JP4180075B2 - Ground injection method - Google Patents

Description

  The present invention uses a boring rod with a built-in position information transmitter to drill the ground in a curved or horizontal arbitrary direction and install an injection pipe in the ground, and inject the injection liquid into the ground through this injection pipe. It relates to ground injection method suitable for liquefaction prevention injection, foundation reinforcement, cavity filling, and soil purification material injection directly under the building, especially with outer pipes having multiple outlets at different axial positions. A ground using a ground injection device comprising a plurality of inner tube packers spaced apart and having an inner tube discharge port between adjacent inner tube packers and an inner tube inserted into the outer tube More specifically, the injection pipe is bent in the ground using a position information transmitter or installed horizontally, or any combination of bending and horizontal, and the inner pipe packer is passed through this injection pipe. Injection material from the inner pipe outlet located in the outer pipe Per To injected into the ground through the outlet, to ground grouting method which can accurately grasp the injection pressure in the ground.

  When injecting an injection material into the ground using a ground injection device consisting of an outer pipe and an inner pipe inserted into the outer pipe, conventionally, the injection pressure in the injection pipe has been measured with a pressure gauge located on the ground surface. It was.

  However, this injection pressure is actually the resistance pressure of the injection pipe and the resistance pressure of the inner pipe outlet added to the original ground injection pressure penetrating between the soil particles, It does not indicate. In particular, by supplying an injection liquid to the inner pipe flow path, the expandable inner pipe packer is expanded by the liquid supply pressure of the injection liquid to form a packer, and the inner pipe discharge port is an injection port composed of pores. In this case, the pressure in the inner pipe becomes high due to the resistance of the injection port, and the actual pressure in the ground cannot be grasped. Therefore, the judgment of how the injection is performed in the ground is confirmed by the change in the injection pressure. There was a problem that I could not.

In other words, this pressure is largely influenced by the liquid supply pressure in the ground part and the resistance pressure of the inner pipe flow path and the discharge port. It is unclear whether the ground has been destroyed and the infusion has gone.
Japanese Patent Application No. 2004-341933

  Therefore, the problem to be solved by the present invention is that the ground injection device is bent in the ground or installed horizontally, or any combination of bending and horizontal is used, and this ground injection device is used between the inner tube packers. When injecting the consolidated material from the inner pipe discharge port to the ground through the outer pipe discharge port, the injection pressure from the discharge port into the ground is directly and accurately grasped, and there is a drawback existing in the above-mentioned known technology. It is to provide an improved ground injection method.

To solve the problems described above, according to the ground grouting of the present invention, bent inlet tube to the ground (the ground injection apparatus), or horizontally, or a bent and horizontal placed in any combination, this injection A ground injection method for injecting an injection solution into a ground through a pipe , wherein the injection pipe is loosely inserted into the outer pipe having a plurality of outer pipe discharge ports at different positions in the axial direction, and a plurality of swellings are provided. A retractable inner tube packer is provided with an interval so as to sandwich the outer tube discharge port. Further, the inner tube packer has a discharge port in the packer in the inner tube packer, and is provided between the inner tube packers provided with the interval. And an inner pipe having an inner pipe discharge port, which is installed in a drilling hole drilled by a boring rod having a built-in position information transmitter at the tip, and injecting the injection liquid into the inner pipe flow path. by feeding, liquid feeding pressure of the infusion solution the inflation and deflation of the tube packer Ground to together to form an outer tube space between inflated plurality of inner tubes packer, ejecting injection liquid from the inner tube the discharge port to the outer tube space, the infusate from outside tube space through the outer tube discharge port by In the ground injection method for injecting into the inside, a pressure transmission member that senses and transmits the pressure in the outer pipe space is installed in the injection pipe, and the pressure sensed in the space is transmitted through the pressure transmission member. It is characterized by measuring and grasping the injection pressure of the ground.

  In the present invention described above, the ground injection device is bent in the ground, or installed horizontally, or any combination of bending and horizontal, and the solidified material is injected into the ground through the ground injection device. When consolidating, as the ground injection device, a ground injection device comprising an outer tube and an inner tube inserted into the outer tube is used, and the outer tube has one outer tube discharge port on the outer tube surface, or A plurality of outer tube discharge ports at different positions in the axial direction, the inner tube is provided with a plurality of inner tube packers spaced apart, and an inner tube discharge port between adjacent inner tube packers; When inserting the inner tube into the outer tube, the inner tube is inserted so that an outer tube discharge port is located between adjacent inner tube packers and a space is formed between the inner tube packers in the outer tube, and the injection Installed in the device is a pressure transmission member that senses and transmits the pressure in the space. Rukoto by, transmitting a pressure sensed by the space through the pressure transmitting member, to grasp the precise injection pressure of the inner tube the discharge port directly by measuring the transfer pressure.

  Further, in the present invention, the strain resistance type pressure sensor located in the space in the injection device, one end connected to the pressure sensor via an amplifier, and the other end connected to a pressure display device on the ground. A pressure transmission member comprising a signal cable is installed, the pressure sensor senses the pressure in the space, and the sensed pressure in the space is transmitted as an electrical signal to the pressure display device through the signal cable via the amplifier, Directly know the exact injection pressure at the outlet.

  Further, in the present invention described above, the pressure transmission member is connected to the space via a tube, a strain resistance type pressure sensor, an amplifier connected to the pressure sensor, and the amplifier connected to the amplifier via a signal cable. A pressure transmission member consisting of a pressure display device on the ground is installed in the ground injection device, and one end of the tube located in the space senses the pressure in the space, and this sensed pressure is transmitted via a pressure sensor and an amplifier. Measured by transmitting to the pressure display device and directly grasping the ground injection pressure.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view of a specific example of a ground injection device according to the present invention, FIG. 2 is a partial cross-sectional view of another specific example of a ground injection device according to the present invention, and FIG. FIG. 4 is a cross-sectional view of still another specific example of the ground injection device, and FIG. 4 is a cross-sectional view of still another specific example of the ground injection device according to the present invention.

  In FIG. 1, a ground injection device A according to the present invention includes an outer tube 1 and an inner tube 2 inserted into the outer tube 1, and a solidified material (ground injection solution) is placed in the ground 3. The ground 3 is consolidated by pouring.

  The outer tube 1 has a plurality of outer tube discharge ports 4 at different positions in the axial direction, and the inner tube 2 includes a plurality of inner tube packers 5 at intervals, and the inner tube packers 5 adjacent to each other, 5 is configured to have an inner tube discharge port 6. The inner tube discharge port 6 is an injection port composed of fine holes.

When the inner tube 2 is inserted into the outer tube 1 described above, the outer tube discharge port 4 is positioned between the adjacent inner tube packers 5 and 5, and the inner tube packers 5 and 5 in the outer tube 1 are disposed. It inserts so that the space 7 may be formed. The inner tube packers 5 and 5 are supplied between the plurality of inner tube packers 5 and 5 by inflating the expandable inner tube packer 5 due to the liquid feeding pressure of the injected solution by sending the injected solution to the inner tube flow path. A tube inner space is formed, and an injection solution is discharged from the inner tube discharge port 6 into the outer tube inner space 7.

  A feature of the present invention is that the pressure in the space 7 is sensed and transmitted in the above-described injection device A of the present invention which is bent in the ground 3 or installed horizontally or in any combination of bending and horizontal. The transmission member 8 is installed in the ground injection device A, and the pressure sensed in the space 7 is transmitted and measured through the pressure transmission member 8 to measure the accurate injection pressure of the inner pipe discharge port 6. .

  Specifically, the pressure transmission member 8 is a tube 8, and one end 11 is positioned at the pressure detection unit 12 in the space 7 to sense the pressure in the space 7, and the other end 13 passes through the inner pipe 2 to the ground. The pressure in the space 7 is measured by the pressure gauge 14 and the pressure in the space 7 between the outer pipe 1 outside the inner pipe discharge port 6 and the inner pipe 2 is measured. . This space 7 communicates with an injection region of a predetermined stage via a rubber sleeve 19 of the outer tube discharge port 4, and the rubber sleeve 19 only covers the outer tube discharge port 4 loosely. Does not exceed the injection pressure of the injection ground of the injection solution at the injection stage

  That is, the injection material from the storage tank 15 passes through the injection pump 16, the flow meter 17, the pressure gauge 18, and the inner tube 2, and further passes through the space 7 from the inner tube discharge port 6, passes through the outer tube discharge port 4, and rubber. The sleeve 19 is expanded and injected into the ground 3. At this time, the injection pressure of the injection solution from the inner pipe discharge port 6 is determined in the injection ground by directly measuring the pressure in the space 7 with the pressure gauge 14 on the ground 3 through the tube 8. it can. Of course, when injecting an infusion solution having a long gelation time, the inside of the tube 8 is filled with the infusion solution filling the space 7 as it is, and the pressure can be directly measured by the pressure gauge 14 to know the injection pressure. If the gelation time is long, there is no possibility of gelation in the tube 8, but if there is a possibility of gelation, the tube 8 may be washed with water with the hand pump 20 occasionally.

  In the conventional injection device, the injection pressure of the injection pump 16 is measured by the pressure gauge 18 and the ground injection pressure is measured, but the display pressure is the resistance pressure in the injection pipe and the resistance pressure from the inner pipe discharge port to the original ground. The actual pressure in the ground is unknown. In particular, when the inner tube discharge port 6 is an injection nozzle made of a thin tube, it is difficult to grasp the change in the ground injection pressure because the resistance pressure of the injection port is large. Since the apparatus of the present invention directly measures the ground injection pressure, it knows the change in the injection pressure at the injection stage, thereby knowing whether it has infiltrated between the soil particles, the change in the situation, and the change in the case of split injection.

  In the above, one end 11 of the tube 8 located in the space 7 can be covered with a film (not shown). In this case, if the pressure in the space 7 is filled with a liquid such as water in the tube 8 by the hand pump 20, the injection pressure in the ground in the space 7 detected by the membrane is applied to the pressure gauge 14 via the liquid. Measured by transmitting and reading this pressure. The film is a thin film, preferably an expansion / contraction film.

  In the case where there are a plurality of spaces 7, as shown in FIG. 2, the branch inner pipe 2a is branched into the inner pipe 2, and the tubes 8, 8 are respectively connected to the pressure detector 12 through the inner pipe 2 and the branch inner pipe 2a. The pressure can be transmitted to the gauges 14 and 14a, and the pressures in the separate spaces 7 at the respective pressure gauges 14 and 14 can be measured.

  Further, as shown in FIG. 3, the pressure transmission member 8 includes an outer tube 1 and an inner tube 2 inserted into the outer tube 1. The outer tube 1 has a plurality of outer tube discharge ports 4 at different positions in the axial direction, the inner tube 2 includes a plurality of inner tube packers 5 at intervals, In addition, an inner tube discharge port 6 is provided between the adjacent inner tube packers 5 and 5, and when the inner tube 2 is inserted into the outer tube 1, the outer tube discharge port is disposed between the adjacent inner tube packers 5 and 5. 4 in the ground injection device A in which the space 7 is formed between the inner tube packers 5 and 5 in the outer tube 1, and thereby the strain resistance type pressure sensor 21 disposed in the space 7. An amplifier 24 connected to the strain resistance pressure sensor 21 via a signal cable 26, and a signal transmitted to the amplifier 24. The pressure transmitting member 8 made of a pressure display device 25. on the ground 3 which is connected via a cable 26 may be installed in the ground implanter A.

  In this case, the pressure sensor 21 senses the pressure in the space 7 and transmits the sensed pressure in the space 7 through the amplifier 24 and the signal cable 26 to the pressure display device 25 as an electrical signal, so that an accurate ground injection pressure can be obtained. I can grasp it.

  Further, as shown in FIG. 4, the pressure transmission member 8 includes an outer tube 1 and an inner tube 2 inserted into the outer tube 1. A ground injection device A for consolidation, wherein the outer tube 1 has a plurality of outer tube discharge ports 4 at different positions in the axial direction, the inner tube 2 includes a plurality of inner tube packers 5 at intervals, and When the inner tube 2 is inserted into the outer tube 1, the outer tube discharge port 4 is provided between the adjacent inner tube packers 5 and 5. In the ground injection device A, in which the space 7 is formed between the inner tube packers 5 and 5 in the outer tube 1 by being inserted so as to be positioned, the strain resistance type pressure connected to the space through the tube 8 A sensor 21, an amplifier 24 connected to the pressure sensor 21, and a signal cable 26 connected to the amplifier 24. The pressure transmitting member 8 made of a pressure display device 25. on board 3 may be installed in the ground implanter A.

  In this case, one end 11 of the tube 8 located in the space 7 senses the pressure in the space 7, and the sensed pressure is transmitted to the pressure display device 25 via the pressure sensor 21 and the amplifier 24, and is measured. Understand proper ground injection pressure.

  In the ground injection device A of the present invention configured as described above, the outer tube discharge port 4 is located between the adjacent inner tube packers 5 and 5 and the space between the inner tube packers 5 and 5 in the outer tube 1 is a space. The inner tube 2 is inserted into the outer tube 1 so that 7 is formed, and a pressure transmission member 8 that senses and transmits the pressure in the space 7 is installed in the injection device A. The pressure sensed in the previous space 7 is transmitted and measured, and the accurate ground injection pressure is grasped.

  The above-described ground injection device A of the present invention is installed on the ground 3 as shown in FIGS. 5 (a) to 5 (d), for example. This will be described in detail. First, as shown in FIG. 5A, the ground 3 is bored, and the casing 27 is inserted therein. Next, as shown in FIG. 5 (b), the outer tube 1 is inserted into the casing 27. The outer tube 1 has a plurality of outer tube discharge ports 4, 4, 4 opened at predetermined intervals at different positions in the axial direction of the tube wall 1 a, and the outer tube discharge ports 4, 4, 4 are Each is covered with a rubber sleeve 19.

  Further, after the seal grout 28 is injected into the casing 27 as shown in FIG. 5 (b), the casing 27 is pulled out as shown in FIG. 5 (c). As a result, the outer tube 1 is sealed with the seal grout 28.

  Next, as shown in FIG. 5 (d), the inner tube 2 is inserted into the outer tube 1. The outer tube 1 has a plurality of outer tube discharge ports 4 at different positions in the axial direction, and the inner tube 2 is provided with a plurality of inner tube packers 5 at intervals, and between the adjacent inner tube packers 5 and 5. An inner tube discharge port 6 is provided.

  When inserting the inner tube 2 into the outer tube 1, the outer tube discharge port 4 is located between the adjacent inner tube packers 5 and 5, and between the inner tube packers 5 and 5 in the outer tube 1. It is inserted so that the space 7 is formed.

  Furthermore, a tube 8 is installed in the inner tube 2 of the injection device A as a pressure transmission member. One end 11 of the tube 8 is located in the space 7 and senses the pressure in the space 7, and the other end is connected to a pressure gauge on the ground 3 (not shown). taking measurement.

The inner pipe packers 5 and 5 are expanded by the liquid feeding pressure of the injected liquid by sending the injected liquid to the inner pipe flow path to form an outer pipe inner space 7 between the plurality of inner pipe packers 5 and 5. The pressure in the space 7 is accurately measured by a pressure gauge on the ground 3 through a tube 8 as a pressure transmission member.

  Furthermore, the thing of the structure shown in FIG. 6 is used as the ground injection apparatus A concerning this invention. In FIG. 6, the outer tube 1 is provided with a plurality of outer tube packers 29 so as to sandwich the outer tube discharge port 4, and the consolidated material is pushed into the outer tube packer 29 through the discharge port 30 in the outer tube packer and the rubber sleeve 31 is pushed. It expands, fills, expands, settles in the ground 3 and is installed. Then, by inserting the inner tube 2 into the outer tube 1 and feeding the injected solution into the flow path of the inner tube 2, the expandable inner tube packer 5 expands due to the pressure of the injected solution and moves up and down. A space 7 in the outer tube 1 is formed between the plurality of inner tube packers 5 and 5 adjacent to each other.

  The injected liquid is further discharged from the inner tube discharge port 6 into the outer tube 1 outer space 32 through the space 7 in the outer tube 1 and the outer tube discharge port 4 and is injected into the ground 3 from here. Further, the inner tube 2 is moved and the injection is repeated. Since the outer space 32 is a columnar injection source having a large surface area, even if it is injected at a large injection rate, the injection rate from the unit area of the injection source is small, so that it can be injected between soil particles at a low pressure. Rapid osmotic injection is possible. The outer tube packer 29 is a water-permeable bag, and the outer tube packer 29 is filled with a caking material and expanded to a diameter larger than the diameter of the hole 33 to form a packer in the soil. The pipe 1 is fixed and installed on the ground 3. In FIG. 6, 34 is a fastener.

  Moreover, in this invention, as shown in FIG. 7, the flow path of the inner tube | pipe 2 can also be made into multiple by providing the multiple inner tubes 2. As shown in FIG. In this case, each of the inner pipe discharge ports 6, 6... 6 is opened to a different outer pipe inner space 7. As a result, not only can multiple injection stages be injected at the same time to enable rapid construction of long injection sections, but also injection materials with different permeability and strength can be injected according to the state of the soil layer, and the main material It is also possible to superimpose and inject the reactant on the injection stage in which the solution is injected, or to inject the solution type grout on the region where the suspension is injected. At this time, although not shown, if a plurality of inner pipe discharge ports are opened in the same outer pipe inner space, two types of injection liquids, for example, a main ingredient compounding liquid (A liquid) and a reactant compounding liquid (B liquid) can be obtained. The mixed liquid is mixed in the space 7 and injected into the ground 3 through the outer tube discharge port 4. The plurality of inner pipes may be parallel pipes or multiple pipes.

Further, the inner pipe discharge port 6 is formed so as to satisfy any of the following (a) to (c).
(A) The inner pipe discharge port 6 is formed in a fine hole. This state is shown in FIG.
(B) The inner tube discharge port 6 is formed in a smaller pore than the inner tube packer 5 discharge port 10. This state is shown in FIGS. 8 (a) and 8 (b).
(C) The area of the inner pipe discharge port is formed smaller than the cross-sectional area of the inner pipe 2 flow path. This state is shown in FIGS. 8 (a) and 8 (b).

  The inner pipe discharge port 6 is covered with a resistor such as a rubber sleeve 31 as shown in FIG. 8C, or a check valve 35 is attached as shown in FIG. 8D. The check valve 35 is configured, for example, such that a ball 36 is applied from the outside to the inner tube discharge port 6 and the ball 36 is pressed by a spring 37. The pores are formed as injection nozzles.

  Furthermore, as shown in FIG. 9, a decompression device 38 can be provided in the inner pipe 2 flow path. Furthermore, as shown in FIG. 10, the inner tube 2 may be formed by connecting with a flexible joint. 10A is an example in which one inner pipe is connected by a flexible joint, and FIG. 10B is an example in which a plurality of inner pipes are connected by a flexible joint.

  The inner tube packer 5 is formed of a synthetic rubber bag which is impermeable and rich in elasticity. Therefore, when the internal pressure due to the injected liquid acts on the inner tube packer 5, the inner tube packer 5 expands and comes into close contact with the inner wall of the outer tube 1 to form a packer. However, when the feeding of the injected liquid is stopped or the pressure of the injected liquid is reduced by the depressurizing device 38 provided in the inner pipe flow path as shown in FIG. 1 away from the inner wall. Therefore, it is possible to immediately move to the next injection stage after completing a predetermined amount of injection at a predetermined stage. The depressurization device 38 only needs to be downstream from the infusion pump, and may be only a valve such as a three-way cock in the figure. When the valve is opened, the injected liquid pressurized in the inner pipe is discharged to the outside, and the inner pipe packer contracts. Furthermore, if the injection liquid in the inner pipe is sucked up by the water absorption pump, it is possible to minimize the leakage of the injection liquid in the inner pipe into the outer pipe when moving the injection stage.

  When the injection depth becomes large or the horizontal length of the injection pipe is increased, the outer pipe 1 is deformed by earth pressure. Therefore, it becomes difficult to insert and move the inner tube 2. However, as shown in FIGS. 10A and 10B, the inner tube 2 can cope with the deformation of the outer tube 1 by providing a hose-like flexible joint 39 made of synthetic rubber at a predetermined position of the inner tube 2. Thus, the inside of the outer tube 1 can be turned. Further, the inner tube packer 5 is a rubber packer and contracts upon completion of injection at a predetermined stage. For this reason, the inner tube 2 can be easily transferred within the outer tube 1. Further, since the conventional air packer is unnecessary, the diameter of the inner tube 2 can be reduced, and from this point, the outer tube can be adapted to deformation. In the present invention, the inner pipe may be formed of a hard pipe, but by forming the inner pipe with a hose on the near side from the range where the inner pipe discharge port exists, it is free with a lifting device with a scraper. It is possible to move in the outer tube.

  When the injection material used in the present invention is gelled in the inner tube packer 5, the packer will not function. Therefore, a material that has a long gelation time and is difficult to clog is desirable. Accordingly, it is preferable that the gelation time in the air is longer than the gelation time in the soil. Such an injection material does not cause gelation in the inner pipe flow path or the inner pipe packer even after the injection solution injected into the soil has gelled. The packer function can be continued by repeatedly contracting and expanding the packer until it is transferred to the injection stage and injected. Further, the pressure in the outer tube inner space 7 can be transmitted to the pressure gauge 14 without gelation even when passing through the tube. Examples of this type of injection material include non-alkaline water glass grout, or grout mainly composed of activated silica obtained by dealkalizing water glass with an ion exchange resin or ion exchange membrane. These grouts have a gel time of 10 hours or more in the air, but retain a gel time of several hours in the soil. Thus, they allow a wide range of injections for a long time. An alkaline water glass grout having a gel time of 1 hour or longer can also be used.

  Here, the basic principle of the packer function will be described with reference to FIG. FIG. 9 is an explanation of an experimental apparatus including the outer tube 1 and the inner tube 2 loosely inserted therein, and the discharge valve 40 is closed to close the outer tube 1, the inner tube 2, the inner tube packer 5, The relationship of the pressure with respect to the minimum unit of the device A of the present invention composed of the outer pipe inner space 7 and the outer pipe outlet 4 will be described.

First, the injection solution is sent from the inner tube flow path of the inner tube 2 at the pressure P ₀ and the flow rate F ₀ . The pressure P ₀ is measured by the pressure gauge 41, and the flow rate F ₀ is measured by the flow meter 42. The inner tube 2 and the inflatable inner tube packer 5 communicate with each other through the inner tube packer outlet 10 and the inner tube packer 5 expands. This internal pressure is the same as the pressure P _{0 of the} injected liquid.

On the other hand, the outer tube discharge port 4 of the outer tube 1 is provided with a flow pressure adjusting device 43. If the pressure regulating valve 44 of the device 43 is opened, the pressure P _{1 in the} outer pipe inner space 7 is naturally lower than P _{0 because the} space 7 is open to the outside. The pressure and flow rate at this time are measured by the pressure gauge 45 and the flow meter 46 of the flow rate pressure adjusting device 43. Therefore, as long as the feeding pressure of the injected liquid is applied to the inner pipe 2, the inner pipe packer 5 expands and is formed as a packer, and the injected liquid discharged from the inner pipe discharge port 6 passes through the outer pipe inner space 7. It is discharged from the outer tube discharge port 4 to the outside.

When the pressure regulating valve 44 is gradually closed to lower the opening degree, the pressure of the pressure gauge 45 rises (P ₁₁ ). At this time, if the liquid feeding flow rate F ₀ is the same, the inner pipe pressure P ₁ becomes higher than the pressure P ₀ . In this case, the pressure P ₁₁ is equivalent to the osmotic resistance pressure of the ground. However, as long as injection is performed in the ground, the pressure P ₁ is higher than the pressure P ₁₁ , so the pressure in the inner tube packer 5 naturally becomes the pressure P ₁ and the pressure in the outer tube inner space 7. since it is maintained higher than the P ₁₁ so that the injection continues.

  However, the inner tube packer 5 is formed until the injected liquid in the inner tube 2 comes out of the inner tube discharge port 6 and is injected into the ground through the outer tube discharge port 4. Since the outer tube inner space 7 is not sufficiently formed before the injection, the injected liquid moves up and down in the outer tube. Therefore, the injected solution moves in the outer tube and is injected into the ground from the unspecified outer tube discharge port 4, which is not preferable because it is not injected into a predetermined injection region. For this reason, it is preferable that the inner tube packer 5 has already been formed at the time of discharge from the inner tube discharge port 6 to the outer tube inner space 7. For this purpose, it is preferable to be in a pressurized state when discharging from the inner tube 2. That is, it is desirable that an initial pressure is generated.

The initial pressure refers to the pressure inside the tube that is generated when the injected liquid is discharged from the discharge port in the air. Usually, the injection rate per stage, that is, the injection rate from one injection section between the upper and lower packers is 2-30 liters / minute, but the initial pressure is 0.1 kgf / cm for such an injection rate. preferably it becomes ² or more, in which case, the inner pipe packer when infusate from the inner tube discharge port for discharging already inflated.

If an internal pressure of 0.1 kgf / cm ² or more is generated as an initial pressure, the packer is brought into close contact with the outer tube wall. In that case, the discharge port diameter is preferably about 0.1 to 3 mm. Actually, the initial pressure can be arbitrarily set by appropriately designing one discharge port diameter, the number of discharge ports, and the elasticity of the inflatable packer corresponding to the injection speed per stage. Can form a strong packer that can withstand Therefore, according to the present invention, the initial pressure can be easily formed by performing the following method, and the inner tube packer can be easily expanded faster than the discharge from the inner tube discharge port.

(A) The inner pipe discharge port is made into a fine hole such as an injection hole.
(B) The area of the inner pipe discharge port is smaller than the cross-sectional area of the inner pipe flow path.
(C) The inner tube packer discharge port is made larger than the inner tube discharge port.
(D) A check valve is provided at the inner pipe discharge port. In FIG. 8D, the injection solution is discharged into the outer tube space only after the pressure of the injection solution in the inner tube becomes larger than the force of the spring 37.
(E) Cover the inner tube discharge port with a discharge resistor. In FIG. 8C, if the rubber sleeve 31 is used and the discharge port is covered, the injected liquid is discharged into the outer pipe inner space when the pressure of the injected liquid in the inner pipe corresponding to the elasticity of the rubber sleeve 31 increases. The
The present invention has been completed based on the above basic principle. In FIG. 9, reference numeral 38 denotes a depressurizing device, which includes a liquid feed valve 47, a three-way cock 48, and a water absorption pump 49. A drain pipe 50 includes a three-way cock 51.

  As can be seen from FIG. 9, the injection pressure is measured by the pressure gauge 41. Therefore, in order to know the actual ground injection pressure during injection after being discharged from the inner pipe discharge port 6, according to the present invention described above, the strain resistance pressure sensor or pore water pressure corresponding to the strain gauge is placed in the outer pipe inner space 7. One of the tubes (pressure transmission member) corresponding to the meter is installed to calculate the liquid pressure of the injected liquid in the outer pipe inner space 7, and the information is collected in the management room of the ground part by wire or wireless in real time. Based on the above, optimal injection can be performed by managing the injection speed, injection pressure, and injection tube operations such as injection interruption and completion. Of course, as in the present invention, a pressure transmission member is provided in the space, and by obtaining the information, fluctuations in the internal pipe pressure and the external osmotic pressure, and information on the pressure difference are obtained by obtaining information on the pressure difference. It is possible to accurately grasp the external gelation status and feed back to the injection management.

  These measurement sensors can usually be installed in the outlet flow path of the inner pipe discharge port 6 of FIG. 8D or FIG. 9, but a strain gauge can be attached to the outer wall between packers of the inner pipe. . Of course, it can also be embedded in the wall surface inside the outer tube. The information is sent to the ground by wire or wirelessly through the inner tube or along a groove or the like provided in the outer tube.

  In the apparatus of the present invention, an inner tube having a plurality of inner tube packers and an infusion liquid flow path is used as the inner tube, and a plurality of injection liquids are injected from the injection nozzles at the inner tube discharge port provided between the many inner tube packers. It is possible to break the seal grout through the outer tube discharge port and simultaneously inject it into the ground. Also in this case, it is possible to accurately measure the injection pressures at a plurality of injection stages simultaneously by providing one end of a strain resistance pressure gauge or a tube as a pressure transmission member in a plurality of outer tube internal spaces.

  FIGS. 11A to 11G are explanatory views of a construction example for installing the ground injection device (injection pipe) in the ground, and FIG. 11A shows the vicinity of the head portion 53 of the boring rod 52. . The head portion 53 of the boring rod 52 (single tube rod) has a tip formed on a tapered surface 54 and is screwed by a screwed body 55.

  As shown in FIG. 11 (b), the head portion 53 incorporates a transmitter that transmits position information in the ground 3, that is, a position information transmitter 56, and is connected to a tow bar 57. The information transmitted from the position information transmitter 56 is received by a receiving locator 59 installed on the ground surface 58 as shown in FIG.

  FIG. 11C is an explanatory view showing a state in which the boring rod 52 (single tube rod 52) is dug into the ground 3 just below the structure 60, and a drilling machine installed on the ground surface 58. The single tube rod 52 in which the position information transmitter 56 is built in is connected to the head portion 53, and digs into the ground 3 together with the injection of a boring fluid such as water while arbitrarily combining bending and horizontal. A reception locator 59 is installed on the ground surface 58, and the reception locator 59 receives radio waves of location information from the underground location information transmitter 56. The drilling machine 61 confirms the drilling direction and position of the boring rod 52 (single pipe rod 52) based on the information, and digs the single pipe rod 52 into the ground 3 while controlling it.

  Since the tip of the head portion 53 of the boring rod 52 is formed on the tapered surface 54, if the boring rod 52 is rotated, it goes straight, and if the rotation is stopped and press-fitted, it bends according to the direction of the taper. The rod 52 is dug in an arbitrary direction. The position of the head portion 53 is grasped by a control (not shown), and this can be fed back to the boring operation. Further, the position of the head portion 53 can be grasped through the boring rod 52 by providing a gyro as a position information device at the tip of the boring rod 52.

  After excavating the single tube rod 52 to a predetermined position in the ground 3, as shown in FIG. 11D, the tow bar 57 is pulled to collect the position information transmitter 56 on the ground. As a result, the boring rod 52 is hollow from the tip to the end. Next, as shown in FIG. 11 (e), the outer tube 1 fitted with a mechanical anchor 62 at the tip is inserted into the cavity in the boring rod 52 while the seal grout 28 is press-fitted.

  Next, when the single tube rod 52 is pulled out while pushing the outer tube 1, as shown in FIG. 11 (f), the mechanical anchor 62 is opened and bites into the drilling wall 9 a, thereby the outer tube 1 is anchored. And, it is fixed in the hole 9 by the seal grout 28.

  Further, after the seal grout 28 is solidified, as shown in FIG. 11 (g), a plurality of inflatable inner tube packers 5, 5,... 5 are provided at intervals, and the inner tube discharges between the packers. The inner tube 2 having the outlet 6 is loosely inserted into the outer tube 1. Next, when the injection solution is press-fitted into the inner tube 2, the injection solution enters the packer through the discharge port 10 in the packer and expands the inner tube packers 5, 5,. An in-pipe space 7 is formed. Further, the injected solution penetrates and injects into the ground through the inner tube discharge port 6 and the outer tube discharge port 4 while breaking the seal grout 28.

  After the injection, the inner pressure of the injected liquid in the inner tube 2 is released to contract the inner tube packer 5 and move the inner tube 2 to the next injection stage. This operation is repeated to permeate and consolidate the predetermined injection region. The outer tube 1 can be fixed using an outer tube packer 29 as shown in FIG. 6 instead of the seal grout 28. As the outer tube packer 29, an inner tube having a double packer (not shown) is used. Cement bentonite or the like is press-fitted into the outer tube packer 29 from the discharge port 30 in the outer tube packer and expanded to form the outer tube packer 29. 1 is fixed in the drilling hole.

  As described above, the injection method according to the present invention is suitable for liquefaction prevention injection under the structure 60 such as a building. For example, a plurality of layers can be stacked in the depth direction below the structure 60 and simultaneously injected, or a plurality of injection tubes can be set in parallel in the horizontal direction below the structure 60 and simultaneously injected. Alternatively, a plurality of layers can be formed simultaneously in the depth direction and the horizontal direction. In the present invention, the boring for installing the injection pipe may be performed from the ground surface near the structure, and horizontally into the foundation ground of the structure with a boring rod incorporating an information transmitter from the vertical pile to the tip. You may go.

  In the present invention described above, a pressure transmission member that senses and transmits the pressure in the space is installed in the injection device, and the pressure sensed in the previous space is transmitted to the pressure gauge through the pressure transmission member, and the transmitted pressure is transmitted to the pressure gauge. By measuring with a pressure gauge on the ground, the injection pressure (solidified material) from the inner pipe outlet located between the inner pipe packers into the ground through the outer pipe outlet is injected into the ground. Can be accurately grasped on the ground and is highly available in the field of ground injection.

It is sectional drawing of one specific example of the ground injection apparatus concerning this invention. It is sectional drawing of the other specific example of the ground injection apparatus concerning this invention. It is sectional drawing of the other specific example of the ground injection apparatus concerning this invention. It is sectional drawing of the other specific example of the ground injection apparatus concerning this invention. The one process figure of the installation process to the ground of this invention injection apparatus is represented. The one process figure of the installation process to the ground of this invention injection apparatus is represented. The one process figure of the installation process to the ground of this invention injection apparatus is represented. The completion figure of the installation process to the ground of this invention injection apparatus is represented. It is sectional drawing of the other specific example of the ground injection apparatus concerning this invention. It is explanatory drawing of this invention injection apparatus provided with multiple inner tubes. It is explanatory drawing showing the discharge port in an inner tube packer, and an inner tube discharge port, Comprising: The relationship of a magnitude | size is represented. It is explanatory drawing showing the discharge port in an inner tube packer, and an inner tube discharge port, Comprising: The relationship of a magnitude | size is represented. Represents a rubber sleeve covered by the inner tube discharge port. It is explanatory drawing of the non-return valve attached to an inner pipe discharge port. It is explanatory drawing of the experimental apparatus for demonstrating the principle of the packer function of this invention. It is explanatory drawing of the state which connected the inner pipe | tube with the flexible joint. It is explanatory drawing of the state which connected the inner pipe | tube with the flexible joint. It is a top view of the boring rod used for this invention. It is sectional drawing of the head part of the boring rod used for this invention. It is explanatory drawing showing the state which is excavating the boring rod directly under a structure. It is sectional drawing of the state which is pulling the tow bar and collect | recovering the transmission locator on the ground. It is sectional drawing of the state which has inserted the outer tube | pipe into the cavity in a boring rod. It is sectional drawing of the state which fixed the outer pipe | tube in the drilling hole. Sectional drawing of the state which inserted the inner pipe | tube in the outer pipe | tube, expanded the inner pipe | tube packer, and was fixed in the outer pipe | tube is represented. ^

Explanation of symbols

A Ground injection device X Injection liquid feeding device 1 Outer tube 1a Tube wall 2 Inner tube 2a Branch inner tube 2b Inner tube flow path 3 Ground 4 Outer tube discharge port 5 Inner tube packer 6 Inner tube discharge port 7 Space 8 Pressure transmission member (tube)
DESCRIPTION OF SYMBOLS 9 Drilling hole 10 Packer discharge port 11 One end 12 Pressure detection part 13 Other end 14 Pressure gauge 14a Pressure gauge 19 Rubber sleeve 20 Hand pump 21 Strain resistance type pressure sensor 22 One end 23 Other end 24 Amplifier 25 Pressure display device 26 Signal cable 29 Outer tube packer 30 Outer port packer outlet

Claims (2)

A ground injection method in which an injection pipe is bent in the ground or installed horizontally or in any combination of bending and horizontal, and an injection solution is injected into the ground through the injection pipe, the injection pipe being axial An outer tube having a plurality of outer tube discharge ports at different positions, and a plurality of expandable and contractible inner tube packers made of an elastically impermeable bag body which are loosely inserted into the outer tube. The inner tube packer further includes an inner tube discharge port, and the inner tube packer has an inner tube discharge port between the inner tube packers provided with the interval. The inner pipe discharge port is formed so as to satisfy one of the following (a) to (c), and is installed in a drilled hole drilled by a boring rod with a built-in position information transmitter at the tip. An inflatable inner tube packer is used to expand the inner tube packer. By supplying the injection liquid to the inner pipe flow path without providing the fluid pipe line, the expandable inner pipe packer is expanded by the liquid supply pressure of the injection liquid, and the inner pipe packer is expanded between the inner pipe packers. In addition to forming a space, the injection solution is discharged from the inner tube discharge port into the inner space of the outer tube, the injection solution is injected from the inner tube space into the ground through the outer tube discharge port, and then the liquid supply of the injection solution is stopped. Or by reducing the pressure of the injection solution in the inner tube, the expandable inner tube packer is contracted, and the inner tube is movable in the outer tube, and injection is repeated in the same manner at a predetermined position. A pressure transmission member that senses and transmits pressure in the space is installed in the space, and the pressure sensed in the space is transmitted to the pressure gauge on the ground through the pressure transmission member and measured. It is characterized by grasping the injection pressure of the ground Ground injection method.
(A) An inner tube discharge port is formed in a pore.
(B) The inner tube discharge port is formed in a smaller pore than the inner tube packer discharge port.
(C) The area of the inner pipe discharge port is formed smaller than the cross-sectional area of the inner pipe flow path. 2. The tube according to claim 1, wherein the pressure transmission member is a tube filled with a liquid, one end is located in the space, the other end is communicated with a pressure gauge on the ground, and the pressure of the injected liquid in the space is controlled by the ground. The ground injection method according to claim 1, wherein the ground injection method is sensed by the upper pressure gauge.