JP2005233680A - Fluid leakage of pipeline search system and its search method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recognize the leaking point of a pipeline correctly, and to speed up and simplify the process for specification of the leakage position. <P>SOLUTION: The fluid leakage of the pipeline search system 2 is constituted such that the search device 4 is arranged in the pipeline 3 laid under the ground, from which the fluid has evacuated. The leakage search device 4 is provided with the neutron moisture meter 20 provided with upper and lower detector parts 20A-20C for measuring thermal neutrons passed through the upper and lower soil of the pipeline 3 emitted from the radiation source RS, and deduces the measurement positions on the pipeline 3 and each measurement data (counts) corresponding to the measurement positions by controlling the travelling of the leakage search device 4 so as to determine the water leakage position on the pipeline 3. When the measurement data of the lower detector parts 20A, 20B are hidden by the back ground of the upper detector part 20C, the increasing/decreasing pattern for each measurement is measured and the filter processing is performed for extracting the number of measurements showing the same pattern continuing predetermined times, and thus, the correct leakage position is determined. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention uses a pipeline fluid leakage exploration system with respect to its exploration method, in particular, the pipeline fluid leakage exploration system to probe the position of the leakage occurring in underground pipelines with a large diameter, such as agricultural water utilization facility that It relates to exploration methods.

  Agricultural waterways began to be pipelined in the 1960s, and in 1990, approximately 200,000 ha of water, 16% of the developed paddy fields, was pipelined. Since then, state-owned projects alone have increased the number of pipelines installed at a rate of 100 to 150 km per year. Maintenance early in buried pipelines, water leakage in some aging is a problem. In addition, in the design of the initial pipeline for measures against earthquake it was not enough, there is a place where deformed by ground motion leakage is a concern. Pipeline diameters used range from 150 mm to 300 mm. Up to now, there is no statistical data on the amount of water leakage from agricultural pipelines, but it is estimated that about 10% of water leakage occurs in consideration of examples such as waterworks. At the design stage, a 5% transport loss is expected, so if a loss of 5% or more occurs due to water leakage, the plan will be hindered. However, in order to use actual situation at the end it can not be accurately determined, the measurement of the amount of water leakage can not be evaluated in the water balance. When a leak location is discovered, a method is used to calculate from the scale, but the fact that the leak location cannot be detected is the reason why the actual leak location cannot be determined.

  Conventionally, as a method of exploring water leakage, in water leakage investigation of underground pipes for water supply (many diameters are 100 mm to 250 mm), a sounding rod connected to a water leakage detector is applied to the ground on the piping, and from the water leakage point to the ground There is known a method for detecting a water leak location by a transmitted water leak sound. The leak noise, sound accompanying the water vigorously ejected by pressure from a water pipe is buried underground, (1) running water sounds, (2) impact sound, fricative and (3) tube, (4) pipe vibration it is a complex tone with four sound elements. Since the water leaking sound combines conditions such as the occurrence of water leakage, soil quality, pipe type, water pressure, depth and the four elements, the water leaking sound does not have a constant frequency distribution. For this reason, research is carried out in the middle of the night with less noise, skill of listening technology is required to investigators. Recently, combined or high bass several filter leak noise, how the two leak detection instrument can not rely on the experience and intuition indexing by correlation distance leak position from the small arrival time differences of leak noise detecting row It has been broken. However, it is a fact that the pseudo sound of water leakage due to car noise makes it difficult to identify the water leakage sound, and the final judgment must rely on many years of experience and intuition.

Therefore, conventionally, the leakage exploration large diameter pipelines are known the following five methods. (1) a method of encapsulating a high pressure gas detecting the leakage to the outside of the pipe, (2) a method of detecting by sealing high pressure air pressure drop section (3) a method of detecting the leakage sounds of water and trapped air (4) A method of measuring a potential difference between a pipe and the ground, and (5) a method of visualizing a dielectric constant distribution by an underground radar (for example, see Non-Patent Document 1).
ShimaHiroshiMasashi, Kazuhiko Kajima, Hideki Kamiya ed. "Resistivity Imaging" Kokin Shoin, March 3, 1995, p189-190

  However, the methods (1) and (2) are difficult to apply to a large-capacity large-diameter pipeline, and the resolution is low even if it is forcibly adopted. (3) The method of is in principle applicable, the actually embodiment significantly lower hit rate. The method (4) is a principle that can be applied to damage of a coated pipe, but in reality, satisfactory results are rarely obtained by interference with artificial noise. The method (5) can be applied only when the ground is hollowed in the shallow area, and there is a limit to detecting the water leaking point of a large-diameter pipeline with a pipe diameter of 400 mm or more. In addition, when a large-diameter pipeline leaks water and a person enters the pipe and conducts a visual inspection, a fatal accident may occur due to a tunnel survey or inspection of sewers, manholes, old wells, water storage tanks, etc. as can be seen, the lack of oxygen accident is a concern. Also, if the pipe diameter is to identify the leakage location, for example 400mm~900mm agricultural irrigation pipeline, because people can not enter into the tube, for example, it is introduced into the pipeline that has been drained a small camera and fiberscope , workers are adapted to visually check the external monitor. However, it is not possible to immediately identify a water leak point due to a flaw inside the pipeline, and it takes a lot of work time based on the experience and intuition of the worker whether the flaw leads to water leak. In addition, when water leaks due to minute scratches that cannot be grasped visually, there is a possibility of overlooking the water leak point.

  The present invention has been made to solve the above-described problems, and provides a pipeline fluid leak search system and a search method thereof that can easily and reliably find a fluid leak location in a pipeline with a simple configuration. it is an object of the present invention to be.

  The pipeline fluid leakage exploration system according to the present invention is a pipeline fluid leakage exploration system embedded in the underground and in which a fluid circulates. The traveling means is disposed in the pipeline from which the fluid is discharged, and the traveling means is radioactive. Thermal neutron measurement means for measuring thermal neutrons emitted from the radiation source and respectively passing through the soil above and below the pipeline are provided, and the travel of the travel means is controlled to control the thermal neutron measurement positions on the pipeline and the corresponding positions. indexing the thermal neutron measurement data is obtained so as to identify the fluid leakage position of the pipeline.

  The pipeline fluid leakage exploration system according to the present invention, the thermal neutron measuring means disposed in the pipeline, and since so that measured while traveling in the pipeline by the traveling unit, the traveling means at a predetermined speed When measuring thermal neutrons that have passed through the soil above and below the pipeline continuously and repeatedly using the thermal neutron measurement means while traveling, the thermal neutron measurement position on the pipeline and its position correspond to the measurement times, traveling speed, and traveling distance. the measurement data of each thermal neutrons that are indexed. For this reason, the position where the fluid component change increases is read from the combined value of the radioactivity variation and the fluid component change that occur randomly based on the determined data, and the fluid leakage position of the pipeline is specified.

  The pipeline fluid leakage exploration system according to claim 2 is a pipeline fluid leakage exploration system embedded in the underground and in which the fluid flows, and is disposed inside the pipeline from which the fluid is discharged, and receives a command signal from the outside. The traveling means whose drive is controlled based on the above and the thermal neutrons that are provided in the traveling means, have a radioactive radiation source, are emitted from the radiation source, and pass through the soil above and below the pipeline, are measured every predetermined time. Thermal neutron measurement means that outputs to the outside, travel distance measurement means that is provided in the travel means, measures the travel distance of the travel means and outputs to the outside, and is disposed on the ground, and the travel means is connected to the input means via the monitor. Thermal neutron measurement values and travel distances output from thermal neutron measurement means and travel distance measurement means, respectively, while operating freely at a constant travel speed Constant values and travel speed data of the travel means are input, these data are stored in the memory and processed, and the measurement position on the pipeline is determined from the travel speed and travel distance for each measurement of thermal neutrons. A central processing unit that obtains data of thermal neutrons above and below the pipeline at the measurement position and identifies the fluid leakage position of the pipeline is provided.

  The pipeline fluid leakage exploration system according to claim 2, continuous thermal neutrons which have passed through the soil in the vertical pipeline respectively by thermal neutron measuring means while traveling at a predetermined speed traveling means pipeline the fluid is discharged When the travel distance required for the thermal neutron measurement is measured by the travel distance measuring means, the thermal neutron measurement data and the travel distance measurement data are output to the central processing unit. When the travel speed and travel distance data are input to the central processing unit in addition to the input data, the measurement position on the pipeline for each measurement of thermal neutrons is determined. Based on the data of thermal neutrons above and below the pipeline at the measurement position, the position where the fluid component change increases is read from the combined value of the radioactivity fluctuation and fluid component change that occur at random. fluid leakage position of the is specified. For this reason, a fluid leak location is specified reliably in real time.

  Further, in the pipeline fluid leakage exploration system according to claim 3, the traveling means includes a vehicle body in which a plurality of chassis are connected to each other so as to be able to be bent, and is allowed to travel along substantially the center line of the pipeline. It is.

  In the pipeline fluid leakage search system according to the third aspect, the vehicle body bends even if the pipeline is bent. Therefore, the leakage location can be searched without being restricted by the installation shape of the pipeline.

  The pipeline fluid leakage exploration system according to claim 4 is characterized in that the thermal neutron measuring means is provided in the upper center of the vehicle body so as to be displaceable in the vertical direction, and the upper moisture for measuring the background thermal neutrons that have passed through the soil above the pipeline. A neutron moisture meter for detection, and a pair of neutron moisture meters for lower moisture detection, which are provided on the left and right sides of the lower part of the vehicle body at a predetermined distance from the inner surface of the pipeline and measure thermal neutrons passing through the soil below the pipeline, it is obtained as comprising a.

  In the claims 4 pipeline fluid leakage exploration system according to the upper moisture detecting neutron moisture meter is provided to be vertically displaced on the central upper part of the vehicle body, the lower the moisture detection neutron moisture meter pipeline inner surface and a predetermined Since the gap is provided at an interval, it is possible to suppress generation of noise components due to friction without making contact with the inner wall of the pipeline when performing measurement. Further, since the neutron moisture meter for detecting the upper moisture is provided on the center of the upper part of the vehicle body so as to be displaced vertically, it can be used for pipelines having different pipe diameters. Furthermore, the pair of neutron moisture meters for detecting the lower moisture is provided on both the left and right sides of the lower part of the vehicle body, so even if sand mud is deposited on the bottom of the pipeline, it can be avoided.

  The pipeline fluid leakage exploration system according to claim 5 is configured such that the neutron moisture meter includes a radiation source that emits fast neutrons and a neutron counter that detects thermal neutrons in the housing. in is provided with a absorbing material to reduce the neutron beam of suppressing noise components interference from other sources.

  In the pipeline fluid leakage exploration system according to the fifth aspect of the present invention, it is possible to suppress interference from other radiation sources and reduce the neutron rays of noise components by the absorber, so that accuracy is improved.

  Pipeline fluid leakage exploration system it is according to claim 6, the central processing unit, a decrease pattern detecting means for an increase or decrease pattern based on the measured values measured respectively by each of the lower moisture detection neutron moisture meter, this The same pattern extraction means for comparing the increase / decrease patterns of the neutron moisture meters for detecting both lower moisture detected by the increase / decrease pattern detection means for each measurement time and extracting the same increase / decrease pattern measurement times, and extracted by the same pattern extraction means From the measurement times of the same pattern, the measurement times where the same pattern appears continuously a predetermined number of times are further extracted, the position on the pipeline corresponding to the extracted continuous measurement times is specified, and the specified position is determined as moisture. provided filtering means and a determining means and leakage points regarded as increasing portion of, according to the specification of the pipeline It is obtained so as to remove the noise component of the background.

  In the pipeline fluid leakage exploration system according to claim 6, the height of the background at the time of embedment differs depending on the specifications of the pipeline, that is, the pipe diameter, pipe thickness and pipe material. Even if the measured thermal neutron measurement value is hidden in the background captured by the upper moisture detection neutron moisture meter, the fluctuation of the radioactivity that occurs at random is also random in the neutron moisture meter for both lower moisture detection Therefore, the same portion more than a certain number of increase / decrease patterns is regarded as a variation portion of moisture change, and the background noise component can be removed by performing the filter process, so that the location of water leakage can be accurately determined.

  The pipeline fluid leakage exploration system according to claim 7 is characterized in that the filter processing means detects moisture in both lower portions at each measurement time for measurement times in which the same pattern extracted by the same pattern extraction means appears continuously a predetermined number of times. The measured values of the neutron moisture meter for use are totaled and statistically processed.

  The pipeline fluid leakage exploration system according to claim 7, in statistical processing data, the measured values of the two lower moisture detection neutron moisture meter is total, and in the surrounding high portion of possible leakage As the area with the highest possibility of water leakage is visually emphasized, the total measurement value is relatively lower compared to the area with high possibility of water leakage even though the presence of water components is recognized in the surrounding area. In addition, it is possible to pinpoint a portion having a high possibility of water leakage very accurately.

  In the pipeline fluid leakage exploration system according to the eighth aspect of the present invention, the traveling means is provided with a photographing device that captures the state inside the pipeline and wirelessly transmits an image to an external monitor.

  The pipeline fluid leakage exploration system according to claim 8, it is possible to perform measurement while observing the internal pipeline external monitor, it can also probe damage location that does not extend to water leakage.

  In the pipeline fluid leakage exploration system according to claim 9, the traveling means outputs the video signal from the imaging device and the data from the thermal neutron measuring means and the traveling distance measuring means to the outside via radio, and externally. Is provided with a wireless communication section for sending a command signal from the traveling means to the control section of the traveling means, and this wireless communication section communicates with the outside through a transfer means disposed inside the pipeline.

  In the pipeline fluid leakage exploration system according to the ninth aspect, since the traveling means can be controlled on the ground through the image of the photographing apparatus, the work is made efficient. Further, since communication is made with the outside through the transfer means in the pipeline, the travel means can be traveled to a long distance and measurement can be performed, and a large amount of data can be obtained in a short time.

  In the pipeline fluid leakage exploration method according to the present invention, a traveling means is disposed inside a pipeline buried in the underground and through which the fluid flows, and the pipeline is discharged from the radioactive ray source to the traveling means. the thermal neutron measuring means for measuring the thermal neutrons and below the soil has passed through each provided, the traveling means thermal neutrons vertical pipeline measured by thermal neutron measuring means while traveling at a predetermined speed, the travel distance and travel speed After determining the thermal neutron measurement position on the pipeline and the data of each thermal neutron corresponding to the position, the fluid leakage position of the pipeline is specified.

  In the pipeline fluid leakage exploration method according to the present invention, the driving means continuously thermal neutrons which have passed through the soil in the vertical pipeline respectively by thermal neutron measuring means while traveling at a predetermined speed in the pipeline fluid is discharged After repeated measurement, the thermal neutron measurement position on the pipeline and the data of each thermal neutron corresponding to the position are determined from the measurement times, travel speed, and travel distance. After the data is determined, the position where the fluid component change increases is read from the combined value of the radioactivity fluctuation and the fluid component change which randomly occur based on the determined data, and the fluid leakage position of the pipeline is specified.

  Moreover, fluid leakage exploration method pipeline according to claim 11, the thermal neutrons under the pipeline side was measured by a lower moisture detection neutron moisture meter respectively provided in the traveling direction left and right sides of the traveling means, the pipeline depending on the specifications, after measuring the thermal neutrons vertical pipeline, determine the increase and decrease patterns of the measurement values measured respectively by each of the lower moisture detection neutron moisture meter, a decrease pattern for both the lower water detecting neutron moisture meter Compared every measurement time, extract the measurement times of the same increase / decrease pattern, further extract the measurement times where the same pattern appears continuously for a predetermined number of times, and extract these consecutive measurements The position on the pipeline corresponding to the time is specified, and the specified position is regarded as a water increase part and is determined as a water leak point.

  In the pipeline fluid leakage exploration method according to claim 11, the height of the background at the time of embedding differs depending on the specifications of the pipeline, that is, the pipe diameter, pipe thickness and pipe material. Even if the measured thermal neutron measurement value is hidden in the background captured by the upper moisture detection neutron moisture meter, the fluctuation of the radioactivity that occurs at random is also random in the neutron moisture meter for both lower moisture detection Therefore, the same portion more than a certain number of times as an increase / decrease pattern can be regarded as a variation portion of moisture change, the background noise component can be removed, and the location of water leakage can be accurately determined.

  Moreover, fluid leakage exploration method pipeline according to claim 12, the same patterns extracted is continuously for a predetermined number of times appears measurement times, each time they measure times measured values of the two lower moisture detection neutron moisture meter after total is obtained by such statistical processing.

  The fluid leakage exploration method pipeline according to claim 12, the data statistical processing on chart, since the measurement values of the two lower moisture detection neutron moisture meter is total, and most likely the leakage site In the surrounding area, the part with high possibility of water leakage is visually emphasized, and the surrounding area has a relatively total measurement value compared with the part with high possibility of water leakage even though the presence of water component is recognized. becomes lower, sites likely water leakage is very accurately pinpoint just by looking at statistics treated charts.

  In the pipeline fluid leakage exploration system according to the present invention, in the pipeline fluid leakage exploration system embedded in the underground and through which the fluid flows, traveling means is disposed in the pipeline from which the fluid has been discharged, and the traveling means is radioactive. Thermal neutron measurement means for measuring thermal neutrons emitted from the radiation source and respectively passing through the soil above and below the pipeline are provided, and the travel of the travel means is controlled to control the thermal neutron measurement positions on the pipeline and the corresponding positions. Since the measurement data of thermal neutrons are determined and the fluid leakage position of the pipeline is specified, the fluid leakage location in the pipeline can be easily and reliably found with a simple configuration. Also, since to measure by running in the pipeline by the traveling means, the work is more efficient.

  Further, in the pipeline fluid leakage exploration method according to the present invention, the traveling means is disposed inside the pipeline where the fluid is circulated underground and the fluid flows, and the traveling means is discharged from the radioactive radiation source. the thermal neutron measuring means for measuring the thermal neutron passing through each pipeline above and below the soil provided, the thermal neutrons in the vertical pipeline measured by the traveling means a thermal neutron measuring means while traveling at a predetermined speed, the traveling speed after indexing the respective thermal neutrons data from the travel distance and the thermal neutron measurement position on the pipeline corresponding to the position, because so as to identify the fluid leakage position of the pipeline, a leak location efficiently fluid Can be found.

  The purpose of the leakage location of the pipeline quickly and accurately identified, the fluid pipeline exhausted, thermal neutron measuring means for measuring the thermal neutron passing through respective soil vertical pipeline is released from the radioactive source The thermal neutron was measured while the thermal neutron measuring means was run by the running means, and the measurement data was made to correspond to the position data on the pipeline.

  The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is an overall view of an exploration system according to an embodiment of the present invention. Exploration system 2 according to the present embodiment, as shown in FIG. 1, a locator 4 tube diameters embedded in the agricultural irrigation facilities are out inside the pipeline 3 400Mm～900mm, disposed on the ground constructed and a 5 computer (central processing unit) for exchanging control signals and data through the exploration device 4 wirelessly.

  As shown in FIGS. 2A and 2B, the exploration device 4 is installed in a traveling vehicle (traveling means) 10 in which front and rear chassis 11A, 11C are connected via a support base 11B, and the traveling vehicle 10. The neutron moisture meter (thermal neutron measuring means) 20 is provided. Each chassis 11A, 11C and support base 11C are connected by connecting pins 12A, 12B, respectively, and these three chassis 11A-11C bend in the traveling direction. A front chassis 11A, the rear chassis. 11C, the wheels 13A, 13B are respectively provided. A battery unit 14 is attached to the rear side of the front chassis 11A. Below the front chassis 11A, a drive motor 15 electrically connected to the battery unit 14 and drive wheels 16 connected to the drive motor 15 via a drive transmission member 18 are arranged.

  The front side of the front chassis 11A, high-sensitivity radio camera 17 is provided and adapted to deliver a wireless video signal to the outside. A neutron moisture meter 20 and an odometer 21 are provided on the support base 11B. The neutron moisture meter 20 measures the scattering of thermal neutrons in which fast neutrons emitted from a radiation source such as Cf-252 are decelerated by soil moisture (hydrogen), and sends the measured values to the outside. The source is 3.7 MBq or less exempted from the Radiation Hazard Prevention Law. Odometer 21 travel distance D1, D2 by the rotation of the measuring disc to be rotated by driving abut rotatably measuring disc on the inner surface of the pipeline, ..., measured Dn, and sends the measurement to the external It is like that.

  Neutron moisture meter 20, as shown in (B) and 3 2, the lower detector (lower moisture detection neutron moisture meter) 20A, 20B and the upper detector (upper moisture detecting neutron moisture meter) 20C and It has. Each of the detection units 20A to 20C has a radiation source RS that emits fast neutrons and two neutron counters 32A and 32B that detect thermal neutrons in a long cylindrical housing 31. An absorbing material (heavy metal plate) 33 that supplements noise component neutrons is attached to the inside of the casing 32 in order to suppress interference from other radiation sources RS and reduce neutron rays of noise components. The support base 11B are frame 34 comprising a pair of plates are provided. At the top of this frame 34, a plurality of mounting holes 37 are drilled vertically depending on the type of pipe diameter of the pipeline. These mounting holes 37, so that the support arm 35 is attached. The upper detection unit 20 </ b> C and the odometer 21 are connected to the support arm 35 via a pin 36. From these upper detector 20C and the odometer 21, and is disposed along the center line L1 of the support 11B. Support arm 35, depending on the type of pipe diameter of the pipeline, adapted to be mounted by choosing the upper and lower mounting holes 37 as appropriate. The mounting position of the support arm 35, the upper detection unit 20C are opposed to each other across a narrow air gap SP1 the predetermined highest portion 3A of the pipeline 3 top and the odometer 21 measuring disc in the pipeline upper surface 3A equivalents and it is adapted to contact. Mounting holes 37 are, for example, pipe diameter of the pipeline is made to correspond to the type of 400mm or 600 mm.

  Upper detection unit 20C is configured to measure the thermal neutron background that has passed through the pipeline 3 above the soil. A pair of lower detecting unit 20A, 20B is, a support 11B in the left and right sides of the lower respectively provided at a lower inner surface with a predetermined narrow gap SP2 pipeline 3, measuring thermal neutrons passing through the soil beneath the pipeline It is supposed to be. A pair of lower detecting unit 20A, 20B from beneath the center line L1 of the support 11B was provided to be shifted to the left and right sides, when the silt containing water at the bottom of the pipeline 3 is slightly deposited, these soil in order to eliminate the effects. In addition, since water flows through the closed space in the pipeline, the sediment does not accumulate so as to hinder travel like an open channel.

  As shown in FIGS. 2A and 2B, the rear chassis 11C is electrically connected to the drive motor 15 and the high-sensitivity wireless camera 17 and controls them based on a command signal from the outside. A control unit 22 and a wireless communication unit 23 that transmits measurement values from the neutron moisture meter 20 and the odometer 21 to the outside and transmits an external command signal to the control unit 22 are provided. Exploration apparatus 4, as shown in FIG. 1, after the drainage pipe line 3, is out from the air valve 6 of the pipeline 3. The air valves 6 are usually arranged at intervals of 100 m to 300 m. A radio repeater (transfer means) 40 is suspended inside the air valve 6 so as to face the space of the pipeline 3. The wireless repeater 40 is electrically connected to the computer 5 via a ground interface 41. The computer 5 controls the traveling vehicle 10 and the high-sensitivity wireless camera 17 of the exploration device 4 through the monitor unit 42 by input means (not shown), and captures measurement data from the neutron moisture meter 20 and measurement data from the odometer 21. in stores, so that the data processing. Note that the high-sensitivity radio camera 17, as shown in FIG. 1, may be provided with monitoring device 43 dedicated to the ground.

  As shown in FIG. 5, the computer 5 determines an increase / decrease pattern detection unit (determining an increase / decrease pattern) based on the measurement values respectively measured by the lower detection units 20 </ b> A and 20 </ b> B and determining an increase / decrease pattern. a decrease pattern detecting means) 51, the same pattern extraction unit for extracting a measurement count as compared to the same increase or decrease pattern for each measurement count the decrease pattern of the decrease pattern detecting unit both lower detecting unit 20A is detected by 51, 30B ( The same pattern extracting means) 52 and the same number of times of measurement of the same pattern extracted by the same pattern extraction unit 52 are further extracted as the number of times of the same pattern continuously appearing a predetermined number of times (in this embodiment, for example, 4 times). and identifies the position on the pipeline corresponding to the measurement count consecutive are those extracted regards specified position with an increase of water leakage And a filter processing unit (filter processing unit) 50 including a determination unit (determination unit) 53 that determines that the location is determined. so that to remove the noise component of the background Te. Then, as shown in FIG. 6, the filter processing unit 50 measures the number of measurement times in which the same pattern extracted by the same pattern extraction unit 52 continuously appears a predetermined number of times (in the table of FIG. for ninth), their measurement times each on both lower detection unit 20A, sum the measurements of 20B, so that statistical processing.

  That is, the measured values of the lower detection units 20A and 20B that are simultaneously measured are combined values of randomly occurring radioactivity fluctuations and moisture change fluctuations. Variation of radioactivity occurs at random, each of the lower detecting unit 20A, decrease pattern 20B is also considered to be random. The increase / decrease pattern here means whether it is increasing or decreasing with respect to the immediately preceding measurement value. Therefore, as shown in FIG. 5, for each of the lower detection units 20 </ b> A and 20 </ b> B, regardless of the background measurement value, as shown in FIG. 6th to 9th) is regarded as a variation portion of moisture change. Then, since the portion regarded as the fluctuation portion should represent the true moisture value, the measurement values of the lower detection units 20A and 20B are the same for the measurement times where the increase / decrease pattern is the same for a certain number of times. also believed to represent the true moisture value. Thus, in the filtering process, finally, the measured values of the respective lower detection units 20A and 20B are added, and as shown in FIG. 6, the peak of the water component is displayed through the statistical process, and the location of the water leakage is specified. I am doing so. As shown in FIG. 10, the pipeline 3 is installed on the base floor below the excavated groove 70, and around it, sand or high-quality earth and sand are used as a compactor (rammer) and a rammer. It is filled with compacted the like.

  Next, the search method according exploration system of the present invention will be described with reference to the action of the exploration system according to the above embodiment. First, in advance, to identify the section of the flow meter there is water leakage position from the section with a pipeline attached likely pipeline 3 first. When the pipeline 3 probing identified, stop the flow of water into the pipe line 3, to discharge the water in the pipeline 3. Next, the computer 5, the interface 41, and, if necessary, the monitor device 43 are installed on the ground near the air valve 6 of the pipeline 3 to be searched, and the air valve 6 is opened. The exploration device 4 is placed in the pipeline 3 from the opened air valve 6, and then the wireless repeater 40 is suspended from the opening of the air valve 6 and placed in the pipeline 3. In the exploration device 4, the support arm 35 is attached in advance to a predetermined attachment hole 37 of the gantry 34 according to the pipe diameter of the pipeline 3, and when the exploration device 4 is arranged in the pipeline 3, The detection unit 20C is opposed to the highest portion 3A on the upper surface of the pipeline 3 with a predetermined gap SP1, and the odometer 21 is configured such that the measurement disk is brought into contact with the upper surface 3A of the pipeline. When the exploration device 4 is arranged in the pipeline 3, a travel start position P0 is determined (see step S1 in FIG. 7), and data of the travel start position P0 is input to the computer 5 (step S2 in FIG. 7). reference).

  Then, the process moves to the measurement work. In the measurement work, the traveling vehicle 10 is driven at a predetermined traveling speed (for example, 2.5 m / min, 10.0 m / min) V1 based on a command from the computer 5 (step of FIG. 7). S3), thermal neutrons are measured for each of the detectors 20A to 20C of the neutron moisture meter 20, and the measured count is output to the computer 5 as thermal neutron measurement data, and the mileage output from the odometer 21 D1, D2,..., Dn are also sequentially output to the computer 5 (see step S4 in FIG. 7). The computer 5, the thermal neutron measurement data background that has passed through the pipeline 3 above the soil from the upper detecting unit 20C is lower detecting unit 20A, the 20B, the thermal neutron measurement data which has passed through the soil in the lower pipeline There are stored are inputted. The computer 5 inputs the input thermal neutron measurement data above the pipeline, thermal neutron measurement data below the pipeline, the travel distance Dn from the travel start point P0, and the travel speed V1 of the traveling vehicle 10. Data processing was performed (see step S5 in FIG. 7), and as shown in FIGS. 4B and 4C, the measurement position (m) and count (cps) of the pipeline 3 were taken on the x-axis and y-axis, respectively. Perform statistical processing on the graph. From this statistical processing result, a position that fluctuates more than the background moisture is determined as a water leak location (see step S6 in FIG. 7).

  4A shows an experimental pipeline in which pipelines having different specifications (tube diameter, tube thickness, and tube material (structure)) are connected, and the graphs shown in FIGS. 4B and 4C. The x-axis measurement positions correspond to the pipeline positions in FIG. The experimental pipeline in FIG. 4A is a centrifugal reinforced concrete pipe C1 having a pipe diameter of φ600 mm and a pipe thickness of 50 mm from the left end to 5 m (measurement position 0-5 m). 8m (measurement position 5-13m) core type prestressed concrete pipe C2 (pipe diameter φ600mm, pipe thickness 69mm (core type prestressed concrete part thickness 44mm, mortar coat thickness 25mm) ) it is connected. Core type prestressed concrete pipe C2 is adapted to mortar coated structure to the tube of the core-type prestressed concrete. For each pipe C1, C2, calibration boxes (see FIG. 4D) B1, B2 containing wet loam (clay) containing water from the direction perpendicular to the pipe axis are inserted below the pipeline. The results of the experiment are shown in the graphs of FIGS. 4B and 4C. The calibration boxes B1 and B2 are both 500 mm in length in the tube axis direction, and can be refilled with materials having various moisture contents. 4B, the traveling vehicle 10 travels at a traveling speed V1 of 2.5 m / min. The graph of FIG. 4C shows the traveling vehicle 10 at a traveling speed V2 of 10 m / minute. travel was a case is shown, respectively.

  Among these graphs subjected to statistical processing, from FIGS. 4A to 4C, the centrifugal reinforced concrete pipe C1 having a pipe diameter of 600 mm and a pipe thickness of 50 mm is measured from 2 m to 2 at both the traveling speeds V1 and V2. Measured values from the lower detectors 20A and 20B within 5 m (thin solid lines are measured values of the lower detector 20A, broken lines are measured values of the lower detector 20B), and measured values of the upper detector 20C serving as the background it can be seen that significantly higher than (thick solid line). The rise portion meets the positions of the calibration box B1 in centrifugal reinforced concrete pipe C1. For this reason, with respect to the centrifugal reinforced concrete pipe C1, the position where the neutron moisture meter 20 fluctuates more than the background moisture is determined as the water leakage location.

  Incidentally, for the core type prestressed concrete pipe C2, in addition to the pipe thickness that thick and 69 mm, the water gathered from the sand around the mortar coating unit, that relatively high water content ratio mortar layer is formed now, the background is high, moisture increase of the leakage point is they've been hidden in the back ground. That is, the measurement values (thin solid lines and broken lines) of the lower detection units 20A and 20B are difficult to discriminate from the measurement values (thick solid lines) of the upper detection unit 20C serving as the background. For this reason, in the present embodiment, such a phenomenon that cannot be grasped only by the measurement of thermal neutrons is considered to be a change with respect to the background by performing a filtering process, and the assumed change part is determined with respect to the background. By highlighting the difference in fluctuation, the leak point is pinpointed accurately. That is, the measured values of the lower detection units 20A and 20B measured at the same time are combined values of the fluctuation of the radioactivity that occurs at random and the fluctuation of the moisture change, and the fluctuation of the radioactivity that occurs at random is detected by each lower detection. Since the increase / decrease pattern of the parts 20A and 20B is also considered to be random, as shown in FIG. so that it regarded as part. And, for the considered variable portion, so it should represent the true moisture value, lower detection unit 20A for measuring times as the number of times or more is decreasing pattern identical, either each of the measurements of 20B true In the filter processing, the measurement values in the table of FIG. 5 are added to the sixth to ninth and FIG. 6 by adding the measured values of the lower detection units 20A and 20B. As shown from the distance 8.5m to 9m in the table, the peak of the water component is displayed through statistical processing to identify the location of water leakage.

  Filter processing is performed in the following manner. First, when measurement values respectively measured by the lower detection units 20A and 20B are input to the computer 5, an increase / decrease pattern detection unit 51 determines increase / decrease compared with the immediately preceding measurement value to obtain an increase / decrease pattern ( (See (1) and (2) in FIG. 5 and step S11 in FIG. 8). Next, the same pattern extraction unit 52 compares the increase / decrease patterns of the lower detection units 20A and 30B detected by the increase / decrease pattern detection unit 51 for each measurement time, and extracts the measurement times of the same increase / decrease pattern (FIG. 5). reference step S12 in (3) and 8). Next, the measurement times (in the present embodiment, for example, four times) in which the same pattern continuously appears among the measurement times of the same pattern extracted by the same pattern extraction unit 52 by the determination unit 53 (see FIG. 5 (6th to 9th measurement times) are further extracted (see step S13 in FIG. 8), and these secondarily extracted measurement times (6th to 9th measurement times in FIG. 5) are extracted. For each of these measurement times, the measured values of the lower detection units 20A and 20B are summed (see (4) in FIG. 5 and step S14 in FIG. 8) on the pipeline corresponding to these extracted successive measurement times. Is identified and statistically processed (see (5) in FIG. 5), and the identified position (see distances 8.5m to 9m in FIG. 6) is regarded as an increased portion of water and determined as a water leak location (FIG. 8). Step S15).

  By performing the filtering process in this manner, even when the measurement values of the lower detection units 20A and 20B are hidden in the background of the upper detection unit 20C, it is possible to easily and reliably identify the water leakage location. Note that this filter processing is not applied only when hidden in the background, and it is needless to say that the processing may be executed even if it is not clear whether it is hidden in the background.

  The exploration method according to the present invention, the vehicle 10, repeated continuously thermal neutrons which have passed through the pipeline 3 and below the soil each neutron moisture meter 20 while traveling at a predetermined speed V1 in drained pipeline within 3 after measuring, the measuring times 1,2, ..., n and the running speed V1 (V2) and the travel distance D1, D2, ..., and a Dn and thermal neutrons measured position on the pipeline 3 each thermal neutron corresponding to the position and the measurement data is indexed. After the measurement data indexing, increasing the position of the water changes from the composite value of the variation and change in moisture of radioactivity occurs at random on the basis of the measurement data indexed is read, the water leakage position of the pipeline 3 is specified.

  Based on the exploration system 2 according to the above configuration, a full-scale model facility and the exploration device 4 were actually made, and experiments were performed using the personal computer 5. The experiment and the results will be described. Figure 9 is an illustration illustrating a life-size model facility, longitudinal section of the model facility (D) in FIG. 4 is shown. As shown in FIG. 9, the model facility dug a part of the ground to a depth of 2.3 m to form a square pyramid-shaped excavation groove 60 in which a slope 61 was formed from the upper opening toward the bottom. G is the ground surface, and experimental pipelines C1 and C2 (see FIG. 4A) are arranged on one side 61A of the slope 61 at a predetermined interval. Experimental pipeline C1, C2 was laid on the sand base floor thickness of 0.5 m. Below the experimental pipeline C1, C2, calibration box grooves 63 and 64 underlying concrete and out of calibration box B1, B2 (see FIG. 4 (A)) to the bottom portion 62 which is pouring is formed The The calibration box grooves 63 and 64 are provided in a direction perpendicular to the tube axes of the experimental pipelines C1 and C2.

  As shown in FIG. 4A, the experimental pipelines C1 and C2 are centrifugal reinforced concrete pipes C1 having a diameter of 600 mm and a pipe thickness of 50 mm from the left end to 5 m. An 8 m core type prestressed concrete pipe C2 (pipe diameter φ600 mm, pipe thickness 69 mm) is connected to the right end. The calibration boxes B1 and B2 are both 500 mm in length in the tube axis direction, and can be refilled with materials having various moisture contents. The calibration box grooves 63 and 64 are respectively provided in the calibration box B1 between 2.0 m-2.5 m from the left end C1L of the centrifugal reinforced concrete pipe C1, and in the calibration box B2 of the core type prestressed concrete pipe C2. It can be disposed between the left end C2L and 3.5 m to 4.0 m (from the left end C1L of the centrifugal reinforced concrete pipe C1 to 8.5 m to 9.0 m). On one side 61A of the slope 61, one side 66 of the experimental pipelines C1 and C2 and both open end portions C1L and C2R are exposed to the outside, and a steel shaft 65 is assembled. 67 is assembled. The Jikukumi 65 and the acrylic plate 67 and is assembled the space SP3 water content ratio is turned sand 68 natural state. An observation window 69 is formed on one side 66 of the experimental pipelines C1 and C2.

  The experimental pipeline C1, C2, open end C1L, the traveling start position P0 locator 4 is placed from one of C2R determined. In the experiment, the calibration box B1, B2 which each packed more wet loam of water component through both calibration box grooves 63 and 64 was conducted disposed below the experimental pipeline C1, C2 (in FIG. 4 (D )reference). Exploration apparatus 4 of FIG. 2 (A), using experimental apparatus having the same configuration as the apparatus shown in (B). The total length of the experimental apparatus 4 is 1575 mm, the width is 310 mm, and the front and rear direction dimensions of the front chassis 11A, the support platform 11B, and the rear chassis 11C are 521 mm, 458 mm, and 375 mm, respectively, and the front chassis 11A and the support platform 11B. The connecting portion dimensions and the connecting portion dimensions of the support base 11B and the rear chassis 11C are both 60 mm. Experimental device 4, to correspond to the tube diameter 600mm laboratory pipeline C1, C2, the support arms 35 are attached to the upper mounting hole 37 of the mount 34.

  The experiment was conducted by running the exploration device 4 in the experimental pipelines C1 and C2. Neutron moisture meter 20 of the upper detecting unit 20C and the lower detector 20A together with travel of the locator 4, 20B and the after repeated continuously measuring thermal neutrons passing through the respective upper and lower soil laboratory pipeline C1, C2, , N, travel speed V1 (V2) and travel distances D1, D2,..., Dn, the thermal neutron measurement position on the experimental pipelines C1, C2 (the left end of the experimental pipeline C1) traveling start position to parts C1L and P0 (0 m), the thermal neutron measurement data (count corresponding to the travel distance (m)) and its position from the position, count here is based on the natural water content of the sand indexed to the say the count deviation) and. FIG. 4B shows a case where the traveling speed is 2.5 m / min, and FIG. 4C shows a case where the traveling speed is 10 m / min. The vertical axis in the figure is shown as the deviation from the natural water content of the back sand.

  The results are shown in FIGS. 4A to 4C. 4B and 4C, the measured values measured by the lower detectors 20A and 20B for the experimental pipeline C1, that is, a centrifugal reinforced concrete pipe having a length of 5 m, a pipe diameter of 600 mm, and a pipe thickness of 50 mm. Compared to the background (thick solid line) measured by the upper detector 20C over the distance from the left end C1L of the experimental pipeline C1 from 2.0 m to 2.5 m. Show significant fluctuations. This position matches the position of the calibration box B1, and it can be seen that the presence of the water component below the experimental pipeline C1 is indicated.

  Moreover, experimental pipeline C2, i.e., length 8m, tube diameter Fai600mm, pipe thickness 69 mm (concrete pipe thickness 44 mm, mortar coat 25 mm) for the core type prestressed concrete tube is in FIG. 4 (B), (C ) as is clear from the lower detection unit 20A, the measurement value measured by 20B, hiding the background, it is no longer able to determine. For this reason, as a result of performing a filter process (refer FIG. 5) about the measured value obtained about the experimental pipelines C1 and C2, the result as shown in FIG. 6 was obtained. FIG 6 a result of removing the noise component of the background as shown in the experimental pipeline C2, i.e., for the core type prestressed concrete tube the distance from the origin (C1L, P0), 9 from 8.5 m. The position fluctuates greatly up to 0 m, and this position matches the position of the calibration box B2, which clearly indicates the presence of the water component below the experimental pipeline C2. In addition, the presence of the water component below the experimental pipeline C1 that matches the position of the calibration box B1 also appears remarkably by this filter processing. Both calibration box B1, B2, a material having a different water content ratio (sand, gravel, clay, etc.) since it way can refill the collects many data for different materials, patterns the by analyzing, it is possible to identify reliably leak location without being dependent on the soil layer below the foundation (see Figure 10).

  Thus, as shown in FIGS. 4B and 4C, when the measurement speed is 2.5 m / min, the count (background) of the portion other than the water leakage point is stable at ± 100. . Moreover, in the leak location of the centrifugal reinforced concrete pipe C1, the counts of the lower detection units 20A and 20B are simultaneously increased by 1000 or more, whereas the count of the upper detection unit 20C shows a value within the background fluctuation. However, at the water leakage position of the core type prestressed concrete pipe C2, the counts of the lower detection units 20A and 20B increased only to about 150, and the peak positions were shifted. The measuring speed 10 m / min, it becomes background ± 300, leakage of the centrifugal force reinforced concrete pipe C1 is detectable as peak, the peak of the leakage of the core type prestressed concrete pipe C2 is thus hidden in the background. For this reason, it is adapted to perform a filter processing. Fig. 6 shows the calculation result obtained by converting the measured value per second to the average value for 6 seconds (0.25m) for the scanning speed of 2.5m / min. , leakage of the seams of the core type prestressed concrete pipe C2 at a distance 8.8m is clearly detected.

  In the above embodiment, the water use pipeline is used for water leakage exploration. However, the present invention is not limited to this, and any other fluid (oil, liquid chemical product) can be used as long as it can be detected by a neutron moisture meter. Needless to say, the present invention can also be applied to an embedded pipeline through which water and sewage water, circulating water in a hot / cold water supply / discharge system, etc. circulate. In the above embodiment, the measurement value of the thermal neutron is made to correspond to the distance from the travel start point P0 based on the travel distance measured by the odometer 21, but it is not limited to this. a measurement of thermal neutron in correspondence to the distance from the travel start point P0 on the basis of a predetermined constant speed running time and the vehicle 10, it is monitored exploration over time leak location Good. Furthermore, as shown in FIG. 10, it may be configured upper detector of two neutron moisture meter 20C1,20C2.

It is explanatory drawing which shows the whole fluid leak investigation system of the pipeline which concerns on one embodiment of this invention. (Example 1) (A), (B) is a plan view and a side view of the locator of FIG. 1, respectively exploration system. It is a longitudinal sectional view showing the arrangement of pipeline in a longitudinal section of the neutron moisture meter provided in the locator of Figure 2. (A) is an explanatory view showing the position of the calibration box B1, B2 and different pipelines of experimental (centrifugal reinforced concrete pipe C1 and the core type prestressed concrete pipe C2) in the model property, (B) and (C) is each graph shows an example of measurement of leakage points of the experimental pipeline, (D) is a sectional view showing a longitudinal section of the model facility. It is an explanatory view showing the method of filter processing, and a graph showing the result of statistical processing. Is a graph showing an example of an application of the filtering. It is a flowchart which shows the determination method when the measured value of a lower part detection part is not hidden in the background of an upper part detection part. Measured value of the lower detection unit is a flowchart showing a determination method using a filter process when the hidden background of the upper detector. Is an explanatory view showing the actual size of the model facility used in the experiment. And soil layer structure of a typical pipeline is an explanatory view showing a measurement position of the pipeline in the upper and lower neutron moisture meter.

Explanation of symbols

2 Fluid leakage exploration system 3 Pipeline 4 Exploration device (traveling means)
20 Neutron moisture meter (thermal neutron measurement means)
20A, 20B Lower detection part 20C Upper detection part RS Radioactive radiation source

Claims (12)

  In a fluid leakage exploration system for pipelines that are buried underground and in which fluid flows, traveling means are placed in the pipeline from which the fluid has been discharged, and the traveling means are discharged from radioactive sources and pass through the soil above and below the pipeline, respectively. A thermal neutron measuring means for measuring the measured thermal neutrons, controlling the travel of the traveling means to determine the thermal neutron measurement position on the pipeline and the measurement data of each thermal neutron corresponding to the position, and the fluid of the pipeline A pipeline fluid leakage exploration system characterized by specifying a leakage position.   In the pipeline fluid leakage exploration system circulating fluid is buried underground, placed inside the pipeline which fluid is discharged, a traveling means for driving is controlled based on a command signal from the outside, to the traveling means A thermal neutron measuring means that has a radioactive ray source, is emitted from this radiation source and passes through the soil above and below the pipeline, and outputs to the outside by measuring the thermal neutrons every predetermined time; and provided in the traveling means, Travel distance measuring means that measures the travel distance of the travel means and outputs it to the outside, and is placed on the ground, and the travel means is freely operated via the monitor by the input means to travel at a constant travel speed, and thermal neutron measurement The thermal neutron measurement value and the mileage measurement value output from the means and the mileage measurement means, respectively, and the traveling speed data of the traveling means are input, and these data are input. Is stored in the memory and processed, and the measurement position on the pipeline is calculated from the traveling speed and distance for each measurement of thermal neutrons, and the data of each thermal neutron above and below the pipeline at these measurement positions. determined, the pipeline fluid leakage exploration system, characterized in that a central processing unit for identifying the fluid leakage position of the pipeline.   Driving means comprises a body which is rotatably connected to bent a plurality of chassis together, the pipeline fluid leakage exploration system according to claim 2, characterized in that it is traveling substantially along the center line of the pipeline.   Thermal neutron measuring means, provided to be vertically displaced on the body top center, an upper moisture detecting neutron moisture meter for measuring the thermal neutron background that has passed through the soil above the pipeline, the pipe on the left and right sides of the vehicle body lower each is provided at a line the inner surface by a predetermined interval, wherein it in claim 3, characterized in that a pair of lower moisture detection neutron moisture meter for measuring the thermal neutron passing through the soil beneath the pipeline pipeline fluid leakage exploration systems.   The neutron moisture meter is configured with a radiation source that emits fast neutrons and a neutron counter that detects thermal neutrons in the housing, and the interference from other radiation sources is suppressed in the housing. pipeline fluid leakage exploration system according to claim 4, characterized in that a absorbent material to reduce the neutron beam.   The central processing unit, decrease pattern detecting means and, both the lower water detection neutrons detected by the increase and decrease pattern detecting means for an increase or decrease pattern based on the measured values measured respectively by each of the lower moisture detection neutron moisture meter The same pattern extraction means that compares the increase / decrease pattern of the moisture meter every measurement time and extracts the measurement times of the same increase / decrease pattern, and the same pattern is continuously selected from the measurement times of the same pattern extracted by the same pattern extraction means And a determination means for determining a position on the pipeline corresponding to the extracted consecutive measurement times, and determining the identified position as a water leakage portion by regarding the specified position as a moisture increase portion. filtering means having provided, and removing the noise component of the background according to the specifications of the pipeline Pipeline fluid leakage exploration system according to Motomeko 4 or 5.   The filter processing means totalizes the measured values of the neutron moisture meters for detecting both lower moisture for each measurement time for which the same pattern extracted by the same pattern extraction means continuously appears a predetermined number of times, and performs statistical processing. The pipeline fluid leakage exploration system according to claim 6.   4. The pipeline fluid leakage exploration system according to claim 2 or 3, wherein the traveling means is provided with a photographing device for copying the state inside the pipeline and transmitting the image wirelessly to an external monitor.   The traveling means outputs the video signal from the imaging device and the data from the thermal neutron measuring means and the traveling distance measuring means to the outside wirelessly, and also transmits the command signal from the outside to the control unit of the traveling means. 9. The pipeline fluid leakage exploration system according to claim 8, wherein a communication unit is provided, and the wireless communication unit communicates with the outside through transfer means arranged inside the pipeline.   Heat is measured by measuring the thermal neutrons that are buried in the underground and where the fluid flows, inside the pipeline where the fluid is discharged, and are emitted from the radioactive source and passed through the soil above and below the pipeline. A neutron measurement means is provided, and thermal neutrons above and below the pipeline are measured by the thermal neutron measurement means while the traveling means is traveling at a predetermined speed, and the thermal neutron measurement position on the pipeline and its position are determined from the traveling speed and traveling distance. A method for investigating pipeline fluid leaks, comprising: determining the location of fluid leaks in a pipeline after determining corresponding thermal neutron data.   Measure the thermal neutrons on the lower side of the pipeline with the lower moisture detection neutron moisture meters respectively provided on the left and right sides of the traveling direction of the traveling means, and after measuring the thermal neutrons above and below the pipeline according to the specifications of the pipeline, seeking decrease pattern of the measurement values measured respectively by each of the lower moisture detection neutron moisture meter, compare the decrease pattern for both the lower water detecting neutron moisture meter for each measurement times to extract measurement count the same increasing or decreasing pattern, Of the extracted measurement times of the same pattern, the measurement times in which the same pattern appears continuously a predetermined number of times are further extracted, and the positions on the pipeline corresponding to the extracted consecutive measurement times are specified and specified. pipeline method of fluid leakage exploration of claim 10, position and judging the leakage point regarded as an increase of the moisture.   12. The measurement process in which the extracted same pattern continuously appears a predetermined number of times, the measured values of the neutron moisture meters for both lower moisture detection are summed for each measurement time, and then statistical processing is performed. pipeline fluid leakage exploration method according.

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