JP7126083B2 - sheet sensor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sheet-like sensor used for concrete filling detection that can reliably detect the filling state of filling such as lining concrete or mortar in constructing a mountain tunnel.

For example, in mountain tunnel construction represented by the NATM construction method, after excavation by blasting, etc., shotcrete is applied to the inner wall of the excavated tunnel by spraying. While sequentially moving the formwork in the direction of the tunnel, a waterproof sheet is stretched along the inner peripheral surface of the shotcrete for each span in the tunnel direction (this surface will be the side wall surface of the rock), The center formwork is installed along the circumferential direction with a distance between it and the side wall of the natural ground, and lining concrete is placed in the space between the side wall of the natural ground and the formwork.

When placing the above-mentioned lining concrete, in order to control whether the lining concrete was densely filled in the space between the side wall of the natural ground and the formwork, the state of concrete filling at the top of the tunnel was checked. A sensor is placed to check the

Various sensors have been developed as the concrete filling detection sensor. For example, Patent Document 1 below discloses a collective electrode in which a plurality of counter electrodes each composed of a first electrode and a second electrode facing each other with a space maintained are arranged in the direction of concrete rising, and A voltage is applied between the first electrode and the second electrode to measure the impedance between the first electrode and the second electrode, and the first electrode and the second electrode are measured according to the impedance measurement result. concrete presence/absence determining means for determining whether or not concrete exists between them; and the number of counter electrodes determined by the concrete presence/absence determining means that concrete exists between the first electrode and the second electrode; , and height calculation means for calculating the run-up height of concrete using the arrangement interval of the counter electrodes.

Patent Document 2 below discloses a cement composition sensor that includes at least two rod-shaped electrodes to which an alternating voltage is applied, and a support that supports the rod-shaped electrodes substantially in parallel.

Furthermore, Patent Document 3 below discloses a detection means having a sensor element (piezoelectric element) that converts electrical energy into mechanical energy, and a sine wave electrical signal whose frequency changes over time within a predetermined range. excitation signal generating means for generating an excitation signal; and frequency characteristic reflecting signal output means for outputting a received signal reflecting frequency characteristics of the detection means when the excitation signal is applied to the detection means. and a multiplying means for multiplying the received signal from the frequency characteristic reflecting signal output means and the excitation signal from the excitation signal generation means, wherein the detection means comprises a parallel-connected natural frequency A fill sensing device is disclosed having a plurality of sensor elements with different .

The sensors according to Patent Documents 1 and 2 detect the filling of concrete by measuring the resistance between the electrodes, and the sensor according to Patent Document 3 outputs an output when the piezoelectric element comes into contact with the filling. Concrete filling is detected by the change in frequency characteristics.

JP-A-2000-146673 JP-A-9-228639 Japanese Patent Application Laid-Open No. 2003-194615

The sensors described in Patent Documents 1 to 3 are all small-piece sensors, and detect the degree of concrete filling at the installation point.

In the case of mountain tunnels, even if the excavation method is a blasting method or mechanical excavation using a free cross section excavator, tunnel boring machine, etc., the excavated wall surface will have considerable unevenness (unevenness). there is

However, the small-piece sensors according to Patent Documents 1 to 3 are only placed at two or three locations at the top of the tunnel at intervals in the longitudinal direction of the tunnel. It was difficult to confirm that the entire top of the tunnel was filled. If the sensor in the form of a small piece were to be installed in the unevenness of the side wall surface of the rock, even if the sensor were to output a filling detection signal due to contact with the concrete, it would not be hollow. There was a risk that the filling of the recessed portion would not be confirmed, and if the recessed portion was not filled with concrete, this portion would become hollow and the durability of the lining concrete would be reduced.

Increasing the number of sensors is an effective way to improve the accuracy of filling detection. As the number of wires increases, it is necessary to perform wiring work while paying attention to the possibility of wire breakage and the matching of signals from connected sensors and positions.

Furthermore, as in the sensors according to Patent Documents 1 and 2, resistance sensors that measure the resistance between electrodes arranged opposite each other with a predetermined separation width to determine whether or not concrete exists between the electrodes are: Since it comes into direct contact with the filling, it has the advantage of being able to distinguish between bleeding water and concrete to some extent by observing the magnitude of the resistance. In addition, there is a possibility that concrete is accidentally adhered between the electrodes, and it is recognized that the concrete is filled even if the entire space is not filled.

Moreover, the sensors according to Patent Documents 1 and 2 use resistance sensors, but the resistance sensors have the problem that they cannot detect disconnection of lead wires extending from the respective electrodes. Specifically, lead wires extending from each electrode may be disconnected during sensor installation work, concrete filling work, or the like. In the case of a resistive sensor, the resistance value between electrodes is constantly monitored, and the change in resistance value is used to identify the filling. From the state where there is no air between the electrodes when it is not filled, water (bleeding water) intervenes between the electrodes as the concrete is filled, and then concrete intervenes. 26, the resistance value between the electrodes theoretically becomes infinite, as shown in FIG. (Air>Water>Concrete). Here, assuming that the water (bleeding water) intervenes between the electrodes and the disconnection occurs during water contact, as shown in FIG. After that, a detection result is obtained that returns to the air resistance value again due to disconnection. In this way, the resistance value after disconnection is at the same level as the resistance value of air when it is not filled, so it is difficult to determine whether this detection result is due to the fact that concrete has not been filled yet or due to disconnection. , it was not possible to accurately grasp the filling situation of concrete.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a sheet-like sensor capable of improving the installation workability of the sensor and reliably detecting the filling state of a filler such as concrete.

In order to solve the above problems, the present invention according to claim 1 is a sheet-like sensor for detecting the filling state of a filling,
A flexible sheet member having a long side and a short side in plan view, and a plurality of sheet members arranged on at least one side surface of the sheet member at intervals along the long side direction. and a sensor that detects the filling status of the filling,
The sheet member includes a base material formed in a sheet shape and wiring along the base material, one end of which is connected to the sensor, and the other end of which is connected to one end of the sheet member in the longitudinal direction. and a plurality of lead wires extending toward
The sensor includes a piezoelectric sensor in which an upper electrode layer, a piezoelectric layer, and a lower electrode layer are laminated in order, or a capacitive sensor in which an upper electrode layer, a dielectric layer, and a lower electrode layer are laminated in order, and two electrodes. and a resistive sensor arranged opposite to one side of the sheet member with a predetermined separation width, and the piezoelectric sensor or the capacitive sensor is arranged on one side of the base material. The resistive sensor is disposed on the opposite surface, and the piezoelectric sensor or the capacitive sensor and the resistive sensor are located close to each other on the front and back surfaces of the base material or overlap in the thickness direction. A sheet-like sensor is provided characterized by an arrangement .

In the first aspect of the invention, a plurality of sensors are arranged on the flexible sheet member, and lead wires connected to the sensors are pre-wired on the sheet member. By simply installing along the length of the tunnel at the top position, multiple sensors are placed at the specified positions, and at the same time the lead wires connecting to these sensors are wired, improving the workability of sensor installation. becomes possible. In addition, since a plurality of sensors can be reliably arranged at predetermined positions without disconnection of lead wires or the like, it is possible to reliably detect the filling state of a filler such as concrete.

In the invention according to claim 1 , two types of sensors, a piezoelectric sensor or a capacitance sensor and a resistance sensor, are used to comprehensively determine the filling of a filling such as concrete. can be reliably detected. Specifically, by measuring the electrical resistance between two electrodes arranged facing each other on one side surface of the sheet member with a predetermined separation width by the resistance sensor, the state of filling and the type of filling are measured. (When concrete is filled, air, bleeding water, or concrete) can be determined. In addition, by detecting a change in voltage or capacitance between electrodes caused by deformation of a layer having a high dielectric constant sandwiched between two thin film electrode layers by the piezoelectric sensor or capacitance sensor, filling The filling and compaction situation can be determined. Since two types of sensors are used in this manner, it is possible to prevent erroneous determination of filling completion due to accidental adhesion of the filling material between the electrodes of the resistive sensor.

In the first aspect of the invention, the piezoelectric sensor or the capacitance sensor is arranged on one side surface of the base material, and the resistive sensor is arranged on the opposite side surface. One side surface on which the piezoelectric sensor or the capacitance type sensor is arranged is arranged facing the installation surface side of the sheet sensor (in the case of placing lining concrete in a mountain tunnel, the waterproof sheet side), By arranging the surface on which the resistance sensor is installed facing the filler side (in the case of concrete lining in a mountain tunnel, the center side), the piezoelectric sensor or the capacitance sensor is activated by filling the filler. is pressed to the installation surface side (ground side), and the resistance type sensor is in direct contact with the filling material such as concrete, so the sensitivity of each sensor is improved.

According to a second aspect of the present invention, the sensor portion composed of the piezoelectric sensor or the capacitance sensor and the resistive sensor is divided into a plurality of parts along the longitudinal direction of the sheet sensor and arranged in rows. A sheet-like sensor according to claim 1 is provided.

In the invention according to claim 2 , the sensor portion composed of the piezoelectric sensor or the capacitance sensor and the resistive sensor is divided into a plurality of parts and arranged in rows along the longitudinal direction of the sheet-like sensor. Therefore, it becomes possible to detect the filling state of the filler for each sensor portion.

According to a third aspect of the present invention, the upper electrode layer of the piezoelectric sensor or the capacitive sensor is electrically connected to one of the two electrodes of the resistive sensor. 2. A sheet-like sensor is provided.

In the invention according to claim 3 , in the case where the piezoelectric sensor or the electrostatic capacitive sensor and the resistive sensor are respectively arranged on the front and back surfaces of the base material, the piezoelectric sensor or the electrostatic capacitive sensor By electrically connecting the upper electrode layer and one electrode in the resistive sensor, the upper electrode layer and one electrode function as a shield electrode (ground), eliminating the need to install a separate shield electrode. As a result, the electrode structure can be simplified, and the cost can be reduced by simplifying the electrode configuration.

As the present invention according to claim 4 , the upper electrode layer in the piezoelectric sensor or the capacitive sensor is composed of a continuous upper electrode layer spanning a plurality of the piezoelectric sensors or the capacitive sensors, The sheet-like sensor according to any one of claims 1 to 3 , wherein one of the two electrodes in the resistive sensor comprises a continuous resistive sensor electrode extending over a plurality of the resistive sensors. be done.

The invention according to claim 4 is a modification relating to an arrangement form of the piezoelectric sensor or the capacitance sensor and the resistive sensor, and the upper electrode layer in the piezoelectric sensor or the capacitance sensor. is a continuous upper electrode layer extending along the longitudinal direction across a plurality of piezoelectric sensors or capacitive sensors, and one of the two electrodes in the resistive sensor arranged to face each other The electrode is a continuous resistive sensor electrode that is continuous along the longitudinal direction across the plurality of resistive sensors. By forming the continuous upper electrode layer and the continuous resistive sensor electrode, it is possible to simplify the process of arranging the electrodes and reduce the manufacturing cost in manufacturing the sheet-like sensor.

As the present invention according to claim 5 , any one of claims 1 to 4 , wherein an adhesive or double-sided tape for fixing the sheet-like sensor is used as the protective layer of the piezoelectric sensor or the capacitive sensor. A sheet sensor is provided.

In the fifth aspect of the invention, since an adhesive or double-sided tape for fixing the sheet-like sensor is used as the protective layer of the piezoelectric sensor or the electrostatic capacitive sensor, the piezoelectric sensor or the electrostatic capacitance sensor is used. It is no longer necessary to separately provide a protective layer of silicon or the like for protecting the surface of the capacitive sensor, so that the sheet sensor can be made thinner and the manufacturing cost can be reduced.

As the present invention according to claim 6 , any one of claims 1 to 5 , wherein a resistor having a resistance value between the resistance value of air and the resistance value of water is formed between the two electrodes of the resistive sensor. A sheet sensor is provided.

According to the sixth aspect of the present invention, the sheet sensor is provided with a disconnection detection function for lead wires extending from the electrodes. Specifically, a resistor having a resistance value between the resistance value of air and the resistance value of water is formed between the two electrodes of the resistive sensor. The mechanism of disconnection detection by this is as follows. Since a resistor having a resistance value between the resistance value of air and the resistance value of water is formed in advance between the electrodes, even if the electrodes are in contact with the air when the filling is not filled, the air resistance and the resistance value of water. After the disconnection, the resistor is not energized and the resistance value of the air intervening in the disconnection portion is detected. Therefore, the resistance value of the air that is greater than the resistance value of the resistor is detected. As a result, disconnection can be detected when the detected resistance value becomes equal to or greater than the resistance value of the resistor arranged between the electrodes. Therefore, it is possible to easily determine whether the wire is broken or when the filler is not filled, so that the filling state of the filler can be reliably grasped.

As the present invention according to claim 7 , the base material has a first base material that covers the lower side of the lead wire and a second base material that covers the upper side of the lead wire, and the sensor includes: The sheet according to any one of claims 1 to 6 , which is connected to the lead wire inserted through a through-hole penetrating through a base material positioned on the sensor side of the first base material and the second base material. A shape sensor is provided.

In the invention according to claim 7 , for example, a wire can be used as the lead wire, and the upper and lower sides of the wire can be laminated with the first base material and the second base material, respectively. The manufacturing cost can be greatly reduced compared to a structure in which printed wiring is formed on the surface of the substrate.

According to an eighth aspect of the present invention, the piezoelectric layer or the dielectric layer is arranged to extend outside the upper electrode layer and the lower electrode layer, and between the substrate and the piezoelectric layer or the dielectric layer. A sheet-like sensor according to any one of claims 1 to 7 is provided, wherein the lower electrode layer and lead wires are arranged.

In the eighth aspect of the invention, the piezoelectric layer or the dielectric layer of the piezoelectric sensor or the capacitive sensor is arranged to extend outside the electrode layer, and the lead wire and the lower electrode layer are arranged between them. Therefore, the lead wires can be routed between the two-layered sheets without the base having a two-layer structure, and the thickness of the sheet-like sensor can be reduced.

As the present invention according to claim 9 , there is provided the sheet-like sensor according to any one of claims 1 to 8 , wherein the lead wires are wired on the opposite side of the two electrodes with the base material interposed therebetween. .

In the ninth aspect of the present invention, when a resistive sensor is included as the sensor, two electrodes of the resistive sensor are arranged on one side surface of the substrate, and lead wires are wired on the other side surface. As a result, the lead wires are arranged on the opposite side surface of the filler, not on the opposite surface side of the filler, so breakage of the lead wires can be prevented more reliably.

As described in detail above, according to the present invention, it is possible to improve the installation workability of the sensor and to reliably detect the filling state of the filler. Therefore, it is possible to improve the quality of concrete and the like by improving the filling detection accuracy of the filler.

FIG. 2 is a partially cutaway perspective view showing the procedure for placing lining concrete in a mountain tunnel. It is a cross-sectional view thereof. FIG. 4 is an enlarged longitudinal cross-sectional view of the top end portion showing the arrangement state of the sheet-like sensor 10; 2A is a plan view of the waterproof sheet side and (B) is a plan view of the center side showing the sheet-like sensor 10. FIG. Fig. 4(A) is a cross-sectional view thereof (a view taken along the line VV in Fig. 4(A)). 4A and 4B are cross-sectional views showing the procedure for processing the piezoelectric layer 22. FIG. FIG. 8 is an enlarged plan view of a resistive sensor 24 according to a modified example; 4 is a graph showing changes in the resistance value of the resistive sensor 24 when the lead wire 18 is broken. 10A shows a sheet sensor 10A according to a second embodiment, (A) is a plan view of the waterproof sheet side, and (B) is a plan view of the center side. FIG. 9 is a transverse cross-sectional view thereof (a view taken along line XX in FIG. 9). FIG. 10A is a plan view of the waterproof sheet side, and FIG. 11B is a plan view of the center side, showing the sheet-shaped sensor 10B according to the third embodiment. FIG. 11 is a cross-sectional view thereof (a view taken along line XII-XII in FIG. 11). 10A is a plan view of the waterproof sheet side, and (B) is a plan view of the center side, showing a sheet sensor 10C according to a fourth embodiment. FIG. FIG. 13 is a cross-sectional view thereof (a view taken along line XIV-XIV in FIG. 13). FIG. 12A is a plan view of the waterproof sheet side, and FIG. 11B is a plan view of the center side, showing the sheet-shaped sensor 10D according to the fifth embodiment. FIG. 15 is a cross-sectional view thereof (a view taken along line XVI-XVI in FIG. 15). FIG. 12A is a plan view of the waterproof sheet side, and FIG. 11B is a plan view of the center side, showing the sheet-like sensor 10E according to the sixth embodiment. FIG. 17 is a cross-sectional view thereof (a view taken along line XVIII-XVIII in FIG. 17). FIG. 10A is a plan view of the waterproof sheet side, and FIG. 11B is a plan view of the center side, showing a sheet-like sensor 10F according to the seventh embodiment. FIG. 19 is a cross-sectional view thereof (a view taken along line XX-XX in FIG. 19). FIG. 12A is a plan view of the waterproof sheet side, and FIG. 11B is a plan view of the center side, showing the sheet-like sensor 10G according to the eighth embodiment. FIG. 21 is a cross-sectional view thereof (a view taken along line XXII-XXII in FIG. 21). (A) is the piezoelectric sensor 20, and (B) is a time-series waveform showing the measurement results of the resistive sensor 24. FIG. FIG. 10 is an enlarged longitudinal cross-sectional view of the top portion showing the arrangement state of the sheet-like sensor 10 according to another embodiment; Fig. 10 is a perspective view of a sheet-like sensor 10 according to another embodiment; 4 is a graph showing changes in resistance due to changes in filling interposed between electrodes of a resistive sensor. 4 is a graph showing changes in the resistance value of a resistive sensor when a lead wire is broken;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiment examples, concrete lining placement in a mountain tunnel will be described in detail.

As shown in FIGS. 1 to 3, the sheet-shaped sensor 10 according to the present invention is sprayed on the inner wall surface of the excavated tunnel every span in the direction of the tunnel after excavation by blasting or the like in constructing a mountain tunnel T. After constructing the shotcrete 1 and driving the rock bolts, the waterproof sheet 2 is pasted on the surface, and the center 3 (lining concrete When installing the formwork 5 of the moving formwork) and placing the lining concrete 4 in the space between the rock wall surface T1 and the formwork 5 of the center 3, this lining concrete 4 (filler) It is preferably used to detect the filling status of the. The shotcrete shown in the figure has a structure in which a steel arch member is also used as a shoring.
The center 3 is installed behind the heavy equipment for tunnel construction, and as shown in FIGS. It is mainly composed of a formwork 5, a support frame 6 that supports the formwork 5, and a running rail 7 laid on the bottom surface of the tunnel T on which the support frame 6 can run.
The formwork 5 is provided along the ground wall surface T1 of the tunnel T, has a smooth outer surface, and is made of a material that is highly releasable from concrete. The formwork 5 is divided into a plurality of parts in the circumferential direction of the tunnel T, and the parts are connected to each other. Further, as shown in FIG. 3, a concrete pouring opening 8 for pouring concrete is provided in the upper part of the formwork member 5 near the wellhead side.
As shown in FIGS. 1 and 2, the formwork 5 is attached to the support frame 6 via a connecting member such as a hydraulic cylinder 6A so as to be movable in the horizontal direction and the vertical direction with respect to the section of the tunnel T. installed.
The support frame 6 is composed of a gate-shaped frame 6B made of a substantially gate-shaped steel frame or the like, and connecting members such as the hydraulic cylinder 6A to which the formwork 5 is attached.
The running rails 7 support the gate frame 6B so as to be able to run, and are laid on the lower surface of the tunnel T in two rows along the longitudinal direction.

The sheet-like sensor 10 is formed in a flexible sheet-like shape, for example, as shown in FIGS. As shown in FIGS. 1 to 3, before the lining concrete 4 is cast, the top end of the natural ground wall surface T1 is attached along the longitudinal direction of the tunnel T to the natural ground side. It is installed along the wall surface T1.

As shown in FIGS. 4 and 5, the sheet-like sensor 10 has a flexible sheet-like structure having long sides and short sides in a plan view. S, and a plurality of sensors (piezoelectric sensor 20, resistive sensor 24, etc.) arranged on at least one side surface of the sheet member S at intervals along the longitudinal direction to detect the filling state of the filling material. and a connector 19 provided at one end of the sheet member S in the longitudinal direction.

The sheet member S has a base material 11 formed in a sheet shape and wiring along the base material 11, one end of which is connected to the sensor, and the other end of the sheet member S in the longitudinal direction of the sheet member S. are connected to the connector 19 provided at one end of the lead wires 18, 18 . . .

By installing the sheet-like sensor 10, when the lining concrete 4 is placed, the placing situation in the direction along the longitudinal direction of the span can be grasped linearly or planarly. In addition, since the sheet-like sensor 10 is formed in a flexible sheet shape, it can be freely deformed along the unevenness (unevenness) of the rock ground side wall surface T1, and the ground rock side wall surface T1 in the installation section thereof can be deformed freely. It is also possible to reliably grasp the filling state of concrete along unevenness, that is, the filling state of recesses that are depressed toward the ground.

Further, in the sheet-shaped sensor 10, a plurality of sensors are arranged on the flexible sheet member S, and the lead wires 18 connected to the sensors are wired in advance on the sheet member S. By simply installing the sensor 10 at the top of the tunnel along the longitudinal direction of the tunnel, a plurality of sensors are arranged at predetermined positions and at the same time lead wires 18 connected to these sensors are wired. Therefore, it is possible to improve the installation workability of the sensor. In addition, since a plurality of sensors can be reliably arranged at predetermined positions without causing breakage of the lead wires 18, the state of concrete filling can be reliably detected.

[Example 1]
The sheet-shaped sensor 10 will be described in more detail below. As shown in FIGS. 4 and 5, the sheet-shaped sensor 10 according to the first embodiment includes an upper electrode layer 21, a piezoelectric layer 22, and a lower electrode layer 23. are stacked in order and provided at predetermined intervals along the longitudinal direction, and two electrodes 25 and 25 are provided on one side surface of the sheet member S at a predetermined separation width. A plurality of resistive sensors 24, 24, . In the sheet-shaped sensor 10 according to the first embodiment, by using two types of sensors, the piezoelectric sensor 20 and the resistance sensor 24, it is possible to comprehensively determine filling and compaction of concrete.

In the sheet-shaped sensor 10 according to the first embodiment, the sensor portion 15 composed of the piezoelectric sensor 20 and the resistive sensor 24 is divided into a plurality of parts and arranged in rows along the longitudinal direction. That is, a plurality of sensor portions 15, 15, .

As shown in FIGS. 1 to 3, the sheet-like sensor 10 is arranged such that the longitudinal direction of the sheet-like sensor 10 is the direction of the tunnel T with respect to the crest of the ground wall surface T1 after the waterproof sheet 2 is pasted. The waterproof sheet 2 is arranged in an orientation that substantially coincides with the longitudinal direction, and is closely attached to the waterproof sheet 2 by a bonding means such as an adhesive or a double-sided tape, so that it can follow the unevenness of the natural rock side wall surface T1 of the tunnel T. It has become.

In the embodiment shown in FIG. 3, the sheet-like sensor 10 is arranged over the entire length of one span in which the lining concrete 4 is placed by the center 3 . In other words, the longitudinal dimension of the sheet-like sensor 10 is approximately equal to the length L of one span of the center 3 . In the case of a general center, the length L of one span is 10.5 m, so the sheet sensor 10 preferably has a longitudinal dimension of 10.5 m or more. By arranging the sensor 10 over the entire length of one span, it becomes possible to grasp the concrete placement state linearly or planarly over the entire length of the placement section in the tunnel direction (the entire length of one span). .

In the sheet-shaped sensor 10 according to the first embodiment, a flexible resin sheet is used as the base material 11, and the piezoelectric sensor 20 is disposed on one side of the base material 11, and the piezoelectric sensor 20 is disposed on the opposite side of the base material 11. The resistive sensor 24 is arranged on the surface. That is, the piezoelectric sensor 20 and the resistive sensor 24 are separately arranged on the front and rear surfaces of the base material 11 .

The material constituting the base material 11 is thermoplastic resin or thermoplastic resin having high heat resistance when coated at a high temperature and having flexibility and high elastic modulus capable of following the unevenness of the ground wall surface T1 of the tunnel T. A curable resin is preferably used.

The planar shape of the base material 11 is formed in a rectangular shape (strip shape) having long sides and short sides. The thickness is preferably 0.3 to 1.5 mm, preferably about 1 mm, and the width is preferably 1 to 500 mm, particularly 100 to 300 mm.

As shown in FIG. 5, the total thickness t of the sheet-like sensor 10 excluding the release material 13, which will be described later, is preferably 5 mm or less, particularly about 0.5 to 2.5 mm. With this thickness, the sheet-shaped sensor 10 can be flexibly deformed along the unevenness of the natural ground.

The measurement principle of the piezoelectric sensor 20 is that the piezoelectric effect of the piezoelectric layer 22 converts mechanical energy such as pressure and vibration into electrical energy, and charges generated in the piezoelectric layer 22 are transferred to the upper electrode layer 21 and the lower electrode layer. 23 to detect filling and compaction of concrete.

In the sheet-like sensor 10, instead of the piezoelectric sensor 20, a capacitive sensor (not shown) in which an upper electrode layer, a dielectric layer and a lower electrode layer are laminated in order may be used. This also applies to embodiments described later. This capacitive sensor can be less costly than the piezoelectric sensor 20 . The measurement principle of this capacitance sensor is to keep a voltage applied at all times and detect changes in the capacitance stored in the dielectric layer by receiving pressure and vibration due to the filling of concrete. It is to understand filling and compaction.

The surface of the piezoelectric sensor 20 is preferably covered with a protective layer 12 in order to prevent short-circuiting between electrode layers, waterproof, protect the electrodes, and remove noise by insulation. As the protective layer 12, silicon rubber or the like having excellent electrical insulation and waterproof properties may be used, but it is preferable to use an adhesive or double-sided tape for fixing the sheet-like sensor 10 to the waterproof sheet 2. .

When the protective layer 12 is composed of an adhesive, as the adhesive, a wide range of known adhesives can be used as long as they have high adhesive strength and excellent electrical insulation and waterproof properties. , butyl rubber or acrylic adhesive.

When an adhesive or double-sided tape is used as the protective layer 12, the protective layer 12 is covered with a peeling material 13 made of paper, plastic, or the like that can be easily peeled off. In order to fix the sheet-like sensor 10 to the waterproof sheet 2, the peeling material 13 is peeled off.

The planar shape of the piezoelectric sensor 20 is preferably formed in a substantially rectangular or square shape, and the dimension in the longitudinal direction of the sheet-shaped sensor 10 is 1 to 100 mm, and the dimension in the lateral direction is 0.5 to 299 mm. is preferred.

Examples of the piezoelectric material forming the piezoelectric layer 22 include organic polyvinylidene fluoride (PVDF) and a copolymer of vinylidene fluoride (VDF) and ethylene trifluoride (TrFE) (P(VDF-TrFE)). Polyamide (PA), polyethylene (PE), polyethylene terephthalate (PET, PETE), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and polylactic acid (PLA) are preferable for this fluorine-based piezoelectric material. , polypropylene (PP), polyamide (PA), polycarbonate (PC), polytetrafluoroethylene (PTFE), polyurethane (PU), polystyrene (PS), polyester, ABS resin (ABS), acrylic resin (PMMA), polyacetal resin A blend of compatible substances such as (POM) may be used.

As the piezoelectric material, particles of inorganic barium titanate, calcium titanate, strontium titanate, lead zirconate titanate (PZT), or the like may be combined with the organic piezoelectric material. .

A known method can be used to process the piezoelectric layer 22 . For example, spray coating, paste coating, silk printing, pad printing, sputtering, vapor deposition, or the like can be used. In particular, by using the spray coating technology disclosed in Japanese Patent Application Laid-Open No. 2013-701, the voltage detection sensitivity can be improved, it is possible to handle complicated shapes, and it is possible to increase the area. Therefore, it is preferable. To explain the outline of the spray coating technique disclosed in this publication, as shown in FIG. . The object to be coated is kept in a positive pole (grounded state), and a high voltage of minus 1 kV to 90 kV is applied to the electrode needle at the tip of the coating sprayer 30 facing the coating surface of the object to be coated, and the object to be coated and the coating are sprayed. forming an electric field 31 with the machine 30; b. Next, the inert gas is jetted toward the object to be coated from the inert gas jetting nozzle at the tip of the coating sprayer 30, and at the same time, at the tip of the coating sprayer 30, a dielectric nozzle with the electrode needle positioned at the center A solution (dielectric solution) in which a dielectric substance is dissolved in a solvent is jetted from a solution jetting nozzle toward an object to be coated, and the droplets of the dielectric solution are given a negative charge, and the coating sprayer 30 is moved. while forming a pre-polarized film on the object to be coated, c. Next, the electric field coating is temporarily stopped, the coating sprayer 30 directed to the object to be coated is moved to the outside of the object to be coated, and the inert gas is discharged from the dielectric solution injection nozzle of the coating sprayer 30. expelling any dielectric solution remaining in the dielectric solution ejection nozzle by d. Next, the coating sprayer 30 is returned to its original position, and the electric field 31 is formed again between the object to be coated and the coating sprayer 30 to further polarize the pre-polarized film (electric field polarization) on the object to be coated. This is performed by a procedure of forming a piezoelectric film.

In addition, according to the spray coating technique, the piezoelectric layer 22 can be formed regardless of the target. It is also possible to directly provide the sheet-like sensor 10 .

The upper electrode layer 21 and the lower electrode layer 23 are formed using a conductive polymer solution or metal paste, such as highly conductive silver, copper, or carbon powder materials.

Next, the resistive sensor 24 will be described in detail. The resistive sensor 24 is composed of two electrodes 25, 25 arranged opposite to each other with a predetermined separation width. It is not covered with a layer or the like and is exposed so that the filled concrete or the like can come into direct contact with it.

The measurement principle of the resistance sensor 24 utilizes the fact that the resistance value (amount of current) between the electrodes 25 differs depending on the substance (air, bleeding water, concrete, etc.) intervening between the two electrodes 25, 25. By detecting this resistance value, the presence or absence of concrete filling and the type of intervening substance (either air, bleeding water, or concrete) are determined.

In this embodiment, the two electrodes 25, 25 constituting the resistive sensor 24 are formed to have substantially the same size and are arranged opposite to each other with a predetermined separation width W in the longitudinal direction of the sheet-like sensor 10. . Therefore, the space between the two electrodes 25, 25 is formed along the short sides of the sheet sensor 10. As shown in FIG.

The separation between the two electrodes 25, 25 is formed with a predetermined separation width W, as shown in FIG. The separation width W is preferably 0.1 to 30 mm, preferably 1 to 10 mm.

The planar shape of each electrode 25 is preferably formed in a rectangular shape long along the direction in which the separated portion of the two electrodes 25, 25 extends. is formed in The dimension of each electrode 25 along the longitudinal direction of the sheet-shaped sensor 10 is 1 to 50 mm, preferably 5 to 20 mm, and the dimension along the short side direction is 0.5 to 299 mm, preferably should be 8 to 30 mm.

Although the arrangement position of the piezoelectric sensor 20 and the arrangement position of the resistive sensor 24 do not necessarily match on the front and rear surfaces of the base material 11, the arrangement positions of the two should substantially match. is preferred. In other words, the piezoelectric sensor 20 and the resistive sensor 24 are preferably arranged at positions close to each other on the front and back surfaces of the substrate 11, preferably at positions overlapping each other in the thickness direction. As a result, the measurement positions of the resistive sensor 24 and the piezoelectric sensor 20 become substantially the same, and the consistency of the measurement results of both can be obtained.

The distance between adjacent piezoelectric sensors 20, 20 arranged along the longitudinal direction should be about 1 to 5000 mm, preferably about 10 to 1000 mm.

The sheet-like sensor 10 is provided with lead wires 18 extending from the upper electrode layer 21 and the lower electrode layer 23 of the piezoelectric sensor 20 and the electrodes 25 of the resistive sensor 24 (FIG. 4A). ).

The lead wire 18 extends toward one end in the longitudinal direction of the sheet-like sensor 10 and extends to the outside as a single flat cable via a connector 19 provided at this end. When multiple small-piece sensors are installed as in the past, it is necessary to arrange a large number of cables extending from each sensor. There were drawbacks such as On the other hand, in the present sheet-like sensor 10, one flat cable extends from the sensor 10, and by connecting this flat cable to an analysis device, the signals obtained at each sensor portion 15 can be easily analyzed. It becomes possible to transmit the data to a device (computer, etc.), which simplifies the installation work, and makes it easy to match the signal from the sensor with the concrete filling detection position.

As the lead wire 18, it is possible to use a wide range of known ones. preferably used.

Preferably, the lead wires 18 are arranged on the side of the base material 11 which is to be the waterproof sheet side when the base material 11 is installed, and the outer surface is covered with an adhesive, double-sided tape, silicon, or the like. That is, it is preferable not to arrange the lead wire 18 on the center side. The lead wires 18 extending from the electrodes 25 of the resistive sensor 24 arranged on the center side are preferably arranged on the surface of the waterproof sheet through the through holes 29 passing through the base material 11 . Since the lead wire 18 is arranged on the waterproof sheet side of the base material 11 and is not arranged on the center side with which the filler comes into contact, breakage of the lead wire 18 can be more reliably prevented.

As shown in FIG. 5, the sheet-like sensor 10 is mounted so that the surface on which the resistive sensor 24 is disposed faces the center 3 side, and the piezoelectric sensor 20 is disposed. This is done by fixing the protective layer 12 (adhesive or the like) provided on the side surface to the waterproof sheet 2 .

As shown in FIGS. 4 and 5, the sheet sensor 10 is preferably provided with a shield electrode 14 made of a highly conductive material for the purpose of grounding for noise removal. The shield electrode 14 is composed of an electrode 14b provided on the surface of the substrate 11 facing the center 3 when the sensor is installed (the surface on which the piezoelectric sensor 20 is arranged), and an electrode 14b provided on the surface of the substrate 11 on which the sensor is installed. An electrode 14a provided on the surface that is sometimes on the side of the waterproof sheet 2 (the surface on which the resistive sensor 24 is arranged), and a connecting member that penetrates the base material 11 and connects the electrodes 14a and 14b. 14c. As shown in FIG. 4, the electrode 14b provided on the surface facing the center 3 when the sensor is installed is formed in a continuous belt-like or linear shape extending substantially over the entire length of the range where the sensor portions 15, 15... are installed. formed. The provision of the electromagnetic shielding electrode 14 eliminates the need for lead wires between the sensor portions 15 and the installation of electromagnetic shielding films, making it possible to reduce the product cost.

The upper electrode layer 21 in the piezoelectric sensor 20 and one electrode 25 of the two electrodes 25 in the resistive sensor 24 may be electrically connected. Specifically, a lead wire connecting the upper electrode layer 21 and the electrode 25 is inserted through a through-hole penetrating the substrate 11 in the thickness direction to electrically connect them. By electrically connecting the upper electrode layer 21 and the electrode 25, the upper electrode layer 21 and the electrode 25 function as a shield electrode (ground), eliminating the need to separately provide a shield electrode, and providing an electrode structure. can be simplified and costs can be reduced.

The detection of the filling by the sheet-like sensor 10 is performed by the piezoelectric sensor 20 , which is caused by the pressure of the lining concrete 4 and the vibration during compaction of the concrete, and the piezoelectric effect caused by the distortion of the piezoelectric layer 22 , which causes the upper electrode layer 21 and the lower electrode layer 21 to move. In the resistive sensor 24, the lining concrete 4 is filled between the two electrodes 25, 25 arranged opposite to each other with a predetermined separation width, so that both electrodes are charged. This is done by measuring the change in voltage between Since the sheet-like sensor 10 is buried in the lining concrete, it detects the vibration from the vibrator during compaction performed after the lining concrete is poured, thereby detecting vibrations at various points in the longitudinal direction of the tunnel. It is also possible to grasp the compaction status.

In the sheet-like sensor 10 according to the first embodiment having the above configuration, the resistance sensor 24 measures the electrical resistance between the two electrodes 25, 25 that are opposed to each other with a predetermined separation width, thereby measuring the concrete and the type of filling (air, bleeding water, concrete). Furthermore, in the piezoelectric sensor 20, by capturing the change in the voltage between the electrodes 21 and 23 caused by the deformation of the piezoelectric layer 22 having a high dielectric constant sandwiched between the upper electrode layer 21 and the lower electrode layer 23, Filling and compaction can be determined. Therefore, by using these two types of sensors, it is possible to reliably grasp the state of concrete filling. In addition, since the two types of sensors are used, it is possible to prevent erroneous determination of filling completion due to accidental adhesion of concrete between the electrodes 25, 25 of the resistive sensor 24. FIG.

In addition, in the sheet-shaped sensor 10 according to the first embodiment, the piezoelectric sensor 20 is arranged on the surface of the base material 11 on the waterproof sheet 2 side. Since the piezoelectric layer 22 is reliably pressed and easily deformed along the unevenness of the natural ground, the sensitivity of the sensor is improved, and the filling state of concrete can be accurately grasped.

Furthermore, in the sheet-like sensor 10 according to the first embodiment, since an adhesive or double-sided tape is used as the protective layer 12 of the piezoelectric sensor 20, the sheet-like sensor 10 is attached to the waterproof sheet 2 with this adhesive or double-sided tape. In addition, there is no need to provide a separate protective layer of silicon or the like, and the sheet sensor 10 can be made thinner, and the followability to the unevenness of the ground is improved, and the manufacturing cost is reduced. can be reduced.

Next, as a modified example of the sheet-like sensor 10 according to the first embodiment, a configuration in which a disconnection detection function for the lead wires 18 extending from the electrodes is added will be described. The disconnection detection function connects a resistor 28 having a resistance value between the resistance value of air and the resistance value of water between the two electrodes 25, 25 of the resistance sensor 24, as shown in FIG. can be added by The resistor 28 is not particularly limited as long as it has a resistance value between the air resistance value and the water resistance value.

The mechanism of disconnection detection by this configuration is as follows. The resistance sensor 24 constantly monitors the resistance value between the electrodes 25, 25, and identifies the filling from the change in the resistance value. Since the resistor 28 is arranged between the electrodes 25, 25 as described above, the resistance value of the resistor 28 is detected when it is not filled, and as shown in FIG. and the resistance value of water. Assuming that bleeding water comes into contact with the filling of concrete, the detected resistance value decreases, and then the contact of concrete further decreases the resistance value. On the other hand, after disconnection, the resistor 28 is not energized and the resistance value between another electrode is detected through the air. An original air resistance value greater than the value will be detected. As described above, the lead wires 18 pass through the through-holes provided in the base material 11, are arranged on the surface facing the waterproof sheet, and are covered with the protective layer 12. For example, the resistance value of the air between the upper electrode layer 21 or the lower electrode layer 23 of the piezoelectric sensor 20 is detected. As a result, when the resistance value to be detected becomes equal to or greater than the resistance value of the resistor 28 arranged between the electrodes 25, 25, disconnection can be detected. As a result, it is possible to easily discriminate between when the wire is disconnected and when the concrete is not filled, so that the state of the concrete filling can be reliably grasped.

[Second form example]
As shown in FIGS. 9 and 10, the sheet sensor 10A according to the second embodiment uses a flexible resin sheet as a base material 11, and the piezoelectric sensor is provided on one side surface of the base material 11. 20 and a resistive sensor 24 are arranged adjacently. That is, the piezoelectric sensor 20 and the resistive sensor 24 are arranged on the same surface on one side of the substrate 11, and are not arranged on the opposite surface.

The arrangement of the piezoelectric sensors 20 and the resistive sensors 24 on one side surface of the base material 11 is such that a plurality of piezoelectric sensors 20, 20 . . . A plurality of resistive sensors 24, 24, .

The piezoelectric sensor 20 and the resistive sensor 24 may be arranged in any direction in the longitudinal direction of the base material 11 , but the piezoelectric sensor 20 and the resistive sensor 24 may be arranged adjacent to each other in the lateral direction of the base material 11 . It is preferable to place Although the separation distance between the piezoelectric sensor 20 and the resistance sensor 24 is arbitrary, it is preferable to provide them at positions close to each other so that the measurement results of the two are matched. The separation distance between them is preferably about 1 to 20 mm.

The surface of the piezoelectric sensor 20 is covered with a protective layer 12 . As the protective layer 12, any known material can be used as long as it is flexible and has excellent electrical insulating properties and waterproof properties, but it is particularly preferable to use silicone rubber.

On the other hand, the resistive sensor 24 is exposed to the outside without being covered with the protective layer 12 . Therefore, the protective layer 12 is formed along the longitudinal direction only in the range on one side of the substrate 11 in the lateral direction where the piezoelectric sensors 20 are arranged. .

An adhesive layer made of adhesive or double-sided tape for fixing the sheet sensor 10 to the waterproof sheet 2 is provided on the surface of the substrate 11 opposite to the surface on which the piezoelectric sensor 20 and the resistive sensor 24 are arranged. 16 are provided. The adhesive layer 16 is covered with a peeling material 13 made of paper, plastic, or the like whose surface can be peeled off.

As shown in FIG. 10, the sheet-shaped sensor 10A is attached so that the surface on which the piezoelectric sensor 20 and the resistive sensor 24 are arranged faces the center 3, and the adhesive layer 16 is provided. The surface facing the waterproof sheet 2 is arranged.

By arranging the sensor portions 15 together on one side of the substrate 11 as in this embodiment, the electrodes need only be installed on one side, and the wiring of the lead wires 18 is only required on one side. becomes easier.

[Third form example]
As shown in FIGS. 11 and 12, the sheet-shaped sensor 10B according to the third embodiment has a piezoelectric sensor 20 arranged on one surface of a substrate 11 and a resistive sensor 20 on the opposite surface. A sensor 24 is provided.

As shown in FIGS. 11 and 12, the sheet-like sensor 10B has a plurality of piezoelectric sensors in which the upper electrode layer of the piezoelectric sensor 20 is arranged in rows along the longitudinal direction of the sheet-like sensor 10B. 20, 20, . It has a structure consisting of continuous resistive sensor electrodes 27 that are continuous along the longitudinal direction across a plurality of resistive sensors 24, 24, . . .

In the piezoelectric sensor 20, the continuous upper electrode layer 26 is arranged continuously along the longitudinal direction, and the piezoelectric layer 22 and the lower electrode layer 23 are divided into a plurality of parts along the longitudinal direction. are lined up. The continuous upper electrode layer 26 is continuously arranged over substantially the entire length of the substrate 11 .

Similarly, in the resistive sensor 24, one electrode (continuous resistive sensor electrode 27) of the two electrodes arranged facing each other is arranged continuously along the longitudinal direction, and the other electrode 25 are divided into a plurality of parts and arranged in a line along the longitudinal direction. The continuous resistance sensor electrode 27 is continuously arranged over substantially the entire length of the substrate 11 . The continuous resistance sensor electrode 27 and the electrode 25 are spaced apart in the short side direction of the sheet-like sensor 10 , and this spaced portion extends along the long side direction of the sheet-like sensor 10 .

The lead wires 18 extending from each electrode are preferably arranged along one side of the surface on which the piezoelectric sensor 20 is arranged. The lead wire 18 connected to the electrode 25 provided on the surface on which the resistive sensor 24 is arranged and the continuous resistive sensor electrode 27 passes through a through hole 29 penetrating through the substrate 11 in the thickness direction. It is preferable to dispose on the surface of the one side.

The continuous upper electrode layer 26 and the continuous resistive sensor electrode 27 are preferably electrically connected. Specifically, as shown in FIG. 11, the lead wire 18a extending from the continuous resistance sensor electrode 27 is inserted into a through hole 29 penetrating through the substrate 11 in the thickness direction, and the piezoelectric sensor 20 is arranged. It is connected to a lead wire 18b extending from the continuous upper electrode layer 26 on one side of the provided surface.

By electrically connecting the continuous upper electrode layer 26 and the continuous resistive sensor electrode 27, the continuous upper electrode layer 26 and the continuous resistive sensor electrode 27 function as a shield electrode (ground). , there is no need to separately provide a shield electrode, the electrode structure can be simplified, and the cost can be reduced.

[Fourth form example]
As shown in FIGS. 13 and 14, the sheet sensor 10C according to the fourth embodiment has a piezoelectric sensor 20 and a resistive sensor 24 arranged adjacent to each other on one side of the substrate 11. , the upper electrode layer of the piezoelectric sensor 20 is composed of a continuous upper electrode layer 26 continuous along the longitudinal direction across the plurality of piezoelectric sensors 20, 20 . . . One electrode of the two electrodes has a structure consisting of a continuous resistive sensor electrode 27 continuous along the longitudinal direction across a plurality of resistive sensors 24, 24, . . . .

A shield electrode 14 serving as a ground is preferably provided on the opposite surface of the substrate 11 .

[Fifth form example]
In a sheet sensor 10D according to the fifth embodiment, as shown in FIGS. 15 and 16, the base material 11 is composed of a first base material 11a covering the lower side of the lead wires 18 and an upper side of the lead wires 18. and a second substrate 11b covering the lower electrode layer 23 of the piezoelectric sensor 20 and the electrodes 25, 25 of the resistive sensor 24, respectively, on the first substrate 11a and the second substrate 11b. The lead wires 18 are connected to the lead wires 18 inserted through the through holes 29a and 29b penetrating through the base material located on the sensor 20 and 24 side. The piezoelectric sensor 20 is arranged on the outer surface of the first base material 11a (the surface opposite to the second base material 11b), and the outside thereof is provided over the entire surface of the first base material 11a. A lower electrode layer 23 is connected to a lead wire 18 inserted through a through hole 29a penetrating through the first base material 11a. On the other hand, the resistive sensor 24 is arranged on the outer surface of the second base material 11b (the surface opposite to the first base material 11a), and the electrodes 25, 25 penetrate the second base material 11b. It is connected to the lead wire 18 inserted through the through hole 29b. The first base material 11a and the second base material 11b are in close contact with each other with the lead wires 18 arranged thereon by an adhesive, heat fusion, or the like with almost no gap.

In this embodiment, for example, a wiring material (wire) made of tin-plated wire or the like is used as the lead wire 18, and the upper and lower sides of the lead wire 18 are respectively a first base material 11a made of polyethylene terephthalate (PET) or the like and a second base material 11a made of polyethylene terephthalate (PET). It is possible to have a laminated structure with two substrates 11b. Therefore, it is possible to significantly reduce the cost compared to a structure in which printed wiring is applied to the surface of the base material 11 by printing. In addition, since the upper and lower portions of the lead wires 18 are covered with base materials 11a and 11b made of a resin material, respectively, when the sheet sensor 10D is installed, the lead wires 18 may be subjected to a strong impact or sharp tip. Breakage of the lead wire 18 can be prevented even if the lead wire 18 is damaged by the

[Sixth form example]
As shown in FIGS. 17 and 18, in the sheet-shaped sensor 10E according to the sixth embodiment, the piezoelectric layer 22 of the piezoelectric sensor 20 extends outside the upper electrode layer 21 and the lower electrode layer 23, and the The lower electrode layer 23 and the lead wire 18 are arranged between the substrate 11 and the piezoelectric layer 22, and the outer surface of the piezoelectric layer 22 (on the side opposite to the substrate 11). The upper electrode layer 21 is arranged on the surface). Between the base material 11 and the piezoelectric layer 22, the lower electrode layer 23 and the lead wires 18 are arranged, and the lower electrode layer 23 is adhered to the piezoelectric layer 22 with almost no gap by adhesive, heat fusion, or the like. It has a non-contact structure.

In addition, in the sheet-like sensor 10E according to the sixth embodiment, one electrode of the two electrodes 25, 25 constituting the resistive sensor 24 is adjacent to the upper electrode layer 21 with a predetermined separation width. 25 are arranged, and the upper electrode layer 21 preferably also serves as the other electrode 25 of the two electrodes 25 , 25 constituting the resistive sensor 24 . That is, as shown in FIG. 18, the electrodes arranged on the outer surface of the piezoelectric layer 22 overlapping the lower electrode layer 23 in the thickness direction with the piezoelectric layer 22 interposed therebetween have a relationship with the lower electrode layer 23 and the piezoelectric layer 22. The two electrodes 25, 25 of the resistive sensor 24 form the upper electrode layer 21 of the piezoelectric sensor 20 and are arranged on the outer surface of the piezoelectric layer 22 with a predetermined separation width. It constitutes one electrode 25 of them. The electrodes 25, 25 (upper electrode layer 21) arranged on the outer surface of the piezoelectric layer 22 are connected to the lead wires 18 inserted through the through holes 29c penetrating the piezoelectric layer 22, respectively. Also, the lower electrode layer 23 is connected to the lead wire 18 between the substrate 11 and the piezoelectric layer 22 .

In the sheet-like sensor 10E according to the sixth embodiment, the lead wires 18 can be wired between the two-layered sheets without the base material 11 having a two-layer structure, and the thickness of the sheet-like sensor can be further reduced. There is Further, since the upper electrode layer 21 of the piezoelectric sensor 20 also serves as one electrode 25 of the resistive sensor 24, cost reduction and wiring simplification can be achieved.

In the above description, the piezoelectric layer 22 of the piezoelectric sensor 20 is arranged on substantially the entire surface of the base material 11, but the piezoelectric layer 22 extends outside the upper electrode layer 21 and the lower electrode layer 23. However, it is sufficient that the lower electrode layer 23 and the lead wire 18 are arranged between the substrate 11 and the piezoelectric layer 22 .

[Seventh form example]
As shown in FIGS. 19 and 20, the sheet sensor 10F according to the seventh embodiment has two electrodes 25, 25 arranged opposite to each other with a predetermined separation width as a sensor for detecting the filling state of the filler. It consists only of the resistive sensor 24 and does not include the piezoelectric sensor 20 or the capacitive sensor. The electrodes 25, 25 of the piezoelectric sensor 20 are arranged on the center side of the base material 11, and the lead wires 18 connected to the respective electrodes 25 pass through the base material 11 through the through-holes 29. 11 is wired between the base material 11 on the side of the waterproof sheet and the protective layer 12 .

Also in this embodiment, the base material 11 is formed in a sheet shape, and the lead wires 18 are wired along the base material 11, so that the installation workability of the sensor can be improved. In addition, since the lead wire 18 is arranged on the waterproof sheet side of the base material 11 and not arranged on the center side with which the filler comes into contact, disconnection of the lead wire 18 can be more reliably prevented.

[Eighth form example]
As shown in FIGS. 21 and 22, the sheet-shaped sensor 10G according to the eighth embodiment has an upper electrode layer 21, a piezoelectric layer 22, and a lower electrode layer 23 laminated in order as a sensor for detecting the filling state of the filler. It consists only of a piezoelectric sensor 20 or a capacitive sensor and does not include the resistive sensor 20 . The piezoelectric sensor 20 is arranged on the waterproof sheet side of the base material 11, and the lower electrode layer 23 is connected to the lead wire 18 wired on the waterproof sheet side.

Also in this embodiment, the base material 11 is formed in a sheet shape, and the lead wires 18 are wired along the base material 11, so that the installation workability of the sensor can be improved.

When constructing a mountain tunnel, the sheet-like sensor 10 according to the first embodiment is installed along the tunnel longitudinal direction at the top of the rock wall surface, and the sheet sensor 10 according to the first embodiment is installed along the rock rock wall surface. When lining concrete is placed in the space between the formwork and the side wall of the natural ground, which are installed along the circumferential direction with a distance of The change in voltage over time was measured. The results are shown in FIG.

As shown in FIG. 23, the voltage measured by the substance (air, bleeding water, concrete) interposed between the two electrodes 25, 25 of the resistive sensor 24 varies. Intervening substances can be identified, and the state of concrete filling can be grasped.

In the piezoelectric sensor 20 as well, a tendency similar to that of the resistive sensor 24 is observed. In addition, in the piezoelectric sensor 20, the piezoelectric layer 22 is pressed against the ground by filling concrete, and deforms into a bowl shape along the unevenness of the side wall of the ground. The part surrounded by the dotted circle in the upper right diagram of FIG. 23(A)). By capturing this change, completion of concrete filling can be determined.

[Other form examples]
(1) As another example of the arrangement of the sheet-shaped sensor 10, as shown in FIG. It may be arranged over a length range (L ₁ ) of 3 or more, preferably 1/2 or more. The road tunnel is provided with a longitudinal gradient of 2% or less for drainage, and the sheet-like sensor 10 is arranged over a predetermined section length from the high side to the low side of the longitudinal gradient. If so, the presence or absence of concrete filling can be reliably grasped.

(2) In the above embodiment, the sensor portions 15, 15 ... provided at predetermined intervals along the longitudinal direction are arranged in a row in the transverse direction, but as shown in FIG. In addition, they may be arranged in a plurality of rows at predetermined intervals in the widthwise direction.

(3) In the above embodiment, the sheet-shaped sensor is used to detect the state of filling of lining concrete in mountain tunnels, but the sheet-shaped sensor can also be used for other purposes. For example, other general concrete, fluidized soil when existing pipes are clogged, pipe-in-pipe grout (air milk, air mortar, etc.), filling materials around rock bolts (mortar, cement milk, etc.), reverse construction method Used to detect the filling status of joint fillers (non-shrink mortar, epoxy resin, etc.), steel plate winding method fillers (non-shrink mortar, underwater mortar, epoxy resin, etc.), and PC grout filling. be able to.

DESCRIPTION OF SYMBOLS 1... Shotcrete, 2... Waterproof sheet, 3... Center, 4... Lining concrete, 5... Form member, 6... Support frame, 7... Running rail, 10, 10A, 10B, 10C, 10D, 10E, 10F 10G...sheet-like sensor, 11...base material, 12...coating layer, 13...separation material, 14...shield electrode, 18...lead wire, 19...connector, 20...piezoelectric sensor, 21...upper electrode layer, 22... Piezoelectric layer 23 Lower electrode layer 24 Resistive sensor 25 Electrode 26 Continuous upper electrode layer 27 Continuous resistive sensor electrode 29 Through hole T Tunnel T1 Side wall of ground

Claims (9)

A sheet-like sensor for detecting a filling state of a filling material,
A flexible sheet member having a long side and a short side in plan view, and a plurality of sheet members arranged on at least one side surface of the sheet member at intervals along the long side direction. and a sensor that detects the filling status of the filling,
The sheet member includes a base material formed in a sheet shape and wiring along the base material, one end of which is connected to the sensor, and the other end of which is connected to one end of the sheet member in the longitudinal direction. and a plurality of lead wires extending toward
The sensor includes a piezoelectric sensor in which an upper electrode layer, a piezoelectric layer, and a lower electrode layer are laminated in order, or a capacitive sensor in which an upper electrode layer, a dielectric layer, and a lower electrode layer are laminated in order, and two electrodes. and a resistive sensor arranged opposite to one side of the sheet member with a predetermined separation width, and the piezoelectric sensor or the capacitive sensor is arranged on one side of the base material. The resistive sensor is disposed on the opposite surface, and the piezoelectric sensor or the capacitive sensor and the resistive sensor are located close to each other on the front and back surfaces of the base material or overlap in the thickness direction. A sheet-shaped sensor characterized by being arranged . 2. The sheet according to claim 1 , wherein the sensor portion comprising the piezoelectric sensor or the capacitance sensor and the resistive sensor is divided into a plurality of parts and arranged in rows along the longitudinal direction of the sheet sensor. shape sensor. 3. The sheet-shaped sheet according to claim 1 , wherein the upper electrode layer of the piezoelectric sensor or the capacitive sensor and one of the two electrodes of the resistive sensor are electrically connected. sensor. wherein the top electrode layer in the piezoelectric or capacitive sensor comprises a continuous continuous top electrode layer spanning a plurality of the piezoelectric or capacitive sensors, and the two electrodes in the resistive sensor; 4. The sheet-like sensor according to claim 1, wherein one of the electrodes comprises a continuous resistive sensor electrode extending over a plurality of said resistive sensors. The sheet-like sensor according to any one of claims 1 to 4 , wherein an adhesive or double-sided tape for fixing the sheet-like sensor is used as a protective layer of the piezoelectric sensor or the capacitive sensor. A sheet-like sensor according to any one of claims 1 to 5 , wherein a resistor having a resistance value between the resistance value of air and the resistance value of water is formed between two electrodes of said resistance sensor. The substrate has a first substrate covering a lower side of the lead wire and a second substrate covering an upper side of the lead wire, and the sensor comprises the first substrate and the second substrate. The sheet-like sensor according to any one of claims 1 to 6 , wherein the lead wire is inserted through a through-hole passing through a base material located on the sensor side of the base material of the sheet-like sensor. The piezoelectric layer or the dielectric layer is arranged to extend outside the upper electrode layer and the lower electrode layer, and the lower electrode layer and the lead wire are arranged between the substrate and the piezoelectric layer or the dielectric layer. The sheet-like sensor according to any one of claims 1 to 7 . The sheet-shaped sensor according to any one of claims 1 to 8 , wherein the lead wires are wired on the opposite side of the two electrodes with the substrate interposed therebetween.

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