JP5974361B2 - Injection pipe used for multi-point injection method - Google Patents

Description

  The present invention relates to an injection pipe used in a multi-point injection method for injecting a ground improvement agent into a ground such as soft ground, and more specifically, a plurality of injections with different nozzle positions for discharging a ground improvement material. In a multi-point injection method in which pipes are bundled and inserted into the injection hole, and then ground improvement agent is injected into the ground in order from the most advanced nozzle, the diameter of the injection hole is reduced to increase work efficiency. In addition, the present invention relates to an injection tube used in a multi-point injection method that enables cost reduction.

  Conventionally, when building a huge structure or a huge facility on soft ground, the ground has been strongly improved by injecting a chemical such as a ground improver into the ground. In the method of injection, since the chemical solution was injected into the ground using a single injection tube, it was sometimes difficult to efficiently improve the ideal ground depending on the ground conditions.

  That is, when the ground is improved by injecting a chemical solution into the ground, it is preferable that the chemical solution is uniformly immersed between the soil particles. It is necessary to inject the chemical solution at the optimum pressure and flow rate for the porosity of the soil, but the soil usually has different hydraulic conductivity and porosity between the soil particles for each layer, so that the chemical solution is evenly immersed between the soil particles. Therefore, it is necessary to inject the chemical solution at the optimum pressure and flow rate for the water permeability coefficient and the porosity between the soil particles in each layer, and the chemical solution into the ground using a single injection tube In the conventional method of injecting, it is not possible to inject the chemical solution with the optimum pressure and flow rate for each layer for each layer, so that depending on the ground situation, the chemical solution can be evenly immersed between the soil particles There were cases where it was difficult.

  Therefore, a multi-point injection method has been proposed as a method that allows chemicals to be evenly immersed between soil particles even in the case of ground where the permeability coefficient and the porosity between soil particles are different for each layer. ing.

  Here, the multipoint injection method will be described with reference to FIG. 5. In this multipoint injection method, first, in FIG. 5A, the underground 32 where the ground is improved is drilled by the casing 31 or the like. Then, the injection hole 33 having a predetermined length is formed, and then the sealing material 34 is injected into the injection hole 33.

  Next, a nozzle 36 for discharging a chemical solution is provided at each tip, and a plurality of injection pipes 35 having different nozzle positions are bundled together and inserted into the injection hole 33.

  And as shown in FIG.5 (b), after the sealing material 34 hardens | cured, while pulling out a casing and supplying the chemical | medical solution sequentially from the injection pipe 35 which has the nozzle 36 located in the innermost part of the injection hole 33, At this time, the chemical solution is supplied at a pressure and flow rate optimum for the water permeability coefficient of each layer and the gap between the soil particles measured in advance, and the chemical solution is discharged from the nozzle 36, whereby the chemical solution penetrates the ground around the nozzle 36. I will let you.

  Then, as shown in FIG.5 (c), after completing the chemical liquid discharge from all the nozzles, the chemical liquid can be penetrated into the location targeted for ground improvement, and the optimum pressure for the ground condition of each layer, Since the chemical liquid can be discharged at a flow rate, the chemical liquid can be uniformly immersed between the soil particles.

JP 2003-232030 A

  However, conventionally, the injection tube used in the above-described multi-point injection method is a general cylindrical polypipe, and therefore the diameter of the bundled state becomes large, thereby increasing the number of injection tubes. When the number of holes is increased, the hole diameter of the injection hole must be increased, and it has been pointed out that the work efficiency becomes worse as the depth of the hole becomes deeper.

  In addition, in the multi-point injection method, the chemical solution is supplied in order from the injection tube in which the nozzle is located at the back of the injection hole, and the chemical solution is not supplied to a plurality of injection tubes at the same time. The injection pipes other than the injection pipe that is injecting the chemical liquid are not supplied with the chemical liquid, but the diameter injection holes for inserting all the injection pipes must be drilled. Waste was also pointed out.

  Furthermore, when the number of injection pipes increases, the drilling diameter of the injection holes must be increased. Therefore, in consideration of work efficiency and cost, it is pointed out that the diameter of the injection pipe cannot be increased. It had been.

  Therefore, the present invention provides an injection for use in a multi-point injection method in which the diameter of the insertion hole into which the injection tube is inserted can be reduced in the multi-point injection method, thereby improving work efficiency and reducing work cost. The challenge is to provide a tube.

The injection tube used in the multipoint injection method of the present invention is
The plurality of injection tubes of the nozzle positions are different with the respective tips having nozzles for the solution discharge, inserted into the injection hole formed in the ground by bundling, in order from the nozzle located on the cutting edge, the injection hole The injection pipe used in the multipoint injection method for discharging a chemical solution such as a ground improvement agent in the interior,
An injection tube main body of a predetermined length in which a flow path is formed;
A nozzle connected to the tip of the injection tube body ;
The nozzle has a flow channel communicating with the flow channel of the injection tube main body inside, and a discharge port that communicates the outside and the flow channel is formed, and when the nozzle receives pressure from the flow channel side of the nozzle, the discharge port And a check valve that closes the discharge port when the pressure is released,
The injection tube main body is formed in a plate-like shape by laying a plurality of elastic tubes in a crushed state, and the plurality of injection tube main bodies are formed in a plate shape.
The injection tube is drilled by the casing and inserted into the injection hole into which the sealing material has been injected. After the sealing material has hardened, the casing is pulled out,
From the injection tube main body to which the nozzle located in the innermost part is connected, the elastic tubes are sent one by one in order of the elastic tubes, so that only one elastic tube expands due to the pressure of the chemical solution, and the other elastic tubes Since the whole of the injection tube body expands in the outer peripheral direction and the chemical solution is discharged from the nozzle discharge port into the injection hole, and the supply of the chemical solution is stopped, the injection tube main body is restored to a flat state. Even when the number of bundles in the point injection method increases, the injection tube inserted into the injection hole has a plate shape of the injection tube main body, so the diameter of the entire bundle can be reduced, and accordingly The injection tube is characterized in that the diameter of the injection hole to be drilled can be reduced .

  The injection tube used in the multi-point injection method of the present invention usually has a flat shape in which the flow path is crushed, but when a fluid is supplied into the flow path, the flow path is opened by the pressure of the fluid, and the whole in the outer circumferential direction. The injection tube main body is constituted by a shrinkable tube that can swell and allow fluid to pass through and restores to a flat shape when the fluid in the flow path is exhausted.

  Therefore, in the injection pipe of the present invention, even when the number of pipes is large in the multi-point injection method, the overall outer diameter in a state where the injection pipes are bundled can be reduced, and the depth of drilling is increased. Accordingly, even when the number of injection tubes bundled together is increased, it is not necessary to increase the diameter of the injection hole, and the problem that the work efficiency is deteriorated can be solved.

  At this time, in the multi-point injection method, the chemical solution is supplied in order from the injection tube where the nozzle is located at the back of the injection hole, and the chemical solution is not supplied to a plurality of injection tubes at the same time. In the case of using the infusion tube of the invention, the infusion tube in which the infusion of the medicinal solution is completed and the supply of the medicinal solution is lost returns to the flat shape again, that is, the infusible tube which is inflated with the infused chemical solution is always 1 Since it is only a book, it is only necessary to drill an injection hole having a diameter that allows a bundle of injection tubes to enter when only one injection tube swells, so the cost of drilling the injection hole is reduced. It is also possible.

  Furthermore, since it is not necessary to increase the diameter of the injection hole even when the number of injection pipes according to the present invention increases, the diameter of the injection pipe can be increased.

It is a perspective view which shows the Example of the injection pipe used for the multipoint injection method of this invention. It is sectional drawing which shows the structure along the longitudinal direction of the Example of the injection pipe used for the multipoint injection method of this invention. It is a figure for demonstrating the injection pipe main body in the injection pipe used for the multipoint injection method of this invention. It is the figure which decomposed | disassembled and showed the Example of the injection pipe used for the multipoint injection method of this invention. It is a conceptual diagram for demonstrating the multipoint injection | pouring method.

  The injection tube used in the multipoint injection method of the present invention has an injection tube body having a predetermined length, and a flow path is formed along the longitudinal direction inside the injection tube body. The distal end and the proximal end are released.

  In addition, the injection tube body is usually flat and the flow path is crushed, and when the fluid is supplied into the flow path and the fluid flows in the fluid, the flow path expands due to the pressure of the fluid and the whole in the outer circumferential direction. When the supply of the fluid to the flow path stops and the fluid in the flow path is exhausted, the contraction tube is crushed again and restored to a flat shape.

  A nozzle is connected to the distal end side of the injection tube body, and a flow path is formed along the longitudinal direction inside the nozzle, and the distal end of the flow path is closed. The proximal end portion communicates with a flow path formed in the injection tube body.

  Further, a discharge port is formed in the side wall of the nozzle, and this discharge port communicates the flow path formed inside the nozzle and the outside.

  Further, a check valve is provided on the outer periphery of the nozzle. When the check valve closes the discharge port formed in the nozzle and receives pressure from the flow path formed in the nozzle to the outside, The nozzle is moved to the outer peripheral side of the nozzle to release the discharge port, and when the applied pressure is released, the original position is restored and the discharge port is closed again.

  Here, the check valve may be a rubber check valve, which can effectively act as a check valve.

  When a rubber check valve is provided, a long rubber cloth may be spirally wound around the outer periphery of the nozzle so that the rubber cloth is formed on the nozzle. When the pressure is applied to the outside from the flow path formed in the nozzle, the part that closes the discharge port moves to the outer peripheral side of the nozzle to release the discharge port, and When the pressure is released, it acts as a check valve that restores the original position and closes the discharge port again.

  An embodiment of an injection pipe (hereinafter simply referred to as “injection pipe”) used in the multipoint injection method of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the injection pipe of this embodiment. 1 is the injection tube of this embodiment.

  FIG. 2 is a cross-sectional view showing the structure along the longitudinal direction of the injection tube of this embodiment. In FIGS. 1 and 2, 2 is an injection tube body.

  That is, the injection tube 1 of the present embodiment has an injection tube body 2, and a nozzle 4 for discharging a chemical solution is connected to the distal end side of the injection tube body 2.

  The injection pipe body 2 has a flow path 3 formed therein, and the flow path 3 has a distal end and a proximal end opened to the outside, and the proximal end portion is connected to a conduit when used. In addition, a pump is connected to the conduit, and a chemical solution such as a ground improvement agent can be supplied into the flow path 3 by the operation of the pump.

  Here, FIG. 3 is a cross-sectional view showing the structure of the injection tube main body 2 oriented in the longitudinal direction, and FIG. 3 (a) shows the injection tube main body 2 shown by the cross section along line AA in FIG. This state is the normal state of the injection tube body 2, and this state is a state in which no chemical solution is supplied into the flow path 3.

  As is apparent from the figure, the injection tube body 2 in the present embodiment is such that the flow channel 3 is crushed in a normal state where no chemical solution is supplied into the flow channel 3, thereby The entire tube body 2 has a flat plate shape.

  On the other hand, FIG. 3B shows a state in which the chemical solution is supplied into the flow path 3, and in this state, the flow path 3 is swollen. That is, the injection tube main body 2 in this embodiment has a flat shape in which the flow path 3 is crushed in a normal state where no chemical solution is supplied. When a fluid is supplied into the flow path 3, the flow path 3 is caused by the pressure of the fluid. 3 swells, and the entire injection tube body 2 swells in the outer circumferential direction.

  Further, the injection tube body 2 of the present embodiment is formed of an elastic material such as rubber, and the flow channel 3 is expanded to the flow channel 3 in a state where the entire injection tube body 2 is expanded in the outer peripheral direction. When the supply of the chemical solution is stopped and the fluid in the flow path 3 runs out, the contraction tube is restored to a flat shape.

  Therefore, in the injection tube 1 of the present embodiment, even when the number of bundles bundled in the multi-point injection method is increased, the diameter of the entire bundled tube body 2 can be reduced because the injection tube body 2 has a flat shape. Accordingly, the diameter of the injection hole to be drilled can be reduced accordingly, the working efficiency for drilling can be improved, and the diameter of the injection tube body can be increased.

  In the multi-point injection method, the chemical solution is supplied in order from the injection tube in which the nozzle is located at the back of the injection hole, and the chemical solution is not supplied to a plurality of injection tubes at the same time. When the example injection tube 1 is used, there is always only one injection tube that is inflated by supplying a chemical solution, so that only a single injection tube is inflated and a bundle of injection tubes is contained. Since it is only necessary to drill the injection hole having a diameter, the cost of drilling the injection hole can be reduced.

  Next, reference numeral 4 in the figure denotes a nozzle for discharging the chemical solution supplied to the flow path 3 of the injection tube body 2 into the injection hole. That is, in the injection tube 1 of the present embodiment, the nozzle 4 is connected to the distal end of the injection tube main body 2, and the flow channel 5 is formed inside the nozzle 4, and this flow channel 5 is formed at the proximal end side. The tip end side is closed in communication with the flow path 3 formed inside the injection tube body 2.

  In addition, a plurality of discharge ports 6 communicating with the flow path 4 formed in the nozzle 4 are formed in the inner wall of the nozzle 4 at a plurality of locations. In other words, the discharge port 6 communicates the flow path 5 with the outside, so that the chemical solution supplied to the flow path 3 of the injection tube body 2 can be supplied to the flow path 5 of the nozzle 4. It is possible to discharge from the discharge port 6 after being guided to.

  Next, 7 is a check valve in the figure. That is, the injection tube 1 of the present embodiment has a check valve 7 that closes the discharge port 6 of the nozzle 4, and this check valve 7 goes outside the chemical solution in the flow path 5 of the nozzle 4. Is allowed to discharge, but has a function of preventing the back flow of the chemical liquid from the outside into the nozzle 4. That is, the check valve 7 closes the discharge port 6, and when the pressure is received from the flow path 5 of the nozzle 4, the discharge port 6 is released to allow the discharge of the chemical solution from the discharge port 6. When the pressure is released, the discharge port 6 is closed.

  Here, the check valve 7 in the present embodiment will be described. In the present embodiment, the check valve 7 is a rubber check valve. That is, in this embodiment, a checker valve 7 is constructed by winding a long rubber cloth spirally around the outer periphery of the nozzle 4 and bonding both ends with glue or the like. When winding, the end portions along the longitudinal direction of the rubber cloth are overlapped with each other, and thereby the outer periphery of the nozzle 4 is completely covered with the check valve 7, whereby the discharge port 6 by the check valve 7 is covered. It can be opened and closed.

  That is, in the present embodiment in which the outer periphery of the nozzle 4 is completely covered with the check valve 7, the chemical liquid that has passed through the flow path 5 of the nozzle 4 reaches the discharge port 6, and thereby the check valve 7 is connected to the nozzle 4. When the pressure by the chemical liquid is applied from the flow path 5 side, the portion receiving the pressure in the check valve 7 expands to the outer peripheral side, and a gap is formed at the end portions that are overlapped with each other. Is discharged outside the nozzle 4 and penetrates into the ground.

  And when the pressure by a chemical | medical solution is cancelled | released, the non-return valve 7 will be restored | restored to the original position, and the clearance gap between the parts which mutually overlap will be lost, and it becomes possible to close the discharge port 6 by this.

  Therefore, in the injection tube 1 of the present embodiment, the chemical liquid can be discharged and penetrated into the ground through the nozzle, and the chemical liquid can be effectively prevented from flowing back to the nozzle 4.

  Here, FIG. 4 is an exploded perspective view of the injection tube 1 of the present embodiment. In the drawing, the base end portion 401 of the nozzle 4 is formed with a stepped outer peripheral portion along the longitudinal direction. The base end portion 401 is inserted into the flow path 3 of the injection tube main body 2, and the nozzle 4 is fixed to the injection tube main body 2 with an adhesive, tape, or the like in this state.

  In FIG. 4, for easy understanding, the check valve 7 is spirally wound with a gap, but when wound around the outer periphery of the nozzle 4, as described above, End portions along the direction are overlapped with each other to completely cover the outer periphery of the nozzle 4.

  Next, the operation of the injection pipe 1 of the present embodiment configured as described above will be described. When the ground improvement is performed by the multi-point injection method using the injection pipe 1 of the present embodiment, refer to FIG. As in the case described above, a predetermined number of injection pipes with different nozzles 4 are bundled together, and pipes such as conduits are connected to the base end portions of the respective injection pipes 1. A pump is connected to a pipe such as a conduit so that a chemical solution can be supplied to each injection pipe 1. For example, in the case of injecting a chemical solution every 500 mm at 10 different locations as seen in the depth direction of the ground, ten injection pipes 1 with the nozzle 4 shifted by every 500 mm are connected with a tape, a band or the like. Bundle them together.

  Then, the injection pipe bundled in this one is inserted into the injection hole into which the sealing material is injected by drilling with a casing or the like, and after the sealing material is solidified, the casing is pulled out, and the nozzle 4 located in the innermost portion. Are sequentially injected from the injection pipe 1 to which the nozzles 4 are connected, the chemical liquid is discharged from the discharge port 6 of the nozzle 4 into the injection hole, and the chemical liquid is infiltrated into the surrounding ground where the nozzle 4 is located. Make improvements.

  At this time, the injection tube main body 2 in the injection tube of the present embodiment is in a form in which the flow channel 3 is crushed and the entire injection tube main body 2 is flat in a normal state where no chemical solution is supplied into the flow channel 3. When the fluid is supplied into the flow path 3, the flow path 3 expands due to the pressure of the fluid, and the entire injection tube main body 2 expands in the outer circumferential direction. In this state, the supply of the chemical solution to the flow path 3 stops and the flow path 3 When the fluid in 3 disappears, it is a shrinkable tube that restores to a flat shape, so even if the number of bundles in one in the multi-point injection method increases, the injection tube body 2 is in a flat shape, so it was bundled Since the overall diameter can be reduced and the diameter of the injection hole to be drilled can be reduced accordingly, it is possible to solve the problem that the working efficiency is deteriorated.

  At this time, in the multi-point injection method, the chemical solution is supplied in order from the injection tube in which the nozzle is located at the back of the injection hole, and the chemical solution is not supplied to a plurality of injection tubes at the same time. Infusion tubes that have completed the injection and have no longer been supplied with the chemical solution return to a flat shape again, that is, since there is always one inflated injection tube that is supplied with the chemical solution, the chemical solution may not be supplied. Unlike the case of using a conventional pipe-shaped injection pipe whose diameter does not change, only the diameter of the injection hole that can accommodate a bundle of injection pipes in a state where only one injection pipe is inflated is drilled. Therefore, it is possible to improve the working efficiency and reduce the cost of drilling the injection hole.

  Furthermore, since it is not necessary to increase the diameter of the injection hole even when the number of the injection holes becomes large, when an injection hole having the same diameter as that of the injection hole when using a conventional injection tube is used, the injection hole It is possible to increase the diameter of the tube.

  Thus, by using the injection pipe of this embodiment in the multi-point injection method, the diameter of the injection hole for inserting the injection pipe can be kept small even when the number of injection pipes is increased. The working efficiency for injection hole drilling in the multi-point injection method can be increased, the cost can be reduced, and the diameter of the injection pipe can be increased.

  In the injection pipe used in the multi-point injection method of the present invention, it is possible to reduce the diameter of the drilling hole when the ground is improved by inserting a plurality of injection pipes into the injection hole. The present invention can be applied to all injection pipes used for ground improvement by insertion.

DESCRIPTION OF SYMBOLS 1 Injection pipe 2 Injection pipe main body 3 Flow path of injection pipe main body 4 Nozzle 5 Nozzle flow path 6 Discharge port 7 Check valve

Claims (3)

The plurality of injection tubes of the nozzle positions are different with the respective tips having nozzles for the solution discharge, inserted into the injection hole formed in the ground by bundling, in order from the nozzle located on the cutting edge, the injection hole The injection pipe used in the multipoint injection method for discharging a chemical solution such as a ground improvement agent in the interior,
A main body (2) of a predetermined length in which a flow path (3) is formed;
A nozzle (4) connected to the tip of the injection tube body (2) ;
The nozzle (4) has a flow path (5) communicating with the flow path (3) of the injection pipe body (2) inside, and a discharge port (6) communicating the outside with the flow path (5). ) Is formed, and when the pressure is received from the flow path (5) side of the nozzle (4), the discharge port (6) is released, and when the pressure is released, a check valve that closes the discharge port (6) ( 7)
The injection tube main body (2) is formed in a plate shape by entirely overlapping a plurality of elastic tubes in a crushed state,
The injection tube is drilled by the casing and inserted into the injection hole into which the sealing material has been injected. After the sealing material has hardened, the casing is pulled out,
From the injection tube main body (2) to which the nozzle (4) located at the innermost part is connected, by sending the chemical solution one by one in order of the elastic tube, only one elastic tube swells due to the pressure of the chemical solution Then, the other elastic tube remains flat, and the entire injection tube body (2) swells in the outer circumferential direction, and the chemical solution is discharged from the discharge port (6) of the nozzle (4) into the injection hole. Since the injection tube body (2) is restored to a flat state when the injection is stopped, the injection tube body (2) is the injection tube inserted into the injection hole even when the number of bundles in the multi-point injection method increases. An injection tube characterized in that since it is plate-like, the diameter of the entire bundle can be reduced, and the diameter of the injection hole to be drilled can be reduced accordingly.   The injection pipe used for the multi-point injection method according to claim 1, wherein the check valve (7) is a rubber check valve.   By wrapping a long rubber cloth around the outer periphery of the nozzle so as to close the discharge port (6), the discharge port (6) is connected to the flow path (5) side of the nozzle (4). 3. A rubber check valve (7) for releasing the discharge port (6) when pressure is applied and closing the discharge port (6) when the pressure is released. Injection pipe used for the multipoint injection method described.

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