JP4164746B2 - Penetration tool and magnetic exploration method used for magnetic exploration - Google Patents

Penetration tool and magnetic exploration method used for magnetic exploration Download PDF

Info

Publication number
JP4164746B2
JP4164746B2 JP2003096322A JP2003096322A JP4164746B2 JP 4164746 B2 JP4164746 B2 JP 4164746B2 JP 2003096322 A JP2003096322 A JP 2003096322A JP 2003096322 A JP2003096322 A JP 2003096322A JP 4164746 B2 JP4164746 B2 JP 4164746B2
Authority
JP
Japan
Prior art keywords
magnetic
exploration
rod
penetrating
axis direction
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.)
Expired - Fee Related
Application number
JP2003096322A
Other languages
Japanese (ja)
Other versions
JP2004301735A (en
Inventor
洋 羽矢
英俊 西岡
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.)
Railway Technical Research Institute
Original Assignee
Railway Technical Research Institute
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 Railway Technical Research Institute filed Critical Railway Technical Research Institute
Priority to JP2003096322A priority Critical patent/JP4164746B2/en
Publication of JP2004301735A publication Critical patent/JP2004301735A/en
Application granted granted Critical
Publication of JP4164746B2 publication Critical patent/JP4164746B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Landscapes

  • Geophysics And Detection Of Objects (AREA)
  • Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Description

【０００１】
【発明の属する技術分野】
本発明は、磁気探査に用いる貫入具および磁気探査方法に関し、特に基礎杭の先端位置を検出する磁気探査に用いる貫入具および磁気探査方法に関する。
【０００２】
【従来の技術】
施行年度の古い構造物の耐震性判定のためや、老朽化した構造物の更新のためには、基礎杭の杭長を確認しておく必要があるが、図面等が存在しない場合には、基礎杭の杭長を調査しなければならない。
【０００３】
従来、基礎杭の杭長を調査するには、両コイル型磁気傾度計を用いた磁気探査方法が行われている。磁気探査方法は、基礎杭の残留磁気や地球磁場による感応磁気を測定することによって杭長を特定するもので、ロータリーボーリング等によって測定対象の基礎杭の近傍に探査孔を掘削し、当該探査孔に両コイル型磁気傾度計を挿入して一定速度で移動させることによって磁気傾度、すなわち磁場の強さの変化率を測定し、杭長を特定する（例えば、非特許文献１参照）。
【０００４】
【非特許文献１】
「磁気探査を用いた橋梁基礎の形状調査法マニュアル」建設省土木研究所、平成１１年３月
【０００５】
【発明が解決しようとする課題】
しかしながら、従来の磁気探査方法では、ロータリーボーリング等によって所定深さの探査孔を掘削する必要があり、大掛かりな機械を必要とすると共に、磁気探査後に探査孔を埋め戻す必要があるため、作業が煩雑になってしまうという問題点があった。また、砂礫層等の緩い地層に探査孔を掘削する場合には、孔壁の崩落を防ぐために非磁性ガイド管を随時挿入する必要があり、作業効率が低下してしまうという問題点があった。
【０００６】
本発明は斯かる問題点を鑑みてなされたものであり、その目的とするところは、探査孔を掘削することなく磁気探査を行うことができ、作業効率を向上させることができる磁気探査に用いる貫入具および磁気探査方法を提供する点にある。
【０００７】
【課題を解決するための手段】
本発明は上記課題を解決すべく、以下に掲げる構成とした。
請求項１記載の発明の要旨は、鋼材を含む基礎杭の近傍の磁気探査を行って、前記基礎杭の先端位置を非接触で検出する磁気探査に用いる貫入具であって、非磁性体で構成され、突状の先端部が形成された筒状体である貫入先端ロッドと、該貫入先端ロッドの中空部に固定され、互いに直交するｘ軸、ｙ軸およびｚ軸の磁気量を測定可能な３次元磁気センサとからなり、前記３次元磁気センサは、ｚ軸が前記貫入先端ロッドの軸方向と一致するように固定されていることを特徴とする磁気探査に用いる貫入具に存する。
また請求項２記載の発明の要旨は、請求項１記載の磁気探査に用いる貫入具を用いて磁気探査を行う磁気探査方法であって、前記貫入先端ロッドの圧入と並行して磁気量を測定することを特徴とする磁気探査方法に存する。
また請求項３記載の発明の要旨は、前記貫入先端ロッドに継ぎロッドを継ぎ足しながら前記貫入先端ロッドを圧入することを特徴とする請求項２記載の磁気探査方法に存する。
また請求項４記載の発明の要旨は、前記貫入先端ロッドおよび前記継ぎロッドの圧入量を検出することによって前記３次元磁気センサの深さを測定することを特徴とする請求項３記載の磁気探査方法に存する。
また請求項５記載の発明の要旨は、前記３次元磁気センサによってｚ軸方向の複数の箇所でそれぞれｘ軸方向の磁気量ＢＸ、ｙ軸方向の磁気量ＢＹおよびｚ軸方向の磁気量ＢＺを測定し、前記磁気量ＢＸと前記磁気量ＢＹとから前記基礎杭に対して垂直な面上の磁気量ＢＨを算出し、当該磁気量ＢＨと前記磁気量ＢＺとから予め測定しておいた地磁気をそれぞれ除去して地磁気を除去した前記基礎杭に対して垂直な面上の磁気量Ｂｈと地磁気を除去したｚ軸方向の磁気量Ｂｚとをそれぞれ算出し、前記磁気量Ｂｈと前記磁気量Ｂｚとに基づく形状解析結果を前記ｚ軸方向の複数の箇所毎に出力することを特徴とする請求項２乃至４のいずれかに記載の磁気探査方法に存する。
【０００８】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて詳細に説明する。
【０００９】
図１は、本発明に係る磁気探査に用いる貫入具の実施の形態の貫入先端ロッドの構成を示す図であり、図２は、本発明に係る磁気探査に用いる貫入具の実施の形態の継ぎロッドの構成を示す図であり、図３は、本発明に係る磁気探査方法の実施の形態で使用する機器構成を示す図であり、図４は、図３に示す形状解析装置の構成を示すブロック図であり、図５は、図３に示す水平磁界算出部における水平磁界の算出方法を説明するための図であり、図６は、図３に示す探査結果算出部において算出された探査結果を説明するための図である。
【００１０】
本実施の形態では、探査孔を掘削する替わりに、図１に示す貫入先端ロッド１と、図２に示す継ぎロッド３とからなる貫入具を測定対象の基礎杭４の近傍に圧入させることによって磁気探査を行う。なお、測定対象の基礎杭４としては、杭（鋼杭，場所打ち杭）の他、ケーソン（鋼製，鉄筋コンクリート製）、井筒（鉄筋コンクリート製）が考えられる。
【００１１】
貫入先端ロッド１は、図１を参照すると、ステンレス鋼製、アルミ合金製等の非磁性体で構成され、突状の先端部が形成されている筒状体であり、後端部には、継ぎロッド３を継ぎ足すための雌ネジ１１が形成されている。また、外周には、目盛り２が軸方向に等間隔に設けられている。なお、本実施の形態で使用する貫入先端ロッド１の先端角は、６０°とし、底面積は、１０ｃｍ２程度とする。
【００１２】
貫入先端ロッド１の中空部分には、互いに直交する向き（ｘ軸、ｙ軸、ｚ軸）の磁界の強さを測定可能な３次元磁気センサ１０が、ｚ軸が貫入先端ロッド１の軸方向と一致するように固定されている。３次元磁気センサ１０は、例えば互いに直交する向きに配置された３つのホール素子からなるもので、静止状態で互いに直交する向きの磁界の強さを測定することが可能な構成となっている。なお、ホール素子の替わりにフラックスゲート型センサやＳＱＵＩＤ型センサ等を用いることもできる。
【００１３】
継ぎロッド３は、図２を参照すると、ステンレス鋼製、アルミ合金製等の非磁性体で構成された筒状体であり、先端部には、貫入先端ロッド１および前段の継ぎロッド３の後端部と螺合する雄ネジ３１が形成されており、後端部には、継ぎロッド３を継ぎ足すための雌ネジ１１が形成されている。また、外周には、目盛り２が軸方向に等間隔に設けられている。
【００１４】
磁気探査に際して、図３に示すように、測定対象の基礎杭４の近傍に貫入先端ロッド１および継ぎロッド３を鉛直に圧入していく。なお、貫入先端ロッド１の圧入には、パイプ（細径鋼管等）を貫入する既存の圧入機を使用することができる。また、貫入先端ロッド１に設けられた３次元磁気センサ１０からの出力ケーブルは、継ぎロッド３を貫通させる必要があるため、コネクタ等で一端切り離すことができるようになっている。なお、出力ケーブルとしてシールドケーブルを使用する場合には、継ぎロッド３は、一般の鋼製材料で構成するようにしても良い。
【００１５】
貫入先端ロッド１および継ぎロッド３の外周に設けられた目盛り２を検出するための目盛り検出センサ５を設置し、貫入先端ロッド１および継ぎロッド３の圧入に並行して、目盛り検出センサ５による目盛り検出タイミングでｘ軸方向、ｙ軸方向、ｚ軸方向の磁界の強さをそれぞれ測定していく。すなわち、３次元磁気センサ１０からの出力は、増幅器６で増幅され、目盛り検出センサ５による目盛り検出タイミングでデータ収集器７に入力される。従って、データ収集器７には、深さ（目盛り２）毎のｘ軸方向、ｙ軸方向およびｚ軸方向の磁界の強さが探査データとして収集されることになる。
【００１６】
形状解析装置８は、図４を参照すると、データ収集器７からの探査データが入力される探査データ入力部８１と、予め測定しておいた地磁気データが記憶される地磁気記憶部８２と、地磁気記憶部８２に記憶されている地磁気データに基づいて探査データから地磁気を除去する地磁気除去部８３と、水平磁界算出部８４と、探査結果算出部８５と、データ出力部８６とからなる。
【００１７】
探査データ入力部８１には、データ収集器７から探査データとして深さ毎のｘ軸方向の磁界の強さＢＸと、ｙ軸方向の磁界の強さＢＹと、ｚ軸方向の磁界の強さＢＺとが入力される。
【００１８】
地磁気記憶部８２に記憶される地磁気は、周囲の磁性体から十分離れた位置に３次元磁気センサ１０を置き、ｚ軸が鉛直方向になるように調整し、ｘ軸方向、ｙ軸方向、ｚ軸方向の３方向成分の磁界の強さ（μＴ）をそれぞれ測定し、当該測定結果をそれぞれ地磁気Ｂｘ０、Ｂｙ０、Ｂｚ０として記憶させておく。
【００１９】
水平磁界算出部８４は、以下に示す式によって水平成分の磁界の強さＢＨを算出する。すなわち、図５に示すように、３次元磁気センサ１０が回転してｘ軸およびｙ軸が変化しても、ｘ軸方向の磁界の強さＢＸと、ｙ軸方向の磁界の強さＢＹとから正確な水平成分の磁界の強さＢＨを算出する。
【００２０】

Figure 0004164746
【００２１】
地磁気除去部８３は、以下に示す式によって水平成分の地磁気Ｂｈ０を算出し、地磁気を除去した水平成分の磁界の強さＢｈ＝ＢＨ−Ｂｈ０と、地磁気を除去した鉛直方向の磁界の強さＢｚ＝ＢＺ−Ｂｚ０を算出する。
【００２２】
Figure 0004164746
【００２３】
探査結果算出部８５は、地磁気を除去した水平成分の磁界の強さＢｈと、地磁気を除去した鉛直方向の磁界の強さＢｚとからｔａｎθ＝Ｂｈ／Ｂｚを算出する。
このようにして深さ毎のｔａｎθ＝Ｂｈ／Ｂｚを算出してプリンタ等のデータ出力部８６にグラフや表として出力する。
【００２４】
基礎杭４を磁石としてみなすと、基礎杭４からは、図６に示すような磁力線がでていることになり、ｔａｎθ＝Ｂｈ／Ｂｚを算出して水平成分の磁界の強さＢｈと鉛直方向の磁界の強さＢｚとの比として捉えることにより、磁力線の角度の変化を検出できるため、データ出力部８６から出力されるグラフや表には、基礎杭４の先端位置を中心とした明らかな変動が確認でき、基礎杭４の杭長を検出することが可能になる。
【００２５】
また、鉛直方向の磁界の強さＢｚのみでは、基礎杭４と３次元磁気センサ１０との離隔が大きいときに誤差が大きくなるが、水平成分の磁界の強さＢｈ、鉛直方向の磁界の強さＢｚとも同じレベルで磁気量が低下するため、ｔａｎθ＝Ｂｈ／Ｂｚとすれば、磁気量が小さくても精度が良く基礎杭４の先端位置を検出することが可能になる。さらに、ｔａｎθ＝Ｂｈ／Ｂｚとすることで、θ＝０で正負が入れ替わり、検出の信頼性が向上する。
【００２６】
以上説明したように、本実施の形態によれば、貫入先端ロッド１および継ぎロッド３を圧入するだけで、貫入先端ロッド１に設けた３次元磁気センサ１０によって磁界の強さを測定できるため、探査孔を掘削することなく磁気探査を行うことができ、作業効率を向上させることができるという効果を奏する。
【００２７】
さらに、本実施の形態によれば、３次元磁気センサ１０によってｚ軸方向の磁界の強さを鉛直方向の磁界の強さとして、ｘ軸方向およびｙ軸方向の磁界の強さを水平成分の磁界の強さとしてそれぞれ測定し、鉛直方向の磁界の強さと水平成分の磁界の強さとから基礎杭４の先端位置を検出することにより、貫入先端ロッド１および継ぎロッド３が回転しても水平成分の磁界の強さを正確に測定でき、精度が良く基礎杭４の先端位置を検出することが可能になるという効果を奏する。
【００２８】
さらに、本実施の形態によれば、貫入先端ロッド１および継ぎロッド３の外周に目盛り２を軸方向に等間隔に設け、目盛り２の検出タイミングで磁界の強さを測定するように構成することにより、作業者が目視により検出タイミングを決定する必要がないため、作業効率が向上するという効果を奏する。
【００２９】
なお、本実施の形態では、貫入先端ロッド１および継ぎロッド３の外周に設けた目盛り２によって深さを検知するように構成しているが、巻き取り式変位計（継ぎロッド３の長さを１ｍとした場合、１ｍ計測用の変位計）を押し込み（圧入）機械本体に設置し、ロッドの押し込み（圧入）量を電気的に検出することによって深さを検知するように構成しても良い。この場合には、継ぎロッド３の継ぎ足し工程で毎回、変位計の目盛り変えを併せて実施する。
【００３０】
なお、本発明が上記各実施の形態に限定されず、本発明の技術思想の範囲内において、各実施の形態は適宜変更され得ることは明らかである。また、上記構成部材の数、位置、形状等は上記実施の形態に限定されず、本発明を実施する上で好適な数、位置、形状等にすることができる。なお、各図において、同一構成要素には同一符号を付している。
【００３１】
【発明の効果】
本発明の磁気探査に用いる貫入具および磁気探査方法は、貫入先端ロッドおよび継ぎロッドを圧入するだけで、貫入先端ロッドに設けた３次元磁気センサによって磁界の強さを測定できるため、探査孔を掘削することなく磁気探査を行うことができ、作業効率を向上させることができるという効果を奏する。
【００３２】
さらに、本発明の磁気探査に用いる貫入具および磁気探査方法は、３次元磁気センサによってｚ軸方向の磁界の強さを鉛直方向の磁界の強さとして、ｘ軸方向およびｙ軸方向の磁界の強さを水平成分の磁界の強さとしてそれぞれ測定し、鉛直方向の磁界の強さと水平成分の磁界の強さとから基礎杭の先端位置を検出することにより、貫入先端ロッドおよび継ぎロッドが回転しても水平成分の磁界の強さを正確に測定でき、精度が良く基礎杭の先端位置を検出することが可能になるという効果を奏する。
【００３３】
さらに、本発明の磁気探査に用いる貫入具および磁気探査方法は、貫入先端ロッドおよび継ぎロッドの外周に目盛りを軸方向に等間隔に設け、目盛りの検出タイミングで磁界の強さを測定するように構成することにより、作業者が目視により検出タイミングを決定する必要がないため、作業効率が向上するという効果を奏する。
【図面の簡単な説明】
【図１】本発明に係る磁気探査に用いる貫入具の実施の形態の貫入先端ロッドの構成を示す図である。
【図２】本発明に係る磁気探査に用いる貫入具の実施の形態の継ぎロッドの構成を示す図である。
【図３】本発明に係る磁気探査方法の実施の形態で使用する機器構成を示す図である。
【図４】図３に示す形状解析装置の構成を示すブロック図である。
【図５】図３に示す水平磁界算出部における水平磁界の算出方法を説明するための図である。
【図６】図３に示す探査結果算出部において算出された探査結果を説明するための図である。
【符号の説明】
１ 貫入先端ロッド
２ 目盛り
３ 継ぎロッド
４ 基礎杭
５ 目盛り検出センサ
６ 増幅器
７ データ収集器
８ 形状解析装置
１０ ３次元磁気センサ
１１ 雌ネジ
３１ 雄ネジ
８１ 探査データ入力部
８２ 地磁気記憶部
８３ 地磁気除去部
８４ 水平磁界算出部
８５ 探査結果算出部
８６ データ出力部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a penetrating tool and a magnetic exploration method used for magnetic exploration, and more particularly to a penetrating tool and a magnetic exploration method used for magnetic exploration for detecting the tip position of a foundation pile.
[0002]
[Prior art]
It is necessary to confirm the pile length of the foundation pile for the seismic assessment of the old structure in the year of enforcement or for the replacement of an aged structure. The pile length of the foundation pile must be investigated.
[0003]
Conventionally, in order to investigate the pile length of a foundation pile, a magnetic exploration method using a double coil type magnetic inclinometer has been performed. The magnetic exploration method specifies the pile length by measuring the residual magnetism of the foundation pile and the sensitive magnetism due to the earth's magnetic field. The exploration hole is excavated in the vicinity of the foundation pile to be measured by rotary boring, etc. The magnetic gradient, that is, the rate of change in the strength of the magnetic field is measured by inserting a double coil type magnetic inclinometer and moving at a constant speed, and the pile length is specified (for example, see Non-Patent Document 1).
[0004]
[Non-Patent Document 1]
"Manual of shape survey method for bridge foundation using magnetic exploration", Ministry of Construction, Public Works Research Institute, March 1999 [0005]
[Problems to be solved by the invention]
However, in the conventional magnetic exploration method, it is necessary to excavate an exploration hole of a predetermined depth by rotary boring or the like, and a large-scale machine is required and the exploration hole needs to be backfilled after magnetic exploration. There was a problem of becoming complicated. In addition, when excavating a survey hole in a loose formation such as a gravel layer, it is necessary to insert a non-magnetic guide tube as needed to prevent the collapse of the hole wall, resulting in reduced work efficiency. .
[0006]
The present invention has been made in view of such problems, and the object of the present invention is to perform magnetic exploration without excavating an exploration hole, and to be used for magnetic exploration that can improve work efficiency. It is in providing a penetrating tool and a magnetic exploration method.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration.
The gist of the invention described in claim 1 is a penetrating tool used for magnetic exploration in which a magnetic exploration is performed in the vicinity of a foundation pile containing steel, and the tip position of the foundation pile is detected in a non-contact manner, It is constructed and can measure the magnetic quantity of x-axis, y-axis, and z-axis that are fixed to the hollow portion of the penetrating tip rod, which is a cylindrical body with a projecting tip portion, and the penetrating tip rod. Ri such Do from the 3D magnetic sensor, the 3D magnetic sensor consists in penetration device for use in magnetic survey characterized that you have been fixed to the z-axis coincides with the axial direction of the penetrating tips rod.
The gist of the invention described in claim 2 is a magnetic exploration method for conducting a magnetic exploration using the penetrating tool used in the magnetic exploration according to claim 1, wherein the magnetic quantity is measured in parallel with the press-fitting of the penetrating tip rod. It exists in the magnetic exploration method characterized by doing .
The gist of the invention described in claim 3 resides in the magnetic exploration method according to claim 2, wherein the penetrating tip rod is press-fitted while adding a splicing rod to the penetrating tip rod .
According to a fourth aspect of the present invention, the depth of the three-dimensional magnetic sensor is measured by detecting the press-fitting amounts of the penetrating tip rod and the joint rod. Lies in the way .
The gist of the invention of claim 5 is that the three-dimensional magnetic sensor calculates the magnetic quantity BX in the x-axis direction, the magnetic quantity BY in the y-axis direction, and the magnetic quantity BZ in the z-axis direction at a plurality of locations in the z-axis direction. The magnetic quantity BH on the surface perpendicular to the foundation pile is calculated from the magnetic quantity BX and the magnetic quantity BY, and the geomagnetism measured in advance from the magnetic quantity BH and the magnetic quantity BZ. The magnetic quantity Bh on the surface perpendicular to the foundation pile from which the geomagnetism is removed and the magnetic quantity Bz in the z-axis direction from which the geomagnetism is removed are respectively calculated, and the magnetic quantity Bh and the magnetic quantity Bz are calculated. 5. The magnetic exploration method according to claim 2, wherein a shape analysis result based on and is output for each of a plurality of locations in the z-axis direction .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0009]
FIG. 1 is a diagram showing a configuration of a penetrating tip rod of an embodiment of an penetrating tool used for magnetic exploration according to the present invention, and FIG. 2 is a joint of an embodiment of the penetrating tool used for magnetic exploration according to the present invention. FIG. 3 is a diagram showing a configuration of a rod, FIG. 3 is a diagram showing a configuration of equipment used in an embodiment of a magnetic exploration method according to the present invention, and FIG. 4 shows a configuration of a shape analysis apparatus shown in FIG. 5 is a block diagram, FIG. 5 is a diagram for explaining a horizontal magnetic field calculation method in the horizontal magnetic field calculation unit shown in FIG. 3, and FIG. 6 is a search result calculated by the search result calculation unit shown in FIG. It is a figure for demonstrating.
[0010]
In this embodiment, instead of excavating the exploration hole, a penetration tool composed of the penetration tip rod 1 shown in FIG. 1 and the joint rod 3 shown in FIG. 2 is pressed into the vicinity of the foundation pile 4 to be measured. Conduct magnetic exploration. In addition, as the foundation pile 4 to be measured, a caisson (made of steel, reinforced concrete) and a well (made of reinforced concrete) can be considered in addition to a pile (steel pile, cast-in-place pile).
[0011]
Referring to FIG. 1, the penetrating distal end rod 1 is a cylindrical body made of a nonmagnetic material such as stainless steel or aluminum alloy and having a projecting distal end portion. A female screw 11 for adding the connecting rod 3 is formed. Moreover, the scale 2 is provided in the outer periphery at equal intervals in the axial direction. Note that the tip end angle of the penetrating tip rod 1 used in the present embodiment is 60 °, and the bottom area is about 10 cm 2 .
[0012]
In the hollow portion of the penetrating tip rod 1, a three-dimensional magnetic sensor 10 capable of measuring the strength of the magnetic field in directions orthogonal to each other (x axis, y axis, z axis) is provided, and the z axis is the axial direction of the penetrating tip rod 1. Has been fixed to match. The three-dimensional magnetic sensor 10 includes, for example, three Hall elements arranged in directions orthogonal to each other, and is configured to be able to measure the strength of magnetic fields in directions orthogonal to each other in a stationary state. Note that a fluxgate type sensor, a SQUID type sensor, or the like can be used instead of the Hall element.
[0013]
Referring to FIG. 2, the joint rod 3 is a cylindrical body made of a non-magnetic material such as stainless steel or aluminum alloy, and has a distal end portion that is behind the penetrating distal rod 1 and the upstream joint rod 3. A male screw 31 that is screwed with the end portion is formed, and a female screw 11 for adding the joint rod 3 is formed at the rear end portion. Moreover, the scale 2 is provided in the outer periphery at equal intervals in the axial direction.
[0014]
At the time of magnetic exploration, as shown in FIG. 3, the penetrating tip rod 1 and the joint rod 3 are press-fitted vertically in the vicinity of the foundation pile 4 to be measured. In addition, the existing press-fitting machine which penetrates a pipe (thin diameter steel pipe etc.) can be used for press-fitting of the penetrating tip rod 1. Further, since the output cable from the three-dimensional magnetic sensor 10 provided on the penetrating tip rod 1 needs to penetrate the joint rod 3, it can be disconnected at one end by a connector or the like. In addition, when using a shielded cable as an output cable, you may make it comprise the joint rod 3 with a general steel material.
[0015]
A scale detection sensor 5 for detecting the scale 2 provided on the outer periphery of the penetrating tip rod 1 and the joint rod 3 is installed, and the scale by the scale detection sensor 5 is parallel to the press-fitting of the penetrating tip rod 1 and the joint rod 3. The magnetic field strengths in the x-axis direction, y-axis direction, and z-axis direction are measured at the detection timing. That is, the output from the three-dimensional magnetic sensor 10 is amplified by the amplifier 6 and input to the data collector 7 at the scale detection timing by the scale detection sensor 5. Therefore, the data collector 7 collects the strength of the magnetic field in the x-axis direction, the y-axis direction, and the z-axis direction for each depth (scale 2) as exploration data.
[0016]
Referring to FIG. 4, the shape analysis device 8 includes an exploration data input unit 81 to which exploration data from the data collector 7 is input, a geomagnetic storage unit 82 to store previously measured geomagnetic data, and geomagnetism. It comprises a geomagnetism removing unit 83 that removes geomagnetism from exploration data based on the geomagnetic data stored in the storage unit 82, a horizontal magnetic field calculating unit 84, an exploration result calculating unit 85, and a data output unit 86.
[0017]
In the search data input unit 81, the magnetic field strength BX in the x-axis direction, the magnetic field strength BY in the y-axis direction, and the magnetic field strength in the z-axis direction for each depth as the search data from the data collector 7. BZ is input.
[0018]
The geomagnetism stored in the geomagnetism storage unit 82 is adjusted so that the z-axis is in the vertical direction by placing the three-dimensional magnetic sensor 10 at a position sufficiently away from the surrounding magnetic body, and the x-axis direction, y-axis direction, z The magnetic field strengths (μT) of the three-direction components in the axial direction are measured, and the measurement results are stored as geomagnetisms Bx 0 , By 0 , and Bz 0 , respectively.
[0019]
The horizontal magnetic field calculation unit 84 calculates the magnetic field strength BH of the horizontal component by the following equation. That is, as shown in FIG. 5, even if the three-dimensional magnetic sensor 10 rotates and the x-axis and the y-axis change, the magnetic field strength BX in the x-axis direction and the magnetic field strength BY in the y-axis direction From the above, the magnetic field strength BH of an accurate horizontal component is calculated.
[0020]
Figure 0004164746
[0021]
The geomagnetism removing unit 83 calculates the horizontal component geomagnetism Bh 0 by the following formula, and the horizontal component magnetic field strength Bh = BH−Bh 0 from which the geomagnetism has been removed and the vertical magnetic field strength from which the geomagnetism has been removed. Bz = BZ−Bz 0 is calculated.
[0022]
Figure 0004164746
[0023]
The exploration result calculation unit 85 calculates tan θ = Bh / Bz from the horizontal component magnetic field strength Bh from which the geomagnetism is removed and the vertical magnetic field strength Bz from which the geomagnetism is removed.
In this way, tan θ = Bh / Bz for each depth is calculated and output to the data output unit 86 such as a printer as a graph or a table.
[0024]
When the foundation pile 4 is regarded as a magnet, magnetic force lines as shown in FIG. 6 are generated from the foundation pile 4, and tan θ = Bh / Bz is calculated to calculate the horizontal component magnetic field strength Bh and the vertical direction. Since the change in the angle of the magnetic lines of force can be detected by grasping it as a ratio with the magnetic field strength Bz, the graph or table output from the data output unit 86 clearly shows the tip position of the foundation pile 4 as the center. The fluctuation can be confirmed, and the pile length of the foundation pile 4 can be detected.
[0025]
Further, when the magnetic field strength Bz in the vertical direction alone is used, the error increases when the separation between the foundation pile 4 and the three-dimensional magnetic sensor 10 is large. However, the magnetic field strength Bh in the horizontal component and the magnetic field strength in the vertical direction are large. Since the magnetic quantity decreases at the same level as the height Bz, if tan θ = Bh / Bz, the tip position of the foundation pile 4 can be detected with high accuracy even if the magnetic quantity is small. Furthermore, by setting tan θ = Bh / Bz, positive and negative are switched at θ = 0, and the detection reliability is improved.
[0026]
As described above, according to the present embodiment, the strength of the magnetic field can be measured by the three-dimensional magnetic sensor 10 provided on the penetrating tip rod 1 only by press-fitting the penetrating tip rod 1 and the joint rod 3. Magnetic exploration can be performed without excavating the exploration hole, and the working efficiency can be improved.
[0027]
Furthermore, according to the present embodiment, the three-dimensional magnetic sensor 10 sets the magnetic field strength in the z-axis direction as the vertical magnetic field strength and the magnetic field strengths in the x-axis direction and the y-axis direction as horizontal components. By measuring the strength of the magnetic field, and detecting the tip position of the foundation pile 4 from the strength of the magnetic field in the vertical direction and the strength of the magnetic field of the horizontal component, it is horizontal even if the penetrating tip rod 1 and the joint rod 3 rotate. The strength of the component magnetic field can be measured accurately, and the tip position of the foundation pile 4 can be detected with high accuracy.
[0028]
Furthermore, according to the present embodiment, the scales 2 are provided at equal intervals in the axial direction on the outer circumferences of the penetrating tip rod 1 and the joint rod 3, and the strength of the magnetic field is measured at the detection timing of the scale 2. Thus, there is no need for the operator to determine the detection timing by visual observation, so that the working efficiency is improved.
[0029]
In the present embodiment, the depth is detected by the scale 2 provided on the outer periphery of the penetrating tip rod 1 and the joint rod 3, but the winding displacement meter (the length of the joint rod 3 is In the case of 1 m, a displacement meter for measuring 1 m) may be installed on the press-in (press-fit) machine body, and the depth may be detected by electrically detecting the push-in (press-in) amount of the rod. . In this case, the displacement gauge is changed every time in the process of adding the connecting rod 3.
[0030]
Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a suitable number, position, shape, and the like in practicing the present invention. In each figure, the same numerals are given to the same component.
[0031]
【The invention's effect】
The penetrating tool and magnetic exploration method used in the magnetic exploration of the present invention can measure the strength of the magnetic field with a three-dimensional magnetic sensor provided on the penetrating tip rod by simply press-fitting the penetrating tip rod and joint rod. Magnetic exploration can be performed without digging, and the working efficiency can be improved.
[0032]
Furthermore, the penetration tool and the magnetic exploration method used in the magnetic exploration of the present invention use the three-dimensional magnetic sensor to set the magnetic field strength in the z-axis direction as the magnetic field strength in the vertical direction and the magnetic field in the x-axis direction and the y-axis direction. By measuring the strength as the strength of the horizontal component magnetic field and detecting the tip position of the foundation pile from the vertical magnetic field strength and horizontal component magnetic field strength, the penetrating tip rod and splice rod rotate. However, the strength of the magnetic field of the horizontal component can be measured accurately, and the tip position of the foundation pile can be detected with high accuracy.
[0033]
Furthermore, in the penetrating tool and the magnetic exploration method used in the magnetic exploration of the present invention, graduations are provided at equal intervals in the axial direction on the outer periphery of the penetrating tip rod and the joint rod, and the magnetic field strength is measured at the graduation detection timing. By configuring, it is not necessary for the operator to determine the detection timing by visual observation, so that the working efficiency is improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a penetrating tip rod according to an embodiment of a penetrating tool used for magnetic exploration according to the present invention.
FIG. 2 is a diagram showing a configuration of a joint rod of an embodiment of an penetrating tool used for magnetic exploration according to the present invention.
FIG. 3 is a diagram showing a device configuration used in the embodiment of the magnetic exploration method according to the present invention.
4 is a block diagram showing a configuration of the shape analysis apparatus shown in FIG. 3. FIG.
5 is a diagram for explaining a horizontal magnetic field calculation method in the horizontal magnetic field calculation unit shown in FIG. 3;
6 is a diagram for explaining a search result calculated by a search result calculation unit shown in FIG. 3; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Penetration tip rod 2 Scale 3 Joint rod 4 Foundation pile 5 Scale detection sensor 6 Amplifier 7 Data collector 8 Shape analysis apparatus 10 Three-dimensional magnetic sensor 11 Female screw 31 Male screw 81 Search data input part 82 Geomagnetic storage part 83 Geomagnetic removal part 84 Horizontal magnetic field calculation unit 85 Search result calculation unit 86 Data output unit

Claims (5)

鋼材を含む基礎杭の近傍の磁気探査を行って、前記基礎杭の先端位置を非接触で検出する磁気探査に用いる貫入具であって、
非磁性体で構成され、突状の先端部が形成された筒状体である貫入先端ロッドと、
該貫入先端ロッドの中空部に固定され、互いに直交するｘ軸、ｙ軸およびｚ軸の磁気量を測定可能な３次元磁気センサとからなり、
前記３次元磁気センサは、ｚ軸が前記貫入先端ロッドの軸方向と一致するように固定されていることを特徴とする磁気探査に用いる貫入具。Conducting magnetic exploration in the vicinity of a foundation pile containing steel, and a penetrating tool used for magnetic exploration to detect the tip position of the foundation pile in a non-contact manner,
A penetrating tip rod which is a cylindrical body formed of a non-magnetic material and having a protruding tip portion formed thereon;
The through is fixed to the hollow portion of the incoming tip rod, Ri Do from the x axis, the magnetic volume 3D magnetic sensor capable of measuring the y-axis and z-axis orthogonal to each other,
The three-dimensional magnetic sensor, penetration tool used in magnetic survey characterized that you have been fixed to the z-axis coincides with the axial direction of the penetrating tips rod. 請求項１記載の磁気探査に用いる貫入具を用いて磁気探査を行う磁気探査方法であって、A magnetic exploration method for performing magnetic exploration using the penetrating tool used for magnetic exploration according to claim 1,
前記貫入先端ロッドの圧入と並行して磁気量を測定することを特徴とする磁気探査方法。A magnetic exploration method characterized by measuring a magnetic quantity in parallel with the press-fitting of the penetrating tip rod. 前記貫入先端ロッドに継ぎロッドを継ぎ足しながら前記貫入先端ロッドを圧入することを特徴とする請求項２記載の磁気探査方法。The magnetic exploration method according to claim 2, wherein the penetrating tip rod is press-fitted while a splicing rod is added to the penetrating tip rod. 前記貫入先端ロッドおよび前記継ぎロッドの圧入量を検出することによって前記３次元磁気センサの深さを測定することを特徴とする請求項３記載の磁気探査方法。The magnetic exploration method according to claim 3, wherein the depth of the three-dimensional magnetic sensor is measured by detecting a press-fitting amount of the penetrating tip rod and the joint rod. 前記３次元磁気センサによってｚ軸方向の複数の箇所でそれぞれｘ軸方向の磁気量ＢＸ、ｙ軸方向の磁気量ＢＹおよびｚ軸方向の磁気量ＢＺを測定し、The three-dimensional magnetic sensor measures a magnetic quantity BX in the x-axis direction, a magnetic quantity BY in the y-axis direction, and a magnetic quantity BZ in the z-axis direction at a plurality of locations in the z-axis direction,
前記磁気量ＢＸと前記磁気量ＢＹとから前記基礎杭に対して垂直な面上の磁気量ＢＨを算出し、A magnetic amount BH on a surface perpendicular to the foundation pile is calculated from the magnetic amount BX and the magnetic amount BY,
当該磁気量ＢＨと前記磁気量ＢＺとから予め測定しておいた地磁気をそれぞれ除去して地磁気を除去した前記基礎杭に対して垂直な面上の磁気量Ｂｈと地磁気を除去したｚ軸方向の磁気量Ｂｚとをそれぞれ算出し、The magnetic quantity Bh on the surface perpendicular to the foundation pile from which the geomagnetism was removed by removing the geomagnetism measured in advance from the magnetic quantity BH and the magnetic quantity BZ and the z-axis direction from which the geomagnetism was removed. Calculate the magnetic quantity Bz,
前記磁気量Ｂｈと前記磁気量Ｂｚとに基づく形状解析結果を前記ｚ軸方向の複数の箇所毎に出力することを特徴とする請求項２乃至４のいずれかに記載の磁気探査方法。5. The magnetic exploration method according to claim 2, wherein a shape analysis result based on the magnetic quantity Bh and the magnetic quantity Bz is output for each of a plurality of locations in the z-axis direction.
JP2003096322A 2003-03-31 2003-03-31 Penetration tool and magnetic exploration method used for magnetic exploration Expired - Fee Related JP4164746B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003096322A JP4164746B2 (en) 2003-03-31 2003-03-31 Penetration tool and magnetic exploration method used for magnetic exploration

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003096322A JP4164746B2 (en) 2003-03-31 2003-03-31 Penetration tool and magnetic exploration method used for magnetic exploration

Publications (2)

Publication Number Publication Date
JP2004301735A JP2004301735A (en) 2004-10-28
JP4164746B2 true JP4164746B2 (en) 2008-10-15

Family

ID=33408427

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003096322A Expired - Fee Related JP4164746B2 (en) 2003-03-31 2003-03-31 Penetration tool and magnetic exploration method used for magnetic exploration

Country Status (1)

Country Link
JP (1) JP4164746B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102184738B1 (en) * 2020-03-12 2020-12-01 에코엔텍 주식회사 soft ground reinforcement system with multiple excavations and soft ground reinforcement method using it

Also Published As

Publication number Publication date
JP2004301735A (en) 2004-10-28

Similar Documents

Publication Publication Date Title
US5589775A (en) Rotating magnet for distance and direction measurements from a first borehole to a second borehole
CN105604066B (en) Application of the resistivity profiling in the detection of building foundation pit building enclosure percolating water
CN109883450A (en) Method for positioning magnetic marker of detector in buried steel pipeline
CN107085240B (en) Slope magnetofluid detection system and method
Segalini et al. Underground landslide displacement monitoring: a new MMES based device
US11299979B2 (en) Magnetic distance and direction measurements from a first borehole to a second borehole
JP3201949U (en) Magnetic detection device and magnetic sensor
Burland et al. A simple and precise borehole extensometer
JP4164746B2 (en) Penetration tool and magnetic exploration method used for magnetic exploration
CN108732628A (en) Along the high-density electric pipeline detection observation procedure and system of pipeline trend
KR100264630B1 (en) Rebar detection and detection method in concrete foundation piles by measuring 3-axis magnetic field in borehole
JPH10185633A (en) Underground displacement measuring device
JP4164747B2 (en) Magnetic exploration method
JPH10318748A (en) Method and system for measuring position
JP5165808B1 (en) Differential magnetic exploration system
CN206721943U (en) A kind of pile foundation displacement auxiliary detection device
CN105937901A (en) Network inclinometry system based on sensor cluster and inclinometry method
CN114658423A (en) Active magnetic measurement system and method used in magnetic shielding mode
JP2005291818A (en) Penetration implement used for magnetic prospecting and magnetic prospecting method
CN113050182A (en) Water area geomagnetic field observation method and system
JP2005291802A (en) Magnetic prospecting method
JP2011133301A (en) Method for surveying bottom depth of underground base structure
JP2010078585A (en) Method for finding the location of buried magnetic object
JP2005291812A (en) Magnetic prospecting method
CN214225443U (en) Instrument fixing device for magnetic measurement in water area

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20050627

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20070308

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20080422

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20080606

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: 20080708

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20080716

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110808

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110808

Year of fee payment: 3

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110808

Year of fee payment: 3

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110808

Year of fee payment: 3

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120808

Year of fee payment: 4

LAPS Cancellation because of no payment of annual fees