JP6773878B1 - Concrete structure internal condition inspection method and system used for that method - Google Patents
Concrete structure internal condition inspection method and system used for that method Download PDFInfo
- Publication number
- JP6773878B1 JP6773878B1 JP2019228782A JP2019228782A JP6773878B1 JP 6773878 B1 JP6773878 B1 JP 6773878B1 JP 2019228782 A JP2019228782 A JP 2019228782A JP 2019228782 A JP2019228782 A JP 2019228782A JP 6773878 B1 JP6773878 B1 JP 6773878B1
- Authority
- JP
- Japan
- Prior art keywords
- elastic wave
- waveform
- concrete structure
- striking
- detection sensor
- 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.)
- Active
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
【課題】複数の弾性波検出センサを用いて、コンクリート構造物の内部に生じた損傷等の有無をコンクリート表面から検査することにより、コンクリート構造物の内部が健全な状態であるかどうかの判定を高い精度で行う。【解決手段】点検領域を囲う境界上の複数の地点に弾性波検出センサを配置し、弾性波検出センサが配置されていない複数の地点に打撃具を配置し、打撃力検出センサを打撃具の各々に対応させて配置する。打撃力検出センサで得られた打撃力計測波形の平滑化された波形の立ち上がり検出点と、弾性波検出センサの各々において得られた計測データに基づき生成される計測波形の平滑化された波形の立ち上がり又は立ち下がりの検出点に基づき、発振地点から受振地点に至る弾性波の伝播時間を算出し、計測波形を高速フーリエ変換し、求められた卓越周波数、１次から５次の周波数、振幅から、弾性波速さを求める。【選択図】図１PROBLEM TO BE SOLVED: To determine whether or not the inside of a concrete structure is in a sound state by inspecting the presence or absence of damage or the like generated inside the concrete structure from the concrete surface by using a plurality of elastic wave detection sensors. Perform with high accuracy. SOLUTION: Elastic wave detection sensors are arranged at a plurality of points on a boundary surrounding an inspection area, striking tools are arranged at a plurality of points where elastic wave detection sensors are not arranged, and striking force detection sensors are used for striking tools. Arrange according to each. The rising detection point of the smoothed waveform of the striking force measurement waveform obtained by the striking force detection sensor and the smoothed waveform of the measurement waveform generated based on the measurement data obtained by each of the elastic wave detection sensors. Based on the rising or falling detection points, the propagation time of the elastic wave from the oscillation point to the vibration receiving point is calculated, the measured waveform is subjected to high-speed Fourier conversion, and the obtained dominant frequency, the 1st to 5th order frequencies, and the amplitude are used. , Find the elastic wave velocity. [Selection diagram] Fig. 1
Description
本発明は、コンクリート構造物の内部に生じた損傷等の有無をコンクリート表面から検査することによりコンクリート構造物の内部が健全な状態であるかどうかの判定を行う、コンクリート構造物内部状況点検方法とその方法に使用するシステムに関するものである。 The present invention is a method for inspecting the internal condition of a concrete structure, which determines whether or not the inside of the concrete structure is in a healthy state by inspecting the inside of the concrete structure for damage or the like from the concrete surface. It concerns the system used for that method.
コンクリート構造物の内部に生じた損傷等を、コンクリート構造物を破壊することなく検出するための様々な手法が提案されている。 Various methods have been proposed for detecting damage and the like generated inside a concrete structure without destroying the concrete structure.
例えば、特開２０１１−１９１２０２には、セメント硬化物の表面に設置された複数の弾性波検出センサが検出する複数の弾性波を用いて表面波トモグラフィ解析を行い、表面波位相速さ分布を表示することによってセメント硬化物の内部に生じた空間を可視化する手法が開示されている。 For example, in Japanese Patent Application Laid-Open No. 2011-191202, surface wave tomography analysis is performed using a plurality of elastic waves detected by a plurality of elastic wave detection sensors installed on the surface of a hardened cement product, and a surface wave phase velocity distribution is obtained. A method of visualizing the space created inside the hardened cement product by displaying it is disclosed.
しかしながら、複数の弾性波検出センサを用いて表面波トモグラフィ解析を行う従来の手法では、受振地点において弾性波検出センサにより得られた弾性波の波形に基づき、弾性波が発振地点から受振地点に到るまでに要する時間（到達時間）を正確に計測することが難しく、解析の精度が低下するおそれがあった。 However, in the conventional method of performing surface wave tomography analysis using a plurality of elastic wave detection sensors, the elastic wave moves from the oscillation point to the vibration receiving point based on the waveform of the elastic wave obtained by the elastic wave detection sensor at the vibration receiving point. It is difficult to accurately measure the time required to reach (arrival time), and there is a risk that the accuracy of analysis will decrease.
また、コンクリートの表面から弾性波を検出するため、表面弾性波の伝播速さだけではコンクリート内部の振動に関する情報が少なく、この点においても内部状態の推定の精度が低下するおそれがあった。 Further, since the elastic wave is detected from the surface of the concrete, there is little information about the vibration inside the concrete only by the propagation speed of the surface acoustic wave, and in this respect as well, the accuracy of estimating the internal state may be lowered.
そこで、本発明は、複数の弾性波検出センサを用いて、コンクリート構造物の内部に生じた損傷等の有無をコンクリート表面から検査することにより、コンクリート構造物の内部が健全な状態であるかどうかの判定を高い精度で行うことを目的とする。 Therefore, the present invention uses a plurality of elastic wave detection sensors to inspect the inside of the concrete structure for damage or the like from the concrete surface to determine whether the inside of the concrete structure is in a sound state. The purpose is to make a judgment of with high accuracy.
本発明に係るコンクリート構造物内部状況点検方法では、点検対象となるコンクリート構造物の点検部位表面において、点検領域を囲う境界上の複数の地点に弾性波検出センサを配置し、前記点検領域における前記弾性波検出センサが配置されていない複数の地点に打撃具を配置し、前記コンクリート構造物における前記弾性波検出センサの配置された平面に対し前記打撃具により与えられる打撃力を検出する打撃力検出センサを前記打撃具の各々に対応させて配置する。 In the method for inspecting the internal condition of a concrete structure according to the present invention, elastic wave detection sensors are arranged at a plurality of points on the boundary surrounding the inspection area on the surface of the inspection site of the concrete structure to be inspected, and the said in the inspection area. Strike force detection that detects the striking force given by the striking tool to the plane on which the elastic wave detection sensor is arranged in the concrete structure by arranging the striking tools at a plurality of points where the elastic wave detection sensors are not arranged. The sensor is arranged so as to correspond to each of the striking tools.
そして、前記打撃力検出センサで得られた打撃力計測波形の平滑化された波形の立ち上がり検出点と、前記弾性波検出センサの各々において得られた計測データに基づき生成される計測波形の平滑化された波形の立ち上がり又は立ち下がりの検出点に基づき、発振地点から受振地点に至る弾性波の伝播時間を算出する。 Then, the rising detection point of the smoothed waveform of the striking force measurement waveform obtained by the striking force detection sensor and the smoothing of the measurement waveform generated based on the measurement data obtained by each of the elastic wave detection sensors. Based on the rising or falling detection points of the waveform, the propagation time of elastic waves from the oscillation point to the vibration receiving point is calculated.
また、前記計測波形を高速フーリエ変換（ＦＦＴ）し、求められた卓越周波数、１次から５次の周波数、及びそれらの振幅から、弾性波速さを求める。 Further, the measured waveform is subjected to a fast Fourier transform (FFT), and the elastic wave velocity is obtained from the obtained dominant frequency, the first to fifth order frequencies, and their amplitudes.
前記計測波形を、前記コンクリート構造物が健全な状態において得られた弾性波基本データに基づき生成される基本波形と比較してもよい。 The measured waveform may be compared with a basic waveform generated based on elastic wave basic data obtained in a sound state of the concrete structure.
コンクリート構造物内部状況点検システムは、点検対象となるコンクリート構造物の点検部位表面において、点検領域を囲う境界上の複数の地点に配置された弾性波検出センサの複数と、前記点検領域における前記弾性波検出センサが配置されていない複数の地点に配置された打撃具の複数と、前記打撃具の各々に対応して配置され、前記コンクリート構造物における前記弾性波検出センサの配置された平面に対し前記打撃具により与えられる打撃力を検出する打撃力検出センサの複数と、前記弾性波検出センサ及び前記打撃力検出センサにより得られた計測データを取得し処理する演算処理装置を備える。
The concrete structure internal condition inspection system includes a plurality of elastic wave detection sensors arranged at a plurality of points on the boundary surrounding the inspection area on the surface of the inspection site of the concrete structure to be inspected, and the elasticity in the inspection area. With respect to a plurality of striking tools arranged at a plurality of points where the wave detection sensor is not arranged and a plane in which the elastic wave detection sensor is arranged, which is arranged corresponding to each of the striking tools and is arranged in the concrete structure. It includes a plurality of striking force detection sensors that detect the striking force given by the striking tool, and an arithmetic processing device that acquires and processes measurement data obtained by the elastic wave detection sensor and the striking force detection sensor.
そして、前記演算処理装置は、前記打撃力検出センサで得られた打撃力計測波形の平滑化された波形の立ち上がり検出点と、前記弾性波検出センサの各々において得られた計測データに基づき生成される計測波形の平滑化された波形の立ち上がり又は立ち下がりの検出点に基づき、発振地点から受振地点に至る弾性波の伝播時間を算出し、前記計測波形を高速フーリエ変換（ＦＦＴ）し、求められた卓越周波数、１次から５次の周波数、及びそれらの振幅から、弾性波速さを求める。 Then, the arithmetic processing device is generated based on the rising detection point of the smoothed waveform of the striking force measurement waveform obtained by the striking force detection sensor and the measurement data obtained by each of the elastic wave detection sensors. Based on the detection points of the rising or falling edges of the smoothed waveform of the measured waveform, the propagation time of the elastic wave from the oscillation point to the vibration receiving point is calculated, and the measured waveform is subjected to high-speed Fourier transformation (FFT) to obtain it. The elastic wave velocity is obtained from the predominant frequency, the 1st to 5th order frequencies, and their amplitudes.
前記演算処理装置は、前記計測波形を、前記コンクリート構造物が健全な状態において取得された弾性波基本データに基づき生成される基本波形と比較表示する表示装置を備えるものであってもよい。 The arithmetic processing unit may include a display device that compares and displays the measured waveform with a basic waveform generated based on elastic wave basic data acquired in a sound state of the concrete structure.
本発明によれば、点検対象となるコンクリート構造物の点検領域内部における、打撃具により与えた弾性波の速さ分布を高い精度で求めることが可能となり、コンクリート構造物の内部が健全な状態であるかどうかの判定を高い精度で行うことができる。 According to the present invention, it is possible to obtain with high accuracy the speed distribution of elastic waves given by the striking tool inside the inspection area of the concrete structure to be inspected, and the inside of the concrete structure is in a sound state. It is possible to determine whether or not there is a presence with high accuracy.
また、弾性波検出センサの各々において得られた計測データに基づき生成される計測波形を、コンクリート構造物が健全な状態において取得された弾性波基本データに基づき生成される基本波形と比較表示することで、コンクリート構造内部状況の簡易診断を行うことができる。 In addition, the measurement waveform generated based on the measurement data obtained by each of the elastic wave detection sensors shall be compared and displayed with the basic waveform generated based on the elastic wave basic data acquired in a healthy state of the concrete structure. Therefore, a simple diagnosis of the internal condition of the concrete structure can be performed.
図１を参照しながら、本発明に係るコンクリート構造物内部状況点検方法及びその方法に使用するシステムの実施形態を説明する。
この実施形態では、図１に示す計測装置１０が使用される。計測装置１０は、点検対象となるコンクリート構造物の点検部位表面に対し平行配置される基板１を有し、基板１に、８個の弾性波検出センサ２と、８個の打撃具３が、基板１を貫通する状態で取り付けられている。なお、図１では、弾性波検出センサ２と打撃具３の基板１への取り付け状態を明確にするため、計測装置１０を部分的に破断して示すものとする。
An embodiment of a method for inspecting the internal condition of a concrete structure according to the present invention and a system used for the method will be described with reference to FIG.
In this embodiment, the measuring device 10 shown in FIG. 1 is used. The measuring device 10 has a substrate 1 arranged in parallel with the surface of an inspection site of a concrete structure to be inspected, and eight elastic wave detection sensors 2 and eight striking tools 3 are mounted on the substrate 1. It is attached so as to penetrate the substrate 1. In FIG. 1, in order to clarify the state in which the elastic wave detection sensor 2 and the striking tool 3 are attached to the substrate 1, the measuring device 10 is partially broken.
点検対象となるコンクリート構造物の点検部位表面において、弾性波検出センサ２の接触点は受振地点と、打撃具３により打撃の与えられる地点は発振地点となるが、弾性波検出センサ２と打撃具３の配置は、発振地点が受振地点のいずれとも異なる場所になるものとされている。この実施形態では、発振地点から受振地点に至る健全経路が構成する多角形の面積の最大面積を小さくし、更に面積上位５０の多角形の面積のバラつきを抑える地点となる配置とされている。ただし、発振地点と受振地点の決め方に制限はなく、点検対象の形状や状態を考慮し最適な配置とすればよい。 On the surface of the inspection site of the concrete structure to be inspected, the contact point of the elastic wave detection sensor 2 is the vibration receiving point, and the point where the impact is applied by the striking tool 3 is the oscillation point, but the elastic wave detection sensor 2 and the striking tool The arrangement of 3 is such that the oscillation point is different from any of the vibration receiving points. In this embodiment, the maximum area of the area of the polygon formed by the sound path from the oscillation point to the vibration receiving point is reduced, and the arrangement is such that the variation in the area of the top 50 polygons is suppressed. However, there is no limitation on how to determine the oscillation point and the vibration receiving point, and the optimum arrangement may be made in consideration of the shape and condition of the inspection target.
また、受振地点は、点検対象となるコンクリート構造物の点検部位表面において、点検領域を囲う境界上に位置するものとなっている。この実施形態では、１辺が２００ｍｍの正方形の内側が点検領域とされている。 In addition, the vibration receiving point is located on the boundary surrounding the inspection area on the surface of the inspection site of the concrete structure to be inspected. In this embodiment, the inside of a square having a side of 200 mm is the inspection area.
なお、この実施形態では、受振地点の数、すなわち、弾性波検出センサ２の数は８個とされているが、その数に制限はなく、点検対象の形状や状態を考慮し最適な数とすればよい。ただし、８個以上とすることが好ましい。また、弾性波を検出する手法に制限はないが、加速度を利用した検出法が好適である。そして、加速度を利用して検出する場合、用いるセンサのレンジは２０Ｇ以上が好ましく、１００Ｇ以上がより好ましく、２００Ｇ以上が更に好ましい。 In this embodiment, the number of vibration receiving points, that is, the number of elastic wave detection sensors 2 is eight, but the number is not limited and is the optimum number in consideration of the shape and state of the inspection target. do it. However, the number is preferably 8 or more. Further, although there is no limitation on the method for detecting elastic waves, a detection method using acceleration is preferable. When detecting using acceleration, the range of the sensor used is preferably 20 G or more, more preferably 100 G or more, and even more preferably 200 G or more.
打撃具３には、ソレノイドを使用した公知のものが採用されているが、点検部位の表面に対し力をコントロールして加えることができるものであれば制限はない。点検部位の形状や状態を考慮し最適なものを採用すればよい。 A known striking tool 3 using a solenoid is used, but there is no limitation as long as the force can be controlled and applied to the surface of the inspection site. The optimum one may be adopted in consideration of the shape and condition of the inspection site.
打撃具３の各々の先端部には、コンクリート構造物に対し打撃具３により与えられる打撃力を検出する打撃力検出センサ４が取り付けられている。打撃力検出センサ４には、圧電・圧縮型の公知のフォースセンサが採用されているが、打撃具３の打撃力を計測できるものであれば制限はない。点検部位の形状や状態を考慮し最適なものを採用すればよい。 A striking force detection sensor 4 for detecting the striking force applied by the striking tool 3 to the concrete structure is attached to each tip of the striking tool 3. A known piezoelectric / compression type force sensor is used for the striking force detection sensor 4, but there is no limitation as long as the striking force of the striking tool 3 can be measured. The optimum one may be adopted in consideration of the shape and condition of the inspection site.
弾性波検出センサ２及び打撃力検出センサ４で得られた計測データは、基板１の上方に配置されている天板５に取り付けられたデータ変換装置６で図示しない演算処理装置で処理できる形式のデータに変換され、当該演算処理装置に入力され、処理されるものとなっている。なお、図１において、各配線の図示は省略されている。 The measurement data obtained by the elastic wave detection sensor 2 and the impact force detection sensor 4 can be processed by an arithmetic processing device (not shown) by the data conversion device 6 attached to the top plate 5 arranged above the substrate 1. It is converted into data, input to the arithmetic processing device, and processed. In FIG. 1, the illustration of each wiring is omitted.
この実施形態では、データ変換装置６として、公知のＡＤコンバータが採用されている。データ変換装置６の仕様は、弾性波検出センサ２、打撃力検出センサ４及び演算処理装置の仕様に応じたものとすればよいが、弾性波検出センサ２として加速度センサを採用した場合、分解能が１０ｂｉｔ以上、好ましくは１２〜２４ｂｉｔ、より好ましくは１８〜２４ｂｉｔで、サンプリング周波数が１ＭＨｚ以上のサンプリングを実行できるものが好ましい。 In this embodiment, a known AD converter is adopted as the data conversion device 6. The specifications of the data conversion device 6 may be those according to the specifications of the elastic wave detection sensor 2, the striking force detection sensor 4, and the arithmetic processing device, but when an acceleration sensor is adopted as the elastic wave detection sensor 2, the resolution is high. It is preferably 10 bits or more, preferably 12 to 24 bits, more preferably 18 to 24 bits, and capable of performing sampling with a sampling frequency of 1 MHz or more.
演算処理装置は、データ変換装置６から取得したデータに基づき、後述のデータ処理及び演算処理ができる機能を備えるものであればよく、公知のパーソナルコンピュータを使用してもよい。 The arithmetic processing unit may be a known personal computer as long as it has a function capable of performing data processing and arithmetic processing described later based on the data acquired from the data conversion apparatus 6.
基板１の四隅には、車輪７が取り付けられている。車輪７の回転数はデータ変換装置６で計測され、演算処理装置に入力されるものとなっている。そして、点検作業が終了した領域から次の点検領域に計測装置１０を移動させる場合、車輪７の回転数に基づき移動距離を算出し、複数の点検領域の相対位置を特定することが可能とされている。 Wheels 7 are attached to the four corners of the substrate 1. The rotation speed of the wheel 7 is measured by the data conversion device 6 and input to the arithmetic processing unit. Then, when moving the measuring device 10 from the area where the inspection work is completed to the next inspection area, it is possible to calculate the moving distance based on the rotation speed of the wheels 7 and specify the relative positions of the plurality of inspection areas. ing.
この計測装置１０を使用して、点検対象となるコンクリート構造物の内部構造を点検する場合、まず、弾性波検出センサ２が点検部位表面に強く押し付けられる状態で、計測装置１０を点検部位表面に配置する。 When inspecting the internal structure of a concrete structure to be inspected using this measuring device 10, first, the measuring device 10 is pressed against the surface of the inspection site while the elastic wave detection sensor 2 is strongly pressed against the surface of the inspection site. Deploy.
計測装置１０の配置作業が完了したら、打撃具３により、点検部位表面に打撃を与える。打撃具３により打撃を与える回数に制限はなく、点検部位の状態等に応じて適宜決めることができる。例えば、各打撃具３で１回ずつ、すなわち、この実施形態では合計８回の打撃を与えることとしてもよく、或いは、各打撃具３で複数回ずつ、すなわち、この実施形態では合計で８の倍数回の打撃を与えることとしてもよい。 When the arrangement work of the measuring device 10 is completed, the striking tool 3 hits the surface of the inspection site. There is no limit to the number of times the hitting tool 3 hits, and it can be appropriately determined according to the condition of the inspection site and the like. For example, each striking tool 3 may be hit once, that is, a total of eight hits in this embodiment, or each striking tool 3 may be hit a plurality of times, that is, a total of eight hits in this embodiment. It may be given a multiple of hits.
また、各打撃具３による打撃は、コンクリート表面及び内部の弾性波の減衰を確認できる時間を確保できる間隔で実施することが好ましい。 Further, it is preferable that the striking by each striking tool 3 is performed at intervals that can secure a time for confirming the attenuation of the elastic waves on the concrete surface and inside.
この実施形態では、各打撃具３で与える打撃の回数が１０とされ、打撃の時間間隔が５００ミリ秒とされ、演算処理装置を介してデータ変換装置６に記憶されている。そして、各打撃具３の動作が、データ変換装置６により制御されるものとなっている。 In this embodiment, the number of hits given by each hitting tool 3 is 10, the hitting time interval is set to 500 milliseconds, and the hits are stored in the data conversion device 6 via the arithmetic processing unit. The operation of each striking tool 3 is controlled by the data conversion device 6.
点検部位表面に打撃具３により打撃が与えられると、その打撃毎に、弾性波検出センサ２及び打撃力検出センサ４で得られた計測データが、データ変換装置６において演算処理装置で処理できる形式のデータに変換され、演算処理装置に入力される。 When a striking tool 3 hits the surface of the inspection site, the measurement data obtained by the elastic wave detection sensor 2 and the striking force detection sensor 4 can be processed by the arithmetic processing device in the data conversion device 6 for each striking. It is converted into the data of the above and input to the arithmetic processing device.
演算処理装置では、打撃力検出センサ４で得られた打撃力計測波形の平滑化された波形の立ち上がり検出点と、弾性波検出センサ２の各々において得られた計測データに基づき生成される計測波形の平滑化された波形の立ち上がり又は立ち下がりの検出点に基づき、発振地点から受振地点に至る弾性波の伝播時間が算出される。 In the arithmetic processing device, the rising detection point of the smoothed waveform of the striking force measurement waveform obtained by the striking force detection sensor 4 and the measurement waveform generated based on the measurement data obtained by each of the elastic wave detection sensor 2 The propagation time of elastic waves from the oscillation point to the vibration receiving point is calculated based on the detection points of the rising or falling edges of the smoothed waveform.
波形の平滑化は、例えば、計測波形に二次多項式をあてはめることにより行うことができる。また、計測波形に二次多項式をあてはめる手法として、公知の手法、例えば、Ｓａｖｉｔｚｋｙ−Ｇｏｌａｙフィルタを採用することができる。 Waveform smoothing can be performed, for example, by applying a quadratic polynomial to the measured waveform. Further, as a method of applying a quadratic polynomial to the measured waveform, a known method, for example, a Savitzky-Goray filter can be adopted.
得られた伝播時間のバラつきが無視できない場合は、複数回の打撃から伝播時間の代表値を選ぶことが好ましい。伝播時間の代表値は、例えば、以下の数式（１）で定義される、各打撃回における発振地点毎の差分の二乗和ｄｉｆｆ［ｎ，ｉ］が最小となる打撃回の伝播時間を代表値として採用してもよい。 When the obtained variation in propagation time cannot be ignored, it is preferable to select a representative value of propagation time from a plurality of hits. The representative value of the propagation time is, for example, the propagation time of the impact times at which the sum of squared diff [n, i] of the difference for each oscillation point at each impact time is minimized, which is defined by the following mathematical formula (1). May be adopted as.
演算処理装置では、更に、算出された伝播時間に基づくトモグラフィ解析が実行され、スローネス分布が求められる。得られたスローネス分布は、演算処理装置が備える表示装置に出力されるため、その出力されたスローネス分布を参照して点検領域の内部状況を点検することができる。 In the arithmetic processing unit, tomography analysis based on the calculated propagation time is further executed, and the slowness distribution is obtained. Since the obtained slowness distribution is output to the display device included in the arithmetic processing unit, the internal condition of the inspection area can be checked with reference to the output slowness distribution.
トモグラフィ解析で使用するセルは、発生地点と受振地点を結ぶ健全経路が通過するものとなるように決定し、ノード（計算点）は、各セルの頂点及び辺上に設けることが好ましい。例えば、この実施形態の２００ｍｍ×２００ｍｍの正方形の検出領域に対して、５セル×５セルの合計２５セルを設け、各セルの１辺を４分割する数のノードを設けてもよい。或いは、１７セル×１７セルの合計２８９セルを設け、各セルの１辺を２分割する数のノードを設けてもよい。ただし、セルとノードの数に制限はなく、点検部位の状態や解析条件等に応じて適宜決めることができる。 It is preferable that the cells used in the tomography analysis are determined so that the sound path connecting the generation point and the vibration receiving point passes through, and the nodes (calculation points) are provided on the vertices and sides of each cell. For example, a total of 25 cells of 5 cells × 5 cells may be provided for a square detection area of 200 mm × 200 mm of this embodiment, and a number of nodes may be provided so as to divide one side of each cell into four. Alternatively, a total of 289 cells of 17 cells × 17 cells may be provided, and a number of nodes that divide one side of each cell into two may be provided. However, the number of cells and nodes is not limited, and can be appropriately determined according to the condition of the inspection site, analysis conditions, and the like.
演算処理装置では、また、点検部位の速さ分布が求められる。速さ分布の算出にあたっては、弾性波検出センサ２の各々において得られた計測データに基づき生成される計測波形を高速フーリエ変換（ＦＦＴ）し、求められた卓越周波数、１次から５次の周波数、及びそれらの振幅から弾性波速さを求める。そして、トモグラフィ解析で使用するセルに、この弾性波速さを与え調和平均から速さ分布を算出する。この際、弾性波速さは、トモグラフィ解析で使用するセルに対し、発振地点から受振地点方向へ、左右２２．５度、合計４５度の影響線内で与えることが好ましい。 In the arithmetic processing unit, the speed distribution of the inspection part is also required. In calculating the speed distribution, the measurement waveform generated based on the measurement data obtained by each of the elastic wave detection sensors 2 is fast Fourier transformed (FFT), and the obtained dominant frequency is the first to fifth order frequency. , And their amplitudes to determine the elastic wave velocity. Then, this elastic wave velocity is given to the cell used in the tomography analysis, and the velocity distribution is calculated from the harmonic mean. At this time, the elastic wave velocity is preferably given within the influence line of 22.5 degrees to the left and right, for a total of 45 degrees, from the oscillation point to the vibration receiving point with respect to the cell used in the tomography analysis.
得られた速さ分布は、既述のスローネス分布と同様に、演算処理装置が備える表示装置に出力されるため、その出力された速さ分布を参照して点検領域の内部状況を点検することができる。 Since the obtained speed distribution is output to the display device provided in the arithmetic processing unit in the same manner as the slowness distribution described above, the internal condition of the inspection area should be checked with reference to the output speed distribution. Can be done.
更にまた、演算処理装置は、コンクリート構造物が健全な状態において得られたデータを弾性波基本データとして、この弾性波基本データに基づき基本波形を生成する。そして、この基本波形は、弾性波検出センサ２の各々において得られた計測データに基づき生成される計測波形と比較可能な形で、演算処理装置が備える表示装置に出力されるため、その出力された波形を参照して点検領域の内部状況を点検することができる。 Furthermore, the arithmetic processing device uses the data obtained in a sound state of the concrete structure as the elastic wave basic data, and generates a basic waveform based on the elastic wave basic data. Then, this basic waveform is output to the display device included in the arithmetic processing unit in a form comparable to the measurement waveform generated based on the measurement data obtained by each of the elastic wave detection sensors 2, and thus is output. The internal condition of the inspection area can be inspected by referring to the waveform.
計測装置１０を使用し、既設道路橋の橋台の内部状況の点検を行った。点検部位のスローネス分布を図２に、速さ分布を図３に、基本波形と計測波形の比較表示を図４及び図５に示す。なお、点検対象の橋台には、予め公知の打音点検が実施されており、その打音点検により変状有と判定された部位と変状無と判定された部位の双方を、点検部位とした。図４及び図５に示す基本波形は、変状無（健全）と判定された部位で得られたものである。また、図４において、中央位置の上下方向に引かれた想像線の左側が健全な場合に得られる波形を、右側が変状有の場合に得らえる波形を示し、いずれの場合においても、中央が発振地点での波形を、その周囲が各受振地点での波形を示している。 The internal condition of the pier of the existing road bridge was inspected using the measuring device 10. The slowness distribution of the inspection site is shown in FIG. 2, the speed distribution is shown in FIG. 3, and the comparative display of the basic waveform and the measured waveform is shown in FIGS. 4 and 5. In addition, the abutment to be inspected has been subjected to a known tapping sound inspection in advance, and both the part determined to have deformation and the part determined to have no deterioration by the tapping sound inspection are referred to as inspection parts. did. The basic waveforms shown in FIGS. 4 and 5 were obtained at sites determined to be normal (healthy). Further, in FIG. 4, the left side of the imaginary line drawn in the vertical direction of the center position shows the waveform obtained when it is sound, and the right side shows the waveform obtained when there is deformation. In any case, The center shows the waveform at the oscillation point, and the periphery shows the waveform at each vibration receiving point.
図２〜５で示された結果は、打音点検や、目視できる部位の状態（表面のひび割れ）と合致することが確認された。 It was confirmed that the results shown in FIGS. 2 to 5 were consistent with the tapping sound inspection and the state of the visible part (crack on the surface).
基本波形と計測波形の比較表示においては、図５に示すように、包絡線をあわせて表示してもよい。これにより、基本波形と計測波形の波形形態の比較を容易に行うことができる。図５は基本波形（健全）と計測波形（損傷）を示している。 In the comparative display of the basic waveform and the measured waveform, the envelope may be displayed together as shown in FIG. This makes it possible to easily compare the waveform forms of the basic waveform and the measured waveform. FIG. 5 shows a basic waveform (healthy) and a measured waveform (damage).
１ 基板
２ 弾性波検出センサ
３ 打撃具
４ 打撃力検出センサ
５ 天板
６ データ変換装置
７ 車輪
１０ 計測装置
1 Substrate 2 Elastic wave detection sensor 3 Strike tool 4 Strike force detection sensor 5 Top plate 6 Data conversion device 7 Wheel 10 Measuring device
Claims (4)
前記点検領域における前記弾性波検出センサが配置されていない複数の地点に打撃具を配置し、
前記コンクリート構造物における前記弾性波検出センサの配置された平面に対し前記打撃具により与えられる打撃力を検出する打撃力検出センサを前記打撃具の各々に対応させて配置し、
前記打撃力検出センサで得られた打撃力計測波形の平滑化された波形の立ち上がり検出点と、前記弾性波検出センサの各々において得られた計測データに基づき生成される計測波形の平滑化された波形の立ち上がり又は立ち下がりの検出点に基づき、発振地点から受振地点に至る弾性波の伝播時間を算出し、
前記計測波形を高速フーリエ変換（ＦＦＴ）し、求められた卓越周波数、１次から５次の周波数、及びそれらの振幅から、弾性波速さを求めることを特徴とするコンクリート構造物内部状況点検方法。 On the surface of the inspection site of the concrete structure to be inspected, elastic wave detection sensors are placed at multiple points on the boundary surrounding the inspection area.
Strike tools are placed at a plurality of points in the inspection area where the elastic wave detection sensor is not placed.
A striking force detection sensor that detects the striking force applied by the striking tool is arranged so as to correspond to each of the striking tools on the plane on which the elastic wave detection sensor is arranged in the concrete structure.
The rising detection point of the smoothed waveform of the striking force measurement waveform obtained by the striking force detection sensor and the smoothed measurement waveform generated based on the measurement data obtained by each of the elastic wave detection sensors. Based on the detection point of the rising or falling of the waveform, the propagation time of the elastic wave from the oscillation point to the vibration receiving point is calculated.
A method for inspecting the internal condition of a concrete structure, which comprises performing a fast Fourier transform (FFT) on the measured waveform and obtaining an elastic wave velocity from the obtained predominant frequency, the first to fifth frequencies, and their amplitudes.
前記点検領域における前記弾性波検出センサが配置されていない複数の地点に配置された打撃具の複数と、
前記打撃具の各々に対応して配置され、前記コンクリート構造物における前記弾性波検出センサの配置された平面に対し前記打撃具により与えられる打撃力を検出する打撃力検出センサの複数と、
前記弾性波検出センサ及び前記打撃力検出センサにより得られた計測データを取得し処理する演算処理装置を備え、
前記演算処理装置は、前記打撃力検出センサで得られた打撃力計測波形の平滑化された波形の立ち上がり検出点と、前記弾性波検出センサの各々において得られた計測データに基づき生成される計測波形の平滑化された波形の立ち上がり又は立ち下がりの検出点に基づき、発振地点から受振地点に至る弾性波の伝播時間を算出し、前記計測波形を高速フーリエ変換（ＦＦＴ）し、求められた卓越周波数、１次から５次の周波数、及びそれらの振幅から、弾性波速さを求めることを特徴とするコンクリート構造物内部状況点検システム。 On the surface of the inspection site of the concrete structure to be inspected, a plurality of elastic wave detection sensors arranged at a plurality of points on the boundary surrounding the inspection area, and
A plurality of striking tools arranged at a plurality of points where the elastic wave detection sensor is not arranged in the inspection area, and
A plurality of striking force detection sensors arranged corresponding to each of the striking tools and detecting the striking force applied by the striking tool with respect to the plane on which the elastic wave detection sensor is arranged in the concrete structure.
It is provided with an arithmetic processing unit that acquires and processes measurement data obtained by the elastic wave detection sensor and the impact force detection sensor.
The arithmetic processing device is a measurement generated based on the rising detection point of the smoothed waveform of the striking force measurement waveform obtained by the striking force detection sensor and the measurement data obtained by each of the elastic wave detection sensors. Based on the rising or falling detection points of the smoothed waveform, the propagation time of the elastic wave from the oscillation point to the vibration receiving point is calculated, and the measured waveform is subjected to high-speed Fourier transformation (FFT) to obtain the predominance. A concrete structure internal condition inspection system characterized in that an elastic wave velocity is obtained from frequencies of the first to fifth orders and their amplitudes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019228782A JP6773878B1 (en) | 2019-12-19 | 2019-12-19 | Concrete structure internal condition inspection method and system used for that method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019228782A JP6773878B1 (en) | 2019-12-19 | 2019-12-19 | Concrete structure internal condition inspection method and system used for that method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP6773878B1 true JP6773878B1 (en) | 2020-10-21 |
| JP2021096197A JP2021096197A (en) | 2021-06-24 |
Family
ID=72830778
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2019228782A Active JP6773878B1 (en) | 2019-12-19 | 2019-12-19 | Concrete structure internal condition inspection method and system used for that method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6773878B1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113218560A (en) * | 2021-04-19 | 2021-08-06 | 中国长江电力股份有限公司 | Ultrasonic real-time estimation method for bolt pretightening force |
| CN113252791A (en) * | 2021-07-08 | 2021-08-13 | 四川升拓检测技术股份有限公司 | Elastic wave tomography scanning detection method based on small cross survey line arrangement mode |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62231634A (en) * | 1986-03-31 | 1987-10-12 | 株式会社東芝 | Ultrasonic diagnostic apparatus |
| JP5271941B2 (en) * | 2010-03-15 | 2013-08-21 | 飛島建設株式会社 | Non-destructive detection system and non-destructive detection method |
| JP5666334B2 (en) * | 2011-02-15 | 2015-02-12 | 佐藤工業株式会社 | Quality diagnosis method for concrete structures |
| US9267925B2 (en) * | 2012-09-07 | 2016-02-23 | Polexpert, Llc | Pole integrity meter and method of determining pole integrity |
| JP5653993B2 (en) * | 2012-12-19 | 2015-01-14 | 日本電信電話株式会社 | Anomaly detection system and anomaly detection method for columnar structures |
| CN104007176B (en) * | 2014-05-12 | 2017-02-15 | 上海交通大学 | Full-wave field detection system and method of complex geotechnical engineering medium |
| JP6856392B2 (en) * | 2017-02-02 | 2021-04-07 | 株式会社東芝 | Deterioration diagnosis method, deterioration diagnosis system and sensor |
| JP2018128278A (en) * | 2017-02-06 | 2018-08-16 | 公益財団法人鉄道総合技術研究所 | Hammer sound inspector and hammer sound system |
| JP6920729B2 (en) * | 2017-09-26 | 2021-08-18 | 京都電子工業株式会社 | Moisture content estimation method for wood and its equipment |
-
2019
- 2019-12-19 JP JP2019228782A patent/JP6773878B1/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113218560A (en) * | 2021-04-19 | 2021-08-06 | 中国长江电力股份有限公司 | Ultrasonic real-time estimation method for bolt pretightening force |
| CN113218560B (en) * | 2021-04-19 | 2022-05-17 | 中国长江电力股份有限公司 | Ultrasonic real-time estimation method for bolt pretightening force |
| CN113252791A (en) * | 2021-07-08 | 2021-08-13 | 四川升拓检测技术股份有限公司 | Elastic wave tomography scanning detection method based on small cross survey line arrangement mode |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2021096197A (en) | 2021-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6171214B2 (en) | Nondestructive inspection system for structures using tomographic analysis | |
| US6360609B1 (en) | Method and system for interpreting and utilizing multimode dispersive acoustic guided waves | |
| CN104976970B (en) | A kind of ultrasonic phase array voussoir self-check system and its method | |
| JP6773878B1 (en) | Concrete structure internal condition inspection method and system used for that method | |
| JP6159926B2 (en) | Simultaneous identification method of transmission point and physical properties (degradation status) in elastic wave tomography performed on measurement object of inhomogeneous physical properties | |
| CN109696480B (en) | Glass fiber composite material acoustic emission source positioning imaging method based on improved time reversal algorithm | |
| JP5271941B2 (en) | Non-destructive detection system and non-destructive detection method | |
| RU2371691C1 (en) | Method for monitoring of machines and structures | |
| US9329155B2 (en) | Method and device for determining an orientation of a defect present within a mechanical component | |
| Zhong et al. | Quasi-optical coherence vibration tomography technique for damage detection in beam-like structures based on auxiliary mass induced frequency shift | |
| CN108226294A (en) | A kind of ultrasonic detection method of lack of penetration weld seam | |
| JP5280407B2 (en) | Damage detection method, damage detection apparatus and program for columnar structure | |
| JP6511892B2 (en) | State determination apparatus for a structure, state determination system, and state determination method | |
| JP2003043019A (en) | Condition measuring instrument for concrete | |
| Ostachowicz et al. | Damage detection using laser vibrometry | |
| JP2002296244A (en) | Method and device for diagnosing concrete structure | |
| CN107807173B (en) | flat plate structure burst type sound emission source positioning method based on power function | |
| Ozevin | Geometry-based spatial acoustic source location for spaced structures | |
| CN104777227A (en) | Internal concrete defect detection method based on principles of three views | |
| Lee et al. | Identification of impact force on a thick plate based on the elastodynamic and higher-order time-frequency analysis | |
| US11796511B1 (en) | Structural monitoring system | |
| JP4074960B2 (en) | Acoustic diagnosis / measurement apparatus using pulsed electromagnetic force, and diagnosis / measurement method thereof | |
| KR20100003648A (en) | Crack monitoring system, crack monitoring method and computer readable medium on which crack monitoring program is recorded | |
| CN104297345B (en) | One-dimensional structure incontinuity on-line detection method | |
| CN111896623A (en) | Method for positioning defects of cast forging through ultrasonic detection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20191220 |
|
| A871 | Explanation of circumstances concerning accelerated examination |
Free format text: JAPANESE INTERMEDIATE CODE: A871 Effective date: 20191220 |
|
| A975 | Report on accelerated examination |
Free format text: JAPANESE INTERMEDIATE CODE: A971005 Effective date: 20200310 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20200318 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20200512 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20200715 |
|
| 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: 20200915 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20201001 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6773878 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R154 | Certificate of patent or utility model (reissue) |
Free format text: JAPANESE INTERMEDIATE CODE: R154 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |