JP2016050457A - Method of pulling out existing pile - Google Patents

Method of pulling out existing pile Download PDF

Info

Publication number
JP2016050457A
JP2016050457A JP2014177933A JP2014177933A JP2016050457A JP 2016050457 A JP2016050457 A JP 2016050457A JP 2014177933 A JP2014177933 A JP 2014177933A JP 2014177933 A JP2014177933 A JP 2014177933A JP 2016050457 A JP2016050457 A JP 2016050457A
Authority
JP
Japan
Prior art keywords
existing pile
ground
water
hollow portion
hollow
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.)
Granted
Application number
JP2014177933A
Other languages
Japanese (ja)
Other versions
JP6455032B2 (en
Inventor
直樹 増井
Naoki Masui
直樹 増井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Obayashi Corp
Original Assignee
Obayashi Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Obayashi Corp filed Critical Obayashi Corp
Priority to JP2014177933A priority Critical patent/JP6455032B2/en
Publication of JP2016050457A publication Critical patent/JP2016050457A/en
Application granted granted Critical
Publication of JP6455032B2 publication Critical patent/JP6455032B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Placing Or Removing Of Piles Or Sheet Piles, Or Accessories Thereof (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a method of pulling out an existing pile efficiently using water pressure.SOLUTION: A method of pulling out an existing pile is for pulling out an existing pile 1 driven in a ground, and includes: a block slab installation step in which a blocking slab 2 is inserted into a hollow part of the existing pile 1 from a head part and made to land on a ground of the hollow part located in the hollow part of the existing pile 1, the blocking slab having a shape that fits in a hollow cross-section of the existing pile 1; a head part sealing step in which the head part of the existing pile 1 is sealed; and a water injection step in which water is injected into the hollow part of the existing pile 1 to cause water pressure to be exerted on the blocking slab 2, thus generating pull-out force that pushes up the existing pile 1.SELECTED DRAWING: Figure 1

Description

本発明は、地盤に打ち込まれた既設杭を引き抜く既設杭の引抜き工法に関する。   The present invention relates to a method for extracting an existing pile that pulls out an existing pile driven into the ground.

海、河川、湖等の水上や陸上の地盤に打ち込まれた鋼管杭等の既設杭は、供用が終了すると引抜いて撤去することが最も望ましいとされている。既設杭を引抜く場合、既設杭と地盤との摩擦力と、既設杭の重量と、既設杭内部の土の重量とが荷重となり、この荷重を超える吊上げ荷重を有する大型の起重機（起重船）が必要であった。特に大きな既設杭の場合には、荷重が巨大なものになるため、この巨大な荷重を超える吊上げ荷重を有する起重機（起重船）が得られないか、得られても借料が極めて高額になり、引き抜き作業を行うことが困難であった。また、引き抜き作業を行う場合、既設杭にわずかに引抜きが生じると、既設杭と地盤との摩擦力が急激に減少するため、起重機（起重船）の制御が煩雑になるという困難性があった。   It is most desirable that existing piles such as steel pipe piles driven into the water such as seas, rivers, lakes, etc. or on the ground be pulled out and removed when the service is completed. When pulling out an existing pile, the friction force between the existing pile and the ground, the weight of the existing pile, and the weight of the soil inside the existing pile serve as loads, and a large hoist with a lifting load exceeding this load (heavy ship) ) Was necessary. Especially in the case of large existing piles, the load will be huge, so a hoist with a lifting load exceeding this huge load will not be obtained, or even if it is obtained, the rent will be extremely high. It was difficult to perform the drawing operation. In addition, when pulling out, if the existing piles are pulled slightly, the frictional force between the existing piles and the ground decreases sharply, which makes it difficult to control the hoist (heavy ship). It was.

そのため、既設杭の引き抜きを行うことなく、既設杭を支障のない深さで切断し、部分的に残置することが、運用上行われていた。場合によっては、既設杭の内部土を一部除去した後に、地中部で既設杭を切断することもあった。しかし、既設杭が水上の地盤に打ち込まれている場合には、水中切断となり、危険を伴う。また、地中部での切断は、更に難しい作業であった。   For this reason, it has been practiced to cut the existing piles at a depth that does not hinder and leave them partially without pulling out the existing piles. In some cases, after removing some of the internal soil from the existing pile, the existing pile was cut off in the ground. However, if the existing pile is driven into the ground, it will be underwater cut, which is dangerous. In addition, cutting in the underground was an even more difficult task.

そこで、既設杭の頭部を閉塞して既設杭の中空部を密閉し、既設杭の中空部に注水することで、既設杭の中空部に位置する地盤に水圧を作用させ、発生する引抜力を利用することで、大型の起重機（起重船）を用いることなく既設杭を引抜く技術が提案されている（例えば、特許文献１参照）。   Therefore, by closing the head of the existing pile, sealing the hollow part of the existing pile, and pouring water into the hollow part of the existing pile, the water pressure acts on the ground located in the hollow part of the existing pile, and the pulling force generated The technique which pulls out the existing pile without using a large sized hoist (lifting ship) is utilized by using (for example, refer patent document 1).

特開平０８-２７７９１号公報Japanese Patent Laid-Open No. 08-27791

しかしながら、従来技術のように、水圧を地盤に作用させる場合、地盤の種類によっては、十分な引抜力を得ることができないという問題点があった。例えば、水圧を作用させる地盤が砂地盤である場合には、砂地盤に水が浸透して既設杭内の水が逸水し、十分な引抜力が得られない。また、水圧によって軟弱化してしまうような地盤である場合には、地盤に均等に水圧を作用させられないため、引き抜けないか、あるいは既設杭が傾いて引き抜き作業が困難なものになっていた。   However, when the water pressure is applied to the ground as in the prior art, there is a problem that a sufficient pulling force cannot be obtained depending on the type of the ground. For example, when the ground on which water pressure is applied is sand ground, water permeates into the sand ground and water in the existing piles escapes, so that sufficient pulling force cannot be obtained. Also, if the ground is softened by water pressure, the water pressure cannot be applied evenly to the ground, so it cannot be pulled out, or the existing piles are tilted, making it difficult to pull out. .

本発明は、このような状況に鑑みてなされたものであり、上述の課題を解消し、水圧によって既設杭を効率良く引き抜くことができる既設杭の引抜き工法を提供することにある。   This invention is made | formed in view of such a condition, and it exists in providing the drawing-out construction method of the existing pile which eliminates the above-mentioned subject and can draw out an existing pile efficiently with water pressure.

本発明の既設杭の引抜き工法は、地盤に打ち込まれた既設杭を引き抜く既設杭の引抜き工法であって、前記既設杭の内空断面に収まる形状の閉塞版を、頭部から前記既設杭の中空部に挿入させ、前記既設杭の中空部に位置する中空部地盤に着地させる閉塞版設置工程と、前記既設杭の頭部を密閉する頭部密閉工程と、前記既設杭の中空部に注水することで、前記閉塞版に水圧を作用させ、前記既設杭を押し上げる引抜力を発生させる注水工程とを有することを特徴とする。
さらに、本発明の既設杭の引抜き工法は、圧力センサーを用いて前記既設杭の中空部内の水圧を測定させ、水圧報知手段によって前記圧力センサーを用いて測定された水圧を報知させても良い。
さらに、本発明の既設杭の引抜き工法は、流量センサーを用いて前記既設杭の中空部に注水する注水量を測定させ、注水量報知手段を用いて前記流量センサーによって測定された注水量を報知させても良い。
さらに、本発明の既設杭の引抜き工法は、前記閉塞版による前記中空部地盤の閉塞率は、０．９０以上であっても良い。 The method for extracting an existing pile according to the present invention is an existing pile extraction method for extracting an existing pile driven into the ground, and a closed plate having a shape that fits in the inner cross section of the existing pile is removed from the head of the existing pile. Inserting into the hollow part, closing plate installation process for landing on the hollow part ground located in the hollow part of the existing pile, head sealing process for sealing the head of the existing pile, and water injection into the hollow part of the existing pile By doing so, it has a water-injection process of generating a pulling force that applies water pressure to the closed plate and pushes up the existing pile.
Furthermore, the existing pile drawing method according to the present invention may be configured to measure the water pressure in the hollow portion of the existing pile using a pressure sensor and to notify the water pressure measured using the pressure sensor by a water pressure notification means.
Furthermore, the drawing method of the existing pile according to the present invention measures the amount of water injected into the hollow portion of the existing pile using a flow sensor, and notifies the water injection amount measured by the flow sensor using a water injection amount notification means. You may let them.
Further, in the existing pile drawing method of the present invention, the blockage rate of the hollow portion ground by the block plate may be 0.90 or more.

本発明によれば、閉塞版を介して中空部地盤に水圧を作用させることで、既設杭を押し上げる引抜力を効率よく発生させることができるため、水圧によって既設杭を効率良く引き抜くことができるという効果を奏する。   According to the present invention, it is possible to efficiently generate a pulling force that pushes up an existing pile by applying water pressure to the hollow ground through the closed plate, so that the existing pile can be efficiently pulled out by water pressure. There is an effect.

本発明に係る既設杭の引抜き工法における閉塞版設置工程及び頭部密閉工程を説明する作業工程説明図である。It is work process explanatory drawing explaining the obstruction plate installation process and head sealing process in the drawing method of the existing pile which concerns on this invention. 図１に示す閉塞版設置工程によって既設杭の中空部に位置する地盤に閉塞版を着地させた状態を示す図である。It is a figure which shows the state which made the obstruction plate land on the ground located in the hollow part of the existing pile by the obstruction plate installation process shown in FIG. 図１に示す密閉板の構成を示す側面図である。It is a side view which shows the structure of the sealing board shown in FIG. 本発明に係る既設杭の引抜き工法における注水工程を説明する作業工程説明図である。It is work process explanatory drawing explaining the water pouring process in the drawing-out method of the existing pile which concerns on this invention. 本発明に係る既設杭の引抜き工法における注水工程で中空部地盤に浸透する浸透流を説明するための説明図である。It is explanatory drawing for demonstrating the osmotic flow which osmose | permeates a hollow part ground in the water injection process in the drawing method of the existing pile which concerns on this invention.

次に、本発明を実施するための形態（以下、単に「実施の形態」という）を、図面を参照して具体的に説明する。   Next, modes for carrying out the present invention (hereinafter, simply referred to as “embodiments”) will be specifically described with reference to the drawings.

本実施の形態の既設杭の引抜き工法は、図１に示すように、中空部を有する既設杭１を水圧によって引き抜く引抜き工法である。以下、海上の地盤である海底面に打ち込まれた既設杭１の引き抜き例について詳細に説明する。   As shown in FIG. 1, the existing pile drawing method according to the present embodiment is a drawing method in which the existing pile 1 having a hollow portion is drawn by water pressure. Hereinafter, an example of pulling out the existing pile 1 driven into the bottom of the sea that is the ground on the sea will be described in detail.

まず、図１（ａ）に示すように、閉塞版２を起重機３で吊り、既設杭１の解放された頭部から中空部に挿入させる閉塞版設置工程を行う。閉塞版２は、既設杭１の内空断面に収まる形状を有し、既設杭１を引き抜く際に用いられる水圧に耐えうる剛性を備えたコンクリート版や鋼版が用いられる。なお、本実施の形態では、既設杭１は、断面形状や中空断面形状が円形である円筒状である。そして、閉塞版２は、既設杭１の内径より若干小さい直径を有する円形で構成されている。閉塞版２の既設杭１の中空部への挿入は、既設杭１の軸に対して閉塞版２をほぼ垂直に吊り下げ、この状態を保ちながら既設杭１の中空部内をゆっくり下降させる。閉塞版２をゆっくり下降させることで、既設杭１の中空部に海水が存在している場合でも、既設杭１と閉塞版２との間隙を通って海水が閉塞版２の下方から上方に移動され、閉塞版２を既設杭１の軸に対してほぼ垂直な状態に保つことができる。   First, as shown in FIG. 1A, a closed plate installation process is performed in which the closed plate 2 is suspended by the hoist 3 and inserted into the hollow portion from the released head of the existing pile 1. The closed plate 2 has a shape that fits in the inner cross section of the existing pile 1, and a concrete plate or a steel plate having rigidity that can withstand the water pressure used when the existing pile 1 is pulled out is used. In addition, in this Embodiment, the existing pile 1 is a cylindrical shape whose cross-sectional shape or hollow cross-sectional shape is circular. The closed plate 2 is formed in a circular shape having a diameter slightly smaller than the inner diameter of the existing pile 1. The closed plate 2 is inserted into the hollow portion of the existing pile 1 by suspending the closed plate 2 almost perpendicularly to the shaft of the existing pile 1 and slowly descending the hollow portion of the existing pile 1 while maintaining this state. Even when seawater exists in the hollow portion of the existing pile 1 by slowly lowering the closed plate 2, the seawater moves upward from below the closed plate 2 through the gap between the existing pile 1 and the closed plate 2. Thus, the closed plate 2 can be kept substantially perpendicular to the axis of the existing pile 1.

閉塞版設置工程では、図１（ｂ）及び図２に示すように、既設杭１の中空部に位置する地盤（以下、中空部地盤と称す）に閉塞版２を着地させる。なお、図２において、（ａ）は閉塞版２を中空部地盤に着地させた状態を横方向から見た既設杭１の縦断面図であり、（ｂ）は上方向から見た既設杭１の横断面図である。閉塞版２を中空部地盤に着地させた状態では、閉塞版２によって、中空部地盤の大部分が閉塞される。閉塞版２による中空部地盤の閉塞率（中空部地盤の面積／閉塞版２の面積）は、０．９０以上であることが好ましい。例えば、既設杭１の内径Ｌを３，０００ｍｍ、閉塞版２の直径を２，９４０ｍｍとすると、既設杭１と閉塞版２との間隙Ｗは、０〜６０ｍｍとなる。そして、中空部地盤の面積は、既設杭１の内径断面積となるため、閉塞版２による中空部地盤の閉塞率は、（２，９４０／３，０００）２＝０．９６となる。なお、本実施の形態のように、閉塞版２の形状を既設杭１の内空断面と同一形状とすることで、閉塞版２による中空部地盤の閉塞率を高くすることができる。 In the closed plate installation step, as shown in FIGS. 1B and 2, the closed plate 2 is landed on the ground located in the hollow portion of the existing pile 1 (hereinafter referred to as the hollow portion ground). 2, (a) is a longitudinal sectional view of the existing pile 1 as seen from the lateral direction when the closed plate 2 is landed on the hollow ground, and (b) is the existing pile 1 as seen from above. FIG. In the state in which the closed plate 2 is landed on the hollow portion ground, the closed plate 2 blocks most of the hollow portion ground. It is preferable that the blockage rate of the hollow part ground by the blockage plate 2 (the area of the hollow part ground / the area of the blockage plate 2) is 0.90 or more. For example, when the inner diameter L of the existing pile 1 is 3,000 mm and the diameter of the closed plate 2 is 2,940 mm, the gap W between the existing pile 1 and the closed plate 2 is 0 to 60 mm. And since the area of a hollow part ground becomes an internal-diameter cross-sectional area of the existing pile 1, the obstruction | occlusion rate of the hollow part ground by the obstruction board 2 will be (2,940 / 3,000) < 2 > = 0.96. In addition, the obstruction | occlusion rate of the hollow part ground by the obstruction | occlusion plate 2 can be made high by making the shape of the obstruction | occlusion plate 2 into the same shape as the hollow section of the existing pile 1 like this Embodiment.

次に、密閉板４を用いて既設杭１の頭部を密閉する頭部密閉工程を行う。密閉板４は、既設杭１の外径とほぼ同一の直径を有し、既設杭１を引き抜く際に用いられる水圧に耐えうる剛性を備えたコンクリート版や鋼版を用いることができる。そして、密閉板４は、溶接等の既知の方法を用いて、既設杭１の頭部に強固に取り付ける。   Next, a head sealing step for sealing the head of the existing pile 1 using the sealing plate 4 is performed. The sealing plate 4 may be a concrete plate or a steel plate having a diameter substantially the same as the outer diameter of the existing pile 1 and having rigidity capable of withstanding the water pressure used when the existing pile 1 is pulled out. The sealing plate 4 is firmly attached to the head of the existing pile 1 using a known method such as welding.

密閉板４には、図３に示すように、既設杭１の中空部に海水を注水するための注水穴４１が形成されていると共に、既設杭１の中空部から空気を排出する空気抜パイプ４２が設けられている。そして、空気抜パイプ４２には、空気抜パイプ４２を開閉する空気抜バルブ４３が設けられている。密閉板４の下面には、既設杭１の中空部の水圧を測定する圧力センサー４４が取り付けられている。   As shown in FIG. 3, a water injection hole 41 for injecting seawater into the hollow portion of the existing pile 1 is formed in the sealing plate 4, and an air vent pipe that discharges air from the hollow portion of the existing pile 1. 42 is provided. The air vent pipe 42 is provided with an air vent valve 43 that opens and closes the air vent pipe 42. A pressure sensor 44 for measuring the water pressure in the hollow portion of the existing pile 1 is attached to the lower surface of the sealing plate 4.

次に、図４に示すように、密閉板４の注水穴４１に水圧ポンプ５から引き回された注入パイプ６を差し込み、水圧ポンプ５によって既設杭１の中空部に注水する注水工程を行う。なお、海上の地盤である海底面に打ち込まれた既設杭１に対しては、図４に示すように、水圧ポンプ５を積んだポンプ船によって、海水を用いて既設杭１の中空部に注水することができる。また、既設杭１の中空部内の空気は、空気抜バルブ４３を開いて空気抜パイプ４２から排出し、全ての空気が排出された後、空気抜バルブ４３を閉じる。これにより、既設杭１の中空部が注水された海水によって満たされた満水状態となる。   Next, as shown in FIG. 4, a water injection process is performed in which the injection pipe 6 drawn from the hydraulic pump 5 is inserted into the water injection hole 41 of the sealing plate 4 and water is injected into the hollow portion of the existing pile 1 by the hydraulic pump 5. In addition, with respect to the existing pile 1 driven into the sea bottom which is the ground on the sea, water is poured into the hollow portion of the existing pile 1 using seawater by a pump ship loaded with a hydraulic pump 5 as shown in FIG. can do. Moreover, the air in the hollow part of the existing pile 1 opens the air vent valve 43 and is exhausted from the air vent pipe 42, and after all the air is exhausted, the air vent valve 43 is closed. Thereby, it will be in the full water state with which the hollow part of the existing pile 1 was satisfy | filled with the injected seawater.

既設杭１の中空部が状態になった後も、水圧ポンプ５によって注水を継続すると、図４に矢印で示すように、既設杭１の内周面と、閉塞版２と、密閉板４とに水圧が均一に作用する。そして、閉塞版２に水圧が作用することで、既設杭１を押し上げる（引抜く）引抜力が発生する。この水圧による引抜力が、既設杭１と地盤との摩擦力、既設杭１の自重、既設杭１内部の土の重量等の荷重を上回ると、既設杭１の押し上げ（引抜き）が開始される。なお、閉塞版２の直径は、既設杭１の内径よりも若干小さいため、既設杭１の押し上げ（引抜き）時に閉塞版２に接して摩擦力が作用することを回避される。   Even after the hollow portion of the existing pile 1 is in a state, when water injection is continued by the hydraulic pump 5, as shown by arrows in FIG. 4, the inner peripheral surface of the existing pile 1, the closed plate 2, the sealing plate 4 and The water pressure acts evenly. Then, when the water pressure acts on the closed plate 2, a pulling force that pushes up (pulls out) the existing pile 1 is generated. When the pulling force due to the water pressure exceeds the load such as the friction force between the existing pile 1 and the ground, the own weight of the existing pile 1, and the weight of the soil inside the existing pile 1, the lifting (pulling) of the existing pile 1 is started. . In addition, since the diameter of the block slab 2 is slightly smaller than the inner diameter of the existing pile 1, it is avoided that a friction force acts on the block slab 2 when the existing pile 1 is pushed up (pulled out).

水圧は、既設杭１の押し上げ（引抜き）が開始される直前が最も高くなり、既設杭１の押し上げ（引抜き）が開始されると、既設杭１の中空部が拡がるため、低下する。従って、この水圧の変化を、圧力センサー４４に接続されたディスプレイ等の報知部７で観測することで、既設杭１の押し上げ（引抜き）の開始を正確に把握することができる。   The water pressure becomes the highest immediately before the push-up (pulling) of the existing pile 1 is started, and when the push-up (pulling) of the existing pile 1 is started, the hollow portion of the existing pile 1 expands and thus decreases. Therefore, by observing the change in the water pressure with the notification unit 7 such as a display connected to the pressure sensor 44, it is possible to accurately grasp the start of the push-up (pull-out) of the existing pile 1.

また、既設杭１の押し上げ（引抜き）が開始された後、既設杭１の中空部に注水した注水量にほぼ比例して既設杭１は押し上げられる。従って、注入パイプ６等に注水量を測定する流量センサー８を設け、流量センサー８に接続されたディスプレイ等の報知部７を見ながら注水量を管理することで、既設杭１の引抜速度を容易に制御することができる。   Moreover, after the push-up (pull-out) of the existing pile 1 is started, the existing pile 1 is pushed up in proportion to the amount of water injected into the hollow portion of the existing pile 1. Therefore, the flow rate sensor 8 for measuring the water injection amount is provided in the injection pipe 6 and the like, and the water injection amount is managed while looking at the notification unit 7 such as a display connected to the flow rate sensor 8, thereby facilitating the pulling speed of the existing pile 1. Can be controlled.

なお、海底面の地盤が砂質土地盤である場合には、図５（ａ）に示すように、注水された海水が既設杭１と閉塞版２との間隙を通って中空部地盤に浸透する浸透流が形成される。しかしながら、閉塞版２による中空部地盤の閉塞率が高い場合（例えば０．９０以上）には、海水の通過率が低く（例えば０．１０未満）になる。そして、中空部地盤の見かけの透水係数は、中空部地盤の実際の透水係数ｋに通過率を乗じた値となる。従って、中空部地盤の見かけの透水係数は、中空部地盤の実際の透水係数よりも低くなり、閉塞版２の設置で浸透流が軽減されたことが分かる。このことは、閉塞版２の設置が、水圧を作用させやすい土質に中空部地盤を改善することと同義であることを意味する。例えば、閉塞版２による中空部地盤の閉塞率が０．９６である場合には、海水の通過率が０．０４になるため、中空部地盤の見かけの透水係数は、中空部地盤の実際の透水係数ｋに通過率０．０４を乗じた値となる。これにより、中空部地盤の見かけの透水係数は、中空部地盤の実際の透水係数ｋよりも２桁近く低くなり、中空部地盤が砂質土地盤であっても、ほぼ粘性土地盤に近似される。また、閉塞版２に作用する水圧によって中空部地盤が締め固められ、中空部地盤が補強される。これにより、浸透流が軽減されるという効果も得られる。   In addition, when the ground on the sea bottom is sandy ground, as shown in FIG. 5 (a), the injected seawater penetrates into the hollow ground through the gap between the existing pile 1 and the closed plate 2. An osmotic flow is formed. However, when the blockage rate of the hollow ground by the blockage plate 2 is high (for example, 0.90 or more), the passage rate of seawater is low (for example, less than 0.10). The apparent water permeability coefficient of the hollow part ground is a value obtained by multiplying the actual water permeability coefficient k of the hollow part ground by the passage rate. Therefore, it can be seen that the apparent hydraulic conductivity of the hollow ground is lower than the actual hydraulic conductivity of the hollow ground, and that the osmotic flow is reduced by the installation of the closed plate 2. This means that the installation of the closed plate 2 is synonymous with the improvement of the hollow portion ground to the soil that is easily subjected to water pressure. For example, when the blockage rate of the hollow part ground by the blockage plate 2 is 0.96, the passage rate of seawater is 0.04, so the apparent permeability coefficient of the hollow part ground is the actual permeability of the hollow part ground. It is a value obtained by multiplying the permeability coefficient k by a passage rate of 0.04. As a result, the apparent hydraulic conductivity of the hollow ground is nearly two orders of magnitude lower than the actual hydraulic conductivity k of the hollow ground, and even if the hollow ground is sandy ground, it is almost approximate to viscous ground. The Further, the hollow portion ground is compacted by the water pressure acting on the closed plate 2 and the hollow portion ground is reinforced. Thereby, the effect that an osmotic flow is reduced is also acquired.

既設杭１と閉塞版２との間隙を通って中空部地盤に浸透する浸透流の流量は、既設杭１の押し上げ（引抜き）が開始されるまでの、注水量に応じた水圧の上昇を圧力センサー４４及び流量センサー８に接続された報知部７によって観測することで推定することができる。そして、推定した浸透流の流量を勘案して注水量を管理することで、既設杭１の引抜速度をより正確に制御することができる。   The flow rate of the osmotic flow that permeates the hollow ground through the gap between the existing pile 1 and the closed plate 2 is the increase in water pressure according to the amount of water injected until the existing pile 1 is pushed up (pulled out). It can be estimated by observing with the notification unit 7 connected to the sensor 44 and the flow rate sensor 8. And the extraction speed | rate of the existing pile 1 can be controlled more correctly by considering the estimated flow volume of the osmotic flow and managing the amount of water injection.

また、海底面の地盤が粘性土地盤である場合には、図５（ｂ）に示すように、注水された海水が既設杭１と閉塞版２との間隙を通って中空部地盤に浸透することがほとんどないが、閉塞版２に作用する水圧によって中空部地盤が締め固められ、中空部地盤が補強される。   In addition, when the ground on the sea bottom is a viscous ground, the injected seawater penetrates into the hollow ground through the gap between the existing pile 1 and the closed plate 2 as shown in FIG. 5 (b). Although there is almost nothing, the hollow portion ground is compacted by the water pressure acting on the closed plate 2 and the hollow portion ground is reinforced.

以上説明したように、本実施の形態によれば、地盤に打ち込まれた既設杭１を引き抜く既設杭の引抜き工法であって、既設杭１の内空断面に収まる形状、すなわち既設杭１の内径Ｌより小さい直径Ｍを有する閉塞版２を、頭部から既設杭１の中空部に挿入させ、既設杭１の中空部に位置する中空部地盤に着地させる閉塞版設置工程と、既設杭１の頭部を密閉する頭部密閉工程と、既設杭１の中空部に注水することで、閉塞版２に水圧を作用させ、既設杭１を押し上げる引抜力を発生させる注水工程とを有する。
この構成により、閉塞版２を介して中空部地盤に水圧を作用させることで、既設杭１を押し上げる引抜力を効率よく発生させることができるため、大型の起重機（起重船）を用いることなく、周囲にある水とポンプ等の簡易な資機材のみで既設杭１を効率良く引き抜くことができる。 As described above, according to the present embodiment, the existing pile 1 is drawn out into the ground, and the existing pile 1 is pulled out, and the shape fits in the inner cross section of the existing pile 1, that is, the inner diameter of the existing pile 1. The closed plate 2 having a diameter M smaller than L is inserted into the hollow portion of the existing pile 1 from the head and landed on the hollow portion ground located in the hollow portion of the existing pile 1; A head sealing step for sealing the head portion and a water injection step for generating a pulling force that pushes the existing pile 1 by applying water pressure to the closed plate 2 by pouring water into the hollow portion of the existing pile 1.
With this configuration, it is possible to efficiently generate a pulling force that pushes up the existing pile 1 by applying water pressure to the hollow ground through the closed plate 2 without using a large hoist (heavy ship). The existing pile 1 can be efficiently pulled out only by surrounding water and simple materials such as a pump.

さらに、本実施の形態は、圧力センサー４４を用いて既設杭１の中空部内の水圧を測定させ、水圧報知手段である報知部７を用いて圧力センサー４４によって測定された水圧を報知させる。
この構成により、水圧の変化を観測することができ、既設杭１の押し上げ（引抜き）の開始を正確に把握することができる。 Further, in the present embodiment, the water pressure in the hollow portion of the existing pile 1 is measured using the pressure sensor 44, and the water pressure measured by the pressure sensor 44 is notified using the notification unit 7 which is a water pressure notification unit.
With this configuration, it is possible to observe a change in water pressure and accurately grasp the start of pushing up (pulling) of the existing pile 1.

さらに、本実施の形態は、流量センサー８を用いて既設杭１の中空部に注水する注水量を測定させ、注水量報知手段である報知部７を用いて流量センサー８によって測定された注水量を報知させる。
この構成により、注水量を管理することで、既設杭１の引抜速度を容易に制御することができる。
また、圧力センサー４４と流量センサー８を併用すると、既設杭１と閉塞版２との間隙を通って中空部地盤に浸透する浸透流の流量を推定することができる。そして、推定した浸透流の流量を勘案して注水量を管理することで、既設杭１の引抜速度をより正確に制御することができる。 Further, in the present embodiment, the amount of water injected into the hollow portion of the existing pile 1 is measured using the flow rate sensor 8, and the amount of water injected measured by the flow rate sensor 8 using the notification unit 7 which is a water injection amount notification means. To let you know.
With this configuration, the extraction speed of the existing pile 1 can be easily controlled by managing the amount of water injected.
In addition, when the pressure sensor 44 and the flow rate sensor 8 are used in combination, the flow rate of the osmotic flow that permeates the hollow ground through the gap between the existing pile 1 and the closed plate 2 can be estimated. And the extraction speed | rate of the existing pile 1 can be controlled more correctly by considering the estimated flow volume of the osmotic flow and managing the amount of water injection.

さらに、本実施の形態は、閉塞版２による中空部地盤の閉塞率は、０．９０以上である。
この構成により、閉塞版２に作用する水圧によって、既設杭１を押し上げる引抜力を効率よく発生させることができる。 Furthermore, in the present embodiment, the blockage rate of the hollow portion ground by the block plate 2 is 0.90 or more.
With this configuration, the pulling force that pushes up the existing pile 1 can be efficiently generated by the water pressure acting on the closed plate 2.

以上、本発明を実施の形態をもとに説明した。この実施の形態は例示であり、それらの各構成要素の組み合わせ等にいろいろな変形例が可能なこと、またそうした変形例も本発明の範囲にあることは当業者に理解されるところである。
例えば、本実施の形態では、断面形状や中空断面形状が円形である円筒状の既設杭１を引抜く例について説明したが、引き抜く対象の既設杭１は、中空部地盤に至る中空部を有していれば、断面形状や中空断面形状が矩形や楕円形等の任意の形状であっても良い。
また、本実施の形態では、閉塞版２の形状を既設杭１の内空断面と同一の円形で構成したが、閉塞版２の形状は、既設杭１を内空断面と異なる形状で構成することもできる。 The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of these components, and that such modifications are within the scope of the present invention.
For example, in the present embodiment, an example in which a cylindrical existing pile 1 having a circular cross-sectional shape or a hollow cross-sectional shape is extracted has been described. However, the existing pile 1 to be extracted has a hollow portion that reaches the hollow portion ground. If so, the cross-sectional shape and the hollow cross-sectional shape may be any shape such as a rectangle or an ellipse.
Moreover, in this Embodiment, although the shape of the obstruction board 2 was comprised by the same circular shape as the internal hollow cross section of the existing pile 1, the shape of the obstruction board 2 comprises the existing pile 1 in a shape different from an internal air cross section. You can also.

１ 既設杭
２ 閉塞版
３ 起重機
４ 密閉板
５ 水圧ポンプ
６ 注入パイプ
７ 報知部
８ 流量センサー
４１ 注水穴
４２ 空気抜パイプ
４３ 空気抜バルブ
４４ 圧力センサー DESCRIPTION OF SYMBOLS 1 Existing pile 2 Blocking plate 3 Hoist 4 Sealing plate 5 Water pressure pump 6 Injection pipe 7 Notification part 8 Flow rate sensor 41 Water injection hole 42 Air vent pipe 43 Air vent valve 44 Pressure sensor

Claims (4)

地盤に打ち込まれた既設杭を引き抜く既設杭の引抜き工法であって、
前記既設杭の内空断面に収まる形状の閉塞版を、頭部から前記既設杭の中空部に挿入させ、前記既設杭の中空部に位置する中空部地盤に着地させる閉塞版設置工程と、
前記既設杭の頭部を密閉する頭部密閉工程と、
前記既設杭の中空部に注水することで、前記閉塞版に水圧を作用させ、前記既設杭を押し上げる引抜力を発生させる注水工程とを有することを特徴とする既設杭の引抜き工法。 It is a method for pulling out an existing pile that has been driven into the ground.
The closed plate installation step of inserting the closed plate of the shape that fits in the hollow section of the existing pile into the hollow portion of the existing pile from the head, and landing on the hollow portion ground located in the hollow portion of the existing pile,
A head sealing step for sealing the head of the existing pile;
A method of drawing an existing pile, comprising: a water injection step of generating a pulling force that causes water pressure to act on the closed plate and pushes up the existing pile by pouring water into a hollow portion of the existing pile. 圧力センサーを用いて前記既設杭の中空部内の水圧を測定させ、
水圧報知手段を用いて前記圧力センサーによって測定された水圧を報知させることを特徴とする請求項１記載の既設杭の引抜き工法。 Using the pressure sensor, the water pressure in the hollow portion of the existing pile is measured,
2. The method for pulling an existing pile according to claim 1, wherein the water pressure measured by the pressure sensor is reported using a water pressure notifying means. 流量センサーを用いて前記既設杭の中空部に注水する注水量を測定させ、
注水量報知手段を用いて前記流量センサーによって測定された注水量を報知させることを特徴とする請求項１又は２記載の既設杭の引抜き工法。 Using the flow sensor, measure the amount of water injected into the hollow part of the existing pile,
The method for pulling an existing pile according to claim 1 or 2, wherein the water injection amount measured by the flow sensor is notified using a water injection amount notification means. 前記閉塞版による前記中空部地盤の閉塞率は、０．９０以上であることを特徴とする請求項１乃至３のいずれかに記載の既設杭の引抜き工法。   The method for extracting an existing pile according to any one of claims 1 to 3, wherein the blockage rate of the hollow portion ground by the block plate is 0.90 or more.
JP2014177933A 2014-09-02 2014-09-02 Pull-out method for existing piles Active JP6455032B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2014177933A JP6455032B2 (en) 2014-09-02 2014-09-02 Pull-out method for existing piles

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2014177933A JP6455032B2 (en) 2014-09-02 2014-09-02 Pull-out method for existing piles

Publications (2)

Publication Number Publication Date
JP2016050457A true JP2016050457A (en) 2016-04-11
JP6455032B2 JP6455032B2 (en) 2019-01-23

Family

ID=55658172

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2014177933A Active JP6455032B2 (en) 2014-09-02 2014-09-02 Pull-out method for existing piles

Country Status (1)

Country Link
JP (1) JP6455032B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111456007A (en) * 2020-04-22 2020-07-28 中交第二航务工程局有限公司 Steel casing pulling-out method

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51148206A (en) * 1975-06-13 1976-12-20 Kensetsu Kikai Chiyousa Kk Method of and apparatus for retracting steellpipe pile
JPS6149024A (en) * 1984-08-11 1986-03-10 Toyo Kensetsu Kk Drawing of cylindrical pile
JPS6183720A (en) * 1984-09-28 1986-04-28 Furukawa Mining Co Ltd Method and device of pulling off steel pipe pile
JPH06101395A (en) * 1992-09-17 1994-04-12 Power Reactor & Nuclear Fuel Dev Corp Measuring method and device for hydraulic slack region of rockbed around cavity
JPH0827791A (en) * 1994-07-20 1996-01-30 Taisei Corp Removal method of existing steel pipe pile
JP2006077567A (en) * 2004-08-12 2006-03-23 East Japan Railway Co Recharge method, its water pouring control method, and water pouring control system
US7090434B1 (en) * 2005-05-03 2006-08-15 Cross Rentals, Inc. Caisson removal process

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51148206A (en) * 1975-06-13 1976-12-20 Kensetsu Kikai Chiyousa Kk Method of and apparatus for retracting steellpipe pile
JPS6149024A (en) * 1984-08-11 1986-03-10 Toyo Kensetsu Kk Drawing of cylindrical pile
JPS6183720A (en) * 1984-09-28 1986-04-28 Furukawa Mining Co Ltd Method and device of pulling off steel pipe pile
JPH06101395A (en) * 1992-09-17 1994-04-12 Power Reactor & Nuclear Fuel Dev Corp Measuring method and device for hydraulic slack region of rockbed around cavity
JPH0827791A (en) * 1994-07-20 1996-01-30 Taisei Corp Removal method of existing steel pipe pile
JP2006077567A (en) * 2004-08-12 2006-03-23 East Japan Railway Co Recharge method, its water pouring control method, and water pouring control system
US7090434B1 (en) * 2005-05-03 2006-08-15 Cross Rentals, Inc. Caisson removal process

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111456007A (en) * 2020-04-22 2020-07-28 中交第二航务工程局有限公司 Steel casing pulling-out method

Also Published As

Publication number Publication date
JP6455032B2 (en) 2019-01-23

Similar Documents

Publication Publication Date Title
JP6093453B2 (en) Ground improvement method
KR101421463B1 (en) Upper multi-suction bucket group pile for increasing lateral resistance
EP2428616B1 (en) Method and apparatus for installing marine equipment, especially offshore wind turbines
JP5595137B2 (en) Landslide prevention method
NL2018568B1 (en) Suction pile re-float provision.
CN104563118B (en) The pre-poured built pile construction method of full-sleeve vibration soil taking
KR20210116664A (en) Vibration pour of foundation
CN108978661B (en) Construction method for removing cast-in-situ bored pile
CN102605788A (en) Double-tube-sinking and inner-tube-drawing bored cast-in-place pile construction method and application
JP6455032B2 (en) Pull-out method for existing piles
CN104711975B (en) Construction technology for long spiral cast-in-situ bored pile
JP2013164103A (en) Embedded pipe structure and method for constructing embedded pipe structure
CN106458292B (en) The method for sucking caisson for installing multistage
CN102605800A (en) Underground continuous wall construction method
KR20030068688A (en) Piling method of suction pile
DK3049579T3 (en) VACUUM ANCHOR
CN202530447U (en) Bored cast-in-place pile structure formed by sinking double pipes and drawing inner pipe
JPH0827791A (en) Removal method of existing steel pipe pile
KR101630522B1 (en) Suction foundation for pre-loading and construction method thereof
JP4311676B2 (en) Construction method using casing
JP2012214980A (en) Construction method for underground wall and extraction method for core material of the underground wall
CN109930602A (en) A kind of Water Cutting vibration immersed tube pile pulling device
JP7122203B2 (en) Embankment body drilling method and discharge pipe construction method
Duan et al. Jetting effect of jackup on actively punching through overlaid sand layer
CN114032906B (en) Automatic shallow biogas cavity recognition and filling equipment and construction method for grouting and filling biogas cavity

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20170817

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20180525

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20180612

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20180717

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20181120

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20181203

R150 Certificate of patent or registration of utility model

Ref document number: 6455032

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150