 2500ηΐιη. The height dimension H2 of the protrusion is in the above-mentioned respective implementations. shape The protrusion interval between the protrusions 16g adjacent to each other in the circumferential direction of the steel pipe pile is not particularly limited. However, the distance between the protrusions 16g adjacent to the circumferential direction of the steel pipe pile may be set at equal angular intervals, for example. The arrangement is the same as that of the boring tool 6, or the boring cutter 6 is disposed at the same equivalence interval or a different arrangement interval. Alternatively, the position of the lower end of the protrusion 16g may be set to be connected to the boring cutter 6. In the upper end portion of the outer peripheral surface 2 of the tapered portion 4 during the forward rotation of the steel pipe pile, when the boring cutter 6 is connected to the projection 16g, the soil boring by the boring cutter 6 and the projection i 6 g can be used. The soil that has been destroyed by the frying force allows the (slag) to effectively flow along the tapered portion to the upper portion. Next, the effect of the construction on the presence or absence of the protrusion 16g provided on the tapered portion 4 is reduced. The results are described with reference to Figs. 7A to 8B, Fig. 11 and Fig. 12. 24 201207198 The shape of the tapered portion of the steel pipe pile used in the test is related to the seventh embodiment shown in the figure and Fig. 7B. The tapered portion 4 of the form has a protrusion The steel pipe pile 1G of the steel pipe pile 1G and the steel pipe pile 17 which has a convex shape in the tapered portion 4 shown in Fig. 8A and the first embodiment are tested. The steel pipe piles 1G and 17 of the test body used for the test are used. There are four cutting knives 6 in the tapered portion 4 at equal angular intervals. The steel pipe coils 1G and (4) of the two test bodies used in the test are the outer diameters of the steel pipe piles 1G and π, which are outside the core portion 9. Any of the diameters (1) is HiOOmm. The length H1 of the steel pipe piles 1G and 17 of the tapered portion 4 in the direction of the central axis c is H1=〇.5D1' and the outer diameter dimension D2 of the tapered portion 4 is fixed. The relationship of the outer dimension 01 of the diameter portion 9 is D2 = 〇 9 m. Further, in the steel pipe pile 1 of the present embodiment in which the projections 16g are provided in the tapered portion 4, the steel bars of the diameter (10) (7) are arranged to be connected to the upper end portion of the boring blade 6 as the projections 16g, and are fixed by welding. The projections 16g The height dimension H2^H2=〇〇16D1, the protrusion 16g is a steel bar. The inclination angle 5 of the protrusion 16g is 45 从 from the directly upper side of the boring cutter 6 to the upper end of the tapered portion 4 so as to be connected to the boring cutter 6 The projections 16g are fixed to the tapered portion 4 by welding to form the steel pipe pile 1G. The ground plate is a soft rock (mudstone) having a uniaxial compression strength of 5 N/min2, and is rotated from the ground plate into the respective steel pipe piles 1 (}, 17 The outer diameter is 〇13 times the depth of the distance. During construction, the construction load per unit area of the pile head of the sizing unit D丨 outer diameter dimension 〇1 (the pile head side) (injection force: kN/m2) And the penetration amount (penetration ratio) with respect to the outer diameter dimension D1, the relationship between the construction load and the penetration amount ( penetration ratio) is shown in Fig. 10 as shown in Fig. 10. 4 In the case of 25 201207198 without steel pipe piles 17 with protrusions 16g, the maximum pressing force is 645kN. /m2, in the case of the steel pipe pile 1 (} of the present embodiment in which the tapered portion 4 has the projection 16g, the press-in force is at most 363 kN/m2. That is, it is understood that the construction load can be reduced by about 30% or more. Therefore, in the case where the tapered portion 4 has the steel tube coil (10) having the projection 16g, the weight can be reduced, so that the weight can be made less. Further, when the construction load can be reduced by about 30% or more, the mechanical machine can be used. The capacity of the construction machinery is reduced. In the existing construction machinery, for example, it is possible to significantly reduce the construction cost by constructing a small construction machine under the n-level. Further, the steel pipe piles 1G and 17 relating to the aforementioned test bodies will be related. The result of the measurement of the average wear amount W in the direction of the center axis C of the steel pipe piles 1G and 17 of the outer peripheral surface of the tapered portion 4 is shown in Fig. 11. From the eleventh figure, the projections 16g are provided in the tapered portion 4. In the steel pipe coil 1〇, the phase pipe pile 17, before the taper portion 4 and the position of the heart (four) shoe paste table U5D1) =: 7:), the average wear amount is significantly reduced to - half no wear, in ...starts with two: a 2% weak average wear amount 'average wear at the upper end of the taper 4'. When 3% is strong:) Front: Flat (the original thickness of the difficult taper 4 is the average value of the burnt amount. The average wear amount (%) is the grinding of the plural test body. The average radial deformation (%) of the steel pipe is thin, 17 relative to the taper shape and the outer circumference 26 201207198 in the half direction (original shape), and the figure is shown in the figure above. Figure 7 矣is- No position measurement (4) The result "·' is not shown in the lower part of Fig. 12. The present invention and the right * 4 meter _ # (, there is a dog 16g cone-shaped department! Point system edge protrusion 16g for measurement. The case where the half-pipe (heart) of the steel pipe pile core 17 is deformed in a concave manner is shown as a _ (negative) deformation in which the outer side of the pipe pile 1G and 17 is bent in the radial direction and the drum is deformed. . , "_ In the steel pipe pile 17 having no protrusions in the tapered portion 4, the front end side of the straight-conical shape in the direction of the Erguang direction is deformed toward the center_down, and the base of the axial direction: (the large side) is bulged. It can be understood that (4), (4) the reversal of the tapered portion 4 (recessed and bulged), in the steel pipe pile 1G of the present invention, the tapered portion 4 is only slightly bulged in the direction of the reel. As can be seen from the graphs of Figs. 11 and 12, in the case of the steel pipe pile 1 of the present invention having the projecting ridges in the tapered portion 4, the steel pipe piles 17 having the shape of the projections in the tapered portion 4 are remarkably The amount of wear and the amount of deformation of the tapered portion 4 is improved. When the projections are provided in the tapered portion 4, the thickness of the portion where the projections are provided is naturally increased in rigidity and the rigidity of the entire tapered portion 4 is also increased. In the steel pipe pile 1 (} in which the outer peripheral surface 2 of the shape portion 4 is provided with the protrusion 16g as described above, the following effects (1) to (4) can be expected. (1) When the pile is rotated and pressed, the protrusion 16g is effectively used. Further, the ground (soil) in the vicinity of the outer peripheral surface 2 of the tapered portion 4 is actively broken (shear-damaged), and the rotation of the pile can be easily performed. (2) The portion of the projection 16g is partially used to bear the resistance of the ground portion in the tapered portion 4. Friction and deformation occur, and it is possible to suppress the wear and deformation of the tapered portion 4 of the 201207198 important member to exert the support performance of the pile, and to improve the soundness (safety) of the pile. The protrusion 16g is set to be continuous on the front side of the boring cutter 6 'the soil which is excavated by the boring cutter 6 The resistance flows along the projections 16g to reduce the resistance of the pile construction. (4) By providing the projections 16g with the mounting angle 5 so as to intersect the axis of the center line c of the steel pipe pile 1G, the pile is rotated. It is found that the soil which is broken by the shearing force of the projections 16g is caused to flow upward by the projections 16g. Further, the resistance of the ground at the time of pile construction can be reduced. In this test, the steel pipe of the seventh embodiment is used. The pile 1G will be described. However, the same effect can be obtained by using the steel pipe piles 1A to 1F of other embodiments. In the present invention, the hard disk is called a rock disk, and the rock disk can be classified into a soft rock system disk (uniaxial compression strength~ Less than 20 MPa) and hard rock series rock disk (uniaxial compressive strength: 20 MPa or more) However, the steel pipe piles 1A to 1G having the end tapered portions before the present invention are applicable to any rock disk in the form of the cutting blade 6. The cross-sectional shape of the outer peripheral surface 2 of the tapered portion 4 and the inner peripheral surface 3 of the tapered portion 4 in the longitudinal direction of the pile is a straight line shape on one side in the longitudinal direction of the pile, and the outer side and the inner side may be straight lines as shown in Fig. 1 Shape, and The cross-sectional shape of the outer circumferential surface 2 of the tapered portion 4 and the inner circumferential surface 3 of the tapered portion 4 in the longitudinal direction of the pile may be convex inward in the radial direction from the center axis of the pile ( It may be recessed inward in the radial direction from the center axis of the pile, and may protrude inward in the radial direction (inward in the semi-transverse direction). When the protrusions 16a to 16e, 16g are provided, 28 201207198 is directly disposed on the tapered portion 4 The outer peripheral surface 2. The size and action of the tapered portion 4 according to the present invention will be described. Here, FIGS. 13A and 13B are diagrams in which the projections 16a to 16e and 16g are omitted. By providing the tapered portion 4 which is reduced in diameter at the front end 4a side of the steel pipe piles 1A to 1G, as shown by arrows in FIG. 13B and arrows in FIG. 15 , the soil is actively flowed to the pile. On the outside, it reduces the amount of soil flowing into the tube. Further, by reducing the opening area of the tapered portion 4, as shown by the arrow C1 in Fig. 13B and the arrow C1 in Fig. 15, the soil flowing into the tube can be reduced and diffused in the radial direction. Thereby, it is possible to suppress the clogging of the soil in the pipe at the tip end portion of the pile, and to reduce the friction between the soil in the pipe and the inner peripheral surface 3 of the piles 1A to 1G, and to reduce the pile pressing force. By providing the tapered portion 4 at the tip end portion of the pile, the resistance of the soil acting on the inner peripheral surface 3 of the tapered portion 4 is increased, and the method of suppressing the friction of the peripheral surface of the pile can be generated by the method of adopting the rotary press-in construction. . Further, by providing the projections 16e and 16g, it is possible to promote the movement of the soil acting on the inner peripheral surface 3 of the tapered portion 4 above the inner peripheral surface 3, thereby reducing the resistance of the soil. The ratio of the outer diameter dimension D2 of the front end 4a of the tapered portion 4 to the outer diameter dimension D1 of the fixed diameter portion of the steel pipe pile is small, and the diameter reduction direction is small, and the length direction of the tapered portion 4 (axis) The ratio (H1/D1) of the length dimension Hi of the direction) to the outer diameter dimension D1 of the fixed diameter portion becomes too small (in other words, when the taper angle Θ (.) of the tapered portion 4 becomes too large When the rotary press-in is applied, the resistance generated by the surface pressure acting on the tapered portion 4 becomes high. As a result, construction obstacles may occur. Therefore, in the embodiment, it is possible to achieve good rotational press-fit workability by limiting the ratio to a predetermined range. 29 201207198 In the present invention, the length m of the tapered portion 4 in the longitudinal direction of the pile (the same direction as the central axis C of the steel pipe), the outer diameter D2 of the front end of the tapered portion 4, and the outer diameter are determined. The outer diameter dimension (1) of the diameter portion and the cone angle 0 have a relationship of tan0 = (D1 - D2) / 2Hl. Further, at the time of construction, the taper portion 4 is vertically combined with the ground direction in the direction in which the taper portion 4 is combined with the ground direction, and has a tapered angle θ which is tapered toward the penetration direction of the pile. Thereby, the shearing force and the compressive force are simultaneously made to the ground, and the effect of expanding the ground to the side is exerted. Therefore, the ground plate can be effectively disturbed, and the resistance at the time of construction of the tapered portion 4 becomes small. By providing the tapered portion 4, since the projected area of the bottom surface of the pile is increased, a reliable supporting force can be obtained by the tapered portion 4 when penetrating into the support layer. In order to ensure the supporting force, the opening end of the opening at the front end 4a can exert a firm supporting force even if the inside of the tube is not sufficiently closed. Since the portion of the projected area of the bottom surface of the tapered portion 4 can bear a high compression load, the steel pipe piles 1A to 1C^S can exert a high supporting force when the normal open end pile is rotated and pressed into the construction. Further, in the hard land in which the restraint pressure of the site is sufficient, the steel pipe coils 1A to 1G surely exert a high supporting force. Therefore, a high support force can be expected when the steel pipe pile which is closed by the front end 4a is penetrated by the rotary press-in construction. When the steel pipe piles 1A to 1G are rotated and pressed into the construction, the steel pipe piles 1A to 1G are alternately moved up and down in the underground during the construction, and when the upper pipe moves, the soil in the pipe falls below the pipe. At the time of the move, the fallen soil 30 201207198 was pushed outside the tube. Thereby, as shown in Fig. 15 and Fig. 16, the height of the soil in the tube can be lowered', and the contact surface between the inner peripheral surface 12 of the sizing portion 9 and the soil in the tube 14 can be reduced. As a result, since the friction between the inner peripheral surface 12 and the soil in the tube 14 is reduced, the construction load can be further reduced. In the present invention, the ratio (H1/D1) of the length H1 of the tapered portion 4 in the longitudinal direction of the pile to the outer diameter D1 of the fixed diameter portion 9 is set to 〇.3 to 5·5 °, that is, H1/D1 is set to 0.3 to 5.5. Further, the 'outer diameter dimension D2 is set smaller than the outer diameter dimension D1 so that the outer diameter dimension D2 of the front end of the tapered portion and the outer diameter dimension D1 of the fixed diameter portion 9 of the steel pipe pile are constant (D2/Dl) That is, the reduction ratio (D2/D1) is in the range of 0.60 to 0.95. As described above, the reason for setting H1/D1 to 0.3 to 5.5 and the reason for setting the outer diameter dimension D2 of the steel pipe piles 1A to 1G will be described with reference to Figs. 16 to 20 . Here, the shape of the tapered portion 4 is the same as that of the steel pipe piles 1A to 1G, and therefore, the steel pipe pile 1A will be described. First, referring to Fig. 19, when the diameter reduction ratio (D2/D1) is 0.9, the length H1 in the direction of the center line C of the tapered portion 4 and the sizing portion having a constant outer diameter are investigated by an experiment. The relationship between the ratio (H1/D1) of the outer diameter dimension D1 of 9 and the necessary pressing force ratio (the necessary pressing force of the steel pipe pile 1A having the tapered portion 4, and the ratio of the necessary pressing force to the straight steel pipe pile 1) After the chart. In the steel pipe pile 1A used in the experiment, the outer diameter dimension (D1) of the sizing portion 9 is iOOmm', the thickness (1) of the steel pipe portion is 4.2 mm, and the outer diameter dimension (D2) of the front end 4a of the tapered portion 4 is 90 mm. Further, the outer diameter dimension (D1) of the steel pipe pile 10 which is straight across the entire length of the outer diameter (D1) and the thickness (1) of the steel pipe portion are the same as those of the steel pipe pile 1A of 31 201207198. It can be understood from Fig. 19 that when 111/〇1 is 0.3, the necessary pressing force ratio is 〇·9, and when the output/〇1 is 0.4, the necessary pressing force ratio is 〇6, and when H1/m is 1_35. 'The necessary pressing force ratio is 0.6, and when 111/〇1 is 5 5, the necessary pressing force ratio is 0.9. As a result, it can be understood that the ratio (H1/D1) of the length H1 in the center cuff line C direction of the tapered portion 4 to the outer diameter dimension D1 of the fixed diameter portion 9 is 0.3 to 5.5, that is, When 〇1 is 〇3 to 5 5, the necessary pressing force ratio is 0.9 or less, and the steel pipe pile 丨8 phase can be reduced by at least 10% of the required pressing force as compared with the straight steel pipe pile 10 shown in Fig. 22A. Further, it can be understood that when H1/D1 is 0_40 to 1.35, the ratio of the required pressing force is 0.6 or less, and the required pressing force can be reduced by 40% in the steel pipe pile 1Α compared with the straight steel pipe pile 1〇. Further, in Fig. 20, a graph in which the experimental value is extracted and connected is shown, which is a ratio of the outer diameter dimension D2 of the distal end 4a to the outer diameter dimension D1 of the sizing portion 9, that is, the diameter reduction ratio (D2/D1). The graph is taken as the horizontal axis, and the steel pipe pile 1A of various reduction ratios is investigated by an experiment and the necessary pressing force ratio is compared. As shown in Fig. 20, when the reduction ratio (D2/D1) is 0.60, the required pressing force ratio is 0.9, and the reduction ratio (D2/D1) is 0.75, the necessary pressing force ratio is 0.6, and the reduction ratio (D2) When /D1) is 0.92, the necessary pressing force ratio is 0.6, and when the reduction ratio (D2/D1) is 0.95, the necessary pressing force ratio is 0.9. As shown in the 19th and 20th figures, it can be understood from the convex diagram that in the range of the diameter reduction ratio (D2/D1) of 0.60 to 0.95, the necessary pressing force ratio is reduced to 0.90 or less, and it is necessary to The press-in force is reduced by at least 10%. Further, in the range of the diameter reduction ratio (D2/D1) of 0.75 to 0.92, the required pressing force ratio becomes 32 201207198 0 06 or less and the required pressing force can be reduced by 40%. Therefore, it is preferable that H1/D1 is 0.3 to 5.5, and the diameter reduction ratio (D2/D1) is 0.60 to 0.95. The better one is to make H1/D1 0.3 to 5.5, and the reduction ratio (D2/D1) is The range of 0.75~〇_92. When the press-in force ratio drops below 〇.9, the weight (weight) can be greatly reduced. For example, if the required pressing force is 86t (ton), the reaction weight is 66t (ton), and the weight of the construction press is 20t (ton), the rotary press-in construction equipment can reduce the necessary pressing force by 10%. 8.6t (tons), and the weight can be reduced by 13% 〇 and 'As shown in Figure 19, it can be seen that when H1/D1 is 0·40~1.35, the ratio of pressure to force can be 〇· Below 6, the weight can be reduced even more. In this way, when the ratio of the pressing force is 〇 6 or less, it is particularly desirable because the rotary press-in construction machine can press the small rotation of the lower stage into the construction machine to rotate the pile into the construction. The resistance reduction mechanism for continuously rolling the steel pipe pile 1 to the ground is described in the 21st and 21st drawings. The second syllabary shows the illustration of the protrusion (6) and the boring cutter 6 which are omitted from the steel pipe pile. The steel pipe pile 1〇 in the 21st and the 2nd steel pipe piles are recognized as follows: a and Μ乍 are the resistance at the front end occlusion portion, b is the resistance at the front end, and b is the tapered portion 4 The resistance generated will be. And c, as the resistance generated by the friction of the outer peripheral surface 2 of the mouth and the mouth P4, and the resistance generated by the inner soil. "In the 21st picture, since it becomes (4), as shown in the figure 'H 1D is smaller (in other words, the cone angle (4) of the taper portion * is larger than 33 201207198), the front end 4a is generated. When the resistance b is increased, in the case of Fig. 21B, when the diameter of the taper is increased, the force a in the front end closing portion is reduced, and the resistance b generated by the tapered portion 4 is reduced. Increasing, as shown in Fig. 21A and Fig. 21B, the horizontal portion (in the range of the reduction ratio of about 70% to 80%) is in a balanced range due to the effect of increasing or decreasing the resistance. The tapered portion 4 of the pile 1A has the function as described above, and by having the protrusion 16a in the tapered portion 4, the shear contact with the soil of the tapered portion 4 can be actively sheared to reduce the contact of the tapered portion 4 with the ground plate. Further, when the inclination angle δ of the projection 16a is 30 to 50, the crushing can be efficiently performed by the internal friction angle φ of the normal disk. The sharp sharp portion 5 toward the boring direction Α1, It is sufficient to make the sharp portion 5 sharp in the direction of the digging. In the foregoing case, it may also have a week toward the pile. To the sharp part. As in the above form, the front end 4a of the tapered portion 4 is set to the direction of the boring direction (the sharp sharp portion 5, even if the ground is hard, by the boring knife 6 and the sharp portion 5, or borrow The tapered portion 5 of the taper portion 4 is used to dig the sharp portion 5 of the cutting blade 6, and the steel pipe can be wound into the ground plate by the surface of the pile-forming device during the work of the pile-punching device. When 1A to 1G or a steel pipe pile 17 having no protruding support is used for construction, similarly to the conventional method, the steel pipe pile can be pressed to the ground by applying a rotational force and a human pressure. The rotary press-in construction machine 7 shown in the figure is used for rotating the press-fit construction of the steel pipe pile P of the front end taper portion, and the like, compared with the conventional steel pipe pile 10, that is, the steel pipe pile. The diameter of the 〇1 and the thickness of the straight 34 201207198 steel official pile 10 is applied, and it is understood that the steel pipe piles 1A to lG of the present invention have a penetration amount per unit of pressing force as shown in Fig. 17, The point of the front end load (kN/m2) shown in Fig. 18 is excellent. Further explanation Fig. 17 shows the construction load when using the outer diameter dimension D1 shown in Fig. 16 and the outer diameter dimension 〇2 of the front end of the tapered portion 4, that is, the pressing force per unit occlusion sectional area of the pile (kN/m2). The relationship between the penetration amount/pile diameter (H2/D1). It is understood that the steel pipe pile ιΑ~ι(} in the present invention is compared with the straight steel pipe pile shown in the 22nd sheet (in the 17th figure, it is recorded as live broadcast). In addition, in Fig. 18', the front end load (kN/m) is shown when the steel pipe is rotated and pressed into the hard disk by a factor of 1 degree I of the outer diameter D1 of the construction to the hard disk. The relationship between the amount of sinking of the front end and the diameter of the pile _. From the first figure, it can be understood that the copper pipe pile 1A to lG in the present invention has a higher front end load and a higher supporting force than the straight pile. In the ic*, the steel pipe piles 1A to 1G of the present invention or the non-protrusive steel pipe coils 17 can be surfaced until the support layer under the soft land is rotated and pressed into the ground plate containing the hard land. In the case of the steel pipe piles ia to ig of the present invention, the steel f #lA to 1G is moved up and down in the ground during the construction, and the soil in the steel pipe pile (the soil inside the official residence) is lowered. As shown in Fig. 15 and Fig. 16, the area of the inner soil and the inner peripheral surface of the steel pipe piles 1A to 1G is reduced. As a result, the portion of the plate having a small adhesion area is reduced, and the burden on the construction machine is reduced, so that the construction can be performed more efficiently. In the state in which the steel pipe piles u1 to 1G are moved up and down, the steel pipe piles 1A to 1G in which the front end taper portion protrudes are held by the construction machine 7 by the rotation pressure 35 201207198, and the hydraulic pressure is rotationally pressed into the construction machine 7. The type of telescopic jack (1) is retracted. Thereby, the steel pipe piles 1A to ig can be easily moved up and down. Further, in the construction method of the steel pipe piles 1A to 1G, when the tapered portions 4 of the steel pipe piles 1A to 1G are finally stopped in the blast layer, the reverse _ tube ia 〜 1G' is used by the protrusions 16a to 16e. 16 g of the soil near the outer peripheral surface of the tapered portion 4 (including soil crushed by gravel or the like) is pressed downward. As a result, the soil near the outer peripheral surface of the tapered portion (including the soil such as gravel) is pressed downward by the projections (6) to 166 and 168, so that the branch floor on the lower side of the pile is tight, and the roll can be supported: As an example of the method for producing the main body portion of the steel pipe of the present invention (4), such as 1A to 1G, the steel pipe pile can be formed by cold material (4), and the shape PX' can also be formed by cold pressing. And the formation of a miscellaneous part. Or, the strip-shaped steel plate is fan-shaped, and the fan-shaped steel plate is processed into a tapered shape by cold bending, and both side edges are joined by splicing. Then, (4) a tapered short tube having substantially the same outer diameter as the steel tube to which the outer diameter portion is to be connected is fixed by fixing the upper end portion of the tapered short tube, and the cone of the root steel tube, P, to form the pile-inhibiting body ^ Further, the taper shape of the root steel pipe can be plastically processed as a steel pipe pile body having a tapered portion. It is possible to fix the dog with the knives of the knives in the shape of the money, and set the dog to the front of the tapered portion with the tapered portion. It is also possible to use a strip-shaped steel plate with a single-sided dog as a fan-shaped protruding steel plate to make a short cone-shaped e = by (4) connecting the upper tube of the short tube (four) to the front end of the one steel tube Steel pipe piles with protrusions, etc. [Brief Description] 36 201207198 Fig. 1A is a front view showing a steel pipe pile having a protruding end portion at a tip end portion according to a third embodiment of the present invention. Figure 1B is a front elevational view of the longitudinal section of the steel pipe pile. The 苐1C diagram is a cross-sectional view taken from the arrow a-a of Figure 1B. Figure 1D is a cross-sectional view taken from the arrow b-b of Figure 1B. Fig. 2A is a perspective view showing a steel pipe pile having a protruding end portion in a second embodiment of the present invention. Figure 2B is a front view of the aforementioned steel pipe pile. Fig. 3A is a front elevational view showing a steel pipe pile having a protruding end portion in a third embodiment of the present invention. Figure 3B is a front elevational view of the longitudinal section of the steel pipe pile. Figure 3C is a cross-sectional view taken from the arrow c-c of Figure 3B. Figure 3D is a representation of the d-d arrow from Figure 3B. Fig. 4A is a perspective view showing a steel pipe pile having a protruding end portion in a fourth embodiment of the present invention. Figure 4B is a front view of the aforementioned steel pipe pile. Fig. 5 is a front elevational view showing a steel pipe pile having a projection at a front end portion according to a fifth embodiment of the present invention. Fig. 6A is a front view showing a steel pipe pile having a protruding end portion at a front end portion according to a sixth embodiment of the present invention. Figure 6B is a front elevational view of the longitudinal section of the steel pipe pile. Figure 6C is a cross-sectional view taken from the arrow e-e of Figure 6B. Figure 6D is a representation of the arrow f-f from Figure 6B. Fig. 7A is a side view showing the shape and mounting range of the steel pipe pile projection 37 201207198 provided in the seventh embodiment of the present invention. Fig. 7B is a cross-sectional view showing the shape and mounting range of the steel pipe pile provided in the seventh embodiment of the present invention. Fig. 8A is an explanatory view showing a comparative example. Fig. 8B is an explanatory view showing a comparative example. Fig. 9 is a front view showing a state in which a steel pipe pile is rotationally pressed into a ground plate by a rotary press-in construction machine. Fig. 10 is a graph showing the relationship between the construction load, the penetration amount, and the press-fitting force of the steel pipe pile of the present invention having a projection at the tapered tip end portion and the steel pipe pile having no projection at the tapered tip end portion. Fig. 11 is a view showing the comparison of the average wear amount of the end portion before the construction of the steel pipe pile having the projection at the tapered front end portion and the steel pipe pile having no projection at the tapered front end portion. Fig. 12 is a view for comparing the average deformation amount of the front end portion of the present invention in the case where the steel pipe pile having a projection at the tapered front end portion and the steel pipe pile having no projection at the tapered front end portion are used. Fig. 13A is a view showing the direction of rotation when the steel pipe pile of the present invention is rotationally pressed into the ground. Fig. 13B is a sectional view of Fig. 13A, and is an explanatory view showing the flow of soil. Fig. 14 is a longitudinal sectional front view showing a state in which the aforementioned steel pipe pile is rotationally pressed into the support layer. Fig. 15 is an explanatory view showing the flow of soil when the steel pipe pile is rotationally pressed into the ground. 38 201207198 Fig. 16 is a longitudinal front view showing the relationship between the press-in depth when the steel pipe pile is laminated to the support, the height of the soil in the pipe, and the size of the vicinity of the front end portion. Fig. 17 is a graph showing the relationship between the press-in force and the ratio of the penetration amount to the pile diameter of the above-mentioned steel pipe pile and the straight pile as a comparative example. Fig. 18 is a graph showing the relationship between the ratio of the amount of the front end sinking to the pile diameter and the load at the front end of the pile, with respect to the steel pipe pile and the straight pile as a comparative example. Fig. 19 is a graph showing the relationship between the ratio of the length of the front end portion to the outer diameter of the steel pipe pile, and the ratio of the required pressing force of the steel pipe pile to the required pressing force of the straight pile. Fig. 20 is a graph showing the relationship between the reduction ratio (D2/D1) of the front end portion and the necessary pressing force ratio. Fig. 21A is a view showing the resistance of the front end side of the steel pipe pile, and is a longitudinal sectional front view showing the straight pile of the comparative example. Fig. 21B is a front elevational view showing the longitudinal direction of the steel pipe pile at the tapered front end portion. Fig. 22A is a front view showing a steel pipe pile as a comparative example. Figure 22B is a front elevational view of the longitudinal section of Figure 22A. Figure 22C is a cross-sectional view taken from the g-g arrow of Figure 22B. [Main component symbol description] 1A...Steel pipe pile 1C...Steel pipe pile 1B··.Steel pipe pile 1D...Steel pipe pile 39 201207198 1E...Steel pipe pile 16g···Protrusion IF...Steel pipe pile 17.. .Steel pipe pile 1G...Steel pipe pile 18... Extension line 2... Outer peripheral surface a·.. Resistance 3... Inner circumferential surface a'.. · Resistance 4... Conical part b·.· Resistance 4a...front end b'...resistance 5...sharp portion C···resistance 5a...recess C'···resistance 5b...sharp portion A1...boring direction 6... Boring knife B1...arrow 7...rotation press-in construction machine C...center axis 8...support layer C1...arrow 9...sizing portion C2...center axis 9a... Rear end D... horizontal line 10... straight steel pipe pile D1... outer diameter size 12... inner circumferential surface D2... outer diameter size 13... jack H1... length 14... inside tube Soil H2 ... height 16a ... protrusion X ... arrow 16b ... protrusion Y ... arrow 16c ... protrusion τ ... resistance 16d ... protrusion Θ ... cone angle 16e · ·. Protrusion δ... angle 40

Claims (1)

201207198 七、申請專利範圍： 1. 一種鋼管樁，係掘削方向的前端開口且為中空者，其特 徵在於： 該鋼管樁包含： 定徑部，係外徑尺寸為一定者；及 前端部，係内形尺寸及外形尺寸朝前述前端逐漸變 小者， 於前述前端部之外周面設有突起，前述突起係從前 述前端朝後端延伸在一部分或全體，且突出於前述前端 部之半徑方向外方。 2. 如申請專利範圍第1項之鋼管樁，其中前述突起係於前 述前端部之前述外周面的周方向隔著間隔設有複數個。 3. 如申請專利範圍第1或2項之鋼管樁，其中前述突起傾斜 成使前述突起之前述後端側成前述定徑部及前述前端 部之旋轉方向的後方。 4. 如申請專利範圍第1或2項之鋼管樁，其中前述突起係相 對前述前端部之中心軸線於周方向傾斜配置，且垂直於 前述中心軸線之面與前述突起之延伸方向的中心軸線 所呈的角度為20°〜70°。 5. 如申請專利範圍第1或2項之鋼管樁，其中前述突起之高 度係規定成前述突起較前述定徑部之外形尺寸位於前 述前端部之前述半徑方向的内側。 6. 如申請專利範圍第2項之鋼管樁，其中於前述前端之周 方向隔著間隔設有複數掘削刀。 41 201207198 7.如申請專利範圍第6項之鋼管樁，其中前述突起之下端 係位於前述掘削刀之上面的正上方。 8·如申請專利範圍第6項之鋼管#，其中前述掘削刀較前 述疋徑部之外形尺寸配置於前述前端部之前述半徑方 向的内側。 9·如申請專利範圍第1項之鋼管樁，其中前述前端部之長 度方向的高度尺寸相對於前述定徑部之外形尺寸的比 為0_3〜5.5 〇 10·如申請專利範圍第1項之鋼管樁，其中前述前端之外徑 尺寸相對於前述定徑部之外徑尺寸的比為〇 6〇〜〇 95。 U·如申請專利範圍第1項之鋼管樁，其中於前述前端部設 有從前述前端突出且朝前述掘削方向尖銳之尖銳部。 2.種鋼管樁的施工方法，係使用如申請專利範圍第丄項 之鋼管樁之鋼管樁的施工方法，其特徵在於： 藉由對前述鋼管樁附與旋轉力及壓入力之旋轉壓 入工法而壓入到地盤時，一面藉由前述突起剪力破壞前 述地盤一面壓入前述鋼管樁。 13.如申睛專利範圍第12項之鋼管樁的施工方法，其中係將 前述鋼管樁旋轉壓入到包含硬質地盤之地盤。 4·如申清專利範圍第丨2項之鋼管樁的施工方法，其中於前 述施工途中，一面在地下使前述鋼管樁旋轉、或者是不 加以旋轉、或組合其等，一面使上下動，藉以降低前述 鋼管樁内之土壤的高度。 15.如申請專利範圍第12項之鋼管樁的施工方法，其中於支 42 201207198 撐層内最後停止打設前述鋼管樁之前述前端部時，逆旋 轉前述鋼管樁，而藉由前述突起將前述前端部之外周面 附近的土壤壓入到下方。 43201207198 VII. Patent application scope: 1. A steel pipe pile, which is a front end opening in the direction of excavation and is hollow, and is characterized in that: the steel pipe pile comprises: a sizing portion, which is a certain outer diameter; and a front end portion The inner dimension and the outer dimension are gradually smaller toward the front end, and a projection is provided on the outer peripheral surface of the front end portion, and the projection extends from the front end toward the rear end in a part or the whole, and protrudes in a radial direction of the front end portion. square. 2. The steel pipe pile according to the first aspect of the invention, wherein the plurality of protrusions are provided at intervals in a circumferential direction of the outer circumferential surface of the front end portion. 3. The steel pipe pile according to claim 1 or 2, wherein the projection is inclined such that the rear end side of the projection is rearward of a rotation direction of the sizing portion and the front end portion. 4. The steel pipe pile according to claim 1 or 2, wherein the protrusion is inclined in a circumferential direction with respect to a central axis of the front end portion, and a central axis perpendicular to the central axis and a central axis of the protrusion extending direction The angle is from 20° to 70°. 5. The steel pipe pile according to claim 1 or 2, wherein the height of the protrusion is such that the protrusion is located on the inner side in the radial direction of the front end portion from the outer diameter of the sizing portion. 6. The steel pipe pile according to item 2 of the patent application, wherein a plurality of boring cutters are provided at intervals in the circumferential direction of the front end. 41 201207198 7. The steel pipe pile of claim 6, wherein the lower end of the protrusion is located directly above the boring cutter. 8. The steel pipe # of claim 6, wherein the boring cutter is disposed outside the diametrical portion of the front end portion in a radial direction. 9. The steel pipe pile according to the first aspect of the patent application, wherein the ratio of the height dimension of the front end portion to the outer dimension of the sizing portion is 0_3 to 5.5 〇10. The pile, wherein the ratio of the outer diameter of the front end to the outer diameter of the sizing portion is 〇6〇~〇95. U. The steel pipe pile according to the first aspect of the invention, wherein the front end portion is provided with a sharp portion that protrudes from the front end and is sharp toward the boring direction. 2. A method for constructing a steel pipe pile, which is a construction method of a steel pipe pile using a steel pipe pile according to the scope of the patent application, characterized in that: a rotary pressing method for attaching a rotary force and a press-in force to the steel pipe pile When pressed into the ground, the steel pipe pile is pressed into one side while the ground plate is broken by the aforementioned protruding shear force. 13. The method of constructing a steel pipe pile according to claim 12, wherein the steel pipe pile is rotationally pressed into a site comprising a hard land. 4. The construction method of the steel pipe pile according to item 2 of the patent scope of the invention, wherein the steel pipe pile is rotated in the ground or not rotated or combined in the middle of the construction, thereby moving up and down Reduce the height of the soil in the aforementioned steel pipe pile. 15. The method of constructing a steel pipe pile according to claim 12, wherein when the front end portion of the steel pipe pile is finally stopped in the support layer of 201207198, the steel pipe pile is reversely rotated, and the aforementioned protrusion is used The soil near the outer peripheral surface of the front end portion is pressed downward. 43
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