JP2019167704A - Grout material injection device and injection method - Google Patents

Abstract

To inject a grout material into the foundation ground at the appropriate pressure and volume.SOLUTION: An injection device 100 comprises: an injection unit 10 for injecting a grout material 6 into a boring hole 3b; an optical fiber cable 40 inserted into an observation hole 7 formed in the vertical direction in the foundation ground 1, and distorted with the displacement of an inner wall of the observation hole 7 in the vertical direction; a strain measurement unit 50 for measuring strains at a plurality of positions in the optical fiber cable 40; and a control unit 30 that calculates a displacement amount of the optical fiber cable 40 using the strain measured by the strain measurement unit 50, and controls the injection unit 10 based on the calculated displacement amount.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus and method for injecting grout material into a foundation ground.

  In dam construction, in order to increase the water barrier and strength of the foundation ground, grouting is performed to form a borehole in the foundation ground and inject grouting material to block cracks in the foundation ground. In grouting, in order to allow more grout material to flow into the crack, it is better that the injection pressure is high and the injection amount is large. However, when the injection pressure is too high or the injection amount is too large, the foundation ground is pushed up by the grout material that has flowed into the cracks, and the desired water shielding and strength may not be obtained. For these reasons, it has been proposed to perform grouting while monitoring the displacement of the foundation ground (Patent Document 1).

  In the grout material injection method disclosed in Patent Document 1, the displacement of the ground surface is measured using a linear scale, and when the displacement amount of the ground surface exceeds a certain value, the injection pressure is changed or the injection is stopped. is doing.

JP-A-8-209673

  The displacement of the foundation ground due to the injection of the grout material may only occur inside the foundation ground. For example, in a foundation ground where two cracks exist in the vertical direction, even if the grout material flows into the lower crack at high pressure and the ground between the two cracks is pushed up and displaced, the upper crack The ground surface may not be displaced only by being narrowed.

  In the method disclosed in Patent Document 1, the displacement of the foundation ground in such a case cannot be detected. Therefore, the grout material cannot be injected into the foundation ground with an appropriate pressure and amount, and the foundation ground may be destroyed.

  The object of the present invention is to inject the grout material into the foundation ground at an appropriate pressure and amount.

  The present invention is an injection device for injecting grout material into a borehole formed in a foundation ground, and is inserted into an injection portion for injecting grout material into a borehole and an observation hole formed in a vertical direction in the foundation ground. The optical fiber cable that is distorted with the displacement of the inner wall of the observation hole in the vertical direction, the strain measurement unit that measures strain at a plurality of positions in the optical fiber cable, and the light that is measured by the strain measured by the strain measurement unit A control unit that calculates a displacement amount of the fiber cable and controls the injection unit based on the calculated displacement amount.

  The present invention is also an injection method for injecting a grout material into a borehole formed in a foundation ground, wherein an observation hole is formed in a vertical direction in the foundation ground, and an optical fiber cable is observed in the observation hole in a vertical direction. It inserts so that it may be distorted with the displacement of the inner wall of a hole, measures the distortion in several positions in an optical fiber cable, and injects grout material into a boring hole based on the measured distortion.

  According to the present invention, the grout material can be injected into the foundation ground with an appropriate pressure and amount.

It is the schematic which shows the structure of the injection apparatus of the grout material which concerns on 1st Embodiment of this invention. It is sectional drawing of a foundation ground, and shows the state which injection | pouring of the grout material to the secondary boring hole was completed. It is sectional drawing of a foundation ground, and shows the state which injection | pouring of the grout material to the tertiary boring hole was completed. It is sectional drawing explaining distortion of the optical fiber cable accompanying the displacement of a foundation ground. It is a block diagram which shows the detail of the controller which concerns on 1st Embodiment. It is a flowchart for demonstrating the process performed by the determination part. It is a block diagram which shows the detail of the controller which concerns on 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment>
First, the grout injection device 100 and the injection method according to the first embodiment of the present invention will be described with reference to FIGS. The grout injection device 100 is used for grouting in dam construction. Grouting is performed to block the cracks in the foundation ground with a grout material and increase the water shielding and strength of the foundation ground.

  First, the grouting procedure will be briefly described with reference to FIGS. Here, a case will be described in which grouting is performed on the foundation ground 1 in which two cracks 2a and 2b exist at intervals in the vertical direction.

  In grouting in dam construction, first, as shown in FIG. 1, a grout material 6 is injected into a plurality of primary boring holes 3a and 3b as boring holes. Next, as shown in FIG. 2, the grout material 6 is injected into the secondary boring hole 4a formed between the primary boring holes 3a and 3b.

  Before the grouting material 6 is injected into the primary boring holes 3a, 3b and the secondary boring hole 4a, the lugeon values in the primary boring holes 3a, 3b and the secondary boring hole 4a are respectively measured. The lugeon value is measured by a so-called lugeon test, and is used for evaluation of water shielding and strength in the foundation ground 1.

  The Lujion value in the primary bore holes 3a, 3b is used to evaluate the water shielding and strength of the foundation ground 1 before the grout material 6 is injected. The Lujion value in the secondary boring hole 4a is used to confirm the improvement in water shielding and strength due to the injection of the grout material 6 into the primary boring holes 3a and 3b. When the lugion value in the secondary boring hole 4a does not satisfy the reference value, after the grout material 6 is injected into the secondary boring hole 4a, the primary boring holes 3a and 3b and the secondary boring holes 4a and 2b are injected as shown in FIG. The grout material 6 is injected into the tertiary boring holes 5a and 5b formed between the boring holes 4a.

  Before the grouting material 6 is injected into the tertiary boring holes 5a and 5b, the Luzion values in the tertiary boring holes 5a and 5b are similarly measured. When the lugion value in the tertiary boring holes 5a and 5b does not satisfy the reference value, the grout material is further injected into a high-order boring hole such as a quaternary boring hole or a quintic boring hole, although illustration is omitted. When the Lugion value in the tertiary boring holes 5a and 5b satisfies the reference value, the grouting is terminated on the assumption that the water shielding and strength of the foundation ground 1 have been increased.

  In addition, even if the lugion value in the tertiary boring holes 5a and 5b satisfies the reference value, a grout material may be injected into the high-order boring hole as necessary.

  In the example shown in FIG. 1, the primary boring hole 3b penetrates the cracks 2a and 2b, and the grout material 6 flows into the cracks 2a and 2b by the injection of the grout material 6 into the primary boring hole 3b. , 2b are blocked. In order to close the cracks 2a and 2b, it is desirable to allow more grout material 6 to flow into the cracks 2a and 2b. For this purpose, the injection pressure is high and the injection amount is large.

  However, when the injection pressure is too high or the injection amount is too large, the foundation ground 1 may be destroyed by being pushed up by the grout material 6 flowing into the cracks 2a and 2b. In this case, the cracks 2a and 2b are not blocked, and there is a possibility that desired water shielding and strength cannot be obtained. For this reason, it is necessary to grasp the displacement of the foundation ground 1 and inject the grout material 6.

  The injection device 100 and the injection method according to the present embodiment grasp the displacement of the foundation ground 1 and inject the grout material 6. Hereinafter, the configuration of the injection apparatus 100 and the procedure of the injection method will be specifically described with reference to FIGS. 1, 4, and 5.

  Here, a case where the grout material 6 is injected into the primary boring hole 3b will be described. Since the case where the grout material 6 is injected into the other boring holes such as the primary boring hole 3a, the secondary boring hole 4a, and the tertiary boring holes 5a and 5b is substantially the same, the description thereof is omitted. Hereinafter, the primary boring hole 3b is also simply referred to as “boring hole 3b”.

  Here, the case where the grout material 6 is injected into the boring hole 3b by the stage injection method will be described.

  In the stage injection method, first, a plurality of zones (stages) are set in the borehole 3b by dividing a preset full length (eg, 25 m) of the borehole 3b by a predetermined length (eg, 5 m) in the vertical direction. Next, from the upper area in the vertical direction, the boring and the injection of the grout material 6 are alternately performed, and the construction is sequentially advanced to the deep part.

  In the example shown in FIG. 1, five zones are set in the borehole 3b, and the first zone Z1, the second zone Z2,..., And the fifth zone Z5 are sequentially arranged from the surface of the foundation ground 1 toward the deep part. In FIG. 1, the injection of the grout material 6 up to the third zone Z3 of the boring hole 3b and the formation of the fourth zone Z4 of the boring hole 3b are completed, and the grout material is injected into the fourth zone Z4. It shows the state.

  As shown in FIG. 1, the injection device 100 includes an injection unit 10 that injects the grout material 6 supplied from a mixer (not shown) into the boring hole 3 b through the injection tube 21. The injection unit 10 includes a pump 11 that sends the grout material 6 to the injection tube 21 and a control valve 12 that controls the flow of the grout material 6 in the injection tube 21.

  The pump 11 is driven by a drive source (not shown) such as a motor or an engine. The control valve 12 is a return valve, for example. By changing the rotation speed of the pump 11 and the opening degree of the control valve 12, the injection pressure and the injection flow rate of the grout material 6 can be changed.

  The pump 11 and the control valve 12 are controlled by a controller 30 as a control unit. The controller 30 includes a central processing unit (CPU) that performs arithmetic processing, a read-only memory (ROM) that stores a control program executed by the CPU, and a random access memory (RAM) that stores a calculation result of the CPU. And a microcomputer including the above. The controller 30 may be composed of a single microcomputer or a plurality of microcomputers.

  The injection tube 21 is inserted up to the third zone Z3 of the primary boring hole 3b. A packer 22 is attached to the tip of the injection tube 21, and the packer 22 closes the outer periphery of the injection tube 21 and the inner wall of the third zone Z3 in the borehole 3b. Thereby, the pressure of the grout material 6 in the 4th area Z4 of the boring hole 3b can be raised, and more grout materials 6 can be flowed into the crack 2b.

  The injection device 100 includes an optical fiber cable 40 installed in the foundation ground 1 and a strain measurement unit 50 that measures the strain of the optical fiber cable 40. A signal output from the strain measurement unit 50 is input to the controller 30.

  The optical fiber cable 40 is inserted into the observation hole 7 formed in the base ground 1 in the vertical direction by boring. The tip of the optical fiber cable 40 is fixed to the bottom of the observation hole 7 using a fast-strength cement 41, and the end of the optical fiber cable 40 extends from the observation hole 7 and is connected to the strain measurement unit 50.

  The optical fiber cable 40 is covered with an epoxy resin while being twisted together with a plurality of steel wires. Therefore, the optical fiber cable 40 can be prevented from being damaged when the optical fiber cable 40 is inserted into the observation hole 7. The number of optical fiber cables 40 twisted together with a plurality of steel wires may be one, or two or more.

  The gap between the inner wall of the observation hole 7 and the optical fiber cable 40 is filled with bentonite 42. The filling of the bentonite 42 is performed in a state where the tip of the optical fiber cable 40 is fixed to the bottom of the observation hole 7 and tension is applied to the optical fiber cable 40. By the bentonite 42, the optical fiber cable 40 is bonded to the inner wall of the observation hole 7 over a range from the bottom of the observation hole 7 to the surface of the foundation ground 1. Therefore, the optical fiber cable 40 is distorted with the displacement of the inner wall of the observation hole 7 in the vertical direction.

  The distortion of the optical fiber cable 40 accompanying the displacement of the inner wall of the observation hole 7 will be specifically described with reference to FIG.

  As shown in FIG. 4, the observation hole 7 passes through the cracks 2a and 2b. In the following, a portion between the surface and the crack 2a of the foundation ground 1 is a first ground layer 1a, a portion between the crack 2a and the crack 2b is a second ground layer 1b, and a portion below the crack 2b. Is the third ground layer 1c. Portions of the optical fiber cable 40 located on the first, second, and third ground layers 1a, 1b, and 1c are referred to as first, second, and third cable portions 40a, 40b, and 40c, respectively. In addition, a portion of the optical fiber cable 40 located between the first and second cable portions 40a and 40b is a fourth cable portion 40d, and a portion located between the second and third cable portions 40b and 40c is a fifth cable. Part 40e.

  The displacement of the inner wall of the observation hole 7, that is, the displacement of the first, second, and third ground layers 1a, 1b, 1c is caused by the flow of the grout material 6 (see FIG. 1) into the cracks 2a, 2b. The grout material 6 is injected into the boreholes (3a, 3b, 4a) in order to increase the water shielding and strength of the foundation ground 1, and the injected grout material 6 flows into the cracks 2a, 2b. When the injection pressure of the grouting material is low, the inflow (filling) of the grouting material in the cracks 2a and 2b becomes insufficient, and the predetermined water shielding and strength cannot be obtained. Therefore, in the grouting, the injection is carried out by setting the injection pressure so that the grouting material is sufficiently filled (filled) into the crack. However, when the injection pressure is high, the optical fiber cable 40 installed in the observation hole 7 is displaced and distorted by the grout material flowing into the cracks 2a and 2b.

  The mechanism of how the optical fiber cable 40 is distorted by the injection of the grout material 6 is not the essence of the present invention, but will be described as follows, for example. First, the displacement of the foundation ground 1 and the distortion of the optical fiber cable 40 that occur when the grout material 6 flows into the crack 2a will be described. The grout material 6 flows into the crack 2a when the grout material 6 is injected into the second zone Z2 (see FIG. 1 and the like) in the boring hole 3b.

  When the grout material 6 flows into the crack 2a, the first ground layer 1a may be pushed up by the grout material 6 flowing into the crack 2a. Since the first cable portion 40a is bonded to the first ground layer 1a via the bentonite 42, the first cable portion 40a is displaced upward in accordance with the displacement of the first ground layer 1a.

  At this time, since the second ground layer 1b is not pushed up, the second cable portion 40b bonded to the second ground layer 1b is not displaced upward. Accordingly, the fourth cable portion 40d between the first cable portion 40a and the second cable portion 40b is pulled, and tensile strain occurs in the fourth cable portion 40d.

  Further, when the grout material 6 flows into the crack 2a, the second ground layer 1b may be pushed down by the grout material 6 flowing into the crack 2a. In this case, the second cable portion 40b is displaced downward with the displacement of the second ground layer 1b. Therefore, the fourth cable portion 40d is pulled, and tensile strain occurs in the fourth cable portion 40d.

  As described above, when the grout material 6 flows into the crack 2a, a part of the optical fiber cable 40 (the first fiber layer 40) is displaced by the upward displacement of the first ground layer 1a, the downward displacement of the second ground layer 1b, or both. 4 Cable part 40d) is subjected to tensile strain. The same applies when the grout material 6 flows into the crack 2b.

  As described above, when the grout material 6 flows into the cracks 2a and 2b and the foundation ground 1 is displaced, at least one of the first, second and third cable portions 40a, 40b and 40c is displaced. The first, second, and third cable portions 40a, 40b, and 40c are bonded to the first, second, and third ground layers 1a, 1b, and 1c by bentonite 42, respectively. The displacement amounts of the cable portions 40a, 40b, and 40c correspond to the displacement amounts of the first, second, and third ground layers 1a, 1b, and 1c, respectively. Therefore, when at least one of the first, second, and third cable portions 40a, 40b, and 40c is displaced, distortion occurs in at least one of the fourth and fifth cable portions 40d and 40e. Therefore, the displacement of the foundation ground 1 can be grasped by measuring the strain in the fourth cable portion 40d and the fifth cable portion 40e. The displacement of the foundation ground 1 can be set in the horizontal direction, the vertical direction, and the like by the optical fiber cable 40, but in this embodiment, the displacement amount in the vertical direction is mainly calculated and grasped.

  The operation of inserting the optical fiber cable 40 into the observation hole 7 and installing it on the foundation ground 1 so that the optical fiber cable 40 is partially distorted with the displacement of the foundation ground 1 is performed before the grout material 6 is injected into the foundation ground 1. Specifically, it is performed before the primary bore holes 3a, 3b are formed in the foundation ground 1.

  By the way, conventionally, in grouting, in order to grasp the displacement of the foundation ground 1, the displacement of the surface of the foundation ground 1 is measured. Since the surface of the foundation ground 1 is the surface of the first ground layer 1a, the amount of displacement of the first ground layer 1a can be grasped by measuring the displacement of the surface of the foundation ground 1. However, since there is a crack 2a between the second ground layer 1b and the first ground layer 1a, the displacement of the second ground layer 1b may be absorbed by the crack 2a and not transmitted to the first ground layer 1a. is there. Therefore, in the measurement of the displacement of the surface of the foundation ground 1 performed conventionally, the displacement amount of the 2nd ground layer 1b cannot be grasped correctly.

  As described above, the optical fiber cable 40 installed on the foundation ground 1 is partially displaced and partially distorted when the first ground layer 1a is partially displaced from the third ground layer 1c. Therefore, by measuring the partial distortion of the optical fiber cable 40, it is possible to accurately grasp the amount of displacement that occurs only inside the foundation ground 1 such as the second ground layer 1b.

  The partial strain of the optical fiber cable 40 is measured by the strain measuring unit 50. The optical fiber cable 40 has the property of slightly scattering the traveling pulse light backward, and the strain measurement unit 50 measures the partial strain of the optical fiber cable 40 using this property.

  Specifically, since the frequency of the scattered light depends on the strain of the optical fiber cable 40, the strain measurement unit 50 enters the optical fiber cable 40 by measuring the frequency of the scattered light by entering the pulsed light into the optical fiber cable 40. 40 strains are measured. In addition, the strain measurement unit 50 measures the time from when the pulsed light is incident on the optical fiber cable 40 until the scattered light generated in the optical fiber cable 40 returns to the strain measurement unit 50, so that the scattered light is The position where the distortion occurs, that is, the position where the distortion occurs is calculated. By detecting the scattered light at a predetermined cycle, strains at a plurality of positions in the optical fiber cable 40 can be measured.

  As described above, the strain measurement unit 50 measures strains at a plurality of positions in the optical fiber cable 40. As described above, since the optical fiber cable 40 is partially distorted even by the amount of displacement generated only inside the foundation ground 1, the strains at a plurality of positions in the optical fiber cable 40 measured by the strain measurement unit 50 are used. Thus, it is possible to accurately grasp the amount of displacement that occurs only inside the foundation ground 1.

  Further, as shown in FIG. 1, the optical fiber cable 40 is divided into first to fifth zones Z1 to Z5 corresponding to the division of the boring holes 3b. The strain measuring unit 50 measures each strain in the first to fifth zones Z1 to Z5 of the optical fiber cable 40. The measured distortion information is input to the controller 30 together with the area information and the information on a plurality of positions.

  As illustrated in FIG. 5, the controller 30 acquires a plurality of strains measured by the strain measuring unit 50 and a displacement that calculates the displacement amount of the optical fiber cable 40 using the acquired plurality of strains. An amount calculation unit 32 and a determination unit 33 that determines whether to continue the injection of the grout material 6 and whether to increase the injection pressure of the grout material 6 based on the calculated displacement amount. The determination by the determination unit 33 is performed every time the grout material 6 is injected into each of the first to fifth zones Z1 to Z5.

  Hereinafter, the configuration and operation of the controller 30 will be described in detail with reference to FIGS. 1 and 5 while explaining the relationship between the area into which the grout material 6 is injected and the amount of displacement of the optical fiber cable 40.

  When grouting is performed, the size and position of a crack in the foundation ground 1 are often not grasped. In such a case, when the grout material 6 is injected into an area where the boring hole 3b is present, it is not known which of the first to fifth areas Z1 to Z5 of the optical fiber cable 40 is displaced. Therefore, it is effective to determine whether or not to continue the injection of the grout material 6 based on the largest displacement amount among the displacement amounts in the first to fifth sections Z1 to Z5 of the optical fiber cable 40.

  As illustrated in FIG. 5, the displacement amount calculation unit 32 of the controller 30 calculates the displacement amounts in the first to fifth sections Z1 to Z5 of the optical fiber cable 40 using the plurality of distortions acquired by the acquisition unit 31. It includes an area displacement amount calculation unit 32a and a maximum displacement amount extraction unit 32b that extracts the largest displacement amount from the calculated displacement amount for each area. The displacement amount extracted by the maximum displacement amount extraction unit 32b is the maximum value of the displacement amounts in the first to fifth sections Z1 to Z5 of the optical fiber cable 40.

  For example, when calculating the displacement amount of the third section Z3 of the optical fiber cable 40, the per-area displacement amount calculation unit 32a performs measurement in a section extending from the tip (lower end) of the optical fiber cable 40 to the upper end of the third section Z3. The amount of expansion / contraction of the section is calculated using a plurality of distortions. The calculated amount of expansion and contraction corresponds to the amount of displacement of the upper end of the third zone Z3 with respect to the tip (lower end) of the optical fiber cable 40. The per-zone displacement amount calculation unit 32a calculates the displacement amount at the upper end of the third zone Z3 as the displacement amount of the third zone Z3. The displacement amounts of the optical fiber cable 40 in the first, second, fourth, and fifth sections Z1, Z2, Z4, and Z5 are similarly calculated.

  The maximum displacement amount extraction unit 32 b outputs the extracted displacement amount to the determination unit 33. Therefore, the partial and maximum displacement amount inside the foundation ground 1 accompanying the injection of the grout material 6 can be grasped, and whether or not the injection of the grout material 6 can be continued can be accurately determined.

  Further, cracks in the foundation ground 1 may be formed in a plurality of areas in the vicinity of the observation hole 7 even if they are in one area in the vicinity of the boring hole 3b. In this case, even if the displacement amount in each section of the optical fiber cable 40 is relatively small, the overall displacement amount of the optical fiber cable 40 may be large. Therefore, it is effective to determine whether or not to continue the injection of the grout material 6 based on the total value of the displacement amounts of the plurality of sections of the optical fiber cable 40.

  As shown in FIG. 5, the displacement amount calculation unit 32 of the controller 30 includes a displacement amount summation unit 32 c that sums the displacement amounts for each area calculated by the area displacement amount calculation unit 32 a. The displacement amount summed by the displacement amount summing unit 32c is the total value of the displacement amounts in the first to fifth sections Z1 to Z5 of the optical fiber cable 40.

  The displacement amount summation unit 32 c outputs the summed displacement amount to the determination unit 33. Therefore, the total displacement amount of the foundation ground 1 accompanying the injection of the grout material 6 can be grasped, and whether or not the injection of the grout material 6 can be continued can be determined more accurately.

  In addition, the displacement total part 32c may be configured to calculate a total displacement amount in at least two of the first to fifth zones Z1 to Z5.

  Based on the maximum displacement amount extracted by the maximum displacement amount extraction unit 32b and the total displacement amount calculated by the displacement amount totaling unit 32c, the determination unit 33 determines whether or not to continue the injection of the grout material 6. Further, it is determined whether or not the injection pressure of the grout material 6 can be increased, and a signal for controlling the pump 11 and the control valve 12 is output based on the determination result. Processing performed by the determination unit 33 will be described with reference to FIG.

  In step S601, the displacement amount calculated by the displacement amount calculation unit 32 is acquired. The displacement amount to be acquired is the maximum value of the displacement amount extracted by the maximum displacement amount extraction unit 32b and the total value of the displacement amount calculated by the displacement amount summation unit 32c.

  In step S602, it is determined whether the maximum value of the displacement amount extracted by the maximum displacement amount extraction unit 32b exceeds a predetermined first threshold value. The first threshold is an allowable displacement amount in one area, and is 0.1 mm, for example.

  If it is determined in step S602 that the maximum displacement amount has exceeded a predetermined first threshold, the process proceeds to step S605. If it is determined in step S602 that the maximum displacement amount does not exceed the predetermined first threshold value, the process proceeds to step S603.

  In step S603, it is determined whether or not the total amount of displacement calculated by the displacement amount totaling unit 32c exceeds a predetermined second threshold value. The second threshold is an overall allowable displacement amount in the five areas, and is 0.4 mm, for example. The second threshold value is preferably larger than the first threshold value and smaller than a value obtained by multiplying the number of areas to be summed by the first threshold value. By making the second threshold value smaller than the value obtained by multiplying the number of areas to be summed by the first threshold value, management when the foundation ground 1 is partially displaced can be eased, while the foundation ground 1 is Management in the case of displacement as a whole can be tightened.

  If it is determined in step S603 that the total amount of displacement exceeds a predetermined second threshold, the process proceeds to step S605. If it is determined in step S603 that the total displacement amount does not exceed the predetermined second threshold value, the process proceeds to step S604.

  In step S604, the injection of the grout material 6 is continued and a signal for increasing the injection pressure of the grout material 6 is output to the pump 11 and the control valve 12. Specifically, a signal for increasing the rotation speed of the pump 11 or increasing the opening degree of the control valve 12 is output. Thereby, injection of grout material 6 is continued in the state where injection pressure was raised. After outputting the signal, the process returns to step S601.

  In step S605, a signal for stopping the injection of the grout material 6 is output. Specifically, a signal for stopping the driving of the pump 11 or closing the control valve 12 is output. Thus, the process performed by the determination unit 33 ends.

  By stopping the driving of the pump 11 or closing the control valve 12, the injection of the grout material 6 into the boring hole 3b is stopped. Therefore, destruction of the foundation ground 1 caused by continuing the injection of the grout material 6 can be prevented. Thereby, the cracks 2a and 2b can be closed with the grout material 6, and the water-proof and strength foundation of the foundation ground 1 can be enhanced.

  According to the above 1st Embodiment, there exists an effect shown below.

  In the injection device 100 and the injection method, the strain measuring unit 50 measures strain at a plurality of positions in the optical fiber cable 40 installed in the foundation ground 1. The controller 30 calculates a displacement amount using the measured strain, and controls the pump 11 and the control valve 12 according to the displacement amount. Since the optical fiber cable 40 is partially distorted according to the displacement of the foundation ground 1, the grout material 6 is injected according to the displacement of the foundation ground 1. Therefore, even when a displacement occurs only inside the foundation ground 1, the grout material 6 can be injected into the foundation ground 1 with an appropriate pressure and amount. Thereby, destruction of the foundation ground 1 can be prevented, and the water shielding and strength of the foundation ground 1 can be increased.

  Moreover, in the injection apparatus 100, when the displacement amount calculated using the strain measured by the strain measuring unit 50 does not exceed the first to third threshold values set in advance, the injection pressure of the grout material 6 is set. Raise. Therefore, the injection pressure of the grout material 6 can be increased while preventing the foundation ground 1 from being destroyed. Therefore, more grout material 6 can be poured into the foundation ground 1, and the water shielding and strength of the foundation ground 1 can be further increased.

  Moreover, in the injection device 100, the displacement amount calculation unit 32a for each section of the controller 30 calculates the displacement amount using the strains in the first to fifth sections Z1 to Z5 of the optical fiber cable 40. Therefore, the displacement amount can be measured by the division corresponding to the division of the boring hole 3b. Therefore, when the grout material 6 is injected into an area where the boring hole 3b is present, the displacement state of the foundation ground 1 in another area can be grasped.

  Moreover, in the injection device 100, the controller 30 controls the pump 11 and the control valve 12 based on the maximum value among the respective displacement amounts in the first to fifth sections Z1 to Z5 of the optical fiber cable 40. Therefore, the grout material 6 can be injected into the foundation ground 1 according to the partial and maximum displacement amount inside the foundation ground 1 accompanying the injection of the grout material 6. Therefore, it is possible to further increase the water shielding and strength of the foundation ground 1.

  In the injection device 100, the controller 30 controls the pump 11 and the control valve 12 based on the total displacement amount in the first to fifth zones Z1 to Z5 of the optical fiber cable 40. Therefore, the grout material 6 can be injected according to the overall displacement of the foundation ground 1 accompanying the injection of the grout material 6. Therefore, it is possible to further increase the water shielding and strength of the foundation ground 1.

  In the injection device 100, the pump 11 and the control valve 12 of the injection unit 10 are controlled by the controller 30, but in the injection method according to this embodiment, the operator controls the pump 11 and the control valve 12 to grout. Material may be injected. In this case, the operator controls the pump 11 and the control valve 12 based on the strain of the optical fiber cable 40 measured by the strain measuring unit 50. Specifically, the operator may control the pump 11 and the control valve 12 by monitoring the strain distribution of the optical fiber cable 40 measured by the strain measuring unit 50, or use the strain of the optical fiber cable 40. Then, the displacement amount of the optical fiber cable 40 may be calculated, and the pump 11 and the control valve 12 may be controlled based on the calculated displacement amount.

  In the injection device 100 and the injection method, the control of the injection unit 10 includes not only the injection pressure but also the injection flow rate. The injection pressure control includes not only increasing / decreasing the injection pressure but also stopping / starting the injection.

Second Embodiment
Next, an injection device 200 and an injection method for the grout material 6 according to the second embodiment will be described with reference to FIG. In the following, differences from the first embodiment will be mainly described, and the same or equivalent configurations as those described in the first embodiment are denoted by the same reference numerals as those in the first embodiment. Description is omitted.

  In grouting, the number, size and position of cracks in the foundation ground 1 are predicted by checking the inner walls of the observation hole 7 and the boring hole 3b at the stage where the observation hole 7 and the boring hole 3b are formed in the foundation ground 1. Is possible. The prediction of the crack in the foundation ground 1 is performed by, for example, an operator or a crack detection device.

  In the injection apparatus 200 according to the second embodiment, the grout material 6 is injected into the foundation ground 1 using the predicted number, size, and position of cracks. Hereinafter, a specific configuration of the injection apparatus 200 will be described.

  As shown in FIG. 7, the displacement amount calculation unit 232 of the controller 230 in the injection device 200 includes a predetermined area displacement amount extraction unit 232 b instead of the maximum displacement amount extraction unit 32 b (see FIG. 5) in the injection device 100. The predetermined area displacement amount extraction unit 232b extracts the displacement amount in the predetermined area of the optical fiber cable 40 from the displacement amount for each area calculated by the area displacement amount calculation unit 32a.

  The predetermined area is set based on information output from the area information output unit 60. The area information output unit 60 is an input device or a crack detection apparatus operated by an operator, and the output information is information on the area of the optical fiber cable 40 that is expected to be distorted with the injection of the grout material 6. It is. Accordingly, the displacement of the ground due to the injection of the grout material 6 is accurately extracted.

  The displacement amount extracted by the predetermined area displacement amount extraction unit 232b is input to the determination unit 33. Therefore, whether or not to continue the injection of the grout material 6 can be determined based on the predicted crack information and the partial displacement inside the foundation ground 1. Therefore, the grout material 6 can be injected into the foundation ground 1 with a more appropriate pressure and amount, the foundation ground 1 can be prevented from being broken, and the water shielding and strength of the foundation ground 1 can be increased.

  The displacement amount calculation unit 232 includes a displacement amount summation unit 32 c, and the total value of the displacement amounts calculated by the displacement amount summation unit 32 c is input to the determination unit 33. Therefore, also in the injection device 200, the overall displacement of the foundation ground 1 accompanying the injection of the grout material 6 can be grasped, and whether or not the injection of the grout material 6 can be continued can be accurately determined.

  Since the process performed by the determination unit 33 is substantially the same as the process of the determination unit 33 in the first embodiment, the description thereof is omitted here.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  In the above-described embodiment, the case where the grout material 6 is injected into the foundation ground 1 by the stage injection method has been described. The present invention is also applicable when injecting the grout material 6.

  Further, the displacement amount calculation unit 32 of the injection apparatus 100 may be configured to include only one of the maximum displacement amount extraction unit 32b and the displacement amount total unit 32c. Similarly, the displacement amount calculation unit 232 of the injection apparatus 200 may be configured to include only one of the predetermined area displacement amount extraction unit 232b and the displacement amount total unit 32c.

  The displacement amount calculation unit 232 of the injection device 200 may include a maximum displacement amount extraction unit 32b. In this case, the grout material 6 can be injected into the foundation ground 1 in accordance with the partial displacement inside the foundation ground 1 even when there is a crack that has not been predicted by the operator or the crack detection device. Therefore, it is possible to further increase the water shielding and strength of the foundation ground 1.

DESCRIPTION OF SYMBOLS 1 ... Foundation ground 3a, 3b, 4a, 5a, 5b ... Boring hole 6 ... Grout material 7 ... Observation hole 10 ... Injection part 11 ... Pump 12 ... Control valve 30 ... Controller (control unit)
DESCRIPTION OF SYMBOLS 40 ... Optical fiber cable 50 ... Strain measuring part 100, 200 ... Injection apparatus

Claims (9)

An injection device for injecting grout material into a borehole formed in the foundation ground,
An injection part for injecting grout material into the borehole;
An optical fiber cable that is inserted into an observation hole formed in a vertical direction in the foundation ground, and is distorted with a displacement of an inner wall of the observation hole in the vertical direction;
A strain measuring unit for measuring strain at a plurality of positions in the optical fiber cable;
Calculating a displacement amount of the optical fiber cable using strain measured by the strain measurement unit, and controlling the injection unit based on the calculated displacement amount;
A grout injection device. The optical fiber cable is divided into a plurality of areas corresponding to the boring holes divided into a plurality of areas in the vertical direction,
The control unit calculates a displacement amount in the plurality of areas of the optical fiber cable using the strain measured by the strain measurement unit, and controls the injection unit based on the calculated displacement amount.
The grout injection device according to claim 1. An injection method for injecting grout material into a borehole formed in the foundation ground,
An observation hole is formed in the foundation ground in the vertical direction, and an optical fiber cable is inserted into the observation hole so as to be distorted with the displacement of the inner wall of the observation hole in the vertical direction.
Measuring strain at a plurality of positions in the optical fiber cable;
Injecting grout material into the borehole based on the measured strain,
Grouting material injection method. When the grout material is injected, the injection pressure of the grout material is changed based on the measured strain.
The method for injecting a grout material according to claim 3. Calculating the amount of displacement of the optical fiber cable using the measured strain, and injecting a grout material into the boring hole based on the calculated amount of displacement;
The method for injecting a grout material according to claim 3 or 4. In the case of dividing the boring hole into a plurality of areas in the vertical direction and injecting grout material for each area,
The optical fiber cable is divided into a plurality of areas corresponding to the division of the boring holes,
Using the measured strain, calculate the amount of displacement in the plurality of areas of the optical fiber cable, and based on the calculated amount of displacement, inject a grout material into the boring hole,
The method for injecting a grout material according to claim 5. Of each displacement amount in the plurality of sections of the optical fiber cable, based on the maximum value, a grout material is injected into the boring hole,
The method for injecting a grout material according to claim 6. Injecting a grout material into the boring hole based on a displacement amount of a predetermined area among the plurality of areas of the optical fiber cable.
The method for injecting a grout material according to claim 6 or 7. Injecting grout material into the boring hole based on a total displacement amount in at least two of the plurality of sections of the optical fiber cable.
The method for injecting a grout material according to any one of claims 6 to 8.

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