JP2585137B2 - Ground improvement method using solidified columns and drilling equipment for ground improvement - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a ground improvement method using a solidified column and a drilling device for the ground improvement, which is applied to, for example, the construction of a mountain tunnel.

(Conventional technology) When constructing a mountain tunnel or the like, for example, when excavating a face under conditions such as soft ground or little soil cover, it is necessary to prevent ground surface subsidence and reach the ground where the face collapses. In order to prevent the effects of
Some protective measures are taken.

FIG. 5 shows the construction status of a tunnel employing the upper half section advanced construction method as an excavation method. In the upper half face on the right side of the figure, the excavator
20 forms a consolidated horizontal column A 'in the ground G.

Among them, the solid horizontal column A 'shown by the solid line on the left is already provided in the ground G, and the one shown by the broken line is the one at the construction stage.

In addition, in FIG. 5, 21 is a sand pump provided in the mine, 22 is a shovel, 23 is a high pressure hose, 24 is a backhoe, 25 is a drain pipe, 26 is a cutter loader, 27 is a pump,
28 is a dehydrating machine, 29 is a backhoe, and 30 is a transformer.

FIG. 6 (a) is a longitudinal sectional view of the upper half section of FIG. 5, and FIG. 6 (b) is a detail of a cross sectional view. That is, FIG.
Indicates that by forming a consolidated horizontal column A 'in the ground G from an arbitrary location of the face, the excavation in the broken line portion protects the face face so as to be stable. FIG. 6 (b) is a cross-sectional view showing that a consolidated horizontal column A 'is continuously formed in a substantially cylindrical shape on the outer peripheral portion of the tunnel T. Is formed.

In FIG. 6 (a), the drilling length is the length for drilling the ground G by the drilling machine 20, and the improved length is the length of the consolidated horizontal column A '.

Such a protection method using the consolidated horizontal column A 'is an effective means in all aspects, such as reliable production, safety, and economic efficiency. It is used for various construction methods.

Next, a conventional drilling machine 20 for forming the consolidated horizontal column A 'and a forming sequence will be described. FIG. 7 shows the details of the drilling machine 20.
A power siebel 32 provided in front of 31, a jet siebel 33 provided behind the rod 31, a support 34a and a gantry 34 for supporting them, rotating disks 35 and 36 and a power unit 39 for moving the gantry 34 by rotation. , Motor 3
7, the crawler 38 and the like.

FIG. 8 shows the order of forming the consolidated horizontal columns A '. In the formation, first, (a) the water is spouted from the tip of the drilling rod 31 and the rod 31 is rotationally penetrated into the ground G to perform drilling.

(B) After reaching an arbitrary drilling length, switch to an injection liquid such as cement milk instead of drilling water. In addition, the tip of the rod 31 is replaced with one for drilling from one for drilling, or one with special processing on the rod tip, and the injection liquid is injected from the hole in the side wall of the rod tip. Prepare to be able to squirt.

(C) While ejecting the injection liquid at a high pressure from the hole in the side wall of the tip of the rod 31, the rod 31 is rotationally pulled out to form a consolidated horizontal column A ′ from the back side of the hole.

(D) Before the face, the pumping of the injection liquid is stopped, the rod 31 is pulled out from the ground G, and a stopper is driven in to prevent the injection liquid from flowing out.

By repeating the above operation, a substantially cylindrical protection wall is constructed.

In the above, as shown in FIGS. 9 (a) and 9 (b),
A conventional drilling rod 31 is used. This drilling rod 31 has a structure in which a tip 31b is provided at the tip of a cylindrical rod body 31a, and the diameter drilled by the tip 31b at the tip is slightly larger than the rod diameter of the rod body 31a. Although large, the size was such that friction did not work during rotational penetration or rotational withdrawal.

FIGS. 10 (a) and 10 (b) show a forming rod 31A.
An injection hole 31d for an injection liquid such as cement milk is formed at an appropriate position on the outer periphery of the rod body 31c, and a tip 31e is provided at the tip.

(Problems to be Solved by the Invention) When drilling is performed using the drilling rod 31 having the above configuration, and high-pressure cement milk is injected into the sand layer using the forming rod 31A by a conventional technique, sand and cement milk are mixed. Are mixed well, and a high-strength, high-quality consolidated horizontal column A 'can be formed. This is because the mixed content of fine particles of earth and sand in the consolidated horizontal column A 'to be formed is small, and the strength of the hardened cement milk is hardly reduced.

However, when pouring into a viscous soil layer, the properties of the soil are poor, and the conventional drilling rod 31 and the forming rod 31
In A, there is no function to discharge the bad cohesive soil layer to the outside, and even if cement milk is simply injected into the bad cohesive layer, the effect of cement milk cannot be used as the base, and the strength after solidification is weak and good consolidation level The formation of the column A 'is impossible, and the pressure of the high-pressure injected cement milk does not dissipate,
There is a problem that the conventional construction method is improperly used for a clay soil layer or the like and is not used because it stays in the ground and the ground is raised.

The present invention has been proposed in view of the above, and it is an object of the present invention to provide a drilling apparatus and a ground improvement method using a method of protecting a cohesive soil layer with a solidified column. Is to provide a law.

(Means for Solving the Problems) (1) According to the present invention, in short, the ground (G) is drilled by the drilling rod (1) provided in the drilling machine, and the formation rod (11) is formed. In the ground improvement method of improving the ground by injecting the injection liquid that becomes a solidified column body into the surrounding ground (G) of the drill hole, the forming rod (11) has a tip (13) at the tip. A rod (14) is wound around the rod body (12) at the rear of the rod body, and the notch (12-
2) Forming a passage (12-3) for discharging the cutting soil between the surrounding ground (G) and the surrounding ground (G), and discharging the cutting earth and sand to the outside while allowing the surrounding ground (G) and the injection liquid such as cement milk or the like to flow. To provide a solidified column, thereby achieving the above object.

(2) In addition, the tip (1)
The rod body (12) at the back of the rod body (12) is provided with a concave and spiral groove (16) that is one step lower than the outer peripheral surface of the rod body (12), and the cut soil is The above object is achieved by providing a solidified column by replacing the surrounding ground (G) with an injection liquid such as cement milk while discharging the liquid.

(3) Further, a drilling rod 1 of a drilling device to be used.
A cylindrical ring bit (4) in which a tip (3) is inserted in front of the rod body (2), and a rod body (2) and a support (6) are provided at the rear of the rod body (2). And a short cylindrical portion (5) larger than the diameter of the rod body (2) is provided to achieve the above object.

(Function) The present invention quickly discharges viscous soil cut by high-pressure injection of an injection liquid such as cement milk in a viscous soil layer or the like without mixing as much as possible with the injected injection liquid such as cement milk or the like. In order to discharge the earth and sand smoothly, a gap is created artificially on the peripheral surface of the construction rod 11 to enable rapid discharge of cutting earth and sand and replacement with an injection liquid such as cement milk. By providing a short cylindrical portion 5 larger than the diameter of the rod main body 2 at the rear of the rod main body 2 so that the earth and sand cut by the use rod 1 is smoothly discharged, a void is artificially generated, and consolidation has been performed so far. The protection method of the solidified column A can be applied to a clay layer where the construction of the column A is not applicable.

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described.

1 (a) and 1 (b) show a rod for drilling a clay or the like used in the present invention, wherein 1 is a rod for drilling and 2 is a component of a lot 1 for drilling. A cylindrical ring bit 4 is provided in front of the hollow cylindrical rod body, and a tip 3 is inserted into the ring bit 4 as shown.

Reference numeral 5 denotes an annular short cylindrical portion made of, for example, steel, which is arranged at the rear portion of the rod body 2 and has strength enough to withstand excavation of a clay soil layer or the like, and is provided on the inner peripheral side of the rod body 2. Are connected by the support 6.

The diameter of the short cylindrical portion 5 is larger than the diameter of the rod body 2 so that a space between the short cylindrical portion 5 and the rod body 2 can be easily provided by the difference. Have the same central axis.

Next, the operation of the drilling rod 1 having the above configuration will be described. First, the drilling rod 1 of the present invention is mounted on a rod of a drilling machine used conventionally. Thereafter, the drilling rod 1 is rotated and penetrated into the ground G by the driving device of the drilling machine in the same manner as when water is supplied from the rear part of the drilling machine rod and water is jetted from the tip of the drilling rod 1. The diameter drilled by the tip 3 and the ring bit 4 is
The earth and sand that has been cut by the drill
After passing through the gap between the rod body 2 and the rod, the gas passes through the gap between the drilled hole in the ground G following the short cylindrical portion 5 and the rod and is smoothly discharged out of the hole.

2 (a) and 2 (b) show an example of a rod for forming a consolidated column of the present invention used after the drilling step. In the figure, reference numeral 11 denotes a forming rod, and 12 denotes a forming rod 11. And a hollow rod body, the front of which is a plug 12-
1 is given. Further, a plurality of steel rods 14 are wound around the rod body 12 in a substantially spiral shape, for example, and are connected to the rod body 12 by welding or the like (not shown). Reference numeral 13 denotes a chip provided in front of the rod body 12, and reference numeral 15 denotes an ejection hole for an infusion liquid such as cement milk, which is bored on the outer periphery of the rod body 12.

Thus, since the rod 14 is wound around the rod body 12 and its height is larger than the thickness of the tip 13 in this example,
In the sectional view, the outer diameter plug drawn by the rod 14 is as shown at 14-1, and the rod 14 is provided with a notch 12-2 at an appropriate position. -2 forms a passage 12-3 for discharging cutting earth and sand.

Next, the operation of the construction rod 11 having the above configuration will be described.

The construction rod 11 is usually mounted on a conventional drilling machine, and inserted into a drilling such as a viscous soil layer formed on the ground G by the drilling rod 1 shown in FIG. High pressure injection of injection liquid such as cement milk from 15. In this case, the earth and sand cut by the high pressure injection is formed by a rod body 12 and a surrounding ground G formed by a spirally arranged rod 14.
, That is, through the discharge passage 12-3, and is discharged out of the hole. That is, as shown in FIG. 4, the solidified column A can be built by replacing the earth and sand in the surrounding ground G of the injection liquid such as cement milk, and the ground around the drilled portion can be improved. it can.

In the above description, the drilling rod 1 having the short cylindrical portion 5 having a larger diameter than the rod main body 2 is used, and after the gap is actively formed in the surrounding ground G by the short cylindrical portion 5, discharge of the cut sand is performed. Using a forming rod 11 having a passage 12-3 for
An example in which the surrounding ground G is replaced with the injection liquid has been described. However, since the spiral rod 14 is protrudingly provided on the outer periphery of the forming rod 11, the present invention is applied after the conventional drilling rod is used. In some cases, it is possible to form a gap between the outer periphery of the rod body 12 and the surrounding ground G by the rod 14 by using the forming rod 11 of It is also possible to replace the surrounding ground G with the injection liquid while discharging the cutting earth and sand through the use passage 12-3.

In the above, generally, the drilling rod 1 is attached to a conventional drilling machine, drilled almost horizontally, and then extended almost horizontally through the forming rod 11 (actually, slightly above the bevel). (Extending toward), which is usually referred to as a mortar horizontal column, but the mounting rod mounting part for drilling of a drilling machine is angled in the mounting direction. It is also possible to use the drilling rod 1 and the forming rod 11 of the present invention, in other words, to build the solidified column A at an angle with respect to the ground G.

The construction of the solidified column A is not limited to a substantially horizontal structure.

(Embodiment 2) Figs. 3 (a) and 3 (b) show another example of the forming rod 11A.
In this example, a concave and spiral groove 16 which is one step lower than the outer peripheral surface of the rod body 12A is provided.
Not only the gap with 12, but also a groove 16 is provided to enable soil removal. Other configurations are the same as the configuration of the forming rod 11 described above.

(Effects of the Invention) As described above, in the ground improvement method and the drilling apparatus used in the present invention, the rod 14 is wound around the formation rod 11, whereby the passage 12 for discharging the cutting earth and sand is formed between the rod 14 and the surrounding ground G. -3
Formed and smooth discharge of earth and sand can be performed, so that it is only necessary to process the conventional rod for formation, and it can be attached to the existing drilling machine, making it relatively easy with a slight improvement Even in a viscous soil layer or the like which has conventionally been unsuitable for the formation of a solidified column, the injected soil injected by high pressure allows the cut earth and sand to be discharged to the outside through the passage, so that the surrounding ground G and the cement Replacement with an infusion liquid such as milk becomes possible, and there is an effect that the ground can be surely improved.

Further, a groove 16 may be provided in the forming rod 11A. In this case, the rod 14 is not required to be attached by welding or the like, and a small forming rod can be provided. This is particularly effective when used in combination with a conventional drilling rod.

Further, since a short cylindrical portion 5 which is connected to the rear portion of the drilling rod 1 by the rod body 2 and the support 6 and is larger than the diameter of the rod body 2 is provided, drilling of the ground G by the drilling rod 1 is performed. Even at times, the discharge of excavated earth and sand becomes easy.

[Brief description of the drawings]

1 (a) is a front view of a drilling rod according to one embodiment of the present invention, FIG. 1 (b) is a side view, FIG. 2 (a) is a front view of the same construction rod, and FIG. Is a side view, FIG. 3 (a)
Is a front view of a forming rod according to another embodiment of the present invention,
Fig. 4 (b) is a side view, Fig. 4 is a conceptual diagram of ground improvement according to the present invention, Figs. 5 and 6 (a), (b) are tunnels formed by a general method of protection by a solid horizontal column. FIG. 7 is an explanatory view of a conventional drilling apparatus, FIG.
9 (a) to 9 (d) are process explanatory views of a conventional method, FIG. 9 (a) is a front view of a drilling rod used in a conventional drilling apparatus, FIG. 9 (b) is a side view, FIG. 10 (a) is a front view of a conventional forming rod, and FIG. 10 (b) is a side view. 1 ... drilling rod 2 ... rod body 3 ... tip 5 ... short cylindrical part 11,11A ... forming rod 12,12A ... rod body 12-3,16 ... ... passage for cutting earth and sand 14 …… Rod 15 …… Venting hole A …… Consolidated pillar G …… Peripheral ground

Claims (5)

(57) [Claims] A drill (1) provided in a drilling machine drills a ground (G), and an injection liquid to be a solidified column is formed around the drilling drill by a forming rod (11). In the ground improvement method of improving the ground by injecting into the ground (G), the formation rod (11) has a tip (13) at a tip,
A rod (14) is wound around the rod body (12) on the rear side, between the rods (14, 14) and the notch (12-2).
Forms a discharge path (12-3) for cutting earth and sand between the surrounding earth (G) and replaces the surrounding earth (G) with an injection liquid such as cement milk while discharging the cutting earth and sand to the outside. A ground improvement method using solidified pillars, characterized by providing solidified pillars. 2. A ground (G) is drilled by a drilling rod (1) provided in a drilling machine, and an injection liquid to be a solidified pillar is formed by a drilling rod (11) around the drilling hole. In the ground improvement method of improving the ground by injecting into the ground (G), the formation rod (11) has a tip (13) at a tip,
The rod body (1)
2) A concave and spiral groove (16), which is one step lower than the outer peripheral surface, is provided to replace the surrounding ground (G) with the injection liquid such as cement milk while discharging the cutting earth and sand to the outside. A ground improvement method using solidified pillars, characterized by providing solidified pillars. 3. The ground (G) is drilled by the drilling rod (1), and the ground (G) is replaced with an injection liquid such as cement milk to form a solidified column. A drilling machine equipped with a drilling machine for injecting an injection liquid such as cement milk into the surrounding ground (G) of the drilling by the rod for drilling (11), wherein the forming rod (11) has a tip (13) at the tip. Has,
A rod (14) is wound around the rod body (12) on the rear side, between the rods (14, 14) and the notch (12-2).
A ground improvement drilling device using a solidified column body, wherein a passage (12-3) for discharging cutting earth and sand is formed between the ground and the surrounding ground (G). 4. A method for drilling a ground (G) with a drilling rod (1) and replacing the ground (G) with an injection liquid such as cement milk to form a solidified column. A drilling machine equipped with a drilling machine for injecting an injection liquid such as cement milk into the surrounding ground (G) of the drilling by the rod for drilling (11), wherein the forming rod (11) has a tip (13) at the tip. Has,
The rod body (1)
2) A drilling device for ground improvement using a solidified column, wherein a concave and spiral groove (16) which is one step lower than the outer peripheral surface is provided. 5. A drilling rod (1) has a cylindrical ring bit (4) into which a tip (3) is inserted in front of a rod body (2), and a rear part of the rod body (2). 5. A fixed column according to claim 3, wherein a short cylindrical portion (5) is provided which is connected to the rod body (2) by the support (6) and is larger than the diameter of the rod body (2). Drilling device for soil improvement by body.