JP2017075478A - Cavity filling detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable secure confirmation of completion of filling with a filling material in filling an underground cavity whose inside is incapable of being viewed from the outside with the filling material, and implement excellent profitability and work efficiency.SOLUTION: A cavity filling detector 1 comprises: a light source unit 2 that is disposed outside a cavity to be filled with a filling material; a detection unit 3 disposed outside the cavity; a light transmission optical fiber 4 that has a light emission end 41 provided inside the cavity and transmits light from the light source unit 2; and a light reception optical fiber 5 that has a light incidence end 51 provided inside the cavity and transmits light received by the light incidence end 51 to the detection unit 3. The light emission end 41 of the light transmission optical fiber 4 and the light incidence end 51 of the light reception optical fiber 5 are arranged so that light emitted from the light emission end 41 is guided, with a constant path and a constant distance, to the light incidence end 51 apart from the light emission end 41. The detection unit 3 recognizably shows that light reception intensity of light input from the light reception optical fiber 5 has been equal to or lower than or lower than a set and stored threshold.SELECTED DRAWING: Figure 2

Description

  The present invention is, for example, a cavity existing on the backside of an existing tunnel, a cavity for placing concrete on the backside of a movable formwork at the time of tunnel construction, a natural cavity, a building under the ground subsidence The present invention relates to a cavity filling detection device for confirming a filling state of a filler into a cavity when filling various underground cavities such as a cavity with the filler.

  Conventionally, there is a tunnel lining back surface cavity filling confirmation device of Patent Document 1 as a device for confirming a filling state of a filler into a cavity. This device measures capacitance of cement mortar using a capacitance type using a dielectric constant of moisture or a TDR type detection unit using pulsed reflected waves, a detection unit detecting foaming pressure for urethane foam, and measuring the detection of the detection unit. The sensor has a fixed measurement length, the upper end is brought into contact with the upper end of the cavity, and the state until filling is continuously monitored within the measurement length is monitored.

Japanese Patent Laid-Open No. 11-287092

  By the way, the device of Patent Document 1 has a structure that requires a capacitance type or TDR type detection unit or a pressure detection unit, and a wiring for transmitting an electric signal to the recording device. And the structure of the electrical wiring is complicated and expensive. And after filling with a filler, since these structures must be left in the filler, there is a problem that the cost is very poor.

  As an apparatus capable of reducing the cost of the portion left in such a filler, the applicant of the present application has previously proposed an apparatus disclosed in Japanese Patent Application No. 2014-153328 (unknown document). This device irradiates the tunnel cavity wall surface with light from the optical fiber for light transmission, receives the reflected light reflected by the wall surface of the tunnel cavity with the optical fiber for light reception, and determines the filling status and filling height of the filler according to the received light information. Detects changes in the filling condition in detail by providing an opening where light leakage occurs on the side of the optical fiber for light transmission, and this opening is gradually shielded by filling with filler. It is possible.

  However, it takes a lot of processing to make a certain opening by deliberately breaking the coating on the side surface of the optical fiber for light transmission, and the manufacturing cost increases.

  In addition, the received light intensity increases as the filling height of the filler increases, and in the process of detecting the filling completion when the received light intensity becomes zero at the final stage, the filling status is not monitored in real time. In some cases, it is not known whether the filling height of the filler is insufficient and the received light intensity is low, or whether the received light intensity is low after the filling is completed. For example, in the case where a plastic material is filled as a filler in the lining of the existing tunnel lining, the filling is not completed within a few minutes. It may be unrealistic to monitor all the time because additional injections to the filling site may be given the next day. In the construction of actually filling the cavity with the filler, it is required that the filling of the filler can be reliably confirmed rather than grasping the filling state of the filler in real time.

  In the method of detecting the filling of the filler by receiving the reflected light reflected by the wall surface of the tunnel cavity with the light receiving fiber, the spring water of the natural ground 205 becomes the accumulated water 209 as shown in FIG. When the cement-type grout material is filled in the cavity 210 as the filling material 208, the water 209 is suspended and the amount of light received by the light-receiving fiber 204 continues to decrease or is not filled. In addition, as shown in FIG. 19B, the reflected light cannot be captured at the light incident end of the light receiving optical fiber 204 due to the unevenness of the tunnel cavity wall surface 206 as shown in FIG. In FIG. 19, 201 is a light source unit, 202 is a detection unit, 203 is a light transmission optical fiber, 204 is a light reception optical fiber, and 205 is a natural ground. 206 tunnel cavity wall 207 lining concrete, 208 filler, 209 accumulated water, 210 is hollow).

  The present invention is proposed in view of the above problems, and when filling the underground cavity where the inside cannot be seen from the outside, it is possible to reliably confirm the completion of the filling of the filler, as well as economy and work. An object of the present invention is to provide a cavity filling detection device having excellent efficiency.

The cavity filling detection device of the present invention includes a light source unit disposed outside a cavity filled with a filler, a detection unit disposed outside the cavity, and a light emitting end provided in the cavity. A light-transmitting optical fiber for transmitting the light, and a light incident end provided in the cavity, and a light-receiving optical fiber for transmitting light received at the light incident end to the detection unit, The light exit end and the light incident end of the light receiving optical fiber are arranged so that the emitted light from the light exit end is introduced at a constant path and a constant distance into the light incident end separated from the light exit end, The detecting unit presents the light receiving intensity of the light input from the light receiving optical fiber so that it can be recognized that the light receiving intensity is equal to or less than a threshold value that is set and stored.
According to this, since the outgoing light from the light emitting end of the light transmitting optical fiber is introduced at a constant path and a constant distance into the light incident end of the receiving optical fiber, the suspended water in the cavity, the cavity It is possible to stably receive the outgoing light with the optical fiber for receiving light without being affected by light reflections on the wall surface unevenness, etc. It is possible to reliably recognize the completion of the material filling. Further, the portion to be left in the filled material is limited to inexpensive ones such as a light transmitting optical fiber and a light receiving optical fiber, and the coating of the light transmitting optical fiber is intentionally broken to form a certain opening. Such processing is unnecessary, and it is economical. In addition, in the construction for filling the filler, it is not necessary to monitor the filling state in real time, and the filling of the filler can be confirmed with excellent work efficiency.

In the cavity filling detection apparatus of the present invention, the detection unit compares the received light intensity of light input from the light receiving optical fiber with a threshold value stored and set, and when the received light intensity is less than or less than the threshold value, Completion of filling of the filler in the peripheral region of the light emitting end and the light incident end is presented in a recognizable manner.
According to this, it is possible to recognize the completion of filling of the filler in the peripheral region of the light emitting end and the light incident end more clearly by the calculation processing of the detection unit.

The cavity filling detection device of the present invention is characterized in that a light emitting end of the light transmitting optical fiber and a light incident end of the light receiving optical fiber are arranged to be opposed to each other.
According to this, an optical path whose state is changed by filling with the filler can be secured between the light emitting end of the light transmitting optical fiber and the light incident end of the light receiving optical fiber, and the light emitting of the light transmitting optical fiber can be secured. Light can be reliably introduced from the end to the light incident end of the light receiving optical fiber at a constant path and a constant distance.

The cavity filling detection apparatus of the present invention is characterized in that light emitted from the light emitting end of the light transmitting optical fiber is introduced into the light incident end of the light receiving optical fiber via one or a plurality of reflecting surfaces.
According to this, an optical path whose state is changed by filling with the filler can be secured between the light emitting end of the light transmitting optical fiber and the light incident end of the light receiving optical fiber, and the light emitting of the light transmitting optical fiber can be secured. Light can be reliably introduced from the end to the light incident end of the light receiving optical fiber at a constant path and a constant distance.

The cavity filling detection device of the present invention is characterized in that the light emitting end of the light transmitting optical fiber and the light incident end of the light receiving optical fiber are supported in the vicinity of the tip of a rod-shaped guide member.
According to this, the light emitting end of the optical fiber for light transmission and the light incident end of the optical fiber for light reception can be installed at a required position in the cavity with a rod-shaped guide member by a simple operation.

In the cavity filling detection device of the present invention, the guide member is a cylindrical filler injection tube, and the light transmitting optical fiber and the light receiving optical fiber are attached to the outside of the guide member substantially along the guide member. It is characterized by that.
According to this, by setting the guide member as a cylindrical filler injection tube, in addition to filling the filler injection tube, the light emitting end of the light transmitting optical fiber and the light incident end of the light receiving optical fiber are installed. Therefore, it is not necessary to use a separate guide member.

The cavity filling detection device of the present invention is characterized in that the light emitting end of the light transmitting optical fiber and the light incident end of the light receiving optical fiber are arranged to face each other with a separation of 1 to 7 mm.
According to this, in the opposed type configuration in which the light emitting end of the light transmitting optical fiber and the light incident end of the light receiving optical fiber are arranged to be opposed to each other, it is possible to confirm the completion of filling of the filler more reliably.

In the cavity filling detection device of the present invention, the light emitted from the light emitting end of the light transmitting optical fiber is introduced into the light incident end of the light receiving optical fiber through one or a plurality of reflecting surfaces, and the light transmitting optical fiber The distance from the light emitting end to the light incident end of the light receiving optical fiber through the reflecting surface is set to 6 to 16 mm.
According to this, in the reflection type configuration in which the light emitted from the light emitting end of the light transmitting optical fiber is introduced to the light incident end of the light receiving optical fiber via the reflecting surface, the completion of filling of the filler can be confirmed more reliably. Can do.

  According to the cavity filling detection device of the present invention, when filling a filling material into an underground cavity where the inside cannot be seen from the outside, completion of filling of the filling material can be surely confirmed with excellent economic efficiency and work efficiency.

The block diagram which shows the cavity filling detection apparatus of embodiment by this invention. Cross-sectional explanatory drawing which shows the example in the case of applying the cavity filling detection apparatus of embodiment to the lining back cavity of the existing sheet pile type tunnel with a filler. The partial expansion perspective view which shows the 1st example of the structure which supports the optical fiber for light transmission, and the optical fiber for light reception in the front-end | tip vicinity of a guide member. The partial expansion perspective view which shows the 2nd example of the structure which supports the optical fiber for light transmission, and the optical fiber for light reception in the tip vicinity of a guide member. The partial expansion perspective view which shows the 3rd example of the structure which supports the optical fiber for light transmission, and the optical fiber for light reception in the front-end | tip vicinity of a guide member. The partial expansion perspective view which shows the 4th example of the structure which supports the optical fiber for light transmission, and the optical fiber for light reception in the front-end | tip vicinity of a guide member. The partial expansion perspective view which shows the 5th example of the structure which supports the optical fiber for light transmission, and the optical fiber for light reception in the front-end | tip vicinity of a guide member. The conceptual explanatory view of the 6th example which is a modification of the 5th example. FIG. 10 is an explanatory perspective view showing a seventh example of a structure for supporting a light-transmitting optical fiber and a light-receiving optical fiber in the vicinity of the tip of a guide member. FIG. 10 is an explanatory perspective view illustrating an eighth example of a structure for supporting a light-transmitting optical fiber and a light-receiving optical fiber in the vicinity of the tip of a guide member. The partial expansion perspective view which shows the 9th example of the structure which supports the optical fiber for light transmission, and the optical fiber for light reception in the front-end | tip vicinity of a guide member. (A) is a partially enlarged perspective view showing a tenth example of a structure for supporting a light transmitting optical fiber and a light receiving optical fiber in the vicinity of the tip of the guide member, and (b) is a partially enlarged view showing the vicinity of the tip of the guide member of the tenth example. Perspective view. The flowchart which shows the detection process of the filling completion of the filler using the cavity filling detection apparatus of embodiment. The longitudinal section explanatory drawing which shows another example of use of the cavity filling detection apparatus of embodiment which installs multiple sensor parts in the direction where a tunnel extends. Cross-sectional explanatory drawing which shows another use example of the cavity filling detection apparatus of embodiment which installs a sensor part in the both ends vicinity of a cavity. (A) is the cross-sectional explanatory drawing which shows another usage example of the cavity filling detection apparatus of embodiment which installs a sensor part in the ceiling end of a tunnel, (b) is the perspective explanatory drawing. (A) is explanatory drawing which shows arrangement | positioning of the optical fiber for light transmission and optical fiber for light reception of the facing type sensor part of an experiment example, (b) is the optical fiber for light transmission, optical fiber for light reception, and a reflecting plate of the reflection type sensor part of an experiment example Explanatory drawing which shows arrangement | positioning. (A) is a graph showing a change in received light intensity as the filling of the cement-type filler in the opposed sensor portion progresses, (b) shows a change in received light intensity as the filling of the cement-type filler in the reflective sensor portion progresses. A graph and (c) are graphs showing a change in received light intensity as the filling of the urethane-based filler in the opposed sensor portion progresses. (A) is sectional explanatory drawing which shows the problem of stored water by the conventional filling detection method, (b) is sectional explanatory drawing which shows the problem of the reflection by the unevenness | corrugation of the cavity wall surface by the conventional filling detection method.

[Cavity Filling Detection Device of Embodiment]
As shown in FIG. 1, a cavity filling detection device 1 according to an embodiment of the present invention is disposed outside a cavity and a light source unit 2 such as a metal halide lamp and a light emitting diode disposed outside the cavity filled with a filler. The light emitting end 41 is provided in the cavity with the detection unit 3, the optical fiber 4 for transmitting light from the light source unit 2, and the light incident end 51 is provided in the cavity, and the light received by the light incident end 51. Is received, and the detection device main body 6 is configured by the detection unit 3 and the light source unit 2.

  The detection unit 3 receives a control processing unit 31 such as a CPU, a storage unit 32 such as a hard disk, a RAM, and an EEPROM, a light receiving unit 33 such as a photodiode, a display unit 34 such as a liquid crystal display, and data such as a threshold value. The storage unit 32 includes a program storage unit 321 that stores a control program to be executed by the control processing unit 31, a threshold storage unit 322 that stores a threshold value of the set received light intensity, and other than the threshold value. A data storage unit 323 for storing the data is provided. The light receiving unit 33 receives the light transmitted from the light receiving optical fiber 5 and acquires the received light intensity.

  The control processing unit 31 of the detection unit 3 determines the received light intensity of the light input from the light receiving optical fiber 5 via the light receiving unit 33 and the threshold value set and stored in the threshold value storage unit 322 according to the stored control program. In comparison, when the received light intensity is less than or less than the threshold value, it is detected that the filling of the filler is completed in the peripheral region of the light emitting end of the light transmitting optical fiber 4 and the light incident end of the light receiving optical fiber 5, and the filling of the region is performed. The completion of material filling is presented in a recognizable manner. The light reception intensity used in the present invention is not an absolute value, and calibration is performed so that the detected light reception intensity can be displayed relatively according to the situation of the cavity where the light emission end 41 and the light incidence end 51 are located. The threshold value is set based on the relative value of the received light intensity. In order to present the completion of filling of the filling material, for example, the display unit 34 displays a notification of the completion of filling. For example, a filling completion lamp or buzzer is separately attached to the detection unit 3 for example. An appropriate method such as turning on a filling completion lamp or sounding a buzzer can be adopted.

  The optical fiber 4 for light transmission and the optical fiber 5 for light reception are, for example, a core and a clad covering the core, which are obtained by cutting an inexpensive optical fiber made of plastic into a desired length, and all sides are coated and cut. At both ends, only the core is exposed to the outside and can emit or receive light. The light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are arranged close to each other, and the light incident from the light emitting end 41 is separated from the light emitting end 41. The end 51 is arranged so as to be introduced at a constant path and a constant distance. The light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are preferably supported and arranged in the vicinity of the tip of the rod-shaped guide member. The sensor unit 7 is configured by the light emitting end 41 of the light transmitting optical fiber 4, the light incident end 51 of the light receiving optical fiber 5, and the outgoing light introduction path.

  The light transmission optical fiber 4 and the light receiving optical fiber 5 or the sensor unit 7 can be provided in one set or a plurality of sets for one detection unit 3, and the light source unit 2 includes the light transmission optical fiber 4 and the light receiving unit. One or a plurality of optical fibers 5 can be provided corresponding to the number of optical fibers 5 or the number of sensor units 7. In addition, it is preferable that the detection unit 3 has a configuration in which the display unit 34 displays and records the transition of the received light intensity input from the light receiving optical fiber 5 over time, so that reference information can be obtained. It is also possible to adopt a configuration in which the completion of filling of the filler is detected and displayed on the display unit 34 or the like without displaying the temporal change of the received light intensity.

  In addition to the configuration of the detection unit 3 described above, the detection unit of the present invention can recognize that the received light intensity of the light input from the light receiving optical fiber 5 is less than or less than a threshold value that is set and stored. The display unit 34 displays a graph of the horizontal axis: time-vertical axis: light intensity, and displays the light intensity setting threshold value as a horizontal line on the graph. For example, a configuration in which an operator who has viewed 34 can recognize that the received light intensity is less than or less than a threshold value that is set and stored is included.

  The cavity filling detection device 1 of the present embodiment can be applied, for example, when filling a filling material into a lining back cavity of an existing sheet pile type tunnel shown in FIG. In the sheet pile type tunnel of FIG. 2, 91 is a natural mountain, 92 is a sheet pile arranged following the natural mountain wall surface over a support work (not shown) installed at predetermined intervals in the tunnel extension direction, 93 The cover concrete is formed on the inner side of the sheet pile 92, 94 is a cavity on the back of the cover, and 95 is a filler filled in the cavity 94 partway.

  In the cavity 94 of the sheet pile tunnel of FIG. 2, five sensor parts 7a, 7b, 7c, 7d, 7e are provided close to the ceiling surface of the cavity 94, respectively, and the sensor parts 7a, 7b, 7c are provided. , 7d, and 7e are spaced apart from each other at five different positions with a certain distance from each other. Each of the sensor portions 7a, 7b, 7c, 7d, and 7e is composed of a light emitting end 41 and a light incident end 51. The light transmitting optical fiber 4 and the light receiving optical fiber 5 are supported by the rod-shaped guide member 8 in the vicinity of the tip. The sensor portions 7a, 7b, 7c, 7d, and 7e are introduced into the cavity 94 and supported by the guide member 8, and are provided at predetermined positions. If the guide member 8 is a cylindrical filler injection tube, the filler injection tube is used to install the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 in addition to the injection of the filler 95. It is preferable that a separate guide member is not required.

  Five sets of the light transmission optical fiber 4 and the light receiving optical fiber 5 are connected to one detection unit 3 in the detection device main body 6, and in the detection device main body 6 corresponding to each pair of the light transmission optical fibers 4. Five light source portions 2 for light transmission are provided. In the detection unit 3 of the detection device main body 6, for each of the five sensor units 7 a, 7 b, 7 c, 7 d, and 7 e, for example, the display unit 34 displays changes with time of received light intensity input from the optical fiber 5 for light reception. Display and record. These five transition screens can be configured to be displayed in parallel on a plurality of screens, for example, on the display unit 34, or to be switched and displayed in accordance with screen switching input from the input unit 35.

  The detection unit 3 compares the received light intensity of the light input from the light receiving optical fiber 5 via the light receiving unit 33 with the threshold value stored in the threshold storage unit 322 for each of the five locations, and the received light intensity. Is less than or less than the threshold value, it is detected that the filling of the filler is completed in the peripheral region of the light emitting end of the light transmitting optical fiber 4 and the light incident end of the light receiving optical fiber 5, and a process of presenting is performed (see FIG. 1). ). In the transition screen of FIG. 2, a dotted horizontal line capable of recognizing completion of filling corresponding to the light intensity setting threshold is displayed. The detector 3 displays the input received light intensity over time, and displays a horizontal line that can recognize filling completion corresponding to the set threshold value of the light intensity. Also, it is possible to make it possible to recognize that the received light intensity is less than or less than the threshold value that is set and stored. In the example shown in FIG. 2, the filling of the filler 95 is completed in the area where the sensor parts 7a, 7b, 7d and 7e are installed, and the filler 95 is filled in the area of the top end where the sensor part 7c is installed. Incomplete filling.

  Here, a structural example in which the light transmitting optical fiber 4 and the light receiving optical fiber 5 are supported in the vicinity of the tip of a rod-shaped guide member will be described. In the first example of FIG. 3, for example, a support 11 made of a transparent material is provided on the outer peripheral surface in the vicinity of the tip of a cylindrical guide member 8a such as a cylindrical PVC pipe filler injection pipe. The bottom surface of the support 11 has a shape that follows the outer peripheral surface of the guide member 8a, and is fixed to the outer peripheral surface by bonding or the like. The support 11 has a substantially rectangular parallelepiped shape, a recess 12 is formed at the center, and a pair of clamping parts 13 are formed at corresponding positions on both sides thereof, so that the slits 14 of the clamping part 13 face sideways. The support portion 11 is attached to the guide member 8a. The light transmitting optical fiber 4 and the light receiving optical fiber 5 are provided so as to be substantially along the guide member 8a, and are attached to the outside of the guide member 8a by being bound by a binding band 15.

  The vicinity of the front end of the light transmission optical fiber 4 is sandwiched and fixed by one sandwiching section 13, and the vicinity of the front end of the light receiving optical fiber 5 is sandwiched and fixed by the other sandwiching section 13, and the light of the light transmission optical fiber 4 is fixed. The emitting end 41 and the light incident end 51 of the light receiving optical fiber 5 are arranged to face each other with a distance substantially corresponding to the width of the recess 12. It is preferable that the distance between the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 which are arranged to face each other is about 1 to 7 mm.

  In the second example of FIG. 4, for example, the tip of a cylindrical guide member 8a such as a filler injection pipe made of a cylindrical PVC pipe is cut out in an L shape, and an L-shaped plate material such as a hinge is provided there. 16 is arranged such that one surface is cut out and disposed on the end surface 81a side, and the other surface is disposed along the protruding portion 82a which is the remaining portion of the notched portion, and is disposed on the protruding portion 82a or the protruding portion 82a and the end surface. It is fixed to 81a by adhesion or the like. Unlike the first example, the support 11a made of a transparent material has a flat bottom surface. The support 11a is provided so as to be placed on one surface of the plate 16 and fixed by bonding or the like. Yes. Other configurations of the support 11a are the same as those of the support 11 of the first example. The support 11a is provided so as to occupy a part of the distal end opening of the guide member 8a, and is attached so that the slit 14 of the sandwiching portion 13 faces sideways. When the slit 14 faces in the lateral direction, it is possible to prevent the filler 95 from jumping or mud or spring water from falling and blocking the light path between the light emitting end 41 and the light incident end 51, and is always appropriate. A high light intensity can be detected.

  As in the first example, the optical fiber for light transmission 4 and the optical fiber for light reception 5 that are provided so as to substantially follow the guide member 8a and are bound and attached by the binding band 15 to the outside of the guide member 8a. The vicinity of the tip of the optical fiber for light 4 is sandwiched and fixed by one sandwiching portion 13, and the vicinity of the tip of the optical fiber for light reception 5 is sandwiched and fixed by the other sandwiching portion 13. The light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are opposed to each other with a distance of approximately 1 to 7 mm, for example, corresponding to the width of the recess 12.

  Further, the third example of FIG. 5 is the same as the second example, except that the light transmitting optical fiber 4 and the light receiving optical fiber 5 are attached to the outside of the guide member 8a by being bound by a binding band 15 and attached. The light receiving optical fiber 5 is inserted into the guide member 8 a and led out to the light source unit 2 and the detection unit 3. When the cylindrical guide member 8a is not a filler injection tube, the light transmitting optical fiber 4 and the light receiving optical fiber 5 can be inserted into the guide member 8a as in the third example. In FIG. 5, 25 is a filler injection tube. Other configurations are the same as those of the second example.

  In addition, the fourth example of FIG. 6 is different from the second example in that the support tool 11a is attached so that the slit 14 of the sandwiching portion 13 faces sideways, and the support tool 11a is positioned above the slit 14 of the sandwiching portion 13. The sandwiching portions 13 and 13 with the slit 14 facing upward are sandwiched and fixed near the tip of the light transmitting optical fiber 4 and the tip of the light receiving optical fiber 5. Yes. When the slit 14 is held by the holding portions 13 and 13 facing upward, the light transmitting optical fiber 4 and the light receiving optical fiber 5 are not easily detached from the holding portions 13 and 13, and the attachment state is further stabilized. Also in this example, the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are spaced apart from each other by a distance substantially corresponding to the width of the recess 12, preferably 1 to 7 mm away from each other. Yes. Other configurations are the same as those of the second example.

  The fifth example of FIG. 7 is a facing type in which the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are spaced apart from each other in the first to fourth examples. On the other hand, this is a reflection type structure in which the light emitted from the light emitting end 41 of the light transmitting optical fiber 4 is introduced into the light incident end 51 of the light receiving optical fiber 5 through one reflector.

  In the fifth example, the tip of a cylindrical guide member 8a made of, for example, a cylindrical PVC pipe is cut out in an L shape, and an L-shaped plate member 16 such as a hinge is cut out on one side thereof. It arrange | positions along the protrusion part 82a which is arrange | positioned on the opposite side to the end surface 81a, and the other surface is the remainder of the part notched, and is being fixed to the protrusion part 82a by adhesion | attachment etc. The reflective plate 17 is fixed to one surface of the plate member 16 so as to face the end surface 81a. In this example, one surface of the plate 16 functions as a roof, and filling is performed from a filling material injection tube in which the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are separately provided. It becomes difficult to wear the material.

  In the illustrated example, the support 11b formed of a transparent material has a substantially rectangular parallelepiped shape, and is provided with a pair of holding portions 13 and 13 in parallel at a predetermined distance. The support 11b is provided so as to occupy a part of the front end opening of the guide member 8a, and the bottom surface thereof is disposed along the other surface of the plate 16 and is fixed by bonding or the like. The clamping parts 13 and 13 are arranged so as to extend in the axial direction of the guide member 8a.

  The light transmitting optical fiber 4 and the light receiving optical fiber 5 are provided by being inserted into the guide member 8a. The light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are reflected by the reflecting plate 17, respectively. It is directed to the surface and is sandwiched between the sandwiching portions 13 and 13 and is arranged in parallel near the reflecting surface of the reflecting plate 17. The light emitting end 41 and the reflecting surface of the reflecting plate 17, and the reflecting surface of the reflecting plate 17 and the light incident end 51 are separated from each other. The distance from the light emitting end 41 to the reflecting surface of the reflecting plate 17, and the reflecting plate 17. The total distance from the reflecting surface to the light incident end 51 is preferably set to 8 to 14 mm, for example, by setting each distance to 4 to 7 mm.

  The sixth example of FIG. 8 is a modification of the fifth example, and the light emitted from the light emitting end 41 of the light transmitting optical fiber 4 is introduced into the light incident end 51 of the light receiving optical fiber 5 through a plurality of reflecting surfaces. To do. In the sixth example, two reflectors each provided with a triangular prism-like reflector 19 inside the L-shaped mounting plate 18 are used, and the reflection by the reflecting surfaces 20 and 20 of the two reflectors 19 and 19 is performed. The light emitted from the light exit end 41 of the optical fiber 4 for light is refracted and reflected by changing the angle by 90 degrees so as to form a U-shaped optical path and introduced into the light incident end 51 of the light receiving optical fiber 5 It is. The mounting plates 18 and 18 are provided, for example, by being fixed to one surface of the plate material 16 of the fifth example by bonding or the like, so that the reflecting surfaces 20 and 20 of the reflectors 19 and 19 are in a predetermined position. Be placed.

  In this case, the distance from the light emitting end 41 to the first reflecting surface 20 where the emitted light is incident, the distance to the second reflecting surface 20 where the reflected light from the first reflecting surface 20 is incident, the second reflecting surface The total distance to the light incident end 51 on which the reflected light 20 is incident is preferably set to 8 to 14 mm, for example.

  The seventh example of FIG. 9 is an opposing type, has an elongated plate-like guide member 8b corresponding to a rod-like guide member, and a fixed plate 81b is provided at the tip of the guide member 8b. The optical fiber for light transmission 4 and the optical fiber for light reception 5 are provided along one surface of the guide member 8b, and are attached by a binding tool 21 provided at an interval.

  The light emitting end 41 side of the light transmitting optical fiber 4 and the light incident end 51 side of the light receiving optical fiber 5 are extended so as to be disposed below the fixed plate 81b. The light transmitting optical fiber 4 and the light receiving optical fiber 5 are fixed by a fixture (not shown) so that the light incident ends 51 face each other at a corresponding position. As a result, the fixing plate 81b functions as a roof, and the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are covered with the filler and the light intensity is prevented from being lost before filling. The The light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are supported near the tip of the guide member 8b. Also in this example, it is preferable that the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are disposed to face each other with a separation of 1 to 7 mm, for example.

  The eighth example of FIG. 10 is a reflection type, and has an elongated plate-like guide member 8c corresponding to a rod-like guide member, and an L-shaped plate member 81c has one surface at the tip of the guide member 8c. The other surface of the L-shaped plate member 81c is fixed to the guide member 8c by bonding or the like so as to be substantially perpendicular to the guide member 8c and have the other surface along the back surface of the guide member 8c. A reflecting plate 17 is provided on the guide member 8c side of one surface of the L-shaped member 81c.

  The optical fiber for light transmission 4 and the optical fiber for light reception 5 are provided in parallel along the front surface of the guide member 8c, and are attached by a binding tool 21 provided at an interval. The light emitting end 41 of the light-transmitting optical fiber 4 and the light incident end 51 of the light-receiving optical fiber 5 are fixed in parallel with the first binding tool 21 and supported near the tip of the guide member 8c for reflection. It is directed to the reflecting surface of the plate 17. The light emitting end 41 and the reflecting surface of the reflecting plate 17, and the reflecting surface of the reflecting plate 17 and the light incident end 51 are separated from each other. The distance from the light emitting end 41 to the reflecting surface of the reflecting plate 17, and the reflecting plate 17. The total distance from the reflecting surface to the light incident end 51 is preferably set to 8 to 14 mm, for example, by setting each distance to 4 to 7 mm.

  Further, the ninth example of FIG. 11 is an opposing type and has an elongated plate-like guide member 8d corresponding to a rod-shaped guide member, and a substantially C-shaped C-shaped portion 81d is formed at the tip of the guide member 8d. Has been. The optical fiber for light transmission 4 and the optical fiber for light reception 5 are provided along one surface of the guide member 8d, and are attached by a binding band 15 provided at an interval, and the optical fiber for light transmission 4, the optical fiber for light reception. 5 is attached to the guide member 8d and the C-shaped portion 81d by fitting a substantially U-shaped attachment 22 from the outside.

  The light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are arranged so as to face each other at the corresponding positions across the slit of the C-shaped portion 81d, and are supported near the tip of the guide member 8d. Is done. Also in this example, it is preferable that the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are disposed to face each other with a separation of 1 to 7 mm, for example.

  The tenth example of FIG. 12 is an opposing type, and has an elongated plate-like guide member 8e corresponding to a rod-like guide member, and a recess 81e is formed at the approximate center of the tip of the guide member 8e. . On one surface side of the guide member 8e, a pair of introduction grooves 82e and 82e are formed at spaced positions. The introduction grooves 82e and 82e are extended in the longitudinal direction of the guide member 8e, bent inward in the vicinity of the distal end, opened at the recessed portion 81e, and opposed to each other at corresponding positions.

  The optical fiber for light transmission 4 and the optical fiber for light reception 5 are fitted in the introduction grooves 82e and 82e, respectively, and are supported by the introduction grooves 82e and 82e even in the vicinity of the tip to prevent separation from the guide member 8e. In the recess 81e, the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are spaced apart from each other, and are disposed opposite to each other at corresponding positions. Also in this example, it is preferable that the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are disposed to face each other with a separation of 1 to 7 mm, for example.

  When performing the filling completion detection process of the filling material in the cavity filling detection device 1 of the present embodiment, as shown in FIG. 13, a required number of sensor units 7 are installed at predetermined positions of the cavity using the guide member 8. (S1). For example, in the case of the cavity 94 of the sheet pile tunnel of FIG. 2, the sensor portions 7a, 7b, 7c, 7d, and 7e are spaced apart from each other in five different locations in the tunnel circumferential surface direction. .

  Next, the light source unit 2 is turned on, and the light incident end 51 of the light receiving optical fiber 5 receives the light emitted from the light emitting end 41 of the light transmitting optical fiber 4. (S2). In this state, injection and filling of the filler 95 and the like are started (S3).

  As the filling of the filling material progresses, for the sensor unit 7 installed in the filled region, the detection unit 3 causes the received light intensity of the light input from the light receiving optical fiber 5 to be less than or less than a set threshold value. Present it so that it can be recognized. When filling is completed for all the sensor units 7 installed, the detection unit 3 for all the sensor units 7 has a light reception intensity of light input from the light receiving optical fiber 5 equal to or less than a threshold value that is set and stored. Alternatively, the fact that it has become less can be recognized and filling of the filler is completed (S4, S5, S6).

  According to the present embodiment, the light emitted from the light emitting end 41 of the light transmitting optical fiber 4 is introduced into the light incident end 51 of the light receiving optical fiber 5 that is separated from the light emitting end 41 by a constant path and a constant distance. The outgoing light can be stably received by the light receiving optical fiber 5 without being affected by the suspension of water, the light reflection on the unevenness of the cavity wall surface, and the optical path of the filling material filled with this stable light reception. It is possible to reliably recognize the completion of filling with the filler by rapidly decreasing by the interruption. Further, the portions to be left in the filled material are limited to inexpensive ones such as the light transmitting optical fiber 4 and the light receiving optical fiber 5, and the opening of the light transmitting optical fiber 4 is deliberately broken to have a certain opening. Processing such as forming is also unnecessary, and is excellent in economic efficiency. In addition, in the construction for filling the filler, it is not necessary to monitor the filling state in real time, and the filling of the filler can be confirmed with excellent work efficiency. Further, the completion of the filling of the filler in the area around the light emitting end 41 and the light incident end 51 can be recognized more clearly by the calculation processing of the detection unit 3.

  In addition, the opposing sensor unit 7 or the reflective sensor unit 7 ensures an optical path whose state changes due to filling with a filler between the light emitting end of the light transmitting optical fiber and the light incident end of the receiving optical fiber. In addition, the light can be reliably introduced from the light emitting end of the light transmitting optical fiber to the light incident end of the light receiving optical fiber with a constant path and a constant distance. Further, the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 can be installed at a required position in the cavity by the rod-shaped guide member 8 by a simple operation.

  When the guide member 8 is a cylindrical filler injection tube, the filler injection tube is added to the filler injection, and the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end of the light receiving optical fiber 5 are added. 51 can be used for installation, and it is not necessary to use a separate guide member.

[Another use example of the cavity filling detection device of the embodiment]
Next, another usage example of the cavity filling detection device of the embodiment will be described. FIG. 14 is an example of use in which a plurality of sensor portions 7f to 7j are installed in the direction in which the tunnel extends. A cavity 103 is formed between the natural ground 101 and the existing lining concrete 102, and the cavity 103 extends in the direction in which the tunnel extends. It is formed to extend. Then, a guide member 8 is provided so as to penetrate the lining concrete 102 at a position spaced in the tunnel extending direction, and the light transmitting optical fiber 4 and the light receiving optical fiber 5 supported in the vicinity of the tip of the guide member 8 are provided. It is introduced into the cavity 103 and the sensor parts 7f to 7j are installed in the cavity 103. The light transmitting optical fiber 4 and the light receiving optical fiber 5 are connected to the detection device body 6. In FIG. 14, reference numeral 104 denotes a filler.

  FIG. 15 shows a usage example in which the sensor portions 7k and 7l are installed in the vicinity of both ends of the cavity 112. The cavity 112 is formed in the underground of the natural ground 111. In the natural ground 111, an injection hole 114 for filling the filler 113 and introducing the light transmitting optical fiber 4 and the light receiving optical fiber 5 is formed, and the light transmitting optical fiber 4 and the light receiving optical fiber 4 are received from the detection device main body 6. The optical fiber 5 is extended and inserted into the injection hole 114, and the sensor portions 7 k and 7 l are installed near both ends of the cavity 112. For example, when filling a natural cavity with underground quarries, abandoned mine sites, air defense pits, limestone or shirasu, etc., when filling the filler filling area and placing the sensor near the end, etc. use.

  FIG. 16 is an example of use in which a single sensor portion 7m is installed at the top of the tunnel. The shotcrete 122 is placed on the peripheral surface of the ground 121, and the mold 123 is separated from the shotcrete 122. In the state of being arranged in a circumferential shape, the concrete is injected and filled into the cavity 124 for placing the lining concrete between the shotcrete 122 and the mold 123 from the blow-up port 126 of the filler injection pipe 125 as a filler. This is a usage example.

  A light transmitting optical fiber 4 and a light receiving optical fiber 5 are extended from the detection device main body 6, and a sensor portion 7 m at the tip thereof is disposed close to the top shot concrete 122. In this way, when the tunnel is newly constructed, the arch top end shape of the filling area is not complicated like the cavities behind the existing tunnel lining, so it is confirmed that the filling of the filling material has been completed without installing multiple sensor parts 7. Is possible. In addition, as for the sensor parts 7f to 7j, the sensor parts 7k and 7l, and the sensor part 7m of each usage example of FIGS.

[Experimental example of opposed sensor unit and reflective sensor unit]
Next, a description will be given of an experimental example in which a change in the received light intensity with the progress of filling of the filling material of the opposed sensor unit and the reflective sensor unit is confirmed. In the experiment example of the opposed sensor unit, as shown in FIG. 17A, the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are spaced apart by a distance d1. While maintaining the structure, the filling material is filled while receiving the light emitted from the light emitting end 41 at the light incident end 51, and the light receiving intensity of the opposed type as the filling proceeds in the detection unit 3. The change of was confirmed.

  In the experiment example of the reflection type sensor unit, as shown in FIG. 17B, the light transmitting optical fiber 4 and the light receiving optical fiber 5 are arranged in parallel, and the light emitting end 41 of the light transmitting optical fiber 4 and the light receiving optical fiber 5 are arranged. The light incident end 51 is disposed toward the reflecting plate 28. The distance between the light emitting end 41 of the light transmitting optical fiber 4 and the reflecting plate 28 and the distance between the light incident end 51 of the light receiving optical fiber 5 and the reflecting plate 28 are the same distance as the distance d2. The distance from the light emitting end 41 to the light incident end 51 of the light receiving optical fiber 5 is twice d2. While maintaining this structure, the filling material was filled while receiving the light emitted from the light emitting end 41 at the light incident end 51, and the detection unit 3 confirmed the change in the reflection-type received light intensity as the filling progressed.

  In the experiment of FIGS. 18A and 18B, the cavity where the opposed sensor unit of FIG. 17A and the reflective sensor unit of FIG. 17B are installed is a cavity in which water exists. An experiment was conducted by filling a filler. The cavity where this water exists is the one in which the water in the cavity is suspended as the filling of the filler progresses, and the light emitted from the optical fiber for light transmission is reflected by the cavity surface and received by the optical fiber for light reception. In the structure for confirming the completion of filling of the filler, it is difficult to accurately confirm the completion of filling.

  FIG. 18 (a) shows the change in the received light intensity with the progress of filling of the cement-based filler when the opposed sensor portion is installed near the upper end of the cavity and the cavity is filled with the cement-based filler. . Regardless of whether the distance d1 is 1 mm, 4 mm, or 7 mm, the received light intensity suddenly drops when the filling of the filler is completed. By setting a threshold value for the received light intensity, the completion of filling of the cement-based filler is clearly recognized. I understand that I can do it.

  FIG. 18B shows a change in received light intensity with the progress of filling of the cement filler when the reflective sensor portion is installed near the upper end of the cavity and the cavity is filled with the cement filler. . Regardless of whether the distance d2 is 4 mm or 7 mm, the light receiving intensity suddenly decreases when the filling of the filler is completed, so that the completion of filling of the cement-based filler can be clearly recognized by setting a threshold of the light receiving intensity. I understand. When the distance d2 was 1 mm, the received light intensity could not be correctly measured because d2 was too small.

  In the experiment of FIG. 18 (c), when the opposed sensor portion of FIG. 17 (a) is installed near the upper end of the cavity and the urethane foam filler is filled in the cavity, the filling progress of the urethane foam filler is progressed. This represents a change in the received light intensity due to. Regardless of whether the distance d1 is 1 mm, 4 mm, or 7 mm, the received light intensity suddenly drops when the filling of the filler is completed. By setting a threshold value of the received light intensity, the filling of the urethane foam filler is clearly completed. It can be recognized. When the distance d1 was 1 mm, the light intensity changed irregularly before filling, and after the light receiving intensity once became zero due to filling, there was a tendency for the light intensity to rise again. This is thought to be because the black and solution-like urethane filled the space between light transmission and reception and once blocked the light, but the density decreased with the subsequent volume expansion due to foaming and the light began to transmit again.

  According to the above experimental example, the change in received light intensity with the progress of filling depends on the condition of the cavity, the properties of the filler, and the arrangement of the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5. Although the state is different, it is confirmed that the light receiving intensity is below a certain level by arranging the light emitted from the light emitting end 41 to be introduced into the light incident end 51 at a constant path and a constant distance. It became clear that the completion of filling could be clearly recognized. However, in the reflective sensor unit, it is difficult to detect a change in received light intensity when the distance d2 from the reflecting plate 28 shown in FIG. It was confirmed that the distance from the end 41 to the light incident end 51 is preferably set to about 6 to 16 mm.

[Modifications of Embodiment, etc.]
The invention disclosed in this specification is specified by changing these partial configurations to other configurations disclosed in this specification, in addition to the respective inventions, embodiments, and examples, to the extent applicable. It includes those specified by adding other configurations disclosed in this specification to these configurations, or those obtained by deleting these partial configurations to the extent that partial effects can be obtained and specifying them as superordinate concepts. .

  For example, the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 are spaced apart from each other, or the light emitted from the light emitting end 41 of the light transmitting optical fiber 4 is used. The reflection type configuration introduced into the light incident end 51 of the light receiving optical fiber 5 through the reflecting surface is appropriate in addition to the above example, and the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end of the light receiving optical fiber 5 are appropriate. 51 is included if it is arranged so that the light emitted from the light emitting end 41 is introduced into the light incident end 51 at a constant path and a constant distance.

  Further, the support structure of the light emitting end 41 of the light transmitting optical fiber 4 and the light incident end 51 of the light receiving optical fiber 5 is appropriate in addition to the above example. Further, the distance of the optical path from the light emitting end 41 of the light transmitting optical fiber 4 to the light incident end 51 of the light receiving optical fiber 5 is appropriate as long as the filling of the filler can be confirmed.

  The present invention includes, for example, a cavity existing on the backside of an existing tunnel, a cavity for placing concrete on the backside of a movable formwork when a tunnel is constructed, an underground quarry, an abandoned mine site, an air pit, a limestone, and a shirasu It can be used to fill various underground cavities such as natural cavities due to the ground and cavities under buildings formed by ground subsidence.

DESCRIPTION OF SYMBOLS 1 ... Cavity filling detection apparatus 2 ... Light source part 3 ... Detection part 31 ... Control processing part 32 ... Memory | storage part 321 ... Program storage part 322 ... Threshold storage part 323 ... Data storage part 33 ... Light receiving part 34 ... Display part 35 ... Input part DESCRIPTION OF SYMBOLS 4 ... Optical fiber for light transmission 41 ... Light emission end 5 ... Optical fiber for light reception 51 ... Light incident end 6 ... Main body of detection device 7, 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j, 7k, 7l, 7m ... sensor part 8, 8a, 8b, 8c, 8d ... guide member 81a ... end face 82a ... projecting part 81b ... fixed plate 81c ... L-shaped plate material 81d ... C-shaped part 11, 11a, 11b ... support tool 12 ... Concave part 13 ... clamping part 14 ... slit 15 ... binding band 16 ... plate material 17 ... reflecting plate 18 ... mounting plate 19 ... reflector 20 ... reflecting surface 21 ... binding tool 22 ... mounting tool 25 ... filler injection tube 28 ... Spray plate 91 ... Ground mountain 92 ... Sheet pile 93 ... Covering concrete 94 ... Cavity 95 ... Filler 101 ... Ground mountain 102 ... Covering concrete 103 ... Cavity 104 ... Filler 111 ... Ground mountain 112 ... Cavity 113 ... Filler 114 ... Injection hole 121 ... Ground mountain 122 ... Sprayed concrete 123 ... Formwork 124 ... Cavity 125 ... Filler injection pipe 126 ... Blowing port 201 ... Light source part, 202 ... Detection part, 203 ... Optical fiber for light transmission, 204 ... Optical fiber for light reception, 205 ... natural ground, 206 ... tunnel cavity wall surface, 207 ... lining concrete, 208 ... filler, 209 ... accumulated water, 210 ... cavity d1, d2 ... distance

Claims (8)

A light source unit disposed outside the cavity filled with the filler,
A detector disposed outside the cavity;
A light emitting end provided in the cavity, and an optical fiber for transmitting light that transmits light of the light source unit;
A light incident end is provided in the cavity, and a light receiving optical fiber that transmits light received at the light incident end to the detection unit,
The light emitting end of the light transmitting optical fiber and the light incident end of the light receiving optical fiber are introduced at a constant path and a constant distance into the light incident end where the light emitted from the light emitting end is separated from the light emitting end. Arranged so that
The cavity filling detection apparatus, wherein the detection unit presents in a recognizable manner that the received light intensity of the light input from the light receiving optical fiber is less than or less than a threshold value that is set and stored. The detection unit compares the received light intensity of the light input from the light receiving optical fiber with a threshold value stored and set, and when the received light intensity is less than or less than the threshold value, the light emitting end and the light incident end The cavity filling detection device according to claim 1, wherein the filling completion of the filler in the peripheral region of the object is presented in a recognizable manner.   The cavity filling detection device according to claim 1 or 2, wherein a light emitting end of the light transmitting optical fiber and a light incident end of the light receiving optical fiber are spaced apart from each other.   3. The cavity filling detection according to claim 1, wherein light emitted from a light emitting end of the light transmitting optical fiber is introduced into the light incident end of the light receiving optical fiber through one or a plurality of reflecting surfaces. apparatus.   5. The cavity filling detection according to claim 1, wherein a light emitting end of the light transmitting optical fiber and a light incident end of the light receiving optical fiber are supported in the vicinity of the tip of a rod-shaped guide member. apparatus. The guide member is a cylindrical filler injection tube;
6. The cavity filling detection device according to claim 5, wherein the optical fiber for light transmission and the optical fiber for light reception are attached to the outside of the guide member substantially along the guide member.   7. The cavity filling detection device according to claim 3, wherein the light emitting end of the light transmitting optical fiber and the light incident end of the light receiving optical fiber are disposed to face each other with a distance of 1 to 7 mm. Outgoing light from the light emitting end of the light transmitting optical fiber is introduced into the light incident end of the light receiving optical fiber through one or a plurality of reflecting surfaces,
7. The distance from the light emitting end of the light transmitting optical fiber to the light incident end of the light receiving optical fiber through the reflecting surface is set to 6 to 16 mm. Cavity filling detection device.

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