JPS5830446B2 - Strainer injection device for soil stabilization chemicals - Google Patents

Description

[Detailed Description of the Invention] The present invention involves polling soil with an injection pipe configured as a double pipe rod, and then individually pressurizing a soil stabilizing chemical solution from above the injection pipe without changing the setup. This relates to a device that mixes the mixed liquid using a strainer equipped with a spool valve function and injects the mixed liquid into the target ground.

Conventionally, strainer injection devices of the above-mentioned type have a number of injection holes drilled in the circumferential side wall of the injection pipe, the lower end of which is closed conically or provided with any suitable closing means, through which the ground is discharged. This method injects a stabilizing chemical into the target ground, but compared to the rod injection method, this method has a much larger effective cross-sectional area than the rod injection method, which causes the chemical to be sprayed over a wide area, causing a sudden rise in pressure. This method is suitable for injecting chemical liquid over a relatively wide area because the possibility of chemical liquid spouting to the ground surface is reduced.

However, in this injection method, after boring the soil to a predetermined depth 1 using a boring machine, a strainer injection pipe is buried in the excavated hole, or depending on the case or the soil, the injection pipe is hammered with a pile hammer. This method has disadvantages in that it is difficult to work, and requires a large number of extra work steps because it is necessary to prevent the strainer from clogging or dirt from entering the pipe.

On the other hand, after the initial chemical injection is performed by filling the strainer injection pipe set in the soil with sand to prevent the chemical from descending or injecting it to other than the intended location, After washing out the sand, a prescribed chemical solution is injected, and this work is repeated to step up and stabilize the ground on the side wall of the strainer, so the work is repetitive, which inevitably lengthens the construction period. As a result, the disadvantage is that the construction costs become high.

Furthermore, when injecting chemicals with a double-tube structure of the boring rod, a metal crown and a pit are attached to the tip of the rod with a strainer, and after polling to a predetermined depth while rotating the rod, the tip of the rod is closed. By injecting a chemical solution into the strainer (the chemical solution penetrates into the soil and improves the ground, but in this construction method, water flows out from the strainer because it passes through the rod during polling work). However, there is a drawback that the soil around the strainer is disturbed, and even if a chemical solution is injected into this area, the desired ground improvement or reinforcement cannot be achieved.

On the other hand, the present invention aims to provide a strainer ordering device for soil stabilizing chemicals that can eliminate the above-mentioned drawbacks, and its gist is that the upper end is connected to a double rod. an upper nipple to be connected to a strainer having spool pulp and water supply pulp therein and a spout hole around the periphery; and a lower nipple to be connected to a crown with a bit.

The above spool pulp is connected to a spool that communicates with the inner pipe of the double pipe rod and has a flow hole near the spout hole of the strainer, and a spool that is connected to the spool in the axial direction. The valve body has a pulp body which is slidably fitted and has a water supply pulp integrally attached to the lower part thereof, and the above-mentioned valve body has an upper end surface exposed to a cylinder chamber communicating with the outer pipe, It also has an annular chamber between it and the spool, a strainer chamber between it and the strainer, and a communication hole that communicates both chambers, and the valve body has an upper position and a lower position in the axial direction. In the spring-biased upper position, the valve body blocks communication between the cylinder chamber and the strainer chamber, and opens the above-mentioned communication hole provided in the sphere to the water supply pulp. This allows the drilling water supplied to the inner pipe to flow down to the lower nipple, and further blocks the spout hole of the strainer. The valve body allows communication between the cylinder chamber and the strainer chamber, switches the communication hole to communicate with the annular chamber, and communicates the strainer nozzle with the strainer chamber, thereby allowing air to flow from the inner pipe. The chemical liquid is introduced into the strainer chamber via the annular chamber and the communication hole of the valve body, where it is combined with the chemical liquid from the outer tube, mixed, and ejected from the spout hole of the strainer. According to the present invention, a double pipe consisting of an inner pipe and an outer pipe is used as a boring rod, and a spool pulp is placed below the double pipe. The soil is polled by rotating a strainer with a double-tube rod structure and a crown bit equipped with a double-tube rod structure and a crown bit. Circulating water is sent from the water supply pulp to the crown pid via the spool pulp, while at the time of chemical injection, the main agent (or auxiliary agent) of the ground stabilizing chemical solution fed from the outer pipe flows through the spool pulp to the outside. The water supply pulp is closed by pressing the inner tube to open it, and the auxiliary agent (or main agent) fed from the inner pipe is mixed at the time of opening the pulp, and the mixed liquid is poured from the strainer's spout hole into the target ground. Poling work and chemical injection work can be performed using the same equipment or setup, and there is no need to install a strainer injection pipe or bury the strainer injection pipe in a pre-poled excavation hole. Since the work is extremely simplified and the construction period can be shortened, construction costs can be reduced, and there is no need for extra work steps due to the strainer becoming clogged or dirt entering the pipe. Workability is also improved, and in addition, during polling, the strainer's spout hole is completely sealed with a sealing ring attached to the spool valve body, water supply valve body, or either of the cooling water or circulating water that passes through the inner pipe. Therefore, the desired ground improvement or reinforcement can be carried out efficiently and effectively without disturbing the ground surrounding the strainer injection pipe.

Next, the present invention will be explained in more detail with reference to an embodiment shown in FIGS. 1 to 3.

First, as shown in Figures 1 and 2, strainer injection pipe 1
The upper end is connected to a double pipe rod (not shown) including an outer pipe and an inner pipe, and the lower end is connected to a metal crown to which a bit is welded, and the outside of the strainer injection pipe is A spool consisting of upper and lower nipples 2, 3 to be connected to the outer tube of the double tube rod and a strainer 4 screwing these nipples, and whose inside is to be connected to the inner tube of the double tube rod. It is composed of a valve 5 and a water supply valve 6 which is integrally formed with the valve by screw means.Basically, cooling or circulating water from a double pipe rod passes through the inner pipe, and mixed chemical solution flows through the outer pipe. It is designed to pass through.

The upper half of the upper nipple 2 has a screw 7 to be connected to the outer tube of the double tube rod, and the lower half has a cylinder chamber 8 and a cylinder wall 9 that protrudes inwardly. .

The strainer 4, which has nipples 2 and 3 screwed onto its upper and lower ends, is provided with, for example, four ejection holes 10 having a trumpet-shaped cross section, and the mixed chemical liquid is discharged from each of these ejection holes. A screw 11 is formed at the bottom of the lower nipple 3 to which a metal crown (not shown) is to be attached.

The spool valve 5 consists of a stepped spool 13 having an axial fluid passage 12 whose lower end is closed, and a stepped spool valve body 14 which is fitted into the stepped spool 13 and slides up and down and has a piston function. The upper edge of the spool is flush with the upper nipple 2 and is provided with mechanical sealing means 15 for a sealing fit with the inner tube (not shown) of the double tube rod, the lower step 16 of which has two A partition plate 19 in a delta arrangement, which delimits a passage space 17 for the chemical liquid flowing through the outer pipe (not shown) of the heavy pipe rod and fixes and supports the stepped portion or spool with a snap ring 18, is attached by an appropriate welding means. They are mounted radially, so that the spool is immovable with the upper nipple 2 without moving in the axial direction, and the lower end of the spool is diametrically bored with a flow hole 20 through which cooling or circulating water passes. It is.

The spool valve body 14, which forms the spool pulp 5 and has a piston function that can move up and down by fitting into the spool 13, is used only during polling. The head part is fitted into the spool 13 via an O-ring 23, and the skirt part is in contact with an inner O-ring 24 and an outer skirt part 22, which is in constant contact with the inner wall. The spool and the strainer are fitted into or brought into contact with each other via O-rings 25, and between the head portion 21 and the skirt portion 22 forming the spool valve body, one side communicates with the strainer chamber 26 and the other side communicates with the spool and the strainer. A plurality of communication holes 2875r (16 in the figure) communicating with the annular chamber 27 of the valve body are provided in a bird-like arrangement.

Furthermore, a water supply valve 6 consisting of a hollow stepped valve body 30, a check valve 31, and a coil spring 32 is connected to the lower part of the spool valve body 14 via a seal ring 29, and is connected to an upper chamber 33 of the valve body. The lower end of the spool 13 forming the spool pulp 5 is located, and the upper chamber communicates with the communication hole 20 formed in the spool, thereby allowing passage of cooling or circulating water, and the lower chamber of the valve body. The check valve 31 installed inside the valve 34 is composed of a steel ball 35, a truncated cone-shaped coil spring 36, and a stop ring 37. This allows cooling or circulating water to flow through the metal crown ( (not shown) can prevent dirt or cutting debris from flowing backwards and clogging the lower chamber housing the coil spring 36, and the lower chamber is provided in the valve body. The cooling or circulating water that has passed through the plurality of water holes 38 is passed through the strainer 4 and the lower nipple 3.
It is sent to the metal crown through the
When transitioning from polling work to drug injection work, the third
As shown in the figure, since the coil spring 32 is compressed and the valve body 30 of the water supply valve 6 comes into contact with the lower nipple 3, the strainer valve function is impaired by the cooling or circulating water remaining below the strainer 4. To prevent this, a cross-shaped relief groove may be provided on the upper surface 39 of the lower nipple.

Therefore, in order to inject a chemical liquid using the device of the present invention having the above configuration, first connect the strainer injection pipe 1 to the injection pipe formed as a double pipe rod, and then attach a metal crown with a bit to this. After setting the boring machine in a known manner, the boring machine is driven to rotate the injection pipe while supplying cooling or circulating water from a double slide pel (not shown) to the inner pipe. It passes through a fluid passage 12 which is bored in the stepped spool 13 of the spool valve 5 which is to be connected to the inner pipe via a mechanical sealing means 15, and reaches the upper chamber 33 of the water supply valve body 30 from the communication hole 20. , the valve is opened by pressing the check valve 31, and the water is sent from the lower nipple 3 to a metal crown with a bit (not shown) through the lower chamber 34 and the water passage hole 38 of the valve body, and is subjected to predetermined polling. After polling reaches a certain depth through such polling operations, the boring machine and water supply pump are stopped, the operation is stopped, and the process is switched to chemical injection. Since the check valve closes due to the supply of circulating water being cut off, dirt or cutting debris will enter and clog the upper chamber 33 of the water supply valve body and the spool 13, and the scum will enter the lower part of the strainer 4. The soil and cutting debris are removed from an escape groove (not shown) provided in the upper surface 39 of the lower nipple 3 by compression of the coil spring 32 during injection of the chemical solution.

Next, when performing chemical injection work, prepare in advance an aqueous solution (liquid A) containing water glass as the main ingredient and an aqueous solution (liquid B) containing carbon dioxide as an auxiliary agent, and strainer injection pipe 1. After connecting the upper part to the grout pump with a double slivel and a hose, etc., feed liquid A from the liquid A port of the double slivel to the outer tube of the double pipe rod at an injection pressure of about 3 to 8 mm. , liquid A reaches the cylinder chamber 8 through the passage space 17 of the upper nipple 2 and presses the head part 21 of the stepped spool valve body 14 with piston function forming the spool valve 5. The stepped valve body 30, which forms the body and the water supply valve 6 integrally formed therewith, descends against the springing force of the coil spring 32, and finally, as shown in FIG. Head part 21 and upper nipple 2
is disengaged from the cylinder wall 10 to form a liquid passage space 40, and the strainer chamber 26 and the spout hole 10 of the strainer 4 communicate with each other, and the lower end surface of the stepped pulp body is brought into contact with the upper surface of the lower nipple 3. The lower end of the spool 13 of the spool valve body and the inside of the spool valve body are in contact with each other.

- annular chamber 27 for sealing fit via ring 24;
and the upper chamber 33 of the stepped pulp body are completely cut off.

At this point, when liquid B is supplied to the liquid B port of the double slivel and flows into the inner tube of the double pipe rod, liquid B passes through the fluid passage 12 of the spool 13 and flows below the spool. After reaching the annular chamber 27 through the perforated communication holes 20, the mixture is mixed in the strainer chamber 26 immediately after being ejected as a jet stream from the communication holes 28, which are perforated in a staggered manner in the spool valve body 14. The mixture is stirred and mixed impulsively without the need for a chamber, and the resulting mixed liquid is injected into the target ground from the spout 10 of the strainer 4 to strengthen or improve the ground.

In the embodiment described above, in order to prevent dirt or cutting debris from entering the valve body 30 of the water supply valve 6 and clogging it when the polling work is completed and the chemical injection work is started. A check valve 31 is installed inside the lower chamber 34 of the valve body, but instead of this, approximately 30~
The same purpose can be achieved by providing a screen 41 of about 40 meshes, and an annular groove 42 having a V-shaped cross section can be formed on the upper surface of the skirt portion 22 of the spool valve body 14 forming the spool valve 5. However, the staggered communication holes 28, which are provided in the spool valve body, are provided in the strainer 4. By locating the chemical liquid in the vicinity of the chemical liquid ejection hole 10, consideration is given to ensuring that the mixed chemical liquid does not solidify in the strainer chamber 26 but solidifies in the target ground.

[Brief explanation of the drawing]

FIG. 1 is an axial longitudinal cross-sectional view showing the strainer injection device according to the present invention in a poling state, and FIG.
FIG. 3 is a cross-sectional view taken along the line -■, and an axial longitudinal cross-sectional view showing the strainer injection device in a state when injecting a chemical liquid. In other words, the correspondence between the main parts shown in the figures and the symbols is as follows. 1... Strainer injection pipe, 2... Upper nipple, 3
... Lower Nimple, 4 ... Strainer, 5 ... Spool valve, 6 ... Water supply valve, 8 ... Cylinder chamber, 10 ... Spout hole, 13 ... Stepped spool, 14
...Stepped spool valve body, 21...Head part, 22...Skirt part, 26...Strainer chamber, 3
0...Stepped valve body, 31...Check valve, 41...Screen.

Claims (1)

[Claims] 1. An upper nipple whose upper end is to be connected to a double pipe rod, a strainer having a spool valve and a water supply valve inside and a spout hole around it, and a crown with a bit. and a spool in which the spool valve is in communication with the inner tube of the double pipe rod and has a flow hole near the spout hole of the strainer, and the spool valve is connected to the lower nipple in the vertical axis direction, and the spool valve is connected to the inner pipe of the double pipe rod and has a flow hole near the spout hole of the strainer. The valve body has a valve body that is slidably fitted in the axial direction and has a water supply valve integrally attached to the lower part, and the above valve body has an upper end surface connected to a cylinder chamber communicating with the outer pipe. The valve body is exposed, and has an annular chamber between it and the spool, a strainer chamber between it and the strainer, and a communication hole that communicates both chambers. In the spring-biased upper position, the valve body prevents communication between the cylinder chamber and the strainer chamber, and connects the communication hole provided in the spool to the water supply valve. The hole is opened to allow the drilling water supplied to the inner pipe to flow down to the lower nipple, and further closes the strainer nozzle, and the lower part is pushed down by the pumped chemical fluid supplied to the outer pipe and enters the cylinder chamber. In this position, the valve body allows communication between the cylinder chamber and the strainer chamber, switches the communication hole to communicate with the annular chamber, and communicates the strainer nozzle with the strainer chamber, thereby allowing the inner pipe to communicate with the annular chamber. The chemical liquid from the water supply valve is guided to the strainer chamber via the annular chamber and the communication hole of the valve body, where it is combined with the chemical liquid from the outer tube, mixed, and ejected from the spout hole of the strainer. A strainer injection device for a chemical solution for ground stabilization, characterized in that a means for preventing backflow of earth and sand or cutting debris is provided on one side. 2. A strainer injection device for the device according to claim 1, wherein the means for preventing backflow of earth and sand or cutting waste is a check valve or a screen.