JP4375896B2

JP4375896B2 - Leakage occurrence position detection device and method

Info

Publication number: JP4375896B2
Application number: JP2000350034A
Authority: JP
Inventors: 健荒井
Original assignee: Maeda Corp
Current assignee: Maeda Corp
Priority date: 2000-11-16
Filing date: 2000-11-16
Publication date: 2009-12-02
Anticipated expiration: 2020-11-16
Also published as: JP2002156305A

Description

【０００１】
【発明の属する技術分野】
本発明は、合成樹脂や合成ゴムなどの電気的絶縁性を有する材料からなる遮水工を敷設して人工的に造られた貯水池、水路、或いは管理型一般廃棄物最終処分場及び管理型産業廃棄物最終処分場などの遮水工構造物に関し、遮水工構造物の遮水工に生じる漏水の発生位置を検知する漏水発生位置検知装置及びその方法に関する。
【０００２】
【従来の技術】
貯水池、水路、或いは管理型一般廃棄物最終処分場及び管理型産業廃棄物最終処分場などの遮水工構造物は、合成樹脂や合成ゴムなどの電気的絶縁性を有する材料からなる遮水工を地盤の窪みに敷設して人工的に造られている。
【０００３】
かかる遮水工構造物は、遮水工に亀裂などの破損が生じると、破損箇所より地盤側へ漏水する。例えば、管理型一般廃棄物最終処分場の場合、遮水工が破損した状態で放置すると、汚染液が漏水して近隣を汚染し、或いは地下水を汚染して公害問題を引き起こしてしまう。そこで、遮水工を用いた遮水工構造物は、漏水（あるいは遮水工の破損）の発生及び発生位置を早期に検知して破損箇所を補修する必要がある。
【０００４】
従来このような遮水工の漏水部の検知方法として、遮水工構造物の内部に設置した電極と外部の地盤側に設置した電極との間に電圧を印加し、前記電圧を印加する電極とは別に、遮水工の表裏どちらかに設置した多数の電極を用いて電位分布を測定し、遮水工の漏水周辺に生じた電位異常を検知することにより漏水位置を特定する方法が知られている。
【０００５】
【発明が解決しようとする課題】
ところで、遮水工の紫外線劣化や熱劣化を防止する保護層で遮水工全体を覆うように設けるよう定められている。これら保護層等の材料は、一般にポリエステルなどの合成繊維の不織布が用いられているが、耐久性の面からは土質材料やコンクリートの方が優れているので、土質材料やコンクリートを用いる場合も多い。いずれにしても、これら保護層等の材料は、電気的絶縁体ではない。従って、保護層等が電気的に漏水と等価であるため、遮水工の上下で電極に電圧を印加しても、保護層等の周辺では電位差異常が発生しても本来検知しようとする漏水によるものなのか、保護層等によるものなのかの区別がつきにくく、漏水発生位置を検出する精度を向上させる上での障害となっていた。この現象は、従来の処分場においても、廃棄物搬入道路や浸出水排水管において同種の測定障害があり、測定精度を低下させている。また、複数の漏水部が発生した場合も同様に、それぞれの漏水部の影響によって電位差が重なり合って個々の漏水の位置が区別がつきにくく、漏水発生位置を検出する精度を向上させる上での障害となっていた。
【０００６】
以上から本発明は、前記問題点に鑑みてなされたものであり、複数の漏水位置が存在しても確実に漏水位置を区別して検知することができ、漏水発生位置を検出する精度を向上させることができる漏水発生位置検知装置及びその方法を提供することを技術的課題とする。
【０００７】
【課題を解決するための手段】
前記課題を達成するために、本発明の漏水発生位置検知装置及びその方法は、以下に示す手段を採用した。すなわち、漏水発生位置検知装置は、地盤に形成した窪みに電気的絶縁体の遮水工を敷設する遮水工構造物と、前記遮水工の表裏どちらかに設置した面電極と、前記面電極の反対側に設置した複数の点電極と、前記複数の点電極から１つを選択し電源の印加側に接続して印加電極とする第１の選択接続手段と、前記印加電極を除く点電極間で電位差を測定する電位差測定手段と、前記印加電極に隣り合う２個の前記点電極を選択して前記電位差測定手段に接続して電位差測定用電極とする第２の選択接続手段と、を備え、前記測定した電位差及び前記印加電極の位置から前記遮水工構造物の漏水位置を検知する漏水発生位置検知装置であって、前記選択された印加電極及び電位差測定用電極を除く全ての点電極と前記面電極を前記電源の他端に接続する第３の選択接続手段を有することを特徴とする。
【０００８】
上記発明によれば、第１の選択接続手段により印加電極と面電極との間に印加された電圧により、(1) 第１の選択接続手段→印加電極→地盤→印加電極と電位差測定用電極以外の点電極→電源４の他端。(2) 第１の選択接続手段→印加電極→地盤→面電極→電源の他端。(3) 第１の選択接続手段→印加電極→漏水→面電極→電源の他端、の回路が形成される。
【０００９】
そして、回路(1)〜(3)によれば、第１の選択接続手段により選択された１個の印加電極と面電極との間に電圧が印加され、第２の選択接続手段により選択された２個の電位差測定用電極間で電位差が測定される。また、第３の選択接続手段により、印加電極と電位差測定用電極を除くすべての点電極が、印加側でない電源の他端に接続されることで遮水工の表裏の電場が同電位となるように制御される。
【００１０】
すなわち、遮水工表裏の電位の制御は、面電極に接続される電源の他端に、選択された１個の印加電極と２個の電位差測定用電極を除くすべての点電極を接続することにより行われる。そして、印加電極と２個の電位差測定用電極を除く遮水工上下を同電位に制御しておけば、印加電極周辺に漏水部がない条件で、電位傾度は理論的に０Ｖが測定され、印加電極周辺に漏水部がある条件で有意な電位差が測定されることになる。また、電位差の変動は漏水周辺でのみ測定され、漏水が複数存在しても従来のように漏水の影響によって電位差が重なり合うことはなく、漏水部を確実に区別して検知することができる。
【００１１】
なお、点電極は単に金属板であるよりも面的に広がりがある方が有利となる。そこで、点電極は裸銅線を矩形枠状に形成したものや、より感度を高めるために裸銅線を螺旋状に形成してもの、などが例示できる。
【００１２】
また、遮水工は電気的絶縁性を有する材質である合成樹脂や合成ゴムが例示できる。また、管理型廃棄物最終処分場等に用いられる保護層は、ポリエステルやポリプロピレンの不織布（遮光マット）を敷設する場合や、土質材料やコンクリートを敷設する場合が例示できる。
【００１３】
また、漏水発生位置検知装置は、上記構成において、前記電位差測定用電極が前記印加電極を中心として全方向における整列線上にある点電極であり、前記第２の選択接続手段が１つの前記印加電極に対して異方向の整列線上にある１組みの隣り合う点電極を複数組み順次選択して前記電位差測定手段に順次接続することを特徴とする。
【００１４】
このような構成によれば、１つの印加電極に対し、異方向に隣り合う電位差測定用電極間の変化の特性を利用して、電位差と電位差の極性と大きさから、漏水位置を特定することが可能となる。例えば、印加電圧と同一位相の電流が漏水部周辺に向かって流れ易くなり、測線方向に隣り合う２個の点電極間では測定値が漏水部の周辺でＮ字型に変化する傾向にあり、測線方向と直角方向に隣り合う２個の点電極間では漏水部を挟んだそれぞれの測線において極性が異なるピークを示す傾向にある。かかる測定する向きの特性を利用することにより、漏水位置の特定精度が向上する。
【００１５】
更に、漏水発生位置検知装置は、上述のような構成において、前記遮水工が前記地盤に接触する部分の近傍に、前記複数の点電極あるいは前記面電極の周辺を取り囲んで配置した環状電極を前記電源の他端に接続したことを特徴とする。
【００１６】
このような構成によれば、複数の点電極あるいは面電極の周辺を取り囲んで配置した環状電極を遮水工構造物内の面電極と同様に印加側でない他端に直接接続することで、環状電極や面電極が遮水工構造物を覆う遮水工表裏の電場を同電位に制御する。この遮水工表裏の電場が同電位に制御される構成から、保護層や地盤等を経由して流れる電流による影響を少なくすることができる。
【００１７】
更に、漏水発生位置検知方法は、地盤に形成した窪みに電気的絶縁体の遮水工を敷設する遮水工構造物とし、前記遮水工の表裏どちらかに面電極を設置し、前記面電極の反対側に複数の点電極を設置し、前記複数の点電極から１つを選択し電源の印加側に接続して印加電極とし、前記印加電極に隣り合う２個の前記点電極を選択して電位差測定用電極とし、前記選択された印加電極及び電位差測定用電極を除く全ての点電極と前記面電極を前記電源の他端に接続し、前記電位差測定用電極間で電位差を測定し、前記測定した電位差及び前記印加電極の位置から前記遮水工構造物の漏水位置を検知することを特徴とする。
【００１８】
このような漏水発生位置検知方法によれば、遮水工構造物内外の電位が同電位となるようにして電位差測定用電極による電位差の変動は漏水周辺でのみ測定され、漏水が複数存在しても従来のように漏水の影響によって電位差が重なり合うことはなく、漏水部を確実に区別して検知することができる。以上の発明の構成要件である二相交流電源は、交替直流電源であってもよい。
【００１９】
【発明の実施の形態】
以下、本発明の実施の形態に係る漏水発生位置検知装置を図１〜図１０に基づいて詳細に説明する。なお、実施の形態に係る漏水発生位置検知装置は、遮水工構造物１に設置されている。また、遮水工構造物１は管理型廃棄物最終処分場の場合として説明する。
【００２０】
遮水工構造物１は、図１に示すように、地盤に形成した窪み１ａに遮水工２を敷設し、遮水工２全体を覆うようにその斜面部に保護層３を積層したものである。そして、遮水工２は電気的絶縁性を有する合成樹脂で形成されている。また、保護層３は電気的絶縁体でないコンクリート材料で形成されており、遮水工構造物１に敷設した遮水工２の表面側と裏面側とが保護層３を経由して電気的短絡回路が形成可能な状態になっている。
【００２１】
なお、管理型廃棄物最終処分場に用いられる保護層３は、ポリエステルやポリプロピレンの不織布（遮光マット）を敷設する場合や、土質材料やコンクリートを敷設する場合があるが、ポリエステルなど合成繊維と比較すると土質材料やコンクリートの方が遮水工の紫外線劣化や熱劣化防止に好適であり、耐久性において非常に優れた素材であることが知られている。また、廃棄物搬入道路等は耐久性において非常に優れたコンクリートを素材として使用している。そこで、この実施の形態ではコンクリート製の保護層３を敷設したものとして説明する。
【００２２】
実施の形態に係わる漏水発生位置検知装置は、遮水工２が敷設された遮水工構造物１内部（表面側）に面電極１２を配置し、遮水工２の裏面側（地盤側）に複数の点電極Ｔ_a1〜Ｔ_m14（図５参照）を所定間隔で配置し、更に遮水工２全体を取り囲むように環状電極１３を配置した電極配置構成を用いている。
【００２３】
面電極１２は導電性の金属箔や金属網等で面状に構成したものである。また、面電極１２は交流電源４の一方４ａに接続している。なお、面電極１２は遮水工構造物１内では、廃棄物から電気伝導度の高い浸出水が出るため、線状電極（例えば、裸銅線）を10m〜20m間隔で格子状に配置してもよい。
【００２４】
一方、点電極Ｔ_a1〜Ｔ_m14は、図５の縦方向にａ〜ｍの１３個、横方向に１〜１４の１４個（計１８２個）配列したものである。これら点電極Ｔ_a1〜Ｔ_m14の外周には、遮水工２が地盤に接触する部分の近傍に、環状電極１３が配置されている。この環状電極１３は面電極１２と同様に、交流電源４の一方４ａに接続している。複数の点電極Ｔ_a1〜Ｔ_m14は、それぞれ電極切替装置１５を介して電位差測定装置５、交流電源４の一方４ａあるいは他方４ｂに接続している。
【００２５】
点電極Ｔ_a1〜Ｔ_m14の接続関係を更に詳しく説明すると、電極切替装置１５は点電極Ｔ_a1〜Ｔ_m14のうち１つ（図５では点電極Ｔ_g5）を選択し交流電源４の印加側である他方４ｂに接続して印加電極Ｔ_g5とする（第１の選択接続手段）。
【００２６】
また、電極切替装置１５は印加電極Ｔ_g5に対し測線上の隣り合う２個の点電極（図６では点電極Ｔ_g4，Ｔ_g6）を選択して電位差測定装置５に接続して電位差測定用電極Ｔ_g4，Ｔ_g6とする（第２の選択接続手段）。なお、電極切替装置１５は、第２の選択接続手段が電位差測定用電極を選択する場合、印加電極Ｔ_g5に対し測線上だけでなく、測線方向に対し直角に交わる整列線上の隣り合う２個の点電極（図７では点電極Ｔ_f5，Ｔ_h5）も選択して電位差測定装置５に接続して電位差測定用電極とする。すなわち、第２の選択接続手段は１つの印加電極に対して、異方向の整列線上にある１組みの隣り合う点電極を複数組み順次選択して電位差測定手段に順次接続する。
【００２７】
更に、電極切替装置１５は、選択された印加電極（例えばＴ_g5）及び電位差測定用電極（印加電極がＴ_g5の場合は、電位差測定用電極がＴ_g4，Ｔ_g6あるいはＴ_f5，Ｔ_h5）を除く全ての点電極、面電極１２及び環状電極１３を交流電源４の一方４ａに接続する（第３の選択接続手段）。
【００２８】
電源４（図１参照）は、印加電極（例えばＴ_g5）と面電極１２との間において、電極切替装置（第１の選択接続手段）１５の選択接続により形成される回路に電圧を印加する。なお、電源４は、交替直流であっても交流であってもよいが、この実施の形態では交流電源を用いる。電源４が交流電源の場合、電極切替装置１５と電位差測定装置５との関係は、図２のブロック図に示すようになる。
【００２９】
すなわち、電位差測定装置５は、印加電極（例えばＴ_g5）と面電極１２との間に印加された電圧により、電位差測定用電極（印加電極がＴ_g5の場合は、電位差測定用電極がＴ_g4，Ｔ_g6あるいはＴ_f5，Ｔ_h5）間で電位差を測定する装置である。そして、図２に示すように、電源４が交流電源の場合、電位差測定装置５は、簡単に電位差を求められる差動回路５ａとすることができる。この時、印加電極の両側にある電位差測定用電極とある地点の電位差を、それぞれ別個に測定し、それらの電位測定値の差をとっても同様の結果が得られる。
【００３０】
そして、印加電極（例えばＴ_g5）と面電極１２との間に印加された電圧により、第２の選択接続手段は電位差測定用電極（印加電極がＴ_g5の場合は、電位差測定用電極がＴ_g4，Ｔ_g6）を選択した場合は、次のような回路が形成される。なお、遮水工２には、漏水Ｌ₁，Ｌ₂，Ｌ₃が発生しているものとする。
【００３１】
すなわち、(1) 電極切替装置１５→印加電極Ｔ_g5→地盤→印加電極Ｔ_g5と電位差測定用電極Ｔ_g4，Ｔ_g6以外の点電極及び環状電極１３→交流電源４の一方４ａ。
(2) 電極切替装置１５→印加電極Ｔ_g5→保護層３→面電極１２→交流電源４の一方４ａ。
(3) 電極切替装置１５→印加電極Ｔ_g5→漏水Ｌ₁，Ｌ₂，Ｌ₃→面電極１２→交流電源４の一方４ａ、の回路が形成される。
【００３２】
そして、回路(1)〜(3)によれば、電極切替装置１５により選択された１個の印加電極（例えば、印加電極Ｔ_g5）と面電極１２との間に交流電源４の電圧が印加される一方で、１個の印加電極（例えば、印加電極Ｔ_g5）と２個の電位差測定用電極（例えば、Ｔ_g4，Ｔ_g6）を除くすべての点電極と面電極１２及び環状電極１３が、印加側でない交流電源４の一方４ａに接続されることで同電位に制御される。
【００３３】
従って、この実施の形態の漏水発生位置検知装置は、回路(1)〜(3)が形成されるように構成したことにより、コンクリートなどの保護層３や地盤等によって遮水工構造物１を覆う遮水工２の表裏の電場が、１個の印加電極と２個の電位差測定用電極を除いて同電位となるように制御される。なお、環状電極１３の太さと保護層３の断面積を比較すると、保護層３の断面積が大きいため、環状電極１３１本だけで保護層３を経由して流れる電流を制御することがむずかしいので、環状電極１３は単数よりも複数であることが好ましい。
【００３４】
上述のように、図１の電極配置から、遮水工２表裏の電位の制御は、面電極１２に接続される交流電源４の一方４ａに、１個の印加電極（例えば、印加電極Ｔ_g5）と２個の電位差測定用電極（例えば、Ｔ_g4，Ｔ_g6）を除くすべての点電極を接続することにより行われる。そして、電位差測定は、遮水工構造物１の地盤側の電位差測定用電極（例えば、Ｔ_g4，Ｔ_g6）の間について行われる。従って、電位差の変動は漏水周辺でのみ測定され、漏水が複数存在しても従来のように漏水の影響によって電位差が重なり合うことはなく、漏水部を確実に区別して検知することができる。
【００３５】
また、この実施の形態では、印加電極（例えば、印加電極Ｔ_g5）と電位差測定用電極（例えば、Ｔ_g4，Ｔ_g6）を除くすべての点電極により遮水工２の表裏の電位を積極的に制御する点があり、点電極が単に金属板であるよりも面的に広がりがある方が有利となる。
【００３６】
そこで、点電極Ｔ_a1〜Ｔ_m14（略してＴ_XYとする）は、図３に示すように、裸銅線を矩形枠状に形成し、この点電極Ｔ_XYに接続するケーブルを介して他の機器と接続している。なお、この点電極Ｔ_a1〜Ｔ_m14は電極の感度を高めるために裸銅線を螺旋状に形成してもよいし（図４の点電極Ｔ_xy参照）、矩形状の金属板でもよい。
【００３７】
ところで、電位差測定用電極（例えば、Ｔ_g4，Ｔ_g6）間の電位差測定は電位差測定装置５で行われる。この電位差測定装置５は、図２に示すように、差動回路５ａとＡ／Ｄコンバータ１８とコンピュータ１９とを有し、差動回路５ａがＡ／Ｄコンバータ１８を介してコンピュータ１９に接続する。
【００３８】
コンピュータ１９は、双方向バスによって相互に接続されたＲＯＭ（リードオンリメモリ）、ＲＡＭ（ランダムアクセスメモリ）、ＣＰＵ（中央処理装置）、入力ポート、出力ポートを具備する。コンピュータ１９の入力ポートは、Ａ／Ｄコンバータ１８を介して差動回路５ａと接続し、出力信号（電位差測定値）が入力される。また、コンピュータ１９の出力ポートは、電極切替装置１５と結線し（図示せず）、点電極の切替の指令を電極切替装置１５に対し出力する。なお、点電極の切替の指令は、後述する選択接続手順に基づき実行される（第１、第２、第３の選択接続手段）。更に、コンピュータ１９の出力ポートは、例えば、ＣＲＴ装置（図示せず）と結線し、ＣＲＴ装置に対し、表示指令（画像データ）を出力する。
【００３９】
ＲＯＭには、漏水発生位置検知処置のプログラムや第１〜第３の選択接続手順のプログラムが記憶されており、ＣＰＵはこれらプログラムを読み出して処理を行う。なお、第１の選択接続手順は、電極切替装置１５において、交流電源４の他方４ｂ（印加側）に接続する点電極Ｔ_a1〜Ｔ_m14を１個ずつ測線方向（図５の左から右へ且つ上から下へスキャンする方向）に１８２（横方向×縦方向；14×13）種類の選択接続手順を順次切り替える手順である。そして、ＣＰＵは１番目（ｉ＝１；例えば点電極Ｔ_a1）から測線方向に１８２番目（ｉ＝１８２；例えば点電極Ｔ_m14）をＲＯＭから読み出して電極切替装置１５を切り替える指令を出力する。すると、指令順番毎に、任意の点電極に交流電圧が印加され、点電極の位置が選択されたことになる。また、第２の選択接続手順は、電極切替装置１５において、第１の選択接続手段が選択した印加電極に対し、測線上に隣り合う２個の点電極（電位差測定電極）を選択して電位差測定装置５に接続する手順である。この時、第３の選択接続手段は印加電極及び電位差測定電極を除く全ての点電極を交流電源４の一方４ａに接続する。更に、第２の選択接続手順は、電極切替装置１５において、第１の選択接続手段が選択した印加電極に対し、測線方向と直角方向に隣り合う２個の点電極（電位差測定電極）を選択して電位差測定装置５に接続する。この時も、第３の選択接続手段は印加電極及び電位差測定電極を除く全ての点電極を交流電源４の一方４ａに接続する。そして、ＣＰＵはかかる第２及び第３の選択接続手順を１番目（ｉ＝１）から１８２番目（ｉ＝１８２）の印加電極毎にＲＯＭから読み出して電極切替装置１５を切り替える指令を出力する。
【００４０】
次に、コンピュータ１９による本発明の漏水発生位置検知処理を図８の流れ図に基づき説明する。
コンピュータ１９は、「ｉ＝１」とし（ステップ１０１）、ＲＯＭに記憶された第１の選択接続手順に従って電極切替装置１５の切替を行い、点電極（及び位置）を選択する（ステップ１０２）。即ち、「ｉ」が１番目（ｉ＝１；点電極Ｔ_a1）となるように、電極切替装置１５で点電極Ｔ_a1と交流電源４の他方４ｂを接続させ、面電極１２に接続する交流電源４の一方４ａとの間に交流電圧を印加し、これら点電極の位置を選択する。
【００４１】
次に、コンピュータ１９は、「ｉ＝１」における第２の選択接続手段において、第１の選択接続手段が選択した印加電極Ｔ_a1に対し、測線上に隣り合う２個の点電極（電位差測定電極）を選択して電位差測定装置５に接続する。なお、点電極Ｔ_a1を印加電極とした場合（図５の配置図のうち角部の点電極；Ｔ_a14，Ｔ_m1，Ｔ_m14も同様）は印加電極と隣り合う２個の点電極が存在しないので（即ち、角部の点電極は電場制御用だけに使用される）、コンピュータ１９は、ステップ１０５の処理に移行する。また、図５に示す最外周の点電極のうち縦方向の点電極（Ｔ_b1〜Ｔ_l1；Ｔ_b14〜Ｔ_l14）を印加電極とした場合は測線上に隣り合う２個の点電極が存在しないので（但し、最外周縦方向の点電極は測線方向と直角方向に隣り合う２個の点電極が存在する）、コンピュータ１９は、ステップ１０４の処理に移行する。しかし、前記した点電極Ｔ_g5を印加電極とした場合（「ｉ＝８９」）のように、印加電極Ｔ_g5に対し測線上の隣り合う２個の点電極（図６では点電極Ｔ_g4，Ｔ_g6）が選択可能であれば、点電極Ｔ_g4，Ｔ_g6を電位差測定装置５に接続して電位差測定用電極とする（第２の選択接続手段）。この時、第３の選択接続手段は印加電極Ｔ_g5及び電位差測定電極Ｔ_g4，Ｔ_g6を除く全ての点電極を交流電源４の一方４ａに接続する。
【００４２】
そして、電位差測定装置５（差動回路５ａ）は電位差測定用電極Ｔ_g4，Ｔ_g6の間の電位差を測定し、Ａ／Ｄコンバータ１８を介してコンピュータ１９に出力する。すると、コンピュータ１９は電位差値を「ｉ＝８９」と共にＲＡＭに記憶する（ステップ１０３）。
【００４３】
次に、コンピュータ１９は、「ｉ＝８９」における第２の選択接続手段において、第１の選択接続手段が選択した印加電極Ｔ_g5に対し、測線方向と直角方向に隣り合う２個の点電極（図７では点電極Ｔ_f5，Ｔ_h5）を選択して電位差測定装置５に接続する。この時も、第３の選択接続手段は印加電極Ｔ_g5及び電位差測定電極Ｔ_f5，Ｔ_h5を除く全ての点電極を交流電源４の一方４ａに接続する。そして、ステップ１０３と同様な手順で電位差測定装置５（差動回路５ａ）は電位差測定電極Ｔ_f5，Ｔ_h5間の電位差を測定し、Ａ／Ｄコンバータ１８を介してコンピュータ１９に出力し、コンピュータ１９は電位差値を「ｉ＝８９」と共にＲＡＭに記憶する（ステップ１０４）。なお、図５に示す最外周の点電極のうち横方向の点電極（Ｔ_a2〜Ｔ_a13；Ｔ_m2〜Ｔ_m13）を印加電極とした場合は測線方向と直角方向に隣り合う２個の点電極が存在しないので、コンピュータ１９は、ステップ１０５の処理に移行する。
【００４４】
次に、コンピュータ１９は、第１の選択切替手順が１８２番目（ｉ＝１８２；点電極Ｔ_m14）まで終了したかどうか判断し（ステップ１０５）、ｉ＝１８２であれば（ステップ１０５：ＹＥＳ）、ステップ１０７以降の処理を行い。一方、ｉ＝１８２でなければ（ステップ１０５：ＮＯ）、ステップ１０６の処理を行う。
【００４５】
ステップ１０６において、コンピュータ１９は、ｉ番目を１だけインクリメントし（ｉ＝ｉ＋１）、ステップ１０２以降の処理を繰り返す。すなわち、コンピュータ１９は、「ｉ＝１」から「ｉ＝１８２」までの処理で測定された電位差値をそれぞれ記憶する。
【００４６】
ステップ１０７において、コンピュータ１９は、ＲＡＭ内に記憶された電位差値をＣＲＴ画面に表示する指令をＣＲＴ装置へ出力する。すると、ＣＲＴ装置はＣＲＴ画面の交差位置に「ｉ＝１」から「ｉ＝１８２」までの測定値を表示する（図９または図１０参照）。
【００４７】
そして、コンピュータ１９は、ＣＲＴ画面に測定値が表示されれば、漏水発生位置検知処理を終了する。
【００４８】
［電位差による漏水発生位置の検知］
次に、漏水発生位置検知装置の測定例である図９または図１０に示す測定結果に基づき漏水発生位置の検知を説明する。なお、図９及び図１０は、図５の点電極の配置図に対応する位置関係を示す座標であり、縦方向にａ〜ｍが記入され、横方向に１〜１４が記入されている。そして、図９及び図１０の座標において、例えば、縦方向の「ａ」と横方向の「１」とで、点電極Ｔ_a1の位置を示す。また、「ａ」ラインの「１」から「ｍ」ラインの「１４」まで進む場合、測線方向は図の「ａ」ライン上を左から右へ「１」〜「１４」まで進んだ後、ラインを１段下の「ｂ」ラインに変えて同様に左から右に進むこととする。更に、図９と図１０の座標では、それぞれの測線に合わせて電位差を図示したもので、それぞれの横軸（測線）の上側が正で下側が負であることを示している。
【００４９】
図９は印加電極毎に、測線上に隣り合う２個の点電極間で測定した電位差を表示した座標図である。図９において、漏水部がない場合、電位差は変化しない。一方、遮水工に漏水部がある場合、印加電圧と同一位相の電流が漏水部周辺に向かって流れ易くなるので、電位差の変化は一様ではなく漏水部周辺で歪みが生じる左右非対称の電位差分布になる。従って、図９のように電位差の変化を破線のグラフにすると漏水部（Ｌ₁，Ｌ₂，Ｌ₃）の周辺でＮ字型を示す。そして、この電位差分布から漏水部に近いほど電位差の絶対値が大きく、漏水位置で０Ｖとなり、この周辺に漏水部が存在することがわかる。
【００５０】
次に、図１０は印加電極毎に、測線方向と直角方向に隣り合う２個の点電極間で測定した電位差を表示した座標図である。図１０において、漏水部がない場合、図９の場合と同様に電位差は変化しない。一方、遮水工に漏水部がある場合、電位差は変動し、変動を破線のグラフにすると漏水部（Ｌ₁，Ｌ₂，Ｌ₃）を挟んだそれぞれの測線において極性が異なるピークを示す。そして、電位差は測線から漏水間の距離が最短の条件で最大値を示す。図１０では、漏水部が測線の右手にある条件で正の最大値となることを示し、漏水部が左手にある条件で負の最大値となることを示す。
【００５１】
この実施の形態によれば、１つの印加電極に対し、異方向に隣り合う電位差測定用電極間の変化の特性を利用して、電位差と電位差の極性と大きさから、漏水位置を特定することが可能となる。
【００５２】
【発明の効果】
本発明によれば、印加電極および電位差測定用電極の周辺以外は、遮水工の表裏が同電位に制御されているため、印加電極周辺に漏水部がない条件で、電位傾度は理論的に０Ｖが測定され、印加電極周辺に漏水部がある条件で有意な電位差が測定されることになる。また、漏水が複数存在しても従来のように漏水の影響によって電位差が重なり合うことはない。従って、電位差の変動は漏水周辺でのみ測定され、漏水部を確実に区別して検知することができる。
【００５３】
また、本発明によれば、遮水工の表裏を同電位に制御することによって、廃棄物処分場の廃棄物搬入道路など、漏水でなくとも遮水工表裏を短絡する経路となる部分が測定障害とならない。
【００５４】
従って、本発明は複数の漏水位置が存在しても確実に漏水位置を区別して検知することができ、漏水発生位置を検出する精度を向上させることができる漏水発生位置検知装置及びその方法を提供することができる。
【図面の簡単な説明】
【図１】遮水工構造物の側断面図である。
【図２】本発明の漏水発生位置検知装置の一部のブロック回路図である。
【図３】点電極の拡大図である。
【図４】点電極の拡大図である。
【図５】点電極の配置図である。
【図６】第２の選択接続手段が電位差測定用電極を選択する説明図であり、測線上に印加電極と隣り合う場合を示す。
【図７】第２の選択接続手段が電位差測定用電極を選択する説明図であり、測線方向と直角方法に印加電極と隣り合う場合を示す。
【図８】本発明の漏水発生位置検出処理の流れ図である。
【図９】電位差の測定結果を表示した座標図であり、測線上に印加電極と隣り合う電位差測定用電極を選択した場合を示す。
【図１０】電位差の測定結果を表示した座標図であり、測線方向と直角方法に印加電極と隣り合う電位差測定用電極を選択した場合を示す。
【符号の説明】
１…遮水工構造物
１ａ…窪み
２…遮水工
３…保護層
４…交流電源
５…電位差測定装置
５ａ…差動回路
１２…面電極
１３…環状電極
１５…電極切替装置
１８…Ａ／Ｄコンバータ
１９…コンピュータ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reservoir, a waterway, or a managed general waste final disposal site and a managed industrial, which are artificially constructed by laying a water barrier made of an electrically insulating material such as synthetic resin or synthetic rubber. The present invention relates to a water leakage occurrence position detecting device and a method for detecting a leakage occurrence position of a water leakage generated in a water shielding work of a water shielding work structure, for a water shielding work structure such as a waste final disposal site.
[0002]
[Prior art]
Impervious structures such as reservoirs, watercourses, managed municipal waste final disposal sites and managed industrial waste final disposal sites are made of materials with electrical insulation properties such as synthetic resin and synthetic rubber. Is artificially constructed by laying in the depression of the ground.
[0003]
Such a water-impervious structure leaks from the damaged part to the ground side when a breakage such as a crack occurs in the impermeable structure. For example, in the case of a managed-type general waste final disposal site, if the impermeable work is left in a damaged state, the contaminated liquid leaks and contaminates the neighborhood, or contaminates the groundwater and causes pollution problems. Therefore, it is necessary to repair the damaged portion of the impermeable structure using the impermeable construction by detecting the occurrence and occurrence position of water leakage (or breakage of the impermeable construction) at an early stage.
[0004]
Conventionally, as a method for detecting a water leakage part of such a water-impervious construction, a voltage is applied between an electrode installed inside the water-impervious construction and an electrode installed on the external ground side, and the voltage is applied to the electrode. Apart from this, it is known how to measure the potential distribution using a number of electrodes installed on either side of the impervious work, and to identify the location of the water leak by detecting potential anomalies that occurred around the water leak of the impervious work. It has been.
[0005]
[Problems to be solved by the invention]
By the way, it is stipulated that the entire impermeable construction is covered with a protective layer that prevents ultraviolet degradation and thermal degradation of the impermeable construction. These protective layers and other materials are generally made of non-woven fabric of synthetic fibers such as polyester. However, in terms of durability, soil materials and concrete are superior, so soil materials and concrete are often used. . In any case, the material such as the protective layer is not an electrical insulator. Therefore, since the protective layer etc. is electrically equivalent to water leakage, even if a voltage is applied to the electrodes above and below the water barrier, even if a potential difference abnormality occurs around the protective layer etc. It is difficult to distinguish whether it is due to a protective layer or the like, which has been an obstacle to improving the accuracy of detecting the location of water leakage. This phenomenon has the same kind of measurement obstacles in the waste carry-in road and the leachate drainage pipe even in the conventional disposal site, and the measurement accuracy is lowered. Similarly, when multiple water leaks occur, the potential difference overlaps due to the influence of the water leaks, making it difficult to distinguish the individual water leaks, which is an obstacle to improving the accuracy of detecting the water leaks. It was.
[0006]
From the above, the present invention has been made in view of the above problems, and even when there are a plurality of water leakage positions, the water leakage positions can be reliably distinguished and detected, and the accuracy of detecting the water leakage occurrence position is improved. It is an object of the present invention to provide a water leak occurrence position detecting device and method thereof.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the water leak occurrence position detecting device and method of the present invention employ the following means. Ie Leakage The water generation position detecting device includes a water-impervious structure for laying a water-impervious structure of an electrical insulator in a depression formed in the ground, a surface electrode installed on either side of the water-impervious structure, Between a plurality of point electrodes installed on the opposite side, a first selective connection means for selecting one of the plurality of point electrodes and connecting it to the power supply application side as an application electrode, and the point electrodes excluding the application electrode And a second selective connection means for selecting two point electrodes adjacent to the application electrode and connecting to the potential difference measurement means to form a potential difference measurement electrode. A water leakage occurrence position detecting device for detecting a water leakage position of the impermeable construction structure from the measured potential difference and the position of the application electrode, wherein all the point electrodes excluding the selected application electrode and the potential difference measurement electrode And the surface electrode is connected to the other end of the power source. It characterized by having a selection connecting means.
[0008]
the above According to the invention, by the voltage applied between the application electrode and the surface electrode by the first selective connection means, (1) the first selective connection means → the application electrode → the ground → the application electrode and other than the electrode for potential difference measurement Point electrode → the other end of the power source 4. (2) First selective connection means → applying electrode → ground → surface electrode → the other end of the power source. (3) A circuit of first selective connection means → applying electrode → water leakage → surface electrode → the other end of the power source is formed.
[0009]
According to the circuits (1) to (3), a voltage is applied between one application electrode selected by the first selective connection means and the surface electrode and is selected by the second selective connection means. The potential difference is measured between the two potential difference measuring electrodes. In addition, the third selective connection means connects all the point electrodes except the application electrode and the potential difference measurement electrode to the other end of the power supply that is not the application side, so that the electric fields on the front and back of the water shielding work have the same potential. To be controlled.
[0010]
That is, the potential control of the front and back of the impervious work is to connect all the point electrodes except the selected one applied electrode and the two potential difference measuring electrodes to the other end of the power source connected to the surface electrode. Is done. If the upper and lower impermeable structures excluding the applied electrode and the two potential difference measuring electrodes are controlled to the same potential, the potential gradient is theoretically measured as 0 V under the condition that there is no water leakage around the applied electrode, A significant potential difference is measured under the condition that there is a water leakage portion around the application electrode. Moreover, the fluctuation of the potential difference is measured only in the vicinity of the water leakage, and even if there are a plurality of water leakages, the potential differences do not overlap due to the leakage of water as in the conventional case, and the water leakage portion can be reliably identified and detected.
[0011]
In addition, it is advantageous that the point electrode has a wide area rather than a simple metal plate. Therefore, the point electrode can be exemplified by a bare copper wire formed in a rectangular frame shape, or a bare copper wire formed in a spiral shape in order to increase sensitivity.
[0012]
Further, the water shielding work can be exemplified by a synthetic resin or a synthetic rubber which is a material having electrical insulation. Moreover, the protective layer used for the management-type waste final disposal site etc. can illustrate the case where the nonwoven fabric (light-shielding mat) of polyester or a polypropylene is laid, and the case where a soil material and concrete are laid.
[0013]
Also Leakage The water generation position detector is the above In the configuration, the potential difference measuring electrode is a point electrode on an alignment line in all directions with the application electrode as a center, and the second selective connection means is on an alignment line in a different direction with respect to one application electrode. A plurality of pairs of adjacent point electrodes are sequentially selected and sequentially connected to the potential difference measuring means.
[0014]
Such a configuration Accordingly, it is possible to identify the water leakage position from the potential difference and the polarity and magnitude of the potential difference using the characteristics of the change between the potential difference measuring electrodes adjacent to each other in one direction with respect to one application electrode. . For example, a current having the same phase as the applied voltage is likely to flow toward the periphery of the leaked portion, and the measured value tends to change to an N shape around the leaked portion between two point electrodes adjacent to each other in the measurement line direction. Between two point electrodes adjacent to each other in the direction perpendicular to the survey line direction, there is a tendency to show peaks having different polarities in each survey line sandwiching the water leakage portion. By using such characteristics of the direction of measurement, the accuracy of specifying the water leakage position is improved.
[0015]
More Leakage The water generation position detector is As above In the configuration, an annular electrode arranged around the periphery of the plurality of point electrodes or the surface electrode is connected to the other end of the power source in the vicinity of a portion where the water shielding work contacts the ground. .
[0016]
Such a configuration According to the present invention, the annular electrode arranged around the periphery of the plurality of point electrodes or the surface electrodes is directly connected to the other end which is not the application side like the surface electrode in the water shielding construction structure. Controls the electric field on the front and back of the impervious structure covering the impermeable structure to the same potential. Since the electric fields on the front and back of the impermeable construction are controlled to the same potential, the influence of the current flowing through the protective layer, the ground, etc. can be reduced.
[0017]
More Leakage The water generation position detection method is a water-impervious structure in which a water-insulating work of an electrical insulator is laid in a depression formed in the ground, and a surface electrode is installed on either side of the water-impervious work, A plurality of point electrodes are installed on the opposite side, one of the plurality of point electrodes is selected and connected to a power supply application side as an application electrode, and two point electrodes adjacent to the application electrode are selected. A potential difference measuring electrode, all the point electrodes except the selected applied electrode and potential difference measuring electrode and the surface electrode are connected to the other end of the power source, a potential difference is measured between the potential difference measuring electrodes, The water leakage position of the impermeable construction is detected from the measured potential difference and the position of the application electrode.
[0018]
Such leak detection position detection method According to the above, the electric potential difference due to the electrode for measuring the potential difference is measured only in the vicinity of the water leak so that the electric potential inside and outside the impermeable structure is the same potential, and even if there are multiple water leaks, Therefore, the potential difference does not overlap with each other, and the water leakage portion can be reliably distinguished and detected. The two-phase AC power supply that is a constituent element of the above invention may be an alternating DC power supply.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a water leakage occurrence position detection device according to an embodiment of the present invention will be described in detail with reference to FIGS. Note that the water leakage occurrence position detection device according to the embodiment is installed in the water-impervious construction 1. The impermeable construction structure 1 will be described as a case of a managed waste final disposal site.
[0020]
As shown in FIG. 1, the impermeable structure 1 is constructed by laying a impermeable structure 2 in a recess 1 a formed in the ground and laminating a protective layer 3 on the slope portion so as to cover the entire impermeable structure 2. It is. And the water-impervious work 2 is formed with the synthetic resin which has electrical insulation. Further, the protective layer 3 is formed of a concrete material that is not an electrical insulator, and the front surface side and the back surface side of the water barrier 2 laid on the water barrier structure 1 are electrically short-circuited via the protective layer 3. The circuit is ready to be formed.
[0021]
The protective layer 3 used in the final disposal site for managed waste may be laid with polyester or polypropylene non-woven fabric (light-shielding mat), or may be laid with soil materials or concrete, but compared with synthetic fibers such as polyester. Then, it is known that soil materials and concrete are more suitable for preventing UV deterioration and thermal deterioration of a water shielding work, and are extremely excellent in durability. In addition, waste carrying roads and the like use concrete having excellent durability as a material. Therefore, in this embodiment, a description will be given assuming that a concrete protective layer 3 is laid.
[0022]
In the water leakage occurrence position detecting device according to the embodiment, the surface electrode 12 is arranged inside the water-impervious structure 1 (surface side) where the water-impervious work 2 is laid, and the back side (ground side) of the water-impervious work 2 A plurality of point electrodes T _a1 ~ T _m14 (Refer to FIG. 5) is arranged at a predetermined interval, and further, an electrode arrangement configuration is used in which the annular electrode 13 is arranged so as to surround the entire impermeable construction 2.
[0023]
The surface electrode 12 is composed of a conductive metal foil, a metal net or the like in a planar shape. The surface electrode 12 is connected to one side 4 a of the AC power source 4. In the impervious structure 1, the surface electrode 12 has leachate with high electrical conductivity from the waste. Therefore, linear electrodes (for example, bare copper wires) are arranged in a grid at intervals of 10 to 20 m. May be.
[0024]
On the other hand, the point electrode T _a1 ~ T _m14 FIG. 5 is an array of 13 a to m in the vertical direction and 14 (a total of 182) 1 to 14 in the horizontal direction. These point electrodes T _a1 ~ T _m14 An annular electrode 13 is arranged in the vicinity of the portion where the impermeable work 2 contacts the ground. Similar to the surface electrode 12, the annular electrode 13 is connected to one side 4 a of the AC power source 4. Multiple point electrodes T _a1 ~ T _m14 Are connected to the potential difference measuring device 5 and one side 4a or the other side 4b of the AC power source 4 via the electrode switching device 15, respectively.
[0025]
Point electrode T _a1 ~ T _m14 In more detail, the electrode switching device 15 includes a point electrode T. _a1 ~ T _m14 1 (point electrode T in FIG. 5) _g5 ) Is selected and connected to the other side 4b on the application side of the AC power supply 4, and the application electrode T _g5 (First selective connection means).
[0026]
In addition, the electrode switching device 15 has an application electrode T _g5 In contrast, two adjacent point electrodes on the survey line (in FIG. _g4 , T _g6 ) Is selected and connected to the potentiometer 5 to connect to the potentiometer 5 _g4 , T _g6 (Second selective connection means). The electrode switching device 15 applies the application electrode T when the second selective connection means selects the potential difference measuring electrode. _g5 Two adjacent point electrodes on the alignment line that intersects at right angles to the direction of the measurement line (in FIG. _f5 , T _h5 ) Is also selected and connected to the potential difference measuring device 5 to form a potential difference measuring electrode. That is, the second selective connection means sequentially selects a plurality of sets of adjacent point electrodes on different alignment lines for one applied electrode and sequentially connects them to the potential difference measuring means.
[0027]
Furthermore, the electrode switching device 15 is configured to select a selected application electrode (for example, T _g5 ) And a potential difference measuring electrode (the applied electrode is T _g5 In this case, the potential difference measuring electrode is T _g4 , T _g6 Or T _f5 , T _h5 All the point electrodes except for () are connected to one side 4a of the AC power supply 4 (third selective connection means).
[0028]
The power source 4 (see FIG. 1) is connected to an application electrode (for example, T _g5 ) And the surface electrode 12, a voltage is applied to the circuit formed by the selective connection of the electrode switching device (first selective connection means) 15. The power source 4 may be an alternating direct current or an alternating current, but an alternating current power source is used in this embodiment. When the power source 4 is an AC power source, the relationship between the electrode switching device 15 and the potential difference measuring device 5 is as shown in the block diagram of FIG.
[0029]
In other words, the potential difference measuring device 5 has an application electrode (for example, T _g5 ) And the surface electrode 12, the potential difference measuring electrode (applied electrode is T _g5 In this case, the potential difference measuring electrode is T _g4 , T _g6 Or T _f5 , T _h5 ) Is a device for measuring the potential difference between the two. As shown in FIG. 2, when the power source 4 is an AC power source, the potential difference measuring device 5 can be a differential circuit 5a that can easily obtain the potential difference. At this time, the same result can be obtained by separately measuring the potential difference between the potential difference measuring electrode on both sides of the applied electrode and the point, and taking the difference between the measured potential values.
[0030]
Then, an application electrode (for example, T _g5 ) And the surface electrode 12, the second selective connection means causes a potential difference measuring electrode (the applied electrode is T _g5 In this case, the potential difference measuring electrode is T _g4 , T _g6 ) Is selected, the following circuit is formed. In addition, there is a water leak L ₁ , L ₂ , L _Three Is assumed to occur.
[0031]
(1) Electrode switching device 15 → applied electrode T _g5 → Ground → Applied electrode T _g5 And electrode T for potential difference measurement _g4 , T _g6 Other than the point electrode and the annular electrode 13 → the AC power source 4a 4a.
(2) Electrode switching device 15 → applied electrode T _g5 → Protective layer 3 → surface electrode 12 → one 4a of AC power supply 4.
(3) Electrode switching device 15 → applied electrode T _g5 → Leakage L ₁ , L ₂ , L _Three A circuit of the surface electrode 12 → the one 4a of the AC power source 4 is formed.
[0032]
According to the circuits (1) to (3), one application electrode selected by the electrode switching device 15 (for example, the application electrode T) _g5 ) And the surface electrode 12, while the voltage of the AC power supply 4 is applied, one application electrode (for example, the application electrode T) _g5 ) And two potentiometric electrodes (for example, T _g4 , T _g6 All the point electrodes except for), the surface electrode 12 and the annular electrode 13 are controlled to the same potential by being connected to one side 4a of the AC power source 4 which is not the application side.
[0033]
Therefore, the water leakage occurrence position detecting device of this embodiment is configured so that the circuits (1) to (3) are formed, so that the water-impervious structure 1 is formed by the protective layer 3 such as concrete or the ground. The electric fields on the front and back sides of the water shielding work 2 to be covered are controlled so as to have the same potential except for one applied electrode and two potential difference measuring electrodes. Note that when the thickness of the annular electrode 13 and the cross-sectional area of the protective layer 3 are compared, it is difficult to control the current flowing through the protective layer 3 using only 131 annular electrodes because the cross-sectional area of the protective layer 3 is large. The number of the annular electrodes 13 is preferably plural rather than one.
[0034]
As described above, from the electrode arrangement of FIG. 1, the electric potential of the front and back of the water shielding work 2 is controlled by one application electrode (for example, application electrode T) on one side 4 a of the AC power supply 4 connected to the surface electrode 12. _g5 ) And two potentiometric electrodes (for example, T _g4 , T _g6 This is done by connecting all point electrodes except). The potential difference measurement is performed by measuring the potential difference on the ground side of the impermeable construction structure 1 (for example, T _g4 , T _g6 ). Therefore, the fluctuation of the potential difference is measured only in the vicinity of the water leakage, and even if there are a plurality of water leakages, the potential differences do not overlap due to the water leakage as in the prior art, and the water leakage portion can be reliably identified and detected.
[0035]
In this embodiment, the application electrode (for example, the application electrode T) _g5 ) And a potential difference measuring electrode (for example, T _g4 , T _g6 There is a point to positively control the front and back potentials of the water shielding work 2 by all point electrodes except for (), and it is advantageous that the point electrode has a surface spread rather than a simple metal plate.
[0036]
Therefore, the point electrode T _a1 ~ T _m14 (T for short _XY 3), a bare copper wire is formed in a rectangular frame shape as shown in FIG. _XY Connected to other devices via a cable connected to This point electrode T _a1 ~ T _m14 In order to increase the sensitivity of the electrode, a bare copper wire may be formed in a spiral shape (the point electrode T in FIG. 4). _xy A rectangular metal plate.
[0037]
By the way, an electrode for potential difference measurement (for example, T _g4 , T _g6 ) Is measured by the potentiometer 5. As shown in FIG. 2, the potential difference measuring device 5 includes a differential circuit 5 a, an A / D converter 18, and a computer 19, and the differential circuit 5 a is connected to the computer 19 via the A / D converter 18. .
[0038]
The computer 19 includes a ROM (Read Only Memory), a RAM (Random Access Memory), a CPU (Central Processing Unit), an input port, and an output port that are connected to each other via a bidirectional bus. The input port of the computer 19 is connected to the differential circuit 5a via the A / D converter 18, and an output signal (potential difference measurement value) is input. The output port of the computer 19 is connected to the electrode switching device 15 (not shown) and outputs a point electrode switching command to the electrode switching device 15. The point electrode switching command is executed based on a selective connection procedure described later (first, second, and third selective connection means). Further, the output port of the computer 19 is connected to, for example, a CRT device (not shown) and outputs a display command (image data) to the CRT device.
[0039]
The ROM stores a program for detecting a leakage occurrence position and programs for first to third selection connection procedures, and the CPU reads these programs and performs processing. The first selective connection procedure is a point electrode T connected to the other 4b (application side) of the AC power supply 4 in the electrode switching device 15. _a1 ~ T _m14 Is a procedure for sequentially switching 182 (horizontal direction × vertical direction; 14 × 13) types of selective connection procedures in the line-of-sight direction (the direction of scanning from left to right and from top to bottom in FIG. 5) one by one. The CPU is first (i = 1; for example, the point electrode T _a1 ) In the direction of the line from i to 182 (i = 182; for example, point electrode T _m14 ) Is read from the ROM and a command to switch the electrode switching device 15 is output. Then, for each command order, an AC voltage is applied to an arbitrary point electrode, and the position of the point electrode is selected. In the second selective connection procedure, the electrode switching device 15 selects two point electrodes (potential difference measurement electrodes) adjacent to each other on the survey line with respect to the application electrode selected by the first selective connection means. This is a procedure for connecting to the measuring device 5. At this time, the third selective connection means connects all the point electrodes except the application electrode and the potential difference measurement electrode to the one 4a of the AC power source 4. Further, in the second selective connection procedure, the electrode switching device 15 selects two point electrodes (potential difference measurement electrodes) adjacent in the direction perpendicular to the measurement line direction with respect to the application electrode selected by the first selective connection means. And connected to the potential difference measuring device 5. Also at this time, the third selective connection means connects all the point electrodes except the application electrode and the potential difference measurement electrode to the one 4 a of the AC power source 4. Then, the CPU reads out the second and third selective connection procedures from the ROM for each of the first (i = 1) to 182nd (i = 182) application electrodes, and outputs a command to switch the electrode switching device 15.
[0040]
Next, the leak detection position detection process of the present invention by the computer 19 will be described based on the flowchart of FIG.
The computer 19 sets “i = 1” (step 101), switches the electrode switching device 15 according to the first selection connection procedure stored in the ROM, and selects a point electrode (and position) (step 102). That is, “i” is the first (i = 1; point electrode T _a1 ) So that the electrode switching device 15 _a1 And the other 4b of the AC power source 4 are connected, and an AC voltage is applied between one side 4a of the AC power source 4 connected to the surface electrode 12, and the positions of these point electrodes are selected.
[0041]
Next, the computer 19 applies the application electrode T selected by the first selective connection means in the second selective connection means at “i = 1”. _a1 On the other hand, two adjacent point electrodes (potential difference measuring electrodes) on the survey line are selected and connected to the potential difference measuring device 5. The point electrode T _a1 As the application electrode (point electrode at the corner in the arrangement of FIG. 5; T _a14 , T _m1 , T _m14 Since the two point electrodes adjacent to the application electrode do not exist (that is, the corner point electrodes are used only for electric field control), the computer 19 proceeds to the process of step 105. Further, among the outermost point electrodes shown in FIG. _b1 ~ T _l1 T _b14 ~ T _l14 ) As the application electrode, there are no two point electrodes adjacent on the survey line (however, the point electrode in the outermost peripheral vertical direction has two point electrodes adjacent in the direction perpendicular to the survey line direction) The computer 19 proceeds to the process of step 104. However, the point electrode T described above _g5 As the application electrode (“i = 89”), the application electrode T _g5 In contrast, two adjacent point electrodes on the survey line (in FIG. _g4 , T _g6 ) Is selectable, the point electrode T _g4 , T _g6 Is connected to the potential difference measuring device 5 to form a potential difference measuring electrode (second selective connection means). At this time, the third selective connection means is the application electrode T. _g5 And potential difference measuring electrode T _g4 , T _g6 All the point electrodes except for are connected to one side 4a of the AC power source 4.
[0042]
The potential difference measuring device 5 (differential circuit 5a) includes a potential difference measuring electrode T. _g4 , T _g6 Is measured and output to the computer 19 via the A / D converter 18. Then, the computer 19 stores the potential difference value together with “i = 89” in the RAM (step 103).
[0043]
Next, the computer 19 applies the application electrode T selected by the first selective connection means in the second selective connection means at “i = 89”. _g5 On the other hand, two point electrodes (in FIG. _f5 , T _h5 ) Is selected and connected to the potentiometer 5. Also at this time, the third selective connection means is the application electrode T. _g5 And potential difference measuring electrode T _f5 , T _h5 All the point electrodes except for are connected to one side 4a of the AC power source 4. Then, the potential difference measuring device 5 (differential circuit 5a) is connected to the potential difference measuring electrode T in the same procedure as in Step 103. _f5 , T _h5 The potential difference between them is measured and output to the computer 19 via the A / D converter 18, and the computer 19 stores the potential difference value together with “i = 89” in the RAM (step 104). Of the outermost point electrodes shown in FIG. _a2 ~ T _a13 T _m2 ~ T _m13 ) Is the application electrode, there are no two point electrodes adjacent in the direction perpendicular to the line-of-measurement direction, so the computer 19 proceeds to step 105.
[0044]
Next, the computer 19 determines that the first selection switching procedure is 182nd (i = 182; point electrode T _m14 ) (Step 105), and if i = 182 (step 105: YES), the processing after step 107 is performed. On the other hand, if i = 182 is not satisfied (step 105: NO), the process of step 106 is performed.
[0045]
In step 106, the computer 19 increments the i-th by 1 (i = i + 1), and repeats the processing after step 102. That is, the computer 19 stores the potential difference values measured by the processes from “i = 1” to “i = 182”.
[0046]
In step 107, the computer 19 outputs a command to display the potential difference value stored in the RAM on the CRT screen to the CRT device. Then, the CRT device displays the measured values from “i = 1” to “i = 182” at the intersection position of the CRT screen (see FIG. 9 or FIG. 10).
[0047]
Then, when the measurement value is displayed on the CRT screen, the computer 19 ends the water leak occurrence position detection process.
[0048]
[Detection of water leakage due to potential difference]
Next, the detection of the water leakage occurrence position will be described based on the measurement result shown in FIG. 9 or FIG. 10 which is a measurement example of the water leakage occurrence position detection device. 9 and 10 are coordinates showing the positional relationship corresponding to the arrangement diagram of the point electrodes in FIG. 5, in which a to m are written in the vertical direction and 1 to 14 are written in the horizontal direction. In the coordinates of FIGS. 9 and 10, for example, the point electrode T is represented by “a” in the vertical direction and “1” in the horizontal direction. _a1 Indicates the position. Also, when going from “1” on the “a” line to “14” on the “m” line, the direction of the survey line goes from “1” to “14” from left to right on the “a” line in the figure, The line is changed to the “b” line that is one step lower, and similarly proceeds from left to right. Further, in the coordinates of FIGS. 9 and 10, the potential difference is illustrated in accordance with each survey line, and indicates that the upper side of each horizontal axis (measurement line) is positive and the lower side is negative.
[0049]
FIG. 9 is a coordinate diagram displaying the potential difference measured between two point electrodes adjacent to each other on the measurement line for each applied electrode. In FIG. 9, when there is no water leakage portion, the potential difference does not change. On the other hand, if there is a water leakage part in the impervious construction, the current with the same phase as the applied voltage is likely to flow toward the periphery of the water leakage part, so the change in potential difference is not uniform and asymmetrical potential difference that causes distortion around the water leakage part. Distribution. Therefore, when the change in potential difference is represented by a broken line graph as shown in FIG. ₁ , L ₂ , L _Three ) Around the N-shaped. And from this potential difference distribution, the closer to the leaked portion, the larger the absolute value of the potential difference becomes 0 V at the leaked position, and it can be seen that there is a leaked portion around this.
[0050]
Next, FIG. 10 is a coordinate diagram displaying the potential difference measured between two point electrodes adjacent to each other in the direction perpendicular to the measurement direction for each applied electrode. In FIG. 10, when there is no water leakage part, the potential difference does not change as in FIG. On the other hand, when there is a water leaking part in the impervious construction, the potential difference fluctuates. ₁ , L ₂ , L _Three ) Shows different peaks in each survey line. And the potential difference shows the maximum value under the condition that the distance between the measurement line and the water leakage is the shortest. In FIG. 10, it shows that a water leak part becomes a positive maximum value on the condition which exists in the right hand of a survey line, and shows that a water leak part becomes a negative maximum value on the condition which exists on the left hand.
[0051]
According to this embodiment, the leakage position is identified from the potential difference and the polarity and magnitude of the potential difference using the characteristics of the change between the potential difference measuring electrodes adjacent to each other in one direction for one applied electrode. Is possible.
[0052]
【The invention's effect】
According to the present invention, since the front and back of the water shielding work are controlled to the same potential except for the periphery of the applied electrode and the potential difference measuring electrode, the potential gradient is theoretically determined under the condition that there is no water leakage portion around the applied electrode. 0V is measured, and a significant potential difference is measured under the condition that there is a water leakage portion around the application electrode. Further, even if there are a plurality of water leaks, the potential differences do not overlap due to the water leaks as in the prior art. Therefore, the fluctuation of the potential difference is measured only around the water leakage, and the water leakage portion can be reliably distinguished and detected.
[0053]
In addition, according to the present invention, by controlling the front and back of the impervious work to the same potential, a part that becomes a path that short-circuits the front and rear of the impervious work, such as a waste carry-in road at a waste disposal site, is measured. It does not become an obstacle.
[0054]
Therefore, the present invention provides a water leakage occurrence position detection apparatus and method that can reliably detect and detect the water leakage position even when there are a plurality of water leakage positions, and can improve the accuracy of detecting the water leakage occurrence position. can do.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a water shielding structure.
FIG. 2 is a block circuit diagram of a part of the water leakage occurrence position detecting device of the present invention.
FIG. 3 is an enlarged view of a point electrode.
FIG. 4 is an enlarged view of a point electrode.
FIG. 5 is a layout diagram of point electrodes.
FIG. 6 is an explanatory diagram for selecting a potential difference measuring electrode by the second selective connection means, and shows a case where the second electrode is adjacent to the application electrode on the measurement line.
FIG. 7 is an explanatory diagram for selecting a potential difference measuring electrode by the second selective connection means, and shows a case where the second electrode is adjacent to the application electrode in a direction perpendicular to the measuring direction.
FIG. 8 is a flowchart of water leakage occurrence position detection processing according to the present invention.
FIG. 9 is a coordinate diagram showing a measurement result of a potential difference, and shows a case where a potential difference measuring electrode adjacent to an applied electrode is selected on a measurement line.
FIG. 10 is a coordinate diagram showing a measurement result of a potential difference, and shows a case where a potential difference measuring electrode adjacent to an application electrode is selected in a direction perpendicular to the measurement direction.
[Explanation of symbols]
1 ... Impervious structure
1a ... hollow
2 ... Impermeable work
3 ... Protective layer
4… AC power supply
5 ... Potential difference measuring device
5a ... Differential circuit
12 ... Surface electrode
13 ... Annular electrode
15 ... Electrode switching device
18 ... A / D converter
19 ... Computer

Claims

A water-impervious structure for laying a water-impervious structure of an electrical insulator in a recess formed in the ground; and
Surface electrodes installed on either the front or back of the impermeable construction,
A plurality of point electrodes installed on the opposite side of the surface electrode;
A first selective connection means for selecting one of the plurality of point electrodes and connecting to a power supply application side to form an application electrode;
A potential difference measuring means for measuring a potential difference between point electrodes excluding the application electrode;
A second selective connection means for selecting two point electrodes adjacent to the application electrode and connecting to the potential difference measurement means to form a potential difference measurement electrode;
A third selective connection means for connecting all the point electrodes excluding the selected applied electrode and the potential difference measuring electrode and the surface electrode to the other end of the power source ;
An annular electrode disposed around the periphery of the plurality of point electrodes or the surface electrode and connected to the other end of the power source, in the vicinity of the portion where the water shielding work contacts the ground,
The provided water leakage generation position detection equipment for detecting the water leakage position of the water-impervious Engineering structure from the position of the measured potential difference and the application electrode.

The potential difference measuring electrode is a point electrode on an alignment line in all directions with the application electrode as a center, and the second selective connection means is a set of alignment lines on a different direction with respect to one application electrode. The water leak occurrence position detecting device according to claim 1, wherein a plurality of sets of adjacent point electrodes are sequentially selected and sequentially connected to the potential difference measuring means.

A water-impervious structure that lays a water-insulating electric insulator in a depression formed in the ground,
Install the surface electrode on either the front or back of the water barrier,
Installing a plurality of point electrodes on the opposite side of the surface electrode;
One of the plurality of point electrodes is selected and connected to the power supply application side to form an application electrode,
Select the two point electrodes adjacent to the application electrode as potential difference measurement electrodes,
Connecting all the point electrodes and the surface electrodes except the selected applied electrode and the potential difference measuring electrode to the other end of the power source;
An annular electrode disposed around the periphery of the plurality of point electrodes or the surface electrode is connected to the other end of the power source in the vicinity of the portion where the water shielding work contacts the ground.
Measure the potential difference between the potential difference measuring electrodes,
A leak detection position detecting method, comprising: detecting a leak position of the impermeable structure from the measured potential difference and the position of the application electrode.