JP2005024484A - Water leakage detection system and water leakage sensor used therefor - Google Patents

Abstract

[Objective] To provide a low-cost water leakage detection system that is easy to construct on viaducts such as expressways.
[Structure] A set of two linearly spaced linear conductors and a sensor resistor connected between the conductors, each terminal end of the conductor or a terminal lead connected to the base An element having the other end of the element as both terminals, wherein the conductor of the element is disposed in a groove provided in a portion in contact with the waterproof layer of the structure covered with the waterproof layer, The element is installed by being filled with a water-permeable filler in the groove, and the measurement principle using the element as one of the four resistors of the Wheatstone bridge circuit is used. It consists of a measuring device to which both terminals are connected.
[Selection] Figure 2

Description

  The present invention relates to a water leakage detection system and a water leakage sensor used therefor, and more specifically, a water leakage detection system for detecting water leakage to a structure due to deterioration of a waterproof sheet or the like embedded in a structure such as a viaduct or the like, and The present invention relates to a water leakage sensor used for this.

  There are many places in modern society that cause harmful effects when water leaks. Among these cases, devices and systems for detecting water leakage have been devised and used especially for cases in which there is a high possibility of water leakage and cases in which damage caused by water leakage is significant. For example, in an industrial waste sewage treatment plant and the like, if water leakage occurs, groundwater and the like are contaminated. Therefore, a leak detection method as described in Patent Document 1 and such an industrial waste sewage treatment plant A sensor line for water leakage detection and the like as described in Patent Document 3 used for water leakage detection has been devised. In addition, a leak sensor as described in Patent Document 2 has been devised for detecting a leak by capturing a special vibration caused by the leak with respect to a leak from a pipe buried in the ground.

Japanese Patent Laid-Open No. 5-52699 JP-A-6-34478 Japanese Patent Application Laid-Open No. 10-62290

By the way, in the viaducts such as highways, water leakage from the pavement surface such as concrete and asphalt prevents water from seeping into the structure such as the viaduct. The number of cases where seats are installed is increasing. However, when water leaks into structural parts such as viaducts due to deterioration of the sheet for preventing water leakage, etc., in the worst case, some of the viaducts etc. May lead to serious accidents such as collapse. However, there seems to be no example of water leakage detection on a viaduct such as an expressway.
Accordingly, the present invention has been made to cope with such a situation, and is intended to provide a low-cost water leakage detection system that is easy to construct on a viaduct such as an expressway and is low in cost.

  The water leakage detection system of the present invention comprises a pair of two linearly spaced antennas and a sensor resistor connected between the antennas, and each base end of the antenna or a terminal connected to the base end An element having the other end of the lead wire as both terminals, wherein the antenna of the element is disposed in a groove provided in a portion in contact with the waterproof layer of the structure covered with the waterproof layer, The input element has a measurement principle in which the groove is filled with a water-permeable filler and the element is used as one of four resistors of a Wheatstone bridge circuit. And measuring the output voltage of the Wheatstone bridge circuit of the measuring device to the structure. It is characterized by comprising determining the presence or absence of water.

  The total resistance value of the element composed of a pair of parallel antennas separated in parallel by the above two and the sensor resistance connected between the antennas is provided in the element in a state where no water leakage occurs. Since the antennas are in an insulated state excluding the sensor resistance, the resistance value of the sensor resistance is obtained. However, when water leakage occurs, the antennas are electrically short-circuited or connected to each other by moisture due to water leakage, so that the entire resistance value of the element changes from the resistance value of the sensor resistor. The water leakage detection system of the present invention utilizes the fact that the overall resistance value of the element changes depending on the presence or absence of water leakage.

Here, the “measurement principle using the element as one of the four resistors of the Wheatstone bridge circuit” in the above water leakage detection system is the following principle. For example, in a Wheatstone bridge circuit composed of four resistors as shown in FIG. 1, the element 1 is a resistor R ₁ , and the other three resistors 1, 2 and 3 are R ₂ , R _3. And R ₄ , the output voltage e of the Wheatstone bridge circuit is E, where the input voltage of the Wheatstone bridge is E.
e = E (R ₁ R ₃ −R ₂ R ₄ ) / [(R ₁ + R ₂ ) (R ₃ + R ₄ )]
It is represented by In general, the four resistors R ₁ , R ₂ , R _3, and R ₄ are all set to have the same resistance value R, and in this case, e = 0 (V). Here, when R ₁ has a resistance value different from R for some reason, an output voltage e corresponding to the resistance value of R ₁ is generated. Therefore, let R be the resistance value of the sensor resistor connected to the element, and the output voltage e generated when water leaks and the resistance value of the element becomes smaller than R due to the moisture, for example. To determine whether there is water leakage.

  In the above water leakage detection system, a low-cost water leakage detection system can be obtained by using a strain measuring device using the principle of a Wheatstone bridge circuit, which is generally used for strain measurement using a resistance strain sensor, as the measuring device. Can be realized.

  Instead of the above-mentioned element, a plurality of linearly spaced antennas, each having two sets, are arranged in series, and the front and base ends of the adjacent antennas are connected via inter-antenna lead wires. The connected continuous antenna and the resistance for the sensor connected between the antennas of the antenna located at the extreme end, each proximal end of the antenna located at the extreme end, or the other end of the terminal lead wire connected to the proximal end You may make it use the continuous element which uses as both terminals.

  In the water leakage detection system, the antenna of the element or the continuous element is disposed and used so as to be positioned at a water leakage detection place of the structure. Moreover, it is preferable to use a cement paste for the filler. Moreover, it is preferable that the thickness of the antenna of the element or the continuous element is 0.3 to 1.0 mm, and the material thereof is stainless steel wire or tin-plated wire. The antenna can be used with a separation distance of 3 to 500 mm.

  When the structure is a concrete structure such as an elevated road or a building, two sets of the antennas are arranged in the groove, and the distance between the antennas is 3 Can be used as ~ 5mm. In addition, a spacer that keeps the separation distance constant may be sandwiched between the antennas.

  Specifically, when the structure is an elevated road, at least one set of the antennas of the element or the continuous element is disposed in the groove provided in the floor slab of the roadside portion of the road. Also good. Or you may make it arrange | position at least 1 set of the said antenna of the said element or the said continuous element in the said groove | channel provided in the floor slab near the road surface where the wheel of the road vehicle which drive | works the road. Further, at least one set of the antennas of the element or the continuous element may be disposed in the groove provided in the floor slab at the end of the floor slab block of the elevated road in the vehicle traveling direction.

  Further, when the structure is an industrial waste final treatment plant, at least two of the grooves are provided, and one of the antennas or two of the continuous elements is provided in a different groove. The antennas can be arranged one by one, and the distance between the antennas can be set to 100 to 500 mm.

  Moreover, the said element used for said water leak detection system or the said continuous element can be produced and used as a water leak sensor.

  According to the water leakage detection system of the present invention, the surface of a structure for detecting water leakage is carved with a cutter or the like in a groove of several millimeters in width and depth, and an antenna or an inter-antenna lead wire is disposed and cement paste. Since it can be constructed simply by filling it in, the construction can be performed easily, and the data logger, which is a strain measuring instrument that is generally used for strain measurement, can be used as a measuring device. Since it can be kept low, construction is easy on a viaduct such as an expressway, and a low-cost water leakage detection system can be constructed.

  When the structure is an elevated road and the at least one set of the antennas of the element or the continuous element is disposed in the groove provided in the floor slab of the roadside portion of the road, the road The surface is generally slightly swollen upward near the center of the road surface for smooth drainage, and accordingly, the vicinity of the center of the road surface of the concrete slab is also slightly swollen upward, causing water leakage. In this case, the water leak is easily collected near the road shoulder, so that the water leak can be reliably detected.

  In the case where the structure is an elevated road, at least one set of the antennas of the element or the continuous element is disposed in the groove provided in the floor slab near the road surface in contact with the wheels of the traveling road vehicle. In this case, it is known that the waterproof sheet installed on the elevated road is likely to deteriorate near the asphalt in contact with the wheels due to the pressure of the wheels when the road vehicle is running. By performing this, water leakage can be detected efficiently.

  In the case where the structure is an elevated road, at least one set of the antennas of the element or the continuous element is placed in the groove provided in the floor slab at the end in the vehicle traveling direction of the floor slab block of the elevated road. In the case of installation, on the elevated road, the bridge part expands and contracts in the vehicle running direction due to the temperature difference between summer and winter, day and night, etc., so the bridge part with a certain length in the vehicle running direction is a unit unit. As for the bridging part in this unit unit, the central part is slightly swollen above the both end parts, and when water leaks, the leaked water accumulates at the bridging end part that is the end of the bridging part in the vehicle running direction. Since it has an easy structure, water leakage can be reliably detected by detecting the water accumulated in this portion.

  When the structure is an industrial waste final treatment plant, at least two grooves are provided, and each pair of antennas is arranged in a different groove with two antennas. It is set as 100-500 mm, and when the leaked water flows between the adjacent grooves, the leak in the industrial waste final treatment plant can be detected by detecting the leak.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 shows a continuous element 11 which is a basic component of the present invention and a data logger 21 which is a measuring device. The continuous element 11 includes a pair of antennas 12 and 12 each having a pair of linearly spaced linear conductive elements arranged in series, and connected at the front end and the base end of the adjacent antennas 12. By connecting the inter-antenna lead wires 17 and 17 to the terminal 16, the antennas 12 are connected in series. A series of the plurality of antennas 12 connected in series is referred to as a continuous antenna. Then, the terminal lead wire 14 is connected to the connection terminal 16 provided at the base end of the antenna 12 located at the extreme end of the continuous antenna, and between the terminal lead wires 14 and 14 in the middle of the terminal lead wire 14. The sensor resistor 13 is connected to. In FIG. 2, an element 1 that does not use a continuous antenna and uses only one set of antennas 12 and 12 is referred to as an element 1. Therefore, the inter-antenna lead wires 17 and 17 are not necessary and connected to the element 1. In other words, the element 1 connects the terminal lead wire 14 to the connection terminal 16 provided at the base end of the two linearly spaced linear antennas 12, and in the middle of the terminal lead wire 14, A sensor resistor 13 is connected between the terminal lead wires 14 and 14. In the water leakage detection system of the present invention, either the element 1 or the continuous element 11 can be used.

  It is preferable to use a stainless steel wire for the antennas 12 and 12 from the viewpoints of prevention of rust and corrosion, strength, and the like. However, the material of the antennas 12 and 12 is not limited to this, and any metal wire other than stainless steel wire, such as a tin-plated wire in which a copper wire is tin-plated, may be used as long as it is linear and conductive. Something like that. The thickness of the antennas 12 and 12 is practically 0.3 to 1.0 mm in diameter. Moreover, although one set of antennas 12 and 12 are spaced apart in parallel, this separation distance differs depending on the object to detect water leakage, and the range can be set to 3 to 500 mm. However, when the structure subject to water leakage is a concrete structure such as an elevated road or a building, it is recommended that the distance between the antennas 12 and 12 be 3 to 5 mm. As will be described later, the stainless steel antennas 12 and 12 are disposed in a groove provided in a portion of the structure covered with a waterproof layer in contact with the waterproof layer, and water leakage due to deterioration of the waterproof layer or the like. Used to detect

The terminal lead wire 14 connected to the element 1 or the continuous element 11 is connected to a data logger 21 that is a measuring device. That is, the element terminal 15 that is the end of the terminal lead wire 14 is connected to the input terminal 22 of the data logger 21. The data logger 21 is a strain measuring device using the principle of a Wheatstone bridge circuit used for strain measurement using a resistance strain sensor. The data logger 21 incorporates a Wheatstone bridge circuit as shown in FIG. 1. The resistor R _{1 in} FIG. 1, which is one of four resistors constituting the Wheatstone bridge circuit, It is an external resistor connected to the input terminal of the data logger 21. The data logger 21 is originally connected with a resistance strain sensor as the resistor R ₁ which is an external resistance. In the present invention, however, the element 1 or the continuous element 11 is connected instead of the resistance strain sensor. Based on the principle described above, the output voltage of the Wheatstone bridge circuit built in the data logger 21 is measured to determine the presence or absence of water leakage in the portion where the element 1 or the continuous element 11 is installed.
When the element 1 or the continuous element 11 is connected to the data logger 21, the base ends of the antennas 12 and 12 of the element 1 or the continuous element 11 are directly connected to the input terminal of the data logger 21 without using the terminal lead wire 14. You may make it do. In this case, the sensor resistor 13 is also directly connected to the input terminal of the data logger 21.

  Next, an experiment conducted for confirming the effect of the water leakage detection system of the present invention and an experimental apparatus used for the experiment will be described. 3A is a plan view of the experimental apparatus used in this experiment, FIG. 3B is a cross-sectional view of the concrete test piece 31 in FIG. 3A, and FIG. FIG. 3 (a), (b) and FIG. 4, in this apparatus, a concrete test piece 31 having a height of about 5 cm and a height of about 30 cm × 30 cm is used as a structure. Three grooves 32 having a depth of 5 mm and a depth of 3 mm are cut in parallel in the front-rear direction at intervals of 50 mm, and the antennas 12 and 12 of the element 1 are disposed therein, respectively. For the antennas 12 and 12, stainless steel wires having a diameter of 0.3 mm are used. These elements 1 are called a 1st water leak sensor, a 2nd water leak sensor, and a 3rd water leak sensor in order from the left. In this experimental apparatus, a waterproof layer is not provided on the surface of the concrete test piece 31.

  In FIG. 4, the element 1 is arranged in such a manner that the antennas 12 and 12 made of stainless steel wires of 0.3 mm are arranged in parallel with a distance of 3 mm on the surface of the base 33 made of double-sided adhesive tape. After bonding, the surfaces of the stainless steel wire and the double-sided pressure-sensitive adhesive tape are covered with a seal 34 such as paper having water absorption. And this base 33 is arrange | positioned so that the back surface of the double-sided adhesive tape may adhere | attach on the surface of the bottom of said groove | channel 32, and the filling material 35 which consists of cement paste which has water permeability is filled in the groove | channel 32. .

The measurement was performed by connecting the element 1 of the first water leak sensor, the second water leak sensor, and the third water leak sensor to the input terminal of the data logger 21. The data logger 21 was a strain measurement data logger TC-31K manufactured by Tokyo Sokki Kenkyujo. The sensor resistance 13 connected to the element 1 is 120Ω, and R ₂ , R ₃ and R _{4 of} the Wheatstone bridge circuit built in the data logger 21 are also 120Ω. The input voltage of the Wheatstone bridge circuit built in the data logger 21 is 2V. Further, a non-contact type hygrometer 18 was installed above the surface of the concrete test side by about 10 mm above the first water leak sensor and the second water leak sensor. In this measurement, the output voltage of the Wheatstone bridge circuit incorporated in the strain measurement data logger TC-31K manufactured by Tokyo Sokki Kenkyujo is converted into μ, which is a unit of distortion, and displayed.

  In the above experimental apparatus, first, water is dripped onto the cement paste of the filler 35 of the first water leakage sensor and soaked into the cement paste, and the humidity on the surface of the cement paste of the filler 35 of the first water leakage sensor is A first experiment was conducted to observe the state of the first water leakage sensor. Next, similarly, water is dropped on the cement paste of the filler 35 of the first water leakage sensor so as to be soaked into the cement paste, and the humidity on the surface of the cement paste of the filler 35 of the second water leak sensor and the second water leakage A second experiment was conducted to observe the state of the sensor. Assuming that the surface of the concrete test piece 31 is covered with a waterproof layer such as a waterproof sheet, the case where water leaks through the waterproof layer due to deterioration of the waterproof layer is assumed. The same state is realized. For this reason, as described above, the waterproof layer is not provided on the surface of the concrete test piece 31.

  FIG. 5 shows the relationship between the humidity in the first water leakage sensor of the first experiment and the output of the data logger 21, and FIG. 6 shows the relationship between the humidity in the second water leakage sensor of the second experiment and the output of the data logger 21. It is the graph which showed. In the graphs of FIGS. 5 and 6, the dotted line represents the humidity (unit:%), and the practice represents the output of the data logger 21 (unit: μ). The horizontal axis represents the elapsed time at the time of measurement (unit: hours: minutes). As described above, the display of the data logger of the measuring apparatus used in the above experiment is in μ, so in the graphs of FIGS. 5 and 6, the unit of output display of the data logger 21 on the vertical axis is μ. It has become.

  The graph of FIG. 5 shows a situation in which water dripping onto the filler 35 of the first water leakage sensor soaks and reaches the first water leakage sensor. According to this graph, after dropping water at 15:01, the humidity at the position of the first water leakage sensor rises to near 95% at 15:10, and the output of the data logger 21 by the first water leakage sensor is also shown. The output of the data logger 21 shows a peak of about -60000μ at 16:47. This clearly indicates that the first water leakage sensor detects water leakage in the experimental apparatus.

Moreover, the graph of FIG. 6 has shown the condition which the water dripped on the filler 35 of a 1st water leak sensor penetrate | infiltrate, and arrives at a 2nd water leak sensor. According to this graph, after dropping water at 13:31, the humidity at the position of the second water leakage sensor increased at 14:21, and the humidity showed a peak at 14:41. The output of the data logger 21 by the sensor also shows a peak of about −5500 μm at 15: 1. Humidity is the humidity of the surface of the portion where the second water leakage sensor is embedded, and the time point when the humidity shows a peak value and the time point when the output of the data logger 21 by the second water leakage sensor shows the peak value are somewhat shifted. Yes. Moreover, since the 1st water leak sensor and the 2nd water leak sensor are 50 mm apart, the output of the data logger 21 is about 1/10 compared with the result of the 1st experiment. However, it can be seen from the graph of FIG. 6 that the second water leakage sensor detects water leakage in the experimental apparatus.
In both the first experiment and the second experiment, no change was recognized in the output of the third water leakage sensor. Therefore, it can be said that the water hung on the filler 35 of the first water leakage sensor does not reach the third water leakage sensor. From the above results, it is understood that leakage of water can be detected by using the above-described element and data logger.

  FIG. 7 is a graph showing the measurement results of the temperature characteristics of the third water leakage sensor performed using the third water leakage sensor separately from the first experiment and the second experiment. Although not shown in FIGS. 3A and 3B, a thermocouple of a thermocouple thermometer is installed in the groove where the third water leakage sensor is installed, and moisture is not wetted in the third water leakage sensor. The temperature characteristics are measured. According to the graph of FIG. 7, an output of about 200 μ / 10 ° C. is generated as the output of the data logger 21 by the third water leakage sensor, which is considered to be a drift that occurs during measurement using the above-described element. However, considering that the absolute value of the output changes on the order of at least 0 μ to 5000 μ at the time of water leakage detection, it is considered that the measurement does not affect the measurement even if the influence of this drift is ignored.

  Next, the water leakage detection system according to the first embodiment of the present invention will be described. The structure in the water leakage detection system of the first embodiment is a concrete elevated road in which a waterproof sheet for preventing water leakage is constructed under asphalt pavement. FIG. 8 is an explanatory view showing a state in which the antenna of the element 1 or the continuous element 11 is embedded in a concrete elevated road, and FIG. 9 is a cross-sectional view of a portion B in FIG. 8 and 9, a groove 44 having a width of 5 mm and a depth of 3 mm is provided on the surface of the concrete floor slab 43 of the elevated road. The bottom surface of the groove 44 is a curved surface that gently swells downward, and when water leaks in the groove 44, water collects near the center of the bottom surface of the groove 44. As in FIG. 4, antennas 12 and 12 made of stainless steel wires of 0.3 mm are arranged in parallel in the groove 44 with a separation distance of 3 mm on the surface of the base 33 made of double-sided adhesive tape. After bonding, the surfaces of the stainless steel wire and the double-sided pressure-sensitive adhesive tape are covered with a seal 34 such as paper having water absorption. And after arrange | positioning this base 33 so that the back surface of the double-sided adhesive tape may adhere | attach on the bottom face of said groove | channel 44, the filling material 35 which consists of a cement paste which has water permeability is filled in the groove | channel 44. FIG. Thereafter, a waterproof sheet 42 is formed on the surface of the concrete floor slab 43 including the surface of the filler 35 to form a waterproof layer, and the surface of the waterproof sheet 42 is further covered with asphalt 41.

  As can be seen from the above structure, since the groove 44 is provided under the waterproof sheet 42 that is the waterproof layer, that is, in a portion that contacts the waterproof sheet 42 that is the waterproof layer, the waterproof sheet 42 that is the waterproof layer is deteriorated. Then, the structure is such that the leaked water easily penetrates into the groove 44. Further, since the antennas 12 and 12 made of stainless steel wire are arranged on the bottom surface of the groove 44 having a curved surface gently bulging downward, when water leaks, water gathers near the center of the bottom surface of the groove 44. Water is easily collected between the antennas 12 and 12, so that water leakage can be reliably detected.

  In order to keep the distance between the antennas 12 and 12 constant when the antennas 12 and 12 made of the stainless steel wires are arranged in parallel at a distance of 3 mm, as shown in FIG. A spacer 40 made of a resin or the like having the above may be used. The spacer 40 has a rectangular parallelepiped shape, and on both the left and right sides, spacer recesses 40a for fitting the antennas 12 and 12 are provided. By fitting the antennas 12 and 12 into the spacer recess 40a as shown in FIG. 10B, the distance between the antennas 12 and 12 can be easily kept constant.

  FIG. 11 is an explanatory diagram specifically explaining the construction method on the concrete elevated road with the embedment of the antennas 12 and 12 of the element 1 or the continuous element 11 in the first embodiment. In FIG. 11, first, a groove 44 having a width of 5 mm and a depth of 3 mm is carved on the surface of the concrete floor slab 43 of the elevated road with a cutter (a), and water leaks in this groove 44 on the concrete elevated road. The antennas 12 and 12 or the antennas 12 and 12 and the inter-antenna lead wires 17 and 17 and the terminal lead wires 14 and 14 are arranged so that the antennas 12 and 12 of the element 1 or the continuous element 11 are located at the detection place. (B). Thereafter, a cement paste is made of ultrafast cement or non-shrinkage cement, poured into the groove 44 and filled (c). After the cement paste has hardened, the waterproof sheet 42 is applied to the surface of the concrete slab 43. A waterproof layer is formed (d). The waterproof sheet 42 used here is generally a rubber material, but is not limited thereto. For example, any sheet-type coating system having a waterproof function such as an asphalt sheet may be used. Further, instead of using a sheet, a method of forming a waterproof layer by coating a waterproof material such as urethane on the surface of the concrete floor slab 43 may be used. After this waterproofing treatment, asphalt is placed on the surface of the waterproof layer (e).

  The element 1 or the continuous element 11 having the antennas 12 and 12 embedded in the first embodiment is measured by connecting to the same data logger as used in the above-described experimental apparatus when judging the presence or absence of water leakage. The presence or absence of water leakage is determined based on the measured value. By using a switch box for switching when measuring the plurality of elements 1 or the continuous elements 11, a system that can easily perform the measurement can be obtained. Further, by adding a device for automatically performing interval measurement to such a system, it is possible to remotely monitor leakage of water on an elevated road by using a system that wirelessly transmits measurement results.

  In the water leakage detection system of the first embodiment, the surface of the concrete floor slab 43 of the elevated road, which is a structure for detecting water leakage, is carved with a stainless wire by carving a groove with a width and depth of several millimeters with a cutter. Since the antennas 12 and 12 and the inter-antenna lead wires 17 and 17 are arranged and filled with cement paste, the construction is easy. Moreover, since the groove carved on the surface of the concrete floor slab 43 is extremely small in both the width and the depth of several millimeters, the groove hardly causes damage to the concrete floor slab 43. Moreover, since a data logger which is a strain measuring instrument generally used for strain measurement can be used as the measuring device, the cost can be kept low. Therefore, according to the water leakage detection system of the first embodiment, it is possible to construct a water leakage detection system that is easy to construct on a viaduct such as an expressway and that is low in cost.

  In the elevated road as shown in FIG. 11, if water leakage detection is performed by evenly arranging antennas on the road surface, the water leakage detection is complete, but the usage amount of the element 1 or the continuous element 11 is small. Increase. Therefore, the second embodiment as shown in FIG. 12 is recommended as a method for efficiently detecting water leakage. 12A is a cross-sectional view in a direction orthogonal to the vehicle traveling direction of the elevated road having the pier 45, and FIG. 12B is an antenna 12, 12 and antenna of the continuous element 11 in this elevated road. FIG. 6 is a plan view showing the arrangement positions of inter-lead wires 17 and 17. In FIG. 12A, 49 is a road vehicle. In the second embodiment, as shown in FIG. 12B, the antenna 12 is disposed near the shoulder of the road. This is because the road surface generally swells upward slightly near the center of the road surface, and the center of the road surface of the concrete slab also swells upward slightly in accordance with this. When a water leak occurs, the water leak tends to accumulate near the shoulder of the road, and in this way, the water leak can be reliably detected. In the second embodiment, the point of measurement by connecting the continuous element 11 to the data logger described above is the same as in the first embodiment, and this is the same in the other embodiments described below. is there.

  A third embodiment as shown in FIG. 13 may be used as a method for efficiently detecting water leakage on an elevated road. Similar to FIG. 12, FIG. 13 (a) is a cross-sectional view of the elevated road having the pier 45 in a direction perpendicular to the vehicle traveling direction, and FIG. 13 (b) is an antenna of the continuous element 11 on this elevated road. 12 and 12 are plan views showing the positions where the antenna lead wires 17 and 17 are disposed. In the third embodiment, as shown in FIG. 13B, the antenna 12 is disposed on the concrete floor slab 43 near the road surface where the road traveling vehicle 49 travels in contact with the road. . It is known that due to the pressure of the wheels when the road vehicle 49 travels, the waterproof sheet constructed on the elevated road is likely to deteriorate in the vicinity of the asphalt directly in contact with the wheels. This is because water leakage detection is efficient in finding water leakage.

  Alternatively, a fourth embodiment as shown in FIG. 14 may be used as a method for efficiently detecting water leakage on an elevated road. FIG. 14 is a cross-sectional view in the vehicle traveling direction on an elevated road having a pier 45. In the fourth embodiment, as shown in FIG. 14, the antennas 12, 12 of the continuous element 11 and the antennas 12, 12 of the continuous element 11 are placed in the grooves 44 provided in the bridge slab 43 of the bridge end 46 in the vehicle traveling direction of the bridge portion of the elevated road. Inter-antenna lead wires 17, 17 are provided. In the figure, 41 is an asphalt and 42 is a waterproof sheet. In an elevated road, the bridge part expands and contracts in the vehicle running direction due to the difference in temperature between summer and winter, day and night, etc., so the bridge part that is a certain length in the vehicle running direction is laid as a unit unit. The bridging portion of this unit unit has a central portion that bulges slightly above both end portions, and when water leaks, the water leaked to the joint portion (bridging end portion 46) that is the end of the bridging portion in the vehicle traveling direction. The structure is easy to accumulate. In the fourth embodiment, water leakage is reliably detected by detecting water accumulated in this portion.

  The water leakage detection system of the present invention can also be used for water leakage detection at industrial waste final treatment plants. 15 (a) and 15 (b) show a fifth embodiment as an example of this, FIG. 15 (a) is a sectional view of an industrial waste final treatment plant, and FIG. 15 (b) is its bottom. FIG. If water leakage occurs at an industrial waste sewage treatment plant, there is a risk of contamination of groundwater with heavy metals or hazardous chemicals. From the viewpoint of preventing this, leakage detection at this industrial waste sewage treatment plant is very important. is there. However, the purpose of this water leak detection is not to prevent the breakage of concrete as in the above-described embodiment, and therefore, when the amount of water leak is larger than that in the above-described embodiment. Even what is detected as water leakage can fully perform its function. Therefore, in the fifth embodiment, as shown in FIGS. 15A and 15B, a plurality of grooves 53 are provided on the bottom surface of the recess provided by excavating the ground 51, and the continuous element 11 is provided therein. Each of the two antennas 12 and 12 is arranged in a different groove one by one, and after filling the groove with cement paste, a waterproof sheet is laid on it, or a waterproof material The waterproof layer 51 is formed by spraying or the like. Industrial waste 54 is deposited on the waterproof layer. In this case, when the leaked water flows between the adjacent grooves 53, the leak is detected. Therefore, even if the separation interval of the antenna 12, that is, the separation interval of the adjacent grooves 53 is about 100 to 500 mm, sufficient water leakage detection is possible.

  In the above description, the description has been given by taking an example of an elevated road and an industrial waste final treatment plant, but the present invention is not limited to these, for example, detection of water leakage in a roof part or a roof part of a concrete building, etc. It can be applied to water leak detection in all fields.

  The element 1 or the continuous element 11 described above can be manufactured as a water leakage sensor, and can be used in each of the above embodiments.

It is a circuit diagram explaining the measurement principle of the water leak detection system of this invention. It is explanatory drawing which showed the data logger which is a continuous element which is a fundamental component in embodiment of this invention, and a measuring device. (A) is a top view of the experimental apparatus performed in order to confirm the effect of the water leak detection system of this invention, (b) is sectional drawing of the concrete test piece in (a). FIG. 4 is an enlarged view of a portion A in FIG. It is the graph which showed the result of the 1st experiment. It is the graph which showed the result of 2nd experiment. It is the graph which showed the measurement result of the temperature characteristic of the 3rd water leak sensor. It is explanatory drawing which showed the embedding state of the antenna of the element or continuous element to the elevated road in 1st Example. It is a perspective view showing the section of the B section of Drawing 8. (A) is a perspective view of a spacer, (b) is a perspective view of an antenna using this spacer. It is explanatory drawing explaining the construction method of the elevated road with embedding of the antenna in 1st Example. (A) is sectional drawing of the direction orthogonal to the vehicle running direction of the elevated road in 2nd Example, (b) showed the arrangement position of the antenna and the lead wire between antennas in this elevated road It is a top view. (A) is sectional drawing of the direction orthogonal to the vehicle running direction of the elevated road in 3rd Example, (b) showed the arrangement position of the antenna and the lead wire between antennas in this elevated road It is a top view. It is sectional drawing of the vehicle running direction of the elevated road in 4th Example. (A) is sectional drawing of the industrial waste final treatment plant in 5th Example, (b) is an enlarged view of the bottom part.

Explanation of symbols

1 Element (R ₁ ) 2 Resistance 2 (R ₂ )
3 Resistance 3 (R ₃ ) 4 Resistance 4 (R ₄ )
11 Continuous element 12 Antenna (stainless steel wire)
13 Sensor Resistance 14 Terminal Lead Wire 15 Element Terminal 16 Connection Terminal 17 Inter-Antenna Lead Wire 18 Non-Contact Hygrometer 21 Data Logger (Measurement Device)
22 Input terminal 31 Concrete test piece 32 Groove 33 Base 34 Seal 35 Filler 40 Spacer 40a Spacer recess 41 Asphalt 42 Waterproof sheet 43 Concrete floor slab 44 Groove 45 Bridge pier 46 Bridge end 49 Road traveling vehicle 51 Ground 52 Waterproof sheet 53 Groove 54 Industrial waste

Claims (15)

A pair of parallelly spaced linear conductive antennas and sensor resistors connected between the antennas, in addition to each base end of the antenna or terminal lead wires connected to the base end An element having both ends as terminals, wherein the antenna of the element is disposed in a groove provided in a portion in contact with the waterproof layer of the structure covered with the waterproof layer, and in the groove The element installed by being filled with a water-permeable filler;
Using a measuring principle that uses the element as one of four resistors of a Wheatstone bridge circuit, and a measuring device in which the two terminals of the element are connected to an input terminal;
A water leakage detection system characterized by determining the presence or absence of water leakage to the structure by measuring the output voltage of the Wheatstone bridge circuit of the measuring device. The water leakage detection system according to claim 1, wherein a strain measuring device using a principle of a Wheatstone bridge circuit used for strain measurement using a resistance strain sensor is used as the measuring device. A continuous antenna in which a pair of two linearly spaced antennas are arranged in series and the front and base ends of adjacent antennas are connected via inter-antenna lead wires, and the endmost A continuous element having both terminals of the base end of the antenna located at the end or the other end of the terminal lead wire connected to the base end. The water leakage detection system according to claim 1, wherein the leak detection system is used instead of the element. The water leak detection system according to any one of claims 1 to 3, wherein the antenna of the element or the continuous element is disposed so as to be located at a water leak detection place of the structure. The water leakage detection system according to any one of claims 1 to 4, wherein cement filler is used for the filler. The water leakage detection system according to any one of claims 1 to 5, wherein a thickness of the antenna of the element or the continuous element is 0.3 to 1.0 mm. The water leakage detection system according to any one of claims 1 to 6, wherein a stainless wire or a tin-plated wire is used for the antenna of the element or the continuous element. The water leakage detection system according to any one of claims 1 to 7, wherein a separation distance of the antenna of the element or the continuous element is set to 3 to 500 mm. When the structure is a concrete building such as an elevated road or a building, two sets of two antennas are arranged in the groove, and the distance between the antennas is 3 to 3. The water leakage detection system according to any one of claims 1 to 8, wherein the water leakage detection system is 5 mm. The water leakage detection system according to claim 9, wherein a spacer that keeps the separation distance of the antenna of the element or the continuous element constant is sandwiched between the antennas. The structure is an elevated road, and at least one set of the antennas of the element or the continuous element is disposed in the groove provided in a floor slab of a roadside portion of the road. The described leak detection system. The structure is an elevated road, and at least one set of the antennas of the element or the continuous element is disposed in the groove provided in a floor slab near a road surface where a wheel of a traveling road traveling vehicle contacts. The water leak detection system according to any one of claims 9 to 11. The structure is an elevated road, and at least one set of the antennas of the element or the continuous element is disposed in the groove provided in the floor slab at the end of the bridge in the vehicle traveling direction. The water leakage detection system according to any one of claims 9 to 12. When the structure is an industrial waste treatment plant, at least two of the grooves are provided, and one set of the antennas is arranged in a different groove with two of the elements or the continuous elements. The water leakage detection system according to any one of claims 1 to 8, wherein the antenna has a separation distance of 100 to 500 mm. The water leak sensor which consists of the said element or the said continuous element used for the water leak detection system of any one of Claims 1-14.

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