JPS63315721A - Foundation pile driving method as well as ground compaction - Google Patents
Foundation pile driving method as well as ground compactionInfo
- Publication number
- JPS63315721A JPS63315721A JP15280487A JP15280487A JPS63315721A JP S63315721 A JPS63315721 A JP S63315721A JP 15280487 A JP15280487 A JP 15280487A JP 15280487 A JP15280487 A JP 15280487A JP S63315721 A JPS63315721 A JP S63315721A
- Authority
- JP
- Japan
- Prior art keywords
- ground
- foundation pile
- foundation
- compaction
- pile
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005056 compaction Methods 0.000 title claims abstract description 31
- 238000000034 method Methods 0.000 title claims description 30
- 230000000149 penetrating effect Effects 0.000 claims description 4
- 230000015572 biosynthetic process Effects 0.000 abstract 1
- 238000002474 experimental method Methods 0.000 description 15
- 230000000694 effects Effects 0.000 description 13
- 229910000831 Steel Inorganic materials 0.000 description 12
- 238000010276 construction Methods 0.000 description 12
- 239000010959 steel Substances 0.000 description 12
- 230000035515 penetration Effects 0.000 description 11
- 238000010586 diagram Methods 0.000 description 9
- 239000004576 sand Substances 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 238000005188 flotation Methods 0.000 description 3
- 239000002689 soil Substances 0.000 description 3
- 230000035939 shock Effects 0.000 description 2
- 238000004904 shortening Methods 0.000 description 2
- 239000002956 ash Substances 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000010882 bottom ash Substances 0.000 description 1
- 239000003818 cinder Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000003921 particle size analysis Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000009705 shock consolidation Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
Landscapes
- Piles And Underground Anchors (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、構造物の荷重を地盤に支持させるための基礎
杭を地盤中に貫入する際の基礎杭打設工法に係わり、特
に、地盤の締固めを必要とされる地盤における基礎杭打
設工法に関するものである。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a foundation pile driving method for penetrating foundation piles into the ground to support the load of a structure, and in particular, to This relates to foundation pile driving methods in ground that requires compaction.
基礎杭は、周知のとおり、構造物を構築する際に、その
構造物を構築する地盤が軟弱であった場合等に、構造物
を支持するための基礎杭を前記構造物が構築される地盤
中に貫入するものである。As is well known, when building a structure, when the ground on which the structure is built is soft, foundation piles are used to support the structure. It penetrates inside.
既成の基礎杭としては、杭を、軟質層の下部にある硬質
層まで届くように極めて長寸のものに形成し、その杭を
介して構造物を硬質層に支持させるようにしたもの（支
持杭）、あるいは、硬質層までは届かないが、軟質層を
構成する地盤と杭との摩擦により前記構造物を支持し得
るようにしたもの（摩擦杭）などがある。An existing foundation pile is one that is extremely long so that it can reach the hard layer below the soft layer, and the structure is supported by the hard layer through the pile (supporting There are also piles that do not reach the hard layer, but can support the structure by friction between the pile and the ground that makes up the soft layer (friction pile).
ところで、基礎杭打設工法、特に上記摩擦杭による基礎
杭打設工法を施工するにあたって、その地盤が砂質地盤
や粘性上地盤のように軟弱であり杭の水平抵抗力が見込
めない場合には、基礎杭打設以前に、地盤の締固め等、
軟弱地盤の改良を施している。By the way, when implementing the foundation pile driving method, especially the above-mentioned foundation pile driving method using friction piles, if the ground is soft such as sandy ground or viscous ground and the horizontal resistance of the pile cannot be expected. , compaction of the ground, etc. before foundation pile driving, etc.
Improvements are being made to the soft ground.
この、軟弱地盤を改良する工法としては従来、例えばバ
イブロ・フローテーション工法やサンド・コンパクショ
ン・パイル工法といったものが知られている。バイブロ
・フローテーション工法は、地盤中に棒状の振動器を貫
入し、振動器部分に水を噴出しながら地盤を振動させて
締固め、さらに、振動器付近に生じる空隙に礫（レキ）
、すなわち小石や砕石等を投入して振動効果および圧入
効果の増大を図る工法である。また、サンド・コンパク
ション・パイル工法は、地盤中に、振動あるいは衝撃荷
重を利用して砂を圧入し、地盤中に圧縮された砂柱を造
成して地盤の相対密度の増加を図る工法である。Conventionally known construction methods for improving soft ground include, for example, the vibroflotation method and the sand compaction pile method. The vibro-flotation method involves penetrating a rod-shaped vibrator into the ground, squirting water into the vibrator area and vibrating the ground to compact it, and then filling the voids near the vibrator with gravel.
In other words, this is a construction method in which pebbles, crushed stones, etc. are added to increase the vibration effect and press-fit effect. In addition, the sand compaction pile method is a construction method that uses vibration or shock loads to force sand into the ground, creating compressed sand columns in the ground to increase the relative density of the ground. .
ところで、上記の基礎杭打設工法、特にそれに伴う地盤
の改良工法においては以下のような不都合が生じている
。すなわち、
■ バイブロ・フローテーション工法は、地盤を振動さ
せつつ礫の投入と振動機のわずかな引き抜きとを交互に
繰り返し、また、サンド・コンパクション・パイル工法
では、砂の投入と圧縮とを交互に繰り返すものであるか
らこれらの作業に手間が掛かり工期を要する。By the way, the following disadvantages occur in the above-mentioned foundation pile driving method, especially in the ground improvement method accompanying it. In other words, ■ The vibroflotation method alternately repeats the introduction of gravel and slight withdrawal of the vibrator while vibrating the ground, and the sand compaction pile method alternates between the introduction of sand and compaction. Since these operations are repeated, they are labor-intensive and require a long construction period.
■ 地盤の締固め具合の判断が難しく、密度の増加が過
剰となった場合には、基礎杭打設が困難となり基礎杭打
設作業か非常に不効率的となるばかりでなく、最悪の場
合には基礎杭の貫入が不可能となる。■ If it is difficult to judge the degree of compaction of the ground and the density increases excessively, it will become difficult to drive foundation piles, making the work extremely inefficient, and in the worst case scenario. Penetration of foundation piles becomes impossible.
■ 地盤の締固め時、およびその後の基礎杭打設時と、
振動機を２度にわたって使用する必要があり工程が非能
率的なものとなることに加えて、機械損料を余分に必要
とし不経済となる。■ During soil compaction and subsequent foundation pile driving,
In addition to the necessity of using the vibrator twice, which makes the process inefficient, additional machine costs are required, which is uneconomical.
といった問題である。This is a problem.
本発明は上記の事情に鑑みてなされたもので、杭打ちと
地盤の締固めとを同時に実施することにより効率的な基
礎杭打設が実現でき、しかし、地盤の締固めも確実に行
うことのできる、地盤締固め併用基礎杭打設工法を提供
することを目的とするものである。The present invention was made in view of the above circumstances, and it is possible to realize efficient foundation pile driving by simultaneously performing pile driving and ground compaction, but it is also important to ensure that the ground is compacted. The purpose of this invention is to provide a foundation pile driving method that combines soil compaction.
本発明に係る地盤締固め併用基礎杭打設工法は、地盤中
に、礫等よりなるドレーン柱を複数本形成した後、それ
らドレーン柱周辺の地盤中に基礎杭を打設することを特
徴とするもので、さらに、前記基礎杭を地盤中に打設す
る際において前記基礎杭を振動させながら行うものを含
むものである。The foundation pile driving method combined with ground compaction according to the present invention is characterized by forming a plurality of drain columns made of gravel or the like in the ground, and then driving foundation piles into the ground around the drain columns. The method further includes driving the foundation pile into the ground while vibrating the foundation pile.
本発明によれば、基礎杭を地盤中に打設した時に、この
杭の打設時の振動により地盤中に過剰水圧か生じ、この
過剰水圧で地盤中の水がドレーン柱内に水平排水されて
地盤が沈下し鉛直方向に圧縮または圧密され、地盤の締
固めがなされる。According to the present invention, when a foundation pile is driven into the ground, excessive water pressure is generated in the ground due to vibration during driving of the foundation pile, and water in the ground is horizontally drained into the drain column due to this excess water pressure. The ground sinks and is compressed or consolidated in the vertical direction, compacting the ground.
以下、本発明の一実施例を図面を参照しながら説明する
。An embodiment of the present invention will be described below with reference to the drawings.
まず、第１図の如く地盤Ｇ中に、所要の深度に達するド
レーン柱ｌを多数造成する。各ドレーン柱ｌは、地盤Ｇ
に竪穴を掘削した後、そこに礫や鉱さい、あるいはシン
ダーアッシュ、ボトムアッシュ（フライアッシュの大塊
）等を投入して造られる。これらドレーン柱ｌの配置は
、例えば第２図の如く地盤Ｇ上に基盤の目を描くような
配置とする。First, as shown in FIG. 1, a large number of drain columns L reaching a required depth are constructed in the ground G. Each drain column l is connected to the ground G
After excavating a pit, gravel, slag, cinder ash, bottom ash (large chunks of fly ash), etc. are poured into it. These drain pillars l are arranged so as to draw the eyes of the foundation on the ground G, for example, as shown in FIG.
しかる後に、抗打ち機を操作して、基礎杭２をドレーン
柱ｌ相互間の地盤Ｇ上、すなわち第２図における鎖線で
示すような位置に吊り下ろし、基礎杭２の下端を第３図
の如く地盤Ｇに当接させる。After that, operate the piling machine to lower the foundation pile 2 onto the ground G between the drain columns L, that is, at the position shown by the chain line in FIG. Bring it into contact with the ground G.
ここで使用される杭打ち機を簡単に説明すれば、第５図
に示すものがその杭打ち機３で、図における符号４はク
ローラクレーン、符号５はクローラクレーン４に支持さ
れるガイドマスト、符号６はガイドマスト５の上端より
懸吊される吊り治具で、この吊り治具６に加振機７を介
して前記基礎杭２が吊り下げされる。加振機７はいわゆ
るバイブロハンマまたはパイルドライバで、基礎杭２に
鉛直方向の振動を与えながら基礎杭２を地盤内に貫入さ
せるものである。To briefly explain the pile driving machine used here, the one shown in FIG. Reference numeral 6 denotes a hanging jig suspended from the upper end of the guide mast 5, and the foundation pile 2 is suspended from this hanging jig 6 via a vibrator 7. The vibration exciter 7 is a so-called vibrohammer or a pile driver, and is used to penetrate the foundation pile 2 into the ground while applying vertical vibration to the foundation pile 2.
第３図の状態となったならば、前記加振機７を作動させ
て基礎杭２に振動を与え、これにより第４図の如く基礎
杭２を地盤Ｇ中の所定深度まで貫入する。このとき、基
礎杭２の振動が、基礎杭２自体の表面積の広さにより地
盤Ｇ内へ伝達し、この振動により地盤Ｇ中に過剰水圧が
生じる。そして、この過剰水圧により地盤Ｇ中の水が貫
入箇所周辺のドレーン柱１内へ水平排水される。したが
って、排水された地盤Ｇは沈下し、鉛直方向に圧縮され
て締固められるのである。以降は同様に、前記杭打ち機
３により地盤Ｇ上のドレーン柱ｌ相互間の他の位置に、
次々に基礎杭２を打ち込んでゆく。When the state shown in FIG. 3 is reached, the vibrator 7 is operated to apply vibration to the foundation pile 2, thereby penetrating the foundation pile 2 into the ground G to a predetermined depth as shown in FIG. At this time, the vibration of the foundation pile 2 is transmitted into the ground G due to the large surface area of the foundation pile 2 itself, and excessive water pressure is generated in the ground G due to this vibration. Then, due to this excess water pressure, water in the ground G is horizontally drained into the drain column 1 around the penetration point. Therefore, the drained ground G sinks and is compressed and compacted in the vertical direction. Thereafter, in the same manner, the pile driver 3 is used to place the drain pillars l on the ground G at other positions between them.
Drive foundation piles 2 one after another.
このような作業により、多数のドレーン柱ｌを配置した
付近−帯の地盤Ｇが締め固められる。ちなみに、上記工
法により沈下した地表面（局所的に発生する穴等）を元
の標高まで回復させる必要かある場合には、機械的な転
圧、締固め、または動圧密工法等により他の場所から運
んだ土砂を締固めればよい。Through such work, the ground G in the area around and around where a large number of drain columns 1 are arranged is compacted. By the way, if it is necessary to restore the ground surface (locally generated holes, etc.) that has subsided due to the above construction method to its original elevation, it may be necessary to restore it to the original elevation by mechanical compaction, compaction, or dynamic consolidation method. All you have to do is compact the earth and sand transported from the ground.
次に、本工法に係わるいくつかの実験結果を示して本発
明の作用効果をより明確にする。ただし実験は、ドレー
ン柱ｌを直径０．５ｍ１深さｌ１ｍのらのとし、杭とし
ては直径１．２ｍ、長さ１２１！１の鋼管とし、第６図
の如くこの鋼管８をドレーン柱１に外嵌するような工法
により行ったものである。加振機７としてはバイブロハ
ンマＶＭ２−２５０００Ａを用いた。ちなみに、この工
法は、本出願人が先に発明、出願した「地盤の締固め工
法および締固め装置」（特願昭６０−２７６３９８号明
細書）に準するものである。Next, some experimental results related to this method will be shown to clarify the effects of the present invention. However, in the experiment, the drain pillar 1 was made into a square with a diameter of 0.5 m and a depth of 1 m, and the pile was a steel pipe with a diameter of 1.2 m and a length of 121!1, and this steel pipe 8 was attached to the drain pillar 1 as shown in Figure 6. This was done using a construction method that involved external fitting. As the vibrator 7, a vibrohammer VM2-25000A was used. Incidentally, this construction method is based on the "Ground Compaction Method and Compaction Apparatus" (Japanese Patent Application No. 60-276398), which was previously invented and filed by the present applicant.
第７図は、鋼管８貫入前の地盤および貫入後の地盤に対
して各々標準貫入試験を行ったときの、地盤の深度とＮ
値（標準貫入試験で試錘をある地層に３０ｃｍ貫入させ
るに要する打撃回数）との関係を、貫入前地盤の地層状
態と共に示したグラフである。この図から明らかなよう
に貫入前のＮ値（線図Ａ）は平均約４．６、貫入後のＮ
値（線図Ｂ）は平均約２３．６ と原地盤の４倍以上で
、貫入後の地盤が貫入前の地盤に対し著しく締め固めら
れることが判る。Figure 7 shows the depth and N of the ground when standard penetration tests were conducted on the ground before and after the steel pipe 8 penetrated.
It is a graph showing the relationship between the value (the number of blows required to penetrate 30 cm of a test weight into a certain stratum in a standard penetration test) together with the stratum condition of the ground before penetration. As is clear from this figure, the average N value before penetration (diagram A) is approximately 4.6, and the N value after penetration
The average value (diagram B) is approximately 23.6, which is more than four times that of the original ground, indicating that the ground after penetration is significantly compacted compared to the ground before penetration.
第８図は、ドレーン柱ｌを形成せず原地盤に単に鋼管８
を打設した場合（線図Ｃ）と、上記の如く、ドレーン柱
ｌを形成した後、それを内包する形態に鋼管８を打設し
た場合（線図Ｄ）の地盤Ｇの沈下量を示したグラフであ
る。加振後の沈下量を比較してみると、ドレーン柱ｌを
形成した場合には２６５〜４０５ｃｍと、鋼管のみを打
設した場合の６５ｃｍ〜７５ｃＩ１１に比較して極めて
沈下量が大きく、水平方向の排水による締固め効果があ
ることが明確に判る。また、ドレーン柱１を形成した場
合（線図Ｄ）、全沈下量の６３％〜７５％が打設時に生
じており、加振を行わず打設のみでも十分な締固め作用
があると判断できる。このことは、杭打ち機３として本
実施例では加振機７が装備されたものを使用しているが
、加振作用を持たないパイルハンマ等による施工も可能
であることを意味するものである。Figure 8 shows a steel pipe 8 simply placed on the ground without forming a drain column l.
The amount of subsidence of the ground G is shown in the case where the drain column 1 is cast (diagram C) and when the steel pipe 8 is cast in a form that encloses the drain column 1 as described above (diagram D). This is a graph. Comparing the amount of settlement after vibration, the amount of settlement in the case of forming the drain column 1 is 265 to 405 cm, which is extremely large compared to 65 to 75 cm in the case of installing only the steel pipe, and the amount of settlement in the horizontal direction It is clearly seen that there is a compaction effect due to drainage. In addition, when drain pillar 1 was formed (diagram D), 63% to 75% of the total settlement occurred during pouring, and it was determined that pouring alone without vibration had sufficient compaction effect. can. This means that although a pile driver 3 equipped with a vibrator 7 is used in this embodiment, it is also possible to perform construction using a pile hammer or the like that does not have a vibrating effect. .
また、第９図は本実験法による締固めの効果を示すため
に、道路橋示方言・同解説（日本道路協会、昭和５５年
５月、ｐ１６〜２０）に基づき、Ｎ値より相対密度Ｄｒ
を求めたものである。実験前と実験後のＤｒを、粒度分
析結果によるＦｃ（７４μ以下の細粒分の含有率）に対
して示している。この図より、実験前の相対密度Ｄｒの
平均値（線図Ｅ）は３８．３％であるが、実験後のＤｒ
平均値（線図Ｆ）では７３．８％ と実験前の２倍近く
となっている。しかも、実験後のＤｒの最小値は約４０
％で、実験前のＤｒの上限近くにあり、本方法による締
固め効果が著しいことが判る。In addition, in order to show the compaction effect of this experimental method, Figure 9 shows the relative density Dr
This is what we sought. The Dr before and after the experiment is shown with respect to Fc (content rate of fine particles of 74μ or less) according to the particle size analysis results. From this figure, the average value of relative density Dr before the experiment (diagram E) is 38.3%, but after the experiment Dr
The average value (diagram F) is 73.8%, nearly double the value before the experiment. Furthermore, the minimum value of Dr after the experiment was approximately 40.
%, which is close to the upper limit of Dr before the experiment, indicating that the compaction effect of this method is remarkable.
さらに第１０図は、道路橋示方言・同解説に基づきＮ値
と平均粒径Ｉ）ｓｏを用いて動的せん断強度比Ｒを求め
、実験前と実験後のＲをＦｃに対して示したものである
。この動的せん断強度比Ｒからは液状化抵抗強度を判断
することができる。ちなみに液状化とは、飽和した砂等
が、振動・衝撃などにより間隙水圧が急激に増大するた
め、せん断抵抗がなくなる現象を言う。この図において
、実験前のＲの平均値（線図Ｈ）は０．１８２ であ
るが、実験後のＲ平均値（線図■）は０．３１０と約１
．７倍となっている。また、実験前のＲの最小値は０．
０２５ 程度であるが、実験後では約Ｏ１であり、Ｒ
の下限値は約４倍増と大きく向上したことが判る。Furthermore, Figure 10 shows the dynamic shear strength ratio R calculated using the N value and the average particle size I)so based on the explanation of the road bridge specification dialect, and shows R before and after the experiment versus Fc. It is something. The liquefaction resistance strength can be determined from this dynamic shear strength ratio R. Incidentally, liquefaction is a phenomenon in which saturated sand loses its shear resistance due to a sudden increase in pore water pressure due to vibrations, shocks, etc. In this figure, the average R value before the experiment (diagram H) is 0.182, but the average R value after the experiment (diagram ■) is 0.310, about 1
．． It is 7 times more. Also, the minimum value of R before the experiment was 0.
025, but after the experiment it was about O1, and R
It can be seen that the lower limit of is greatly improved by about 4 times.
ところで、本発明に係る基礎杭打設工法は、多数形成さ
れたドレーン柱Ｉの間に基礎杭２を打ち込むものであり
、ドレーン柱１を内包する形態に鋼管８を打設する上記
実験例とは全くの同一ではない。従って、数値的なもの
が上記実験例と全て一致するものとはならないが、地盤
Ｇ内に埋設されるものとしての杭が、鋼管よりも体積を
有することを考慮すれば、むしろ上記実験例よりら良好
な締固め効果が発揮されると判断できる。By the way, the foundation pile driving method according to the present invention is to drive the foundation piles 2 between the drain columns I formed in large numbers, and is different from the above experimental example in which the steel pipe 8 is driven in a form that includes the drain columns 1. are not exactly the same. Therefore, although the numerical values do not all match the above experimental example, if we consider that the pile buried in the ground G has a larger volume than the steel pipe, it is actually better than the above experimental example. It can be judged that a good compaction effect is achieved.
このように本工法は、基礎杭２の打込みと、地盤Ｇの締
固めすなわち地盤改良とを同時に行うものである。しか
も、その際の地盤の締固めは、例えばバイブロ・フロー
テーション工法のように砂等の投入と振動器の引き抜き
を繰り返すものではなく、単に基礎杭２を地盤中に一度
だけ打ち込めばよいものであるから、杭打ち作業との同
時施工と相まって極めて効率的なものとなる。また、基
礎杭２は、既に締固めを施された地盤に打設されるもの
ではなく、軟質な地盤に打ち込まれるものであるから打
ち込みが容易で、これによる基礎杭打設工程のさらなる
効率化、すなわち工期短縮およびコストダウンが実現さ
れる。In this manner, this construction method simultaneously performs driving of the foundation piles 2 and compaction of the ground G, that is, ground improvement. Moreover, the compaction of the ground at that time does not involve repeating the injection of sand and the removal of vibrators as in the case of the vibro-flotation method, for example, but it is simply a matter of driving the foundation piles 2 into the ground once. This makes it extremely efficient when combined with pile driving work. In addition, the foundation pile 2 is not driven into the already compacted ground, but into soft ground, so it is easy to drive, which further improves the efficiency of the foundation pile driving process. In other words, shortening of construction period and cost reduction are realized.
なお、本実施例では、上記基礎杭２を一般的な既成杭と
しているが、この基礎杭２を、その外表面に径方向に突
出する突出部が多数形成されたものなどとしてもよく、
このようにした場合には、杭の打ち込みによる地盤Ｇへ
の振動伝達がより向上し、この結果、地盤内の水の水平
排水がより確実になされ、締固め作用が増大する。In this embodiment, the foundation pile 2 is a general prefabricated pile, but the foundation pile 2 may be formed with a large number of protrusions projecting in the radial direction on its outer surface.
In this case, vibration transmission to the ground G due to pile driving is further improved, and as a result, horizontal drainage of water in the ground is more reliably achieved, and the compaction effect is increased.
〔０発明の効果 〕
以上説明したとおり、本発明に係る地盤締固め併用基礎
杭打設工法は、地盤中に、礫等よりなるドレーン柱を複
数本形成した後、それらドレーン柱周辺の地盤中に基礎
杭を打設するものとしたから、基礎杭の打込みと同時に
地盤の締固めを行うことができる。しかし、その際の地
盤の締固めは、例えばバイブロ・フローテーション工法
のように砂等の投入と振動器の引き抜きとを繰り返すも
のではなく、単に基礎杭を地盤中に打ち込むことにより
なされるものであるから、打ち作業との同時施工と相ま
って、地盤の締固めを要する基礎地盤における基礎杭打
設作業を極めて効率的なものとする。また、基礎杭が、
既に締固めを施された地盤に打設されるものではなく、
軟質な地盤に打ち込まれるものであるから打ち込みが容
易で、これによるさらなる工期短縮およびコストダウン
を実現する、等の優れた効果を奏するものである。[0 Effects of the Invention] As explained above, the foundation pile driving method combined with ground compaction according to the present invention, after forming a plurality of drain columns made of gravel etc. in the ground, Since the foundation piles are to be driven at the site, the ground can be compacted at the same time as the foundation piles are driven. However, the compaction of the ground in this case is not done by repeatedly putting in sand and pulling out a vibrator, as is the case with the vibro-flotation method, for example, but by simply driving foundation piles into the ground. This makes the foundation pile driving work in the foundation ground, which requires soil compaction, extremely efficient when combined with the simultaneous construction with the driving work. In addition, the foundation pile
It is not installed in the ground that has already been compacted,
Since it is driven into soft ground, it is easy to drive, and this has excellent effects such as further shortening the construction period and reducing costs.
第１図ないし第４図は本発明の一実施例による基礎打設
工法をその工程に従って示したもので、第１図は地盤中
に造成されたドレーン柱を示す断面図、第２図はドレー
ン柱の配置例を示したドレーン柱の平面図、第３図は基
礎杭の打設開始状部をドレーン柱と共に示した断面図、
第４図は基礎杭の打設状態をドレーン柱と共に示した断
面図。
第５図は杭打ち機の一例を示した側面図。第６図は１本
発明に係わる実験例を示したもので、鋼管の打設状態を
ドレーン柱と共に示す断面図。第７図ないし第１０図は
第６図に示した実施例により得られたデータの一部を示
すもので、第７図はＮ値を鋼管貫入前と鋼管貫入後にお
いて比較したグラフ、第８図は地盤の沈下量を鋼管のみ
打設した場合とドレーン柱を形成した場合とにおいて比
較したグラフ、第９図は相対密度Ｄｒを実験前と実験後
とにおいて比較したグラフ、第１Ｏ図は動的せん断強度
比Ｒを実験前と実験後とにおいて比較したグラフである
。
Ｇ・・・・・・地盤、 ｌ・・・・・・ドレーン柱、
２・・・・・・基礎杭、７・・・・・・加振機。Figures 1 to 4 show the foundation pouring method according to the steps according to an embodiment of the present invention. A plan view of a drain column showing an example of the arrangement of the columns, FIG. 3 is a sectional view showing the starting point of foundation pile driving together with the drain column,
Figure 4 is a sectional view showing the driving state of foundation piles together with drain columns. FIG. 5 is a side view showing an example of a pile driver. FIG. 6 shows an experimental example according to the present invention, and is a sectional view showing the installation state of a steel pipe together with a drain column. Figures 7 to 10 show some of the data obtained by the example shown in Figure 6, where Figure 7 is a graph comparing the N value before and after penetration of the steel pipe, and Figure 8 is a graph comparing the N value before and after penetration of the steel pipe. Figure 9 is a graph comparing the amount of ground subsidence when only steel pipes are placed and when drain columns are formed. Figure 9 is a graph comparing the relative density Dr before and after the experiment. 3 is a graph comparing the target shear strength ratio R before and after the experiment. G...Ground, l...Drain pillar,
2... Foundation pile, 7... Vibrator.
Claims (2)
地盤中に貫入する際の基礎杭打設工法であって、地盤中
に、礫等よりなるドレーン柱を複数本形成した後、それ
らドレーン柱周辺の地盤中に基礎杭を打設することを特
徴とする地盤締固め併用基礎杭打設工法。(1) A foundation pile driving method for penetrating foundation piles into the ground to support the load of a structure in the ground, after forming a plurality of drain columns made of gravel etc. in the ground, A method for driving foundation piles combined with ground compaction, which is characterized by driving foundation piles into the ground around these drain columns.
とを特徴とする特許請求の範囲第１項記載の地盤締固め
併用基礎杭打設工法。(2) The foundation pile driving method combined with ground compaction according to claim 1, characterized in that the foundation pile is driven into the ground while being vibrated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15280487A JPS63315721A (en) | 1987-06-19 | 1987-06-19 | Foundation pile driving method as well as ground compaction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15280487A JPS63315721A (en) | 1987-06-19 | 1987-06-19 | Foundation pile driving method as well as ground compaction |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63315721A true JPS63315721A (en) | 1988-12-23 |
Family
ID=15548518
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15280487A Pending JPS63315721A (en) | 1987-06-19 | 1987-06-19 | Foundation pile driving method as well as ground compaction |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63315721A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0665914A (en) * | 1992-08-18 | 1994-03-08 | Penta Ocean Constr Co Ltd | Ground compaction method |
| JP2020180458A (en) * | 2019-04-24 | 2020-11-05 | 株式会社竹中工務店 | Ground liquefaction suppression structure |
| WO2020240779A1 (en) * | 2019-05-30 | 2020-12-03 | 株式会社アサヒテクノ | Ground improvement method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53123511A (en) * | 1977-04-04 | 1978-10-28 | Chiyoda Chem Eng Construct Co | Method and device for stabilizing sandy ground |
| JPS60250122A (en) * | 1984-05-25 | 1985-12-10 | Takechi Koumushiyo:Kk | Foundation pile structure for preventing liquefaction of ground |
-
1987
- 1987-06-19 JP JP15280487A patent/JPS63315721A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53123511A (en) * | 1977-04-04 | 1978-10-28 | Chiyoda Chem Eng Construct Co | Method and device for stabilizing sandy ground |
| JPS60250122A (en) * | 1984-05-25 | 1985-12-10 | Takechi Koumushiyo:Kk | Foundation pile structure for preventing liquefaction of ground |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0665914A (en) * | 1992-08-18 | 1994-03-08 | Penta Ocean Constr Co Ltd | Ground compaction method |
| JP2020180458A (en) * | 2019-04-24 | 2020-11-05 | 株式会社竹中工務店 | Ground liquefaction suppression structure |
| WO2020240779A1 (en) * | 2019-05-30 | 2020-12-03 | 株式会社アサヒテクノ | Ground improvement method |
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