JPH0860976A - Method for constructing fore pile and drilling device for use therein - Google Patents

Abstract

PURPOSE: To prevent a hardener from flowing out in excess so as to prevent ground subsidence resulting from excessive sludge by drilling a hole by means of high-pressure injection while rotating and pressing an inner bit into the ground, and sucking and discharging sludge by means of a suction force derived from a jet, and drilling the hole to a predetermined position, and then injecting the hardener. CONSTITUTION: A triple injection pipe 37 is inserted into a reinforcing steel pipe 33 and an inner bit 39 is installed. The bit 39 is projected, rotated and pressed into the ground 55. A hole is drilled by high-pressure injection from a nozzle 41. At the same time, boring water W is injected into the reinforcing steel pipe 33 from injection nozzles 57, 61 under high pressure. Sludge is discharged from a sludge suction hole 69 by means of a suction force derived from a jet. The hole is drilled to a fixed position, and a hardener G and an accelerator G' are ejected simultaneously from the injection nozzles 57, 61. A hardened portion 67 is formed by the mixing of the surrounding earth, the hardener G and the accelerator G'. The amount of the unhardened hardener G flowing out through the gap between the reinforcing steel 33 and the ground 55 can thus be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a fore pile in excavation work for tunnels, underground tunnels, etc. and a drilling device used therefor.

In the present specification, the "fore pile" refers to a cylindrical hardened layer formed by mixing a hardener and surrounding soil.

[0003]

2. Description of the Related Art In recent years, there has been an increase in large-scale tunnel construction in tunnel construction in which a structure is built in the upper part or a collapsible ground where the covering of the earth mass is thin.

For this reason, as an auxiliary construction method for large excavating machines, the tunnel cross section is cut ahead of the cutting face before the tunnel is excavated for the purpose of preventing the loosening of the ground at the time of excavation and the collapse of the face and crown. The front-end construction method that stabilizes the face is widely adopted by forming the fore pile in an arch shape along the edge.

FIGS. 5 to 8 show a method for constructing a fore pile by the first receiving method disclosed in Japanese Patent Publication No. 4-42520. In this conventional method, first, the bit 1 and the injection device 3 are attached to the tip portion. The high-pressure injection pipe 5 is inserted into the peripheral ground 9 of the ground 7 to be excavated in the direction of the shaft excavation, and the ground 9 is drilled to a predetermined position.

When the ground 9 has been drilled to a predetermined position, the hardening material G is pressure-fed to the high-pressure injection pipe 5 as shown in FIGS. The fore pile 11 is formed on the ground 9 by rotating the pipe 5 and retreating the pipe 5, and as shown in FIG. 8, such fore piles 11 are successively formed along the ground 7 to be excavated to form arches. After constructing the lined lining body 13,
The tunnel is excavated by repeating the process of excavating and excavating the ground 7 to be excavated on the inner side of the lining body 13 within the range of the length of the lining body 13 and performing the supporting lining.

FIGS. 9 and 10 show a method for forming a fore pile using the double rotary type boring device shown in FIG. 11. In this conventional method, as shown in FIG. After inserting the high-pressure injection pipe 17 equipped with the above into the reinforcing steel pipe 19, projecting the inner bit 15 at the tip from the tip of the reinforcing steel pipe 19 and holding these coaxially by the rotary units 21 and 22, respectively, When the injection pipe 17 and the reinforcing steel pipe 19 are simultaneously press-fitted into the peripheral ground 9 of the ground to be excavated, the hardening material G is injected at high pressure from the injection device 21 mounted on the high-pressure injection pipe 17 to form a columnar shape in the improved formation portion m. The solidified formation part 23 is formed, and then the high-pressure injection pipe 17 is pulled out while leaving the reinforcing steel pipe 19 in the ground as shown in FIG. 10 to form the fore pile 25 having the reinforcing steel pipe 19 as a core material on the ground 9. Construction It is intended to.

Then, as in the above-mentioned conventional method, the fore piles 25 are successively formed adjacent to each other to construct an arch-shaped lining body, and the ground to be excavated inside the lining body is within the length of the lining body. The tunnel is being excavated by repeating the process of excavating and excavating and supporting the lining.

In addition, in FIG. 11, 27 is a reinforcing steel pipe 19.
Drilling bit attached to the tip of the
Reference numeral 31 indicates a high-pressure swivel.

[0010]

The problems to be solved by the invention are as follows.
In the conventional example shown in FIG. 1, along with the formation of the solidification forming portion 23, the sludge is discharged from the soil discharge swivel 29 to the outside through the space between the high pressure injection pipe 17 and the reinforcing steel pipe 19. As a result, a large amount of uncured hardened material G flows out together with the soil removal, and this conventional method is a conventional jet grout method that is performed vertically to the ground for the purpose of improving soft ground. Since it is carried out horizontally or slightly upward in the direction of advancing part excavation, there is a problem that a large amount of the uncured hardened material G injected at high pressure flows out from the gap between the ground 9 and the reinforcing steel pipe 19. It was

Also in the conventional examples shown in FIGS. 5 to 8, the hardened material G injected at high pressure from the high-pressure injection pipe 5 is discharged as mud from the gap between the ground 9 and the high-pressure injection pipe 5 together with the soil discharge. It has been pointed out that there is a drawback that a large amount of it will flow out.

As described above, in the conventional method, a large amount of the curing material flows out during the formation of the fore pile, so that a large amount of the curing material is required. Also, if the amount of discharge is larger than the amount of inflow (excessive amount of sludge), there is a possibility that a cavity will be created between the upper part of the fore pile and the ground, and a void will be created between the upper part of the fore pile and the ground. There was a risk that the entire ground would sink due to the collapse of the ground around the lining body.

The present invention has been devised in view of the above circumstances, and is a method for constructing a fore pile, which prevents excessive outflow of a hardened material when constructing a fore pile and prevents ground subsidence due to excessive mud discharge during construction. And a drilling device used for this.

[0014]

In order to achieve the above object, a method for constructing a fore pile according to a first aspect of the present invention is an inner bit mounted on a tip of an injection pipe by inserting the injection pipe into a reinforcing steel pipe. After projecting from the tip of the reinforcing steel pipe, at the same time, these were simultaneously pressed into the peripheral ground of the ground to be excavated in the direction of the mine excavation, and the drilling water sent to the injection pipe was injected into the injection hole of the inner bit. From the direction of travel to high-pressure jets to drill holes in the ground, and at the same time high-pressure jetting of drilling water from the nozzle of the drilling water mounted on the tip side of the jetting pipe to the inside of the reinforcing steel pipe, and suction by the jet flow. The soil is sucked and discharged from the mud suction port provided in the reinforcing steel pipe by force, and when the ground is drilled to a predetermined position, the reinforcing steel pipe and the injection pipe are similarly rotationally pressed into the ground and High-pressure jet of water for drilling , Each of the injection nozzles mounted on the tip side of the injection pipe, simultaneously injecting a hardening material and a hardening accelerating material at high pressure sideways from the injection holes provided in the reinforcing steel pipes, and the surrounding soil and hardening material and hardening accelerating material. The solidification formation part is rapidly solidified by mixing with and the sludge is sucked from the sludge suction port by the suction force of the jet water for high-pressure jetting from the above-mentioned injection nozzle, and this is drilled. After diluting it with water to prevent it from solidifying and discharging it, and then forming a solidified formation part to a predetermined position, the injection pipe is pulled out together with the inner bit and collected to put the fore pile with the reinforcing steel pipe as the core material in the ground It is to create.

The drilling device according to claim 2, which is used for forming a fore pile, has a drilling bit mounted at its tip.
A reinforcing steel pipe with a mud suction port and a hardening material injection port opening on the tip side peripheral wall, and an inner bit is attached to the tip, and the inner bit is projected from the tip of the reinforcing steel pipe and inserted into the reinforcing steel pipe. A triple injection pipe, a rotary drive mechanism for rotating and moving the triple injection pipe in the front-back direction, and a rotary drive mechanism for rotating and moving the reinforcing steel pipe forward. The triple injection pipe is a reinforcing steel pipe. Hardening material supply pipe equipped with an injection nozzle for laterally high-pressure injection of the hardening material from the injection port, and an injection nozzle for laterally high-pressure injection of the hardening accelerator from the reinforcing steel pipe injection hole. Material supply pipe,
It consists of a water injection pipe for drilling that communicates with the water injection hole for drilling provided in the inner bit.The water injection pipe for drilling is installed on the inner bit side of the mud suction port, and is drilled backward in the reinforcing steel pipe. It is characterized in that an injection nozzle for injecting high-pressure water for injection is installed.

[0016]

According to the method for constructing a fore pile according to claim 1, after the injection pipe is inserted into the reinforcing steel pipe and the inner bit attached to the tip of the injection pipe is projected from the tip of the reinforcing steel pipe, At the same time, these are rotated and pressed into the peripheral ground of the ground to be excavated toward the advancing direction of the pit, and the drilling water sent to the injection pipe is jetted at high pressure from the injection hole of the inner bit in the advancing direction to cut the ground. A high-pressure jet of water for drilling holes is made from the nozzle for drilling water, which is attached to the tip of the injection pipe, to the inside of the reinforcing steel pipe, and the suction force of the jet flow creates a sludge suction port on the reinforcing steel pipe. When the ground is drilled to the specified position, the reinforcing steel pipe and the injection pipe are likewise rotationally pressed into the ground and the inner pipe is used for high-pressure injection of drilling water. Each injection nozzle mounted on the tip side of High-pressure injection of the hardening material and hardening accelerator from the injection ports provided in the reinforcing steel pipes simultaneously at the same time to mix the surrounding soil with the hardening material and hardening accelerator to quickly solidify the solidified formation part. Along with the creation, the suction force of the jet water for high pressure injection from the jet nozzle described above sucks the sludge from the sludge suction port and dilutes it with the water for drilling to prevent its solidification. After discharging and forming the solidified formation portion to a predetermined position, the fore pile having the reinforcing steel pipe as the core material is formed in the ground by extracting and recovering the injection pipe together with the inner bit.

Further, according to the drilling device of the second aspect, the drilling device is mounted on the boom of the drilling machine for use, like the conventional drilling device. First, the drilling device is mounted. The boring machine is run in front of the ground to be excavated and the height direction of the boring device is determined by the base rod.At the same time, the position operation mechanism is used to determine the elevation angle of the boring device and the position of the target ground wall surface by the left and right inclination. Determine.

Then, the drilling water is fed into the drilling water injection pipe, and the drilling water is injected at high pressure from the inner bit in the traveling direction, and at the same time, the rotary injection mechanism causes the triple injection pipe and the reinforcing steel pipe to reach the ground. Rotate and press-fit, and drill the ground to the front of the improved formation area with the drill bit, inner bit, and drilling water.

At this time, since a part of the drilling water is jetted at high pressure from the jet nozzle of the drilling water injection pipe toward the rear in the reinforcing steel pipe, the jet flow causes the drilled soil to be scraped. It is sucked from the mud suction port together with the hole water, passes through between the reinforcing steel pipe and the hardening material supply pipe, and is discharged to the outside from the rear of the reinforcing steel pipe.

Thus, after finishing drilling the ground to a predetermined position in this manner, the hardening accelerator and the hardening material are respectively laterally jetted from the jet nozzle at a high pressure, and the reinforcing steel pipe and triple jet pipe are ground. When it is further press-fitted into the inside, the surrounding soil is mixed with the hardening material and the hardening accelerating material, and the solidification forming part is quickly formed in the ground. And since part of the drilling water is still being injected from the injection nozzle to the rear in the reinforcing steel pipe at high pressure, the discharged sludge mixed with the soil, the hardening material and the hardening accelerator is discharged from the sludge suction port by the jet flow. Sucked. Then, when the sludge is sucked from the sludge suction port, the hardening material is diluted by the drilling water sprayed from the spray nozzle, so that the hardening material in the sludge does not solidify with the hardening accelerator and the sludge is discharged. Will be discharged smoothly.

After the solidified formation portion is formed in the improved formation portion of the ground in this way, the rotary drive mechanism is retracted and the triple injection pipe is pulled out and recovered together with the inner bit, and the fore pile having the reinforcing steel pipe as the core material is recovered. Creation of is completed.

[0022]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a sectional view of the ground at the time of forming a fore pile according to the first embodiment of the boring device according to claim 2, in which 33 is a cylindrical reinforcing member having a ring bit 35 attached to its tip. A steel pipe 37 is a triple injection pipe inserted into the reinforcing steel pipe 33, and an inner bit 39 attached to the tip of the triple injection pipe 37 projects from the tip of the reinforcing steel pipe 33.

Although not shown, a rotary drive mechanism is connected to the rear ends of the reinforcing steel pipe 33 and the triple injection pipe 37, respectively, and the triple injection pipe 37 is rotated in the direction of the arrow and moved forward and backward by the rotary drive mechanism. The reinforcing steel pipe 33 is also movable in the same direction by the rotary drive mechanism.
Simultaneously with 7, it can rotate in the direction of the arrow and can move forward.

The triple injection pipe 37 is located at the center as shown in FIGS. 1 and 2, and is a hole water injection pipe 43 communicating with the hole water injection hole 41 of the inner bit 39.
Hardening material supply pipe 45 having a diameter larger than that of the hole water injection pipe 43
And a hardening accelerating material supply pipe 47 having a diameter larger than that of the hardening material supply pipe 45.
It is arranged coaxially with the reinforcing steel pipe 33 via 9, 51 and 53.

Then, the drilling water W fed to the drilling water injection pipe 43 is high-pressure jetted in the traveling direction from the drilling water jet hole 41 to drill the ground 55. or,
An injection nozzle 57 for injecting a curing accelerator G ', such as water glass, at a high pressure to the side is attached to the peripheral wall of the distal end of the curing accelerator supply pipe 47 located on the outermost side, and the curing agent supply located inside thereof is further supplied. A passage pipe 59 that penetrates the peripheral wall of the hardening accelerator supply pipe 47 is inserted into the peripheral wall of the pipe 45, and a jet nozzle 61 for laterally high-pressure jetting a hardening material G such as cement milk at the tip thereof is a jet nozzle. It is mounted at a position slightly ahead of 57.

On the other hand, on the peripheral wall of the reinforcing steel pipe 33, two injection ports 63, 65 are provided corresponding to the injection nozzles 57, 61.
The reinforcing steel pipe 33 and the triple injection pipe 37 are formed in the front-rear direction at the same time by rotationally press-fitting them into the ground 55 to inject high-pressure water for drilling water W from the inner bit 39 in the advancing direction, and the injection nozzle 57. When 61 and 61 respectively simultaneously inject the hardening material G and the hardening promoting material G'to the lateral side at a high pressure, the surrounding soil is mixed with the hardening material G and the hardening promoting material G'and solidified in the ground 55 in about 30 seconds. The solidification forming part 67 is formed.

Further, the reinforcing steel pipe 33 is provided with the above injection port 6
A sludge suction port 69 is opened on the opposite side of 3, 65. Further, an L-shaped passage pipe 71 is inserted into the water injection pipe for drilling 43 penetrating the peripheral walls of the hardening material supply pipe 45 and the hardening accelerator supply pipe 47, and is attached to the tip of the passage pipe 71. The attached injection nozzle 73 is arranged on the inner bit 39 side of the sludge suction port 69.

Then, a part of the hole-forming water W supplied to the hole-forming water injection pipe 43 passes through the passage pipe 71 and then the injection nozzle 7
When high-pressure jetting is performed from 3 to the inside of the reinforcing steel pipe 33, the sludge S in which the soil is mixed with the hardening material G and the hardening accelerating material G'is sucked by the jet flow from the mud suction port 69, and the jetting is performed. The hardening material G passes through between the reinforcing steel pipe 33 and the hardening promoting material supply pipe 47 and is discharged from the mud discharge port 75 provided on the rear end side of the reinforcing steel pipe 33. It reacts with the curing accelerator G'and quickly solidifies.

However, when the sludge S is sucked from the sludge suction port 69, the concentration of the hardening material G is reduced by the drilling water W sprayed from the spray nozzle 73, so that the hardening material G in the sludge S is diluted. Does not solidify with the hardening accelerator G ',
Can be discharged smoothly.

The drilling device 77 according to the present embodiment is constructed in this way, and one embodiment of the construction method according to claim 1 is carried out as follows using the drilling device 77. The drilling device 77 is used by being mounted on a boom of a drilling machine (not shown) similarly to the drilling device shown in FIG.
A drilling machine equipped with 7 is run in front of the ground to be drilled, and the height direction of the drilling device 77 is determined by the base rod. Determine the position with the ground wall.

Then, the drilling water W is fed into the drilling water injection pipe 43, and the drilling water W is jetted from the inner bit 39 in the advancing direction at a high pressure. The reinforcing steel pipe 33 is rotationally press-fitted into the ground 55, and the ground 55 is drilled with the ring bit 35, the inner bit 39, and the drilling water W until just before the improved forming portion m shown in FIG.

At this time, a part of the drilling water W is jetted from the jet nozzle 73 toward the rear in the reinforcing steel pipe 33 at a high pressure, so that the jet flow of the drilled water causes the drilled water W to be drilled. The steel pipe 3 for reinforcement is sucked together with the sludge suction port 69.
3 and the hardening material supply pipe 45, and is discharged to the outside from the mud discharge port 75.

Thus, after finishing the drilling of the ground 55 to the predetermined position, the injection accelerators 57 and 61 respectively inject the hardening accelerator G'and the hardening material G to the high pressure sideways to reinforce. When the steel pipe 33 and the triple injection pipe 37 are further rotationally pressed into the ground 55, the surrounding soil is mixed with the hardening material G and the hardening accelerating material G ', and the solidification forming portion 67 is rapidly formed in the ground 55. It And since a part of the drilling water W is still being jetted from the jet nozzle 73 to the rear inside the reinforcing steel pipe 33 at high pressure, the sludge S obtained by mixing the soil with the hardening material G and the hardening accelerating material G ′ is the same. It is sucked from the sludge suction port 69 by the jet flow. Then, when the sludge S is sucked from the sludge suction port 69, the hardening material G is generated by the drilling water W sprayed from the spray nozzle 73.
Since the hardened material G in the sludge S is not solidified with the hardening accelerator G ′, the sludge S is smoothly discharged from the sludge discharge port 75.

After the solidified formation portion 67 is formed in the improved formation portion m in this way, the rotary drive mechanism is retracted and the triple injection pipe 37 is pulled out and collected together with the inner bit 39 as shown in FIG. The creation of the fore pile with the core material is completed.

Then, by sequentially repeating such steps to successively form the fore piles, the lining body is constructed in an arch shape along the periphery of the opening of the pit and the stability of the face is ensured. Similarly to the above, the excavation of the tunnel will be performed by excavating the ground to be excavated inside the lining body within the range of the length of the constructed lining body or less.

As described above, also by the boring device 77 and the construction method of this embodiment using the same, it is possible to form a fore pile having the reinforcing steel pipe 33 as the core material, similarly to the conventional example shown in FIG. It is possible.

In the above-described embodiment, since the instantaneous solidifying solidified formation 67 is formed in the ground 55 by using the hardening material G and the hardening promoting material G ', the reinforcing steel pipe 33 is conventionally used.
There is no risk that the uncured curing material G will flow out through the gap between the ground and the ground 55, and the curing material G injected from the injection nozzle 61 will be rapidly solidified by the curing accelerator G ′. With the formation of the solidification forming portion 67, the outflow amount of the uncured hardened material G discharged through the space between the reinforcing steel pipe 33 and the triple injection pipe 37 to the outside also decreases.

Therefore, according to one embodiment of the method of the present invention using the boring device 77, as compared with the conventional method shown in FIG. It is possible to eliminate the possibility that a cavity will be created between the two and to prevent the curable material G from flowing out unnecessarily and reduce the usage amount.

Further, as described above, even if the sludge S is sucked from the sludge suction port 69, the hardening material G is thinned by the drilling water W sprayed from the spray nozzle 73, so that the sludge S is discharged.
There is no possibility that the hardening material G inside will be solidified with the hardening accelerator G ′ and cause clogging.

Therefore, the sludge S is smoothly discharged from the sludge discharge port 75, and the fore pile can be efficiently constructed. However, since the boring device 77 according to the present embodiment can be used by mounting it on the boom of an existing boring machine, it has an advantage that it does not require the improvement of the boom of an existing boring machine. .

FIG. 4 is a sectional view of the essential portions of a second embodiment of the hole drilling device according to the second aspect of the present invention. As shown in the drawing, the hole drilling device 79 of this embodiment is the same as that of the hardening accelerator G '. Instead of the injection nozzle 57, an injection nozzle 81 is attached to the outer periphery of the curing accelerator supply pipe 47 so as to cover the periphery of the injection nozzle 61, and the curing material G by the injection nozzle 61 and the curing accelerator G ′ by the injection nozzle 81 are attached. The mixed liquid is simultaneously and laterally injected at high pressure from the injection port 65 provided in the reinforcing steel pipe 33.

Since the other construction is the same as that of the boring device 77 of the first embodiment, the same parts are designated by the same reference numerals, and their description will be omitted. Thus, even if the drilling device 79 according to the present embodiment is used, the intended purpose can be achieved as in the case of using the drilling device 77 according to the first embodiment.

[0043]

As described above, according to the method for forming a fore pile according to the first aspect, in forming the fore pile along the tunnel cross section in front of the face, a hardening material and a hardening accelerator are used. Since an instantaneous solidification formation part is formed in the ground by using it, there is no risk of uncured hardening material flowing out through the gap between the reinforcing steel pipe and the ground as in the past, and from the injection nozzle. Since the hardening material injected into the ground is rapidly solidified by the hardening accelerator, the uncured hardening material discharged to the outside through the space between the reinforcing steel pipe and the injection pipe with the formation of the solidification forming part. Outflow will also be reduced.

Therefore, as compared with the conventional construction method, the possibility that a cavity is formed between the upper part of the fore pile and the ground due to excessive sludge discharge at the time of construction is eliminated, and the curing material is prevented from being wasted out. It is possible to reduce the amount of wood used.

Furthermore, since the hardening material in the mud sucked from the mud suction port of the reinforcing steel pipe is thinned by the hole drilling water jetted from the jet nozzle, the hardening material in the mud solidifies with the hardening accelerator. There is no risk of clogging and clogging, sludge is discharged smoothly, and efficient fore pile construction is possible.

Similarly, with the drilling device according to the second aspect of the invention, since the instantaneous solidification solidified formation portion is formed in the ground by using the hardening material and the hardening accelerator, the gap between the reinforcing steel pipe and the ground is formed. There is no risk of uncured hardened material flowing out through the pipe, and the hardened material injected from the injection nozzle into the ground is quickly solidified by the hardening accelerating material. The outflow amount of the uncured curing material discharged to the outside through the space between the triple injection pipe and the injection pipe is also reduced.

Therefore, it is possible to prevent a void from being generated between the upper part of the fore pile and the ground due to excess sludge during construction, and to prevent wasteful outflow of the hardener to reduce the amount of hardener used. It is possible to reduce.

Even if the sludge is sucked from the sludge suction port of the reinforcing steel pipe, the hardening material is diluted by the drilling water sprayed from the spray nozzle, so that the hardening material in the sludge serves as a hardening accelerator. There is no risk of solidification and clogging, and the sludge can be discharged smoothly.

Furthermore, since the boring device according to the present invention can be mounted on the boom of an existing boring machine for use,
It has the advantage that it does not require any special improvements to existing drilling machines.

[Brief description of drawings]

FIG. 1 is a sectional view of the ground at the time of forming a fore pile by a first embodiment of a hole drilling device according to a second aspect of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view of the ground showing a pulled-out state of the triple injection pipe at the time of forming the fore pile.

FIG. 4 is a sectional view of an essential part of a second embodiment of a hole drilling device according to a second aspect of the present invention.

FIG. 5 is an explanatory view showing a conventional fore pile construction method.

FIG. 6 is a cross-sectional view of the tunnel.

FIG. 7 is an explanatory view showing a method for forming a fore pile.

FIG. 8 is a cross-sectional view of a tunnel in which a fore pile lining body is formed.

FIG. 9 is an explanatory view showing another conventional method for forming a fore pile.

FIG. 10 is an explanatory view showing a state in which a high-pressure injection pipe is pulled out from a reinforcing steel pipe.

FIG. 11 is a side view of a conventional drilling device.

[Explanation of symbols]

 33 Steel pipe for reinforcement 35 Ring bit 37 Triple injection pipe 39 Inner bit 41 Water injection hole for drilling 43 Water injection pipe for drilling 45 Hardening material supply pipe 47 Hardening accelerator supply pipe 55 Ground 57, 61, 73, 81 Injection nozzle 63, 65 injection port 67 solidification formation part 69 drainage suction port 75 drainage port 77, 79 drilling device G hardening material G'hardening accelerator S discharge mud W drilling water

Claims (2)

[Claims] 1. An injection pipe is inserted into a reinforcing steel pipe, an inner bit attached to the tip of the injection pipe is projected from the tip of the reinforcing steel pipe, and then these are simultaneously excavated in the direction of excavation Rotationally press-fitted into the ground around the target ground, the drilling water sent to the jet pipe was jetted at high pressure from the inner bit jet hole in the direction of travel to drill the ground and was mounted on the tip side of the jet pipe. A high-pressure jet of drilling water is jetted backward from the drilling water injection nozzle into the reinforcing steel pipe, and the suction force of the jet causes suction and discharge of the soil from the mud suction port provided in the reinforcing steel pipe. After drilling the ground up to the point where the reinforcing steel pipe and the injection pipe were similarly press-fitted into the ground and the drilling water was injected at high pressure from the inner bit, the hardening material was injected from each injection nozzle mounted on the tip side of the injection pipe. And hardening accelerator, respectively, for reinforcing steel Simultaneously high-pressure injection from the injection port provided in the pipe to the side, and rapidly solidify the solidification formation part by mixing the surrounding soil with the hardening material and the hardening accelerator,
The sludge is sucked from the sludge suction port by the suction force of the jet water for high-pressure jetting from the jet nozzle described above, and is diluted with the drilling water to prevent its solidification and then discharged. After forming the solidified formation part to the position, the injection pipe together with the inner bit is pulled out and collected, and the fore pile with the reinforcing steel pipe as the core material is formed in the ground. 2. A reinforcing steel pipe having a drilling bit attached to the tip thereof, and a mud suction port and an injection port of a hardening material and the like opening to a peripheral wall of the tip side, and an inner bit attached to the tip of the reinforcing steel pipe. A triple injection pipe inserted into the reinforcing steel pipe by projecting the inner bit from the rotary injection mechanism, a rotary drive mechanism for rotating the triple injection pipe in a forward and backward direction, and a rotary drive for rotating the forward reinforcing steel pipe in a forward direction. The triple injection pipe consists of a hardening material supply pipe equipped with an injection nozzle for laterally high-pressure injecting the hardening material from the injection hole of the reinforcing steel pipe, and a hardening accelerator from the injection hole of the reinforcing steel pipe. It consists of a hardening accelerator supply pipe equipped with a jet nozzle for high-pressure jetting to the side, and a water injection pipe for drilling that communicates with the water injection hole for drilling provided in the inner bit. Inner bit of sludge suction port It is installed on the side, drilling apparatus for fore pile reclamation, characterized in that the injection nozzle for high-pressure injection is mounted drilling water to the reinforcing steel within the rear.