JPS6323326B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is applicable to injecting a chemical solution by mixing two components into the ground after drilling and inserting one injection pipe into the ground during chemical injection work carried out for soil improvement such as strengthening the ground or water stopping. The present invention relates to a liquid drug injector that can simultaneously inject from a plurality of locations in the vertical direction over a wide area under substantially uniform conditions without excessive press-fitting.

Various technologies have already been developed for chemical injection methods, which stabilize the soil quality by injecting chemical into the ground in a required area for the purpose of strengthening weak ground or preventing water leakage or springing caused by excavation work. , and has been put into practical use. However, when inserting an injection rod into the ground and injecting a chemical over a wide area in the vertical direction, the injection rod should be rotated to the required depth and drilled into the ground, and then the rod should be inserted one after another. The rod can be pulled up in stages and the chemical solution is forced into the required section through the rod, or the drug solution can be injected over a wide area at once through discharge holes that are pre-drilled at appropriate pitches from the tip to the middle of the rod. Methods of injecting chemical solutions are being adopted, but the former method requires a lot of work, and the injection pressure that forces the chemical solution into the ground rapidly can damage soft parts and weak cracks in the strata. This method has the disadvantage that the so-called escaping phenomenon in which the chemical solution migrates to the eyes, etc., increases the consumption of the chemical solution, and also causes local condensation.Therefore, it is necessary to press fit gently, which naturally reduces workability. This will result in higher construction costs. In addition, in the case of the latter method, conventionally, due to the flow resistance inside the rod, the press-ined chemical liquid through the rod did not spray out a constant amount from each discharge hole, and the corresponding part was weak or had low resistance. A large amount of liquid will be injected, and in extreme cases, only some holes will no longer function as liquid spouting holes, making it difficult to inject chemicals evenly, resulting in unstable geological improvement, which is another inconvenience. It is something. Of course, it is difficult to expect an improvement in efficiency since it is necessary to perform slow injection in order to aim for uniform chemical injection with workability.

In order to solve this problem, the present invention provides an injection pipe rod that is inserted through excavation and drilling for ground improvement, and is provided with a multi-stage nozzle portion that evenly sprays a predetermined amount of the injection chemical at a low discharge rate. The nozzle part maintains a closed state against the injection pressure of the anti-friction fluid during drilling,
When injecting chemical liquid, the supply pressure of the chemical liquid on the inner pipe side is increased to blow the stopper of the ejection nozzle part into the ground and open it, and at the same time, the mixed two-part chemical liquid is forced into the ground from each ejection nozzle part arranged in multiple stages. However, it is an object of the present invention to provide a chemical liquid injector configured such that by moving the injection tube rod stepwise in the axial direction as necessary, uniform chemical liquid injection can be performed simultaneously over a wide range in the axial direction.

That is, the present invention provides a double-tube chemical injection rod with a cutting blade at the tip of the rod: At the tip of the rod, pressurized water supplied to the outer tube during excavation is allowed to flow into the cutting blade by opening a liquid outlet. , a control valve is provided that closes the liquid outlet leading from the outer tube to the cutting blade by the liquid pressure supplied to the inner tube when the chemical is injected, and the rod connecting body in the middle has a hole that communicates with the inner tube. The rod is connected to the outer tube by fitting or by screwing or welding, and an annular passage between the inner tube and the outer tube is provided at the intermediate connecting portion of the rod connecting body. Correspondingly, a plurality of upper and lower communication holes are arranged, and at appropriate positions of the intermediate connecting part of the rod connection body, there are holes of extremely small diameter that intersect the axis and communicate with the inner tube side and the outer tube side. A liquid ejection piece is fixedly provided with an injection nozzle and communicated with a chemical liquid ejection hole, and the outer tube side injection nozzle is closed and the inner tube side liquid pressure is applied to the chemical liquid ejection hole of the liquid ejection piece. It is fitted with a stopper that releases the chemical into the ground and opens the ejection hole when it acts through the injection nozzle on the inner pipe side.

Below, one embodiment of the device of the present invention will be described in detail with reference to the drawings. In FIGS. 1 to 4, 1 is 2.
It is a double-tube type injection tube rod, 2 is the outer tube, 3 is the inner tube, and the lower half of the injection tube rod is approximately uniform in length to the required length, and from the middle part to the tip is cut for drilling. The inner and outer tubes 2 and 3 are connected through a plurality of rod connectors 10 up to the attachment portion of the blade 4, and the rod connectors 10 are arranged at required intervals. 30 is a cutter bit attachment piece attached to the tip of the injection tube rod, and 5 is a well-known rotary joint to which drug solution supply tubes from a pump (not shown) are connected to the inner and outer tubes, respectively.

As shown in FIGS. 2 to 4, the rod connecting body 10 has a diameter approximately equal to the outer diameter of the outer tube 2 as the injection tube rod 1 and a suitable length, and has a central portion extending in the axial direction. It has a central hole 11 with a diameter approximately equal to the inner diameter of the inner tube 3, and at both upper and lower ends of the central hole 11 are inner tube fitting portions formed at appropriate lengths and diameters into which the ends of the inner tube 3 can be inserted. 12 respectively, and screws 13 are provided on the outer periphery of both the upper and lower ends so that the two ends of the outer tube can be screwed and fixed.
A plurality of upper and lower communication holes 14 are provided at appropriate intervals at positions corresponding to the annular space formed by the outer tube 2 and the inner tube 3 when they are connected. The holes are drilled through concentrically parallel to the axis. However, this vertical communication hole 14 is not provided in one place on a straight line passing through the center in the cross section, and the communication hole 14' provided in the opposite position is not provided vertically but is provided in the middle part from the upper side. The holes are drilled only up to the piece 20 mounting hole 15. Note that the upper and lower communication holes are not specified above, and known means for vertical communication can be adopted. Further, at a suitable position in the middle of the rod connecting body 10, a stepped mounting hole 15 and a stepped bolt hole 16 for fitting and mounting a liquid jet piece are provided in a straight line crossing the axis.
The liquid spouting piece 20 which is drilled as shown in the third figure and fitted into the mounting hole 15 has a large diameter head portion 20' and the center hole 11 so that its outer diameter fits into the mounting hole 15. The liquid spouting piece 20 has a narrow diameter portion 20'' projecting in length, and the liquid spouting piece 20 is provided with an O-ring packing 2 at a suitable location on the outer periphery of the head portion 20' and between the end face of the step and the step of the mounting hole.
3 and 23' are interposed to seal the inside and outside, and furthermore, a stepped liquid jet hole 21 is bored in the axis of the liquid jet piece 20, and a screw hole 22 is connected to the rear end. Furthermore, when installed, a liquid injection nozzle 24 having an extremely small diameter hole is bored in the liquid injection hole 21 at a position corresponding to the communication hole 14' on the outer tube side, and A liquid injection nozzle 24' having an extremely small diameter hole facing the liquid injection hole 21 is bored at the upper side of the protruding part. A nozzle piece having a sloped surface formed in the above is inserted into a hole with a concave slope formed in advance in the liquid ejection piece 20, and is attached integrally with an adhesive. The liquid ejecting piece 20 is fixed integrally by screwing a bolt 17 into a screw hole 22 from a bolt hole 16 located opposite to the mounting hole 15. At this time, the injection nozzles 24, 24' are both fixed facing toward the chemical liquid supply side (upper side in the figure). A stopper 26 is fitted into the liquid ejection hole 21 of the liquid ejection piece 20, and seal rings 25 are provided on the inner peripheral surface of the liquid ejection hole 21 at positions on both sides of the liquid injection nozzle 24 communicating with the outer tube side.
is fitted to prevent liquid leakage.

Next, as shown in FIG. 5, the crown cutter attachment piece 30 at the tip of the injection tube rod 10 has an appropriate length to match the outer diameter of the injection tube, and has an upper half 31 and a lower half 3.
The upper half 31 is provided with a connection fitting hole 33 for the inner tube 3 at the center, and a male threaded portion 34 for screwing the outer injection tube is provided at the upper part of the outer periphery. A cylinder 36, which forms a part of the shutoff valve 35, is provided at the bottom of the connection fitting hole 33 of the inner pipe and opens downward. A piston 37 is inserted into the connecting portion 3 between the central portion and the outer peripheral forming portion.
1' is provided with a large number of concentric holes 39 for liquid medicine on the outer tube side. Valve 35' at the tip of the piston 37 inside the cylinder 36
The partition wall 3 is bored centering around the through hole 35″ into which the partition wall 3 is fitted.
8, and a cylindrical piece 40 equipped with a crown cutter bit of a known structure is screwed to the lower part. Note that when the valve element 35' on the piston 37 side forming the shutoff valve 35 is fitted with an O-ring packing 41 on the outer periphery and inserted into the through hole 35'' of the partition wall 38, the O
A ring packing 41 is used for sealing, and a communication hole 33' is provided between the inside of the cylinder 36 and the inner tube insertion part 33.

When the device of the present invention thus constructed is inserted into the target ground for improvement, the injection pipe rod 1 is rotated in a predetermined direction by means similar to conventional methods (rotated in the direction of screwing in each connection part). (to prevent the threaded part from loosening and coming off), press an anti-friction liquid (e.g. water) for drilling into the inside of the outer tube 2 and send it to the crown cutter 4 part at the tip of the rod to drill it to the required depth. . At this time, for the liquid passing through the flow path in the outer tube 2, the liquid spout hole 21
A stopper 26 is fitted inside, and the liquid injection hole 2 is closed by the seal rings 23, 25 and the stopper 26.
Since the cutter mounting piece 3 is closed, it will not leak to the outside depending on the hydraulic pressure acting on this part (this is configured in advance), and the cutter mounting piece 3
The shutoff valve 35 in 0 acts on the end surface of the protruding side of the valve 35' since the top surface side of the piston 37 is at or near atmospheric pressure relative to the pressure of the liquid flowing through the through hole 39 on the outer tube side. cylinder 36 due to the differential pressure with the anti-friction fluid pressure.
The piston 37 is pushed back inside, and the valve 35' is separated from the through hole 35'', that is, the valve is opened, and the liquid is supplied to the cutting portion without any hindrance, facilitating the entry of the injection pipe rod into the excavation.

After the injection pipe rod 1 has entered the target depth for soil improvement, the supply of the excavation reduction abrasive liquid is stopped, and instead of this, two kinds of well-known coagulation chemicals are added to the inside of the inner pipe 3, for example, as a hardening agent. The agent liquid (hereinafter referred to as B liquid) is supplied to the inside of the outer tube 2, and the main agent liquid for coagulation (hereinafter referred to as A liquid) is supplied to the inside of the outer tube 2.
When both liquids are supplied to the inner tube 3 side first, hydraulic pressure acts directly on the piston 37 of the shutoff valve 35 provided in the cutter attachment piece 30 at the tip of the rod 1, causing the piston 37 to close at the tip. The valve 35' is pushed into the through hole 35'' to close the flow to the crown cutter attachment side, and the supply of both chemical solutions is directed from the spout hole to the ground after the rod is once filled in both the inner and outer pipes. It will erupt.

Therefore, when supplying liquid to the rod, A and B
If both liquids are made almost equal and the supply pressure is extremely high (for example, 100 kg/cm ² ) and the same amount is pumped, the liquid pressure flowing into the spaces in both the inner and outer pipes 2 and 3 will cause each rod connection to Liquid spouting piece 20 provided in 10
The liquid pressure acts from the injection nozzle 24' on the rear end of the stopper 26 fitted in the liquid ejecting piece 20, and the high-pressure liquid B momentarily blows the stopper 26 into the ground, causing the liquid to eject orifice. 21 opens. Then, the B liquid is ejected from the injection nozzle 24', and the A liquid is ejected from the injection nozzle 24 through the communication hole 14' extending toward the outer pipe side, into the liquid ejection hole 21, where they are mixed and at the same time It is injected toward the side at high speed, and as the injection tube rod rotates, the mixed chemical solution is forced into the surrounding ground. (7th
(See figure) This injection of the chemical into the ground is carried out simultaneously from each of the plurality of ejection holes 21 provided in the lower half of the injection pipe rod 1 to the corresponding portions as described above. , at this time, the injection nozzle 24 flows out first into the liquid injection hole 21,
The holes 24' have extremely small diameters, and the supply pressure of each chemical solution to be supplied is extremely high.
The depressurization caused by the pressure loss of the liquid due to the flow in the pipe between the pipes becomes almost negligible at any position, and as a result, the liquid is ejected under almost the same conditions. By passing through an injection nozzle with an extremely small diameter, the pressure head is converted to a velocity head, lowering the injection pressure into the ground, and at the same time, preventing excessive discharge volume and increasing the velocity head. Since the chemical solution can be injected deep into the body, localized condensation of the chemical solution can be prevented.

In addition, by increasing the supply pressure and injecting at a low discharge at the injection part, the ground does not bulge, the injection range can be set to almost the same level, preventing excessive chemical injection, and simultaneous injection at multiple positions. Since the injection is carried out in a single injection operation, it is possible to widen the injection range in the vertical direction, and when it is necessary to increase the depth and injection work over a wide range of vertical directions, it is necessary to use an injection pipe rod. After first digging to the deepest point and injecting the chemical, the second step is to pull the rod up to an appropriate size and inject the chemical again.If necessary, pull the rod up again to the desired size and inject the chemical. By repeating this operation, a wide range of chemical injection work can be performed in the vertical direction within the range that can be injected from a single injection pipe rod, making it significantly more efficient than conventional construction methods. Improvements can now be measured. In addition, during such an operation, after the stopper is pushed out into the ground by the initial chemical injection, the liquid spout hole 21 in each liquid spouting piece 20 is closed until the rod is pulled up and the next chemical injection is performed at the required location.
After the supply of both chemical solutions is stopped, the two chemical solutions that have flowed into the injection hole 21 become mixed and condense and remain, keeping the liquid injection hole 21 in a closed state, so that the injection tube rod 1 It acts to prevent earth and sand from entering into this hole when it moves up, and when it moves upward and moves to the injection operation by force-feeding the chemical solution, the injection nozzles 24, 24'
The condensed agent is blown open like a stopper by the high-speed jet ejected from the stopper, and does not interfere with the injection operation.

The pitch of the liquid ejection holes provided in the injection tube rod can be set arbitrarily, but in some cases, the intervals may be set relatively large, and when injecting the chemical liquid, the liquid ejection holes may be set at a relatively large interval. It is effective to raise the rod by, for example, 1/2 of the set pitch of the ejection holes, because it is possible to effectively inject a chemical solution over a wide range by arranging a small number of liquid ejection holes.

As described above, according to the device of the present invention, if the injection pipe rod enters the excavation at one location, the ground around the rod can be improved in the required range in the vertical direction. It was possible to accomplish the purpose of the work by reducing the number of places where the rods were driven, and as a result, work efficiency was significantly improved, making it possible to carry out ground improvement economically.

It goes without saying that the device of the present invention can be used by being inserted not only in the vertical direction as described above, but also in the lateral direction. In addition, if necessary, the rod connecting body can be welded to the intermediate outer tube to connect them together.
Even with this configuration, if a failure occurs in the liquid ejecting section, the liquid ejecting piece can be removed and repaired, so there is no problem. Furthermore, the control valve provided inside the rod tip is similar to the above embodiment, and when the anti-friction fluid flow pipe is on the inner pipe side, the anti-friction fluid is cut by the hydraulic pressure acting on the outer pipe side. This problem can be solved by incorporating a valve having a piston structure configured to close the outlet to the blade.

The structure of the liquid jetting part is not limited to the above embodiment, and for example, as shown in FIG. Then, the injection nozzle pieces 27 and 27' each having an independent extremely small diameter hole are installed, and the liquid ejected from both injection nozzle pieces is arranged so that the liquid is mixed and simultaneously ejected outward. It is also possible to insert a stopper 26' into the hole.

[Brief explanation of the drawing]

The drawings show one embodiment of the chemical liquid injection device of the present invention, in which Fig. 1 is a view showing the whole, Fig. 2 is a longitudinal sectional view showing the connection part of the injection pipe rod, and Fig. 3 is a liquid jetting part. Fig. 4 is an enlarged detailed view of Fig. 3, Fig. 5 is an enlarged cross-sectional view of the main connection part of the crown cutter attachment piece at the tip of the injection tube rod, Fig. 6 is a separate view of the liquid spouting part. An example diagram, FIG. 7, is a diagram showing an injection mode when liquid medicine is injected. 1... Injection tube rod, 2... Outer tube, 3... Inner tube, 4...
Cutting blade for drilling, 10...Rod connection body, 11...Central hole, 12, 33...Inner tube insertion part, 13...Screw, 14
...Upper and lower communication hole, 14'...Communication hole, 15...Mounting hole,
16... Bolt hole, 17... Bolt, 20... Liquid jet piece, 21... Liquid jet hole, 24, 24'... Liquid injection nozzle, 26... Stopper, 27, 27'... injection nozzle piece,
30...Cutter mounting piece, 35...Shutoff valve, 35'...
Valve, 35″...through hole, 36...cylinder, 37...piston.

Claims (1)

[Claims] 1. In a double-tube liquid chemical injection rod equipped with a cutting blade at the tip of the rod: At the tip of the rod, when liquid is injected, liquid pressure supplied to the inner tube side is applied to the cutting blade from the outer tube side. A control valve is provided to close the liquid outlet, and the intermediate rod connecting body has a hole in the axis that communicates with the inner pipe, and is fitted with the inner pipe, and is connected to the outer pipe by screwing or welding. and a plurality of upper and lower communication holes are arranged in the intermediate connecting part of the rod connecting body corresponding to the annular passage between the inner pipe and the outer tube, and the intermediate connecting part of the rod connecting body At an appropriate position of the connecting part, a liquid ejecting piece is fixed, which has an extremely small diameter injection nozzle that intersects the axis and communicates with the inner tube side and the outer tube side, and communicates with the chemical liquid ejection hole. and close the outer tube side injection nozzle to the chemical liquid injection hole of the liquid injection piece.
A chemical liquid injection device, characterized in that a stopper is fitted therein to release the chemical liquid into the ground and open the chemical liquid ejection hole when liquid pressure on the inner pipe side acts through the injection nozzle.