JPS60250122A - Foundation pile structure for preventing liquefaction of ground - Google Patents

Abstract

PURPOSE:To prevent the liquefaction of the ground by dissipating void water quickly rising during the earthquake by a method in which a draining material is packed around a knotted pile as a core material to form a foundation pile, and a water communication means is vertically led to the knots of the pile. CONSTITUTION:A drain material 2, e.g., gravels, etc., is packed around a custom-made knotted pile 1 as a core material to form a foundation pile in the ground which is liable of liquefaction. A vertical through hole 6 as a means of connecting the walls of upper and lower drain materials 4. Since the drain materials 2 so formed are vertically connected with each other through the hole 6, void water ready to quickly rise during the earthquake is exactly dissipated through the portion of the drain materials 2 to prevent the occurrence of excess void water pressures responsible mainly for the liquefaction of the ground.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、構築物の基礎として液状化し易い砂地盤にお
いても上部構築物を充分に支えるとともに地震時にも安
全で且つ強固な、地盤の液状化防止機能を備えた基礎杭
構造に関する。[Detailed Description of the Invention] Industrial Application Field The present invention provides a ground liquefaction prevention function that sufficiently supports an upper structure even in sandy ground that is easily liquefied as a foundation for a structure, and that is safe and strong even in the event of an earthquake. Regarding the foundation pile structure.

従来の技術 地震時に砂地盤が液状化し、地盤としての支持力を失な
い構築物が沈下倒壊した例は既に多く知られている。こ
の地盤液状化の原因は、水で飽和した緩い砂地盤の間隙
水圧が地震時に急上昇し、その結果過剰間隙水圧が発生
して砂地盤の支持力を失なわしめるものとされている。Conventional technology There are already many known cases in which sandy ground liquefies during an earthquake, causing structures that do not lose their supporting capacity as the ground to sink and collapse. The cause of this ground liquefaction is said to be that the pore water pressure in loose sand saturated with water increases rapidly during an earthquake, resulting in excess pore water pressure that causes the sand to lose its bearing capacity.

そのため構築物の敷地地盤が液状化のおそれのある砂地
盤である場合、上記液状化を防止する対策が必要であり
、特に構築物を支える基礎杭周囲に液状化防止対策がな
されていないと、該基礎杭周辺で地盤が液状化し基礎杭
の支持力が失なわれる危険性がある。Therefore, if the site ground of the structure is sandy ground that is at risk of liquefaction, measures to prevent the above liquefaction are required.In particular, if measures are not taken to prevent liquefaction around the foundation piles that support the structure, the foundation There is a risk that the ground around the piles will liquefy and the bearing capacity of the foundation piles will be lost.

一方、構築物を支える基礎杭構造として、従来より節付
杭を芯材としその周囲に砂利、砕石等を充填した構造の
もの（所謂節杭基礎）が存する。この基礎杭は、第１１
図のように節付杭（１′）をハンマー（１１’）、油圧
押込機等で地中に巨人する際に、節部（３’）　ＩＩ人
に伴ない生じる杭周間隙に砂利、砕石等（２′）を充填
するか、第１２図［ａｌ　［ｂ’ｌのように節付杭（１
′）を圧入するための下孔（１，２’）をスクリューオ
ーガー（１３’）等で掘孔しておき、この下孔（１２’
）内に節付杭（ＩＩ）を吊下圧入する際に杭周間隙に砂
利、砕石等を充填することにより造成されるものである
が、前記砂利等の充填は単に杭周地盤を締め固め改良し
て基礎杭支持力を強化することを目的とするもので、地
盤液状化の主因である地震時の過剰間隙水圧の発生を防
止、消散させることは考えられていない。On the other hand, as a foundation pile structure for supporting a structure, there has conventionally been a structure in which a knotted pile is used as a core material and the surrounding area is filled with gravel, crushed stone, etc. (so-called knotted pile foundation). This foundation pile is the 11th
As shown in the figure, when a knotted pile (1') is pushed into the ground with a hammer (11') or a hydraulic pusher, the knots (3') are filled with gravel and crushed stone in the gaps around the pile that are created by the work. etc. (2') or fill with knotted piles (1) as shown in Figure 12 [al [b'l
Drill pilot holes (1, 2') for press-fitting the holes (12') with a screw auger (13'), etc.
) is created by filling the gap around the pile with gravel, crushed stone, etc. when suspending and press-fitting the knotted pile (II) into the pile. The purpose of this improvement is to strengthen the supporting capacity of foundation piles, and it is not intended to prevent or dissipate excessive pore water pressure during earthquakes, which is the main cause of ground liquefaction.

発明が解決しようとする間肩点 この発明者らは、上記節付杭を用いた基礎杭構造、特に
節付杭周囲の砂利、砕石等の透水性の良い材料つまりド
レーン材の充填構造に着目し、前記杭周充填物をドレー
ン壁としてこの基礎杭自体に過剰間隙水圧゛の発生を防
止、消散させるためのドレーン効果を持たせることによ
り、地盤液状化を防止しようとしたのであるが、前記杭
周充填物は杭周地盤より透水性が良くても、節付杭特有
の節部の存在のために上下方向に連続性のあるドレーン
効果は得らず、過剰間隙水圧の発生を防止、消散する機
・能を充分に発揮できない。Problems to be Solved by the Invention The inventors focused their attention on a foundation pile structure using the above-mentioned knotted piles, and in particular, a structure filled with highly permeable materials such as gravel and crushed stone around the knotted piles, that is, drain material. However, an attempt was made to prevent ground liquefaction by using the pile surrounding filling as a drain wall and giving the foundation pile itself a drain effect to prevent and dissipate the generation of excess pore water pressure. Even if the pile surrounding filling has better water permeability than the surrounding ground, it does not provide a continuous drainage effect in the vertical direction due to the presence of knots unique to knotted piles, preventing the generation of excessive pore water pressure. Unable to fully demonstrate dissipated functions/functions.

すなわち、十記節付杭による基礎杭構造により過剰間隙
水圧の発生を防止し、消散させるには、その効果をより
確実なものとするため杭周充填物によるドレーン効果（
ドレーン壁としての効果）に上下方向の連続性を持たせ
ることが肝要であるが、一般に節付杭周囲に砂利、砕石
、鉱滓等を充填した基礎杭にあっては、第１１図および
第１２図に例示する施工法や地盤の硬軟により杭周充填
物の充填状況が多少異なるも、第１３図に示すように杭
周充填物（２′）は節付杭（１′）の節部（３′）が原
因で上下に断続した状態となる場合か多く、そのため該
杭周充填物によるドレーン効果、つまり過剰間隙水圧の
発生を防止、消散させる効果が大幅に減殺され、殆んと
期待できないことになる。In other words, in order to prevent and dissipate excessive pore water pressure through a foundation pile structure using ten-knotted piles, the drain effect (
It is important to have continuity in the vertical direction (effective as a drain wall), but in general, for foundation piles filled with gravel, crushed stone, slag, etc. around knotted piles, Although the filling situation of the pile circumference filler differs slightly depending on the construction method illustrated in the figure and the hardness and softness of the ground, as shown in Figure 13, the pile circumference filler (2') 3') is often the cause of vertical discontinuity, and as a result, the drain effect of the filler around the pile, that is, the effect of preventing and dissipating the generation of excess pore water pressure, is greatly diminished and can hardly be expected. It turns out.

なお、−上記杭周充填物の上下方向の連続性を確保する
ために、その充填径を節部より径大とし充填厚を外方へ
厚くするのは、砂利等の充填相料が多量に必要となり経
済的無駄が多く好ましくない。また節部を有さない杭即
ち円筒杭を用いたのでは、充填物を地中に圧入し、地盤
を締、め固める効果がなくなり、期待する杭支持力が得
られない。Furthermore, in order to ensure vertical continuity of the above-mentioned pile circumferential filling, the filling diameter is made larger than the joints and the filling thickness is increased outwards because a large amount of filling phase material such as gravel is used. This is not desirable as it is necessary and causes a lot of economic waste. Furthermore, if piles without joints, that is, cylindrical piles, are used, the effect of press-fitting the filler into the ground, compacting and compacting the ground is lost, and the expected pile supporting capacity cannot be obtained.

間頓点を解決するための手段 」二記に鑑み、本発明では、節付杭周囲に砂利等のドレ
ーン材を充填した基礎杭における上記の間順点を解決し
、上下方向に連続性のあるドレーン効果つまり透水性を
確保するために、節伺杭における節部上下のドレーン材
壁部を連通させる通水手段および／または杭体内外を連
通ずる通水孔を設けることとし、これにより過剰間隙水
圧の発生を確実に防止、消散でき、ドレーン材の充填に
よる地盤締め固め効果とともに液状化防止機能を併せ持
つ、安全かつ強固な基礎杭構造を提供するものである。In view of the above mentioned ``Means for Resolving Interruption Points'', the present invention solves the above-mentioned interruption points in foundation piles filled with drainage material such as gravel around knotted piles, and creates continuity in the vertical direction. In order to ensure a certain drainage effect, that is, water permeability, water passage means for communicating the drain material walls above and below the joints in the joint pile and/or water passage holes for communicating the inside and outside of the pile body are provided. It provides a safe and strong foundation pile structure that can reliably prevent and dissipate the generation of pore water pressure, has a soil compaction effect by filling with drain material, and has a liquefaction prevention function.

すなわち、本発明の要旨は、節付杭を芯材としその周囲
にドレーン材を充填して造成してなる基礎杭てあって、
前記節付杭には節部上方のドレーン祠壁部を連通させる
通水手段および／または抗体内外を連通させる通水孔を
所要個所に設け、基礎杭を上下方向に透水可能に構成し
てなる液状化防ＩＬ基礎抗構造にある。That is, the gist of the present invention is that a foundation pile is constructed by using a knotted pile as a core material and filling the surrounding area with drain material,
The knotted pile is provided with water passage means for communicating the drain shrine wall above the knot and/or water passage holes for communicating the inside and outside of the antibody at required locations, so that the foundation pile is configured to be permeable to water in the vertical direction. It is in the liquefaction prevention IL basic structure.

作　用 上記の構成よりなる本発明の基礎杭構造によれば、杭周
に充填された節部上下のドレーン材壁部が節部の存在に
も拘らず通水手段により連通して、杭周充填物であるド
レーン材の部分が上下方向に連続性のあるドレーン壁と
なり、あるいは杭体内外を連通させる通水孔により節付
杭の内孔か抗外部と通水自在な上下方向の透水路となり
、地震時に急上昇しようとする間隙水圧は前記ドレーン
材の部分を通じ、あるいは通水孔から節付杭の内孔を通
して′確実に消散され、地盤液状化の主因である過剰間
隙水圧の発生が防しトされる。Effect According to the foundation pile structure of the present invention having the above-described configuration, the drain material walls above and below the joints filled around the pile are communicated with each other by the water passage means despite the presence of the joints, and the walls around the pile are The part of the drain material that is the filler becomes a drain wall that is continuous in the vertical direction, or the water passage that connects the inside and outside of the pile body allows water to flow freely between the inner hole of the knotted pile and the outside of the pile body. Therefore, the pore water pressure that is about to rise rapidly during an earthquake is reliably dissipated through the drain material or through the inner hole of the knotted pile from the water hole, preventing the generation of excessive pore water pressure, which is the main cause of ground liquefaction. is written.

実施例 次に本発明の実施例を図面に基いて説明する第１図〜第
３図の実施例において、（Ａ）は既製の節付杭（１）を
芯桐としその周囲に砂利、砕石その他のドレーン材（２
）を充填してなる本発明に係る基礎杭を示し、液状化の
おそれのある砂地盤を含む構築物敷地地盤において構築
物を支えるよう所要個所に造成されてなる。しかして前
記節付杭（１）には、各節部（３）上下のドレーン材壁
部ｔ４１　＋４１を連通させる通水手段として節部（３
）の外周部所要個所に上下方向の切欠溝（５）か形成さ
れている。この切欠溝（５）としては１図示のごとき平
面略弧形をなすものに限らず、平面略凹状その他の任意
の形状に切欠形成できるとともに、その数も１〜数個等
適宜設定でき、さらに節部（３）ケに数や形状を異にし
ておくこともできるが、その溝の大きさく深さや溝幅等
）は節部（３）によりドレーン材（２）を地中に抑圧充
填する効果を切欠ｉ＊ｉ５）による節部間欠損により大
きく減殺しない程度が好ましい。また施工時における節
部（３）によるドレーン材（２）の充填状況を考えれば
、上下に相隣る節部ｔ３＋　＋３＋の切欠溝（５１（５
）が互に周方向に位置をすらせて形成しておくのが望ま
しく。Embodiments Next, embodiments of the present invention will be explained based on the drawings. In the embodiments shown in FIGS. 1 to 3, (A) is a ready-made knotted pile (1) with a core paulownia surrounded by gravel and crushed stone. Other drain materials (2
) is shown, and is constructed at required locations to support a structure in the ground of a building site, which includes sandy ground that is at risk of liquefaction. Therefore, the knotted pile (1) has the knotted portion (3) as a water passage means for communicating the upper and lower drain material walls t41+41 of each knotted portion (3).
) are formed with vertical notch grooves (5) at required locations on the outer periphery. The notched grooves (5) are not limited to the generally arcuate planar shape shown in the figure 1, but can be formed in a generally concave planar shape or any other arbitrary shape, and the number of the notched grooves can be set as appropriate, such as from one to several pieces. The number and shape of the joints (3) can be different, but the size, depth, groove width, etc. of the grooves should be determined by suppressing and filling the drain material (2) into the ground using the joints (3). It is preferable that the effect is not significantly reduced by the internodal defect caused by the notch i*i5). Also, considering the filling situation of the drain material (2) through the joints (3) during construction, the notch grooves (51 (5)
) are desirably formed so that they are spaced from each other in the circumferential direction.

また最下段の節部（３）には必ずしも切欠溝（５）を設
けておかなくともよい。Further, the cutout groove (5) does not necessarily have to be provided in the lowest node (3).

この実施例の基礎杭構造によれは、ドレーン１Ａ（２１
が第２図のように通水手段である切欠溝（５）内にも充
填され、節部（３）上下のドレーン材壁部１４＋　＋４
）が前記切欠溝（５）を介して通水可能に連通され、以
って杭周充填物であるドレーン材（２）により上下方向
に連続性のあるドレーン壁が造成されることになる。そ
のため、地震時に急上昇しようとする地盤の間隙水圧は
前記上下方向に連続性のある杭周のドレーン材（２）の
部分つまりドレーン壁を通じて消散され、過剰間隙水圧
の発生そのものを防止できる。Depending on the foundation pile structure of this example, drain 1A (21
As shown in Fig. 2, the notched groove (5) serving as the water passage means is also filled, and the drain material walls 14+ +4 above and below the node (3) are filled.
) are communicated with each other through the notched groove (5) so that water can pass therethrough, thereby creating a vertically continuous drain wall using the drain material (2) which is the filler around the pile. Therefore, the pore water pressure in the ground that is about to rise rapidly during an earthquake is dissipated through the vertically continuous drain material (2) around the pile, that is, the drain wall, and the occurrence of excessive pore water pressure itself can be prevented.

また第４図および第５図の実施例は、上記の変更例を示
すもので、節部（３）−上下のドレーン材壁部ｔ４１　
＋４１を連通させる通水手段として、上記切欠溝（５）
の代りに節部（３）を上下方向にｍ通する孔（６）を所
要個所に設けた場合を示している。この実施例の場合に
も、節部（３）上下のドレーン利壁部１４）　１４）が
前記通水手段である孔（６）を介して通水可能に連通さ
れ、杭周に充填されたドレーン材（２）により上下方向
に連続性のあるドレーン効果を発揮でき、地震時には上
記同様に間隙水圧をドレーン材（２）の部分を通じて消
散でき、過剰間隙水圧の発生そのものを防止できる。Further, the embodiments shown in FIGS. 4 and 5 show the above-mentioned modification example, and the joint part (3) - the upper and lower drain material wall parts t41
The above-mentioned notch groove (5) serves as a water passage means for communicating +41.
Instead, holes (6) are provided at required locations to allow the joints (3) to pass m in the vertical direction. In the case of this embodiment as well, the joint portion (3) and the upper and lower drain wall portions 14) are communicated with each other through the hole (6) serving as the water passage means, and the pile is filled with water. The drain material (2) can exert a continuous drain effect in the vertical direction, and in the event of an earthquake, the pore water pressure can be dissipated through the drain material (2) in the same way as described above, and the occurrence of excessive pore water pressure itself can be prevented.

さらに第６図〜第８図の実施例においては、本発明に係
る基礎杭（Ａ）を上下方向に透水可能に構成する手段と
して、−に記節部（３）における上下方向の通水手段に
代えて、杭体内外つまり節付杭（１）の内孔（７）と外
部とを連通させる径方向の通水孔（８）を節部（３）　
（３１間の胴部（９）および節部（３）等の所要個所に
設け、節付杭（１）の内孔（７）を透水路として利用す
べくなした場合を示している。Furthermore, in the embodiments shown in FIGS. 6 to 8, as a means for configuring the foundation pile (A) according to the present invention to be permeable to water in the vertical direction, water passage means in the vertical direction in the marking portion (3) at - Instead, a radial water hole (8) that communicates between the inside and outside of the pile body, that is, the inner hole (7) of the jointed pile (1), and the outside is connected to the joint (3).
(This figure shows a case in which the inner hole (7) of the knotted pile (1) is used as a permeation channel.)

前記通水孔（８）の数や位置は任意に決定できるが、各
節部ｆ３１　（３）間の胴部（９）にそれぞれ少なくと
も−の通水孔（８）を設けて、節部（３１１３１間のド
レーン材壁部（４）を通水孔（８）および内孔（７）を
介して連通させておくのが、ドレーン効果の連続性を補
なう−Ｌで特に望ましい。また節付杭（１）の内孔（７
）は、透水路として利用することから空洞のままでもよ
いが、図示のように水（１０）を満たすか、または杭周
に充填するドレーン材（２）と同様のドレーン材を充填
しておくのが望ましい。Although the number and position of the water holes (8) can be determined arbitrarily, at least - water holes (8) are provided in the body (9) between the joints f31 (3). 31131 It is particularly desirable for the drain material wall (4) to be communicated via the water passage hole (8) and the inner hole (7) in order to compensate for the continuity of the drain effect. Inner hole (7) of stake (1)
) may remain hollow since it will be used as a permeation channel, but fill it with water (10) as shown in the diagram or fill it with drain material similar to the drain material (2) that is filled around the pile. is desirable.

この実施例の基礎杭構造の場合、節付杭（１）の内外が
通水孔（８）により連通し、かつ節付杭（１）の内孔（
７）が上下方向に連続した透水路の役目を果すため、優
れたドレーン効果を発揮し、地僕時に急上昇しようとす
る周囲地盤の間隙水圧はドレーン拐壁部（４）に吸収さ
れるとともに前記通水孔（８）さらには節付杭（１）の
内孔（７）を通じて消散され、上記同様に過剰間１隙水
圧の発生を防止できることになる。In the case of the foundation pile structure of this example, the inside and outside of the knotted pile (1) are communicated through the water hole (8), and the inner hole of the knotted pile (1) (
7) acts as a continuous permeation channel in the vertical direction, so it exhibits an excellent drain effect, and the pore water pressure of the surrounding ground that is about to rise rapidly during earthwork is absorbed by the drain wall (4) and The water is dissipated through the water passage hole (8) and further through the inner hole (7) of the knotted pile (1), and the generation of excessive pore water pressure can be prevented in the same way as described above.

なお、本発明は、−ｈ記した実施例のほか、図示してい
ないが、節部上下のドレーン拐壁部を節部において連通
させる切欠溝等の通水手段と、抗体内外を連通させる通
水孔とを節付杭に併設して実施することも可能であり、
この場合基礎杭によるドレーン効果をさらに高め、過剰
間隙水圧の発生を一層確実に防止、消散できる。In addition to the embodiments described in -h, although not shown in the drawings, the present invention provides water passage means such as notched grooves that communicate the drain walls above and below the node at the node, and a passageway that connects the inside and outside of the antibody. It is also possible to install water holes alongside knotted piles,
In this case, the drainage effect of the foundation pile can be further enhanced, and excess pore water pressure can be more reliably prevented and dissipated.

上記のことき節付杭（１）を用いた本発明に係る基礎杭
（Ａ）は、第９図および第１０図のように。A foundation pile (A) according to the present invention using the above-described knotted pile (1) is shown in FIGS. 9 and 10.

構築物敷地地盤（Ｂ）における構築物（Ｃ）の柱下や壁
下あるいはフーチング（Ｄ）の下等に列状、あるいは散
在状に造成しておくもので、この基礎杭（Ａ）の造成施
工は、従来のこの種基礎杭と同様に、例えば第１１図の
ハンマー等による１人打設工法あるいは第１２図［ａＨ
ｂ］の下孔を利用する属人工法等により行ない、節部巨
人もしくは圧入によって生じる杭周間隙にドレーン材を
充填する。また上記のように造成する基礎杭（Ａ）の設
置場所以外に液状化防止対策を要する個所には、例えば
第９図および第１０図に示すように上記と同様のドレー
ン材のみよりなるドレーン柱（Ｅ）をバイブロ、ケーシ
ング等を用いた周知の工法で造成しておくものとする。These foundation piles (A) are constructed in rows or in a scattered manner under the pillars, walls, or footings (D) of the structure (C) in the ground (B) of the construction site. , as well as conventional foundation piles of this kind, for example, by the one-person driving method using a hammer or the like as shown in Fig. 11, or by the method shown in Fig. 12 [aH
Drain material is filled into the gap around the pile created by the joint giant or press-fitting, using the method using the pilot hole described in b). In addition to the installation location of the foundation pile (A) constructed as described above, in locations where liquefaction prevention measures are required, for example, as shown in Figures 9 and 10, drain pillars made only of the same drain material as above are used. (E) shall be constructed using a well-known construction method using vibro, casing, etc.

この場合のドレーン柱（Ｉｉ）の打設深度（長さ）、間
隔等は節付杭（１）による基礎杭（Ａ）とは関係なく液
状化のおそれのある地盤の性状にあわせて決定すればよ
い。前記のドレーン柱（Ｅ）に代えて、縦横に連続した
ドレーン壁を打設しておくこともてきる。In this case, the driving depth (length), spacing, etc. of the drain pillars (Ii) should be determined in accordance with the properties of the ground that is at risk of liquefaction, regardless of the foundation pile (A) made of knotted piles (1). Bye. Instead of the drain pillar (E) described above, it is also possible to install continuous drain walls vertically and horizontally.

上記のように節付杭（１）による基礎杭（Ａ）に加え、
構築物敷地地盤（Ｂ）”にドレーン柱（Ｅ）やドレーン
壁を併せて打設した場合には、地盤の液状化防止効果が
さらに増大し、基礎杭（Ａ）とドレーン柱（Ｅ）両者の
相乗効果により地盤のせん断芯力がさらに増大すること
とあわせて、強固にしてかつ地震時にも安全な基礎杭構
造となる。In addition to the foundation pile (A) with knotted piles (1) as mentioned above,
If drain columns (E) and drain walls are also driven into the building site ground (B), the effect of preventing liquefaction of the ground will further increase, and both the foundation piles (A) and drain columns (E) will be This synergistic effect further increases the shear core force of the ground, resulting in a foundation pile structure that is both strong and safe in the event of an earthquake.

上記本発明で用いるドレーン材としては、砂利、砕石、
鉱滓、コンクリート破砕物その他の粒径３〜６０ｍｍ程
度で柱体あるいは壁体に造成した場合に透水性のよｌ、
Ｙもの（透水係数１０−１〜１Ｏ−２ａ／ｓｅｃ　程度
）が好適に用いられる。Drain materials used in the present invention include gravel, crushed stone,
Water-permeable materials such as mine slag, crushed concrete, and other particles with a particle size of about 3 to 60 mm are used when built into pillars or walls.
A material having a hydraulic conductivity of about 10-1 to 1 O-2 a/sec is preferably used.

発明の効果 上記したように本発明の基礎杭構造によれば、節部上下
のドレーン材壁部を連通させる通水手段により上下方向
に連続性のあるドレーン壁と由 なる杭周のドレーン材の部分、あるいは杭体ガ外を連Ｊ
ｌさせる通水孔により透水路として作用する節付杭の内
孔によつＣ１節付杭を芯材として節部つまり外方への突
出部分を有するものであるにも拘らず、またドレーン材
の充填径が節部と同程度か僅かに大きい程度てあっても
、基礎杭として上下方向に連続性のあるドレーン効果を
発揮でき、地震時に急上昇しようとする間隙水圧を前記
ドレーン材の部分あるいは部付杭内孔を通じ確実に消散
させ得て、過剰間隙水圧の発生そのものを防止でき、延
いては地盤液状化を防止できる。しかも節付杭周囲への
ドレーン相充填により、従来の節付杭による基礎杭と同
様に杭周充填物による地盤締め固め改良効果て杭支持力
を増大でき、前記液状化防止機能とあわせてきわめて強
固なかつ地震時にも安全な基礎杭構造となる。Effects of the Invention As described above, according to the foundation pile structure of the present invention, the drain wall that is continuous in the vertical direction and the drain material around the pile connected by the water flow means that communicates the drain material walls above and below the joint. Part or the outside of the pile body
Despite the fact that the inner hole of the knotted pile acts as a permeation channel due to the water passage hole that causes the water to pass through, the C1 knotted pile is used as the core material and has a knot, that is, an outwardly protruding part. Even if the filling diameter of the material is the same as or slightly larger than that of the joint, it can exert a continuous drain effect in the vertical direction as a foundation pile, and the pore water pressure that is about to rise rapidly during an earthquake can be absorbed by the part of the drain material or It can be reliably dissipated through the inner hole of the attached pile, and the generation of excess pore water pressure itself can be prevented, which in turn can prevent ground liquefaction. Furthermore, by filling the area around the knotted pile with drain phase, the pile supporting capacity can be increased due to the soil compaction improvement effect of the pile circumferential filling, similar to that of conventional foundation piles using knotted piles. The foundation pile structure is strong and safe even in the event of an earthquake.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の１実施例を示す縦断面図、第２図は同
一部の拡大断面図、第３図は同横断面図、第４図および
第５図は上記実施例の変更例を示す一部の縦断面図と平
面図、第６図は他の実施例を示す縦断面図、第７図およ
び第８図は同一部の拡大断面図と横断面図、第９図およ
び第１０図は基礎杭とドレーン柱とを組合せた造成状態
を示す略示平面図および一部の縦断面図、第１１図およ
び第１２図［ａ］［ｂ’ｌはそれぞれ節付杭の施工状態
を例示する縦断面図、第１３図は従来の部付杭基礎を例
示する縦断面図である。 （Ａ）・・基礎杭、（１）・・・節付杭、（２）・ドレ
ーン材、（３）・・節部、（４）・・ドレーン材壁部、
（５）・・・切欠溝、（６）・・・孔、（７）・・内孔
、（８）・・・通水孔、特許出願人　株式会社武智工務
所 第　２　図 第　３　図　１ 第５図　９第４図 第１２ 釘ゝ“］］図　（ａ） （ｂ） 第１３図Fig. 1 is a longitudinal sectional view showing one embodiment of the present invention, Fig. 2 is an enlarged sectional view of the same part, Fig. 3 is a transverse sectional view of the same, and Figs. 4 and 5 are modifications of the above embodiment. 6 is a vertical sectional view showing another embodiment, FIGS. 7 and 8 are enlarged sectional views and cross sectional views of the same part, and FIGS. Figure 10 is a schematic plan view and partial vertical cross-sectional view showing the construction state in which foundation piles and drain columns are combined, and Figures 11 and 12 [a] and [b'l respectively show the construction state of knotted piles. FIG. 13 is a vertical cross-sectional view illustrating a conventional partial pile foundation. (A) Foundation pile, (1) Knotted pile, (2) Drain material, (3) Knot, (4) Drain material wall,
(5)... Notch groove, (6)... Hole, (7)... Inner hole, (8)... Water hole, Patent applicant: Takechi Construction Co., Ltd., Figure 2, Figure 3, Figure 1 Figure 5 9 Figure 4 Figure 12 Nail “]] Figure (a) (b) Figure 13

Claims (1)

【特許請求の範囲】 １、　節付杭を芯材としその周囲にドレーン材、を充填
して造成してなる基礎杭であって、前記節付杭には節部
上下のドレーン材壁部を連通させる通水手段および／ま
たは抗体内外を連通させる通水孔を所要個所に設け、基
礎杭を上下方向に透水可能に構成してなることを特徴・
　とする液状化防止基礎杭構造。 ２、　通水手段が、節部外周に形成された上下方向の切
欠溝である特許請求の範囲第１項記載の液状化防止基礎
杭構造。 ３、上下に相隣る節部の荀欠溝が互に周方向に位置をず
らせて形成されている特許請求の範囲第２項記載の液状
化防止基礎杭構造。 ４、　通水手段が節部を上下に１通する孔である特許請
求の範囲第１項記載の液状化防止基礎杭構造。 ５、　ドレーン材が、砂利、砕石、鉱滓、コンクリート
破砕物その他の主として粒径３〜６０ｒａｍ程度のもの
からなる特許請求の範囲第１項、第２項、第３項または
第４項のいずれか１項に記載の液状化防止基礎杭構造。[Scope of Claims] 1. A foundation pile constructed by using a knotted pile as a core material and filling the periphery with drain material, the knotted pile having drain material walls above and below the knots. The foundation pile is characterized by providing water passage means for communication and/or water passage holes for communication between the inside and outside of the antibody at required locations so that water can permeate in the vertical direction.
Foundation pile structure to prevent liquefaction. 2. The liquefaction prevention foundation pile structure according to claim 1, wherein the water passage means is a vertical notch groove formed on the outer periphery of the joint. 3. The liquefaction prevention foundation pile structure according to claim 2, wherein the grooves of the vertically adjacent joint portions are formed so as to be shifted in position from each other in the circumferential direction. 4. The liquefaction-preventing foundation pile structure according to claim 1, wherein the water passage means is a hole that passes through the joint part up and down. 5. Any one of claims 1, 2, 3, or 4, in which the drain material is composed of gravel, crushed stone, slag, crushed concrete, or other materials with a particle size of approximately 3 to 60 ram. The liquefaction prevention foundation pile structure according to item 1.