KR20080112611A - Grouting method by direct-boring using the duplicate steel pipe - Google Patents

Abstract

A direct-boring double steel pipe grouting method is provided to perform direct-boring work and to improve the shear stress of a reinforcement area with a double steel pipe structure, to perform grouting work closely with a small quantity of grout materials, to extend the reinforcement length in case of using a urethane solution having the fast gel time as a grout material, and to perform grouting work evenly and closely. A direct-boring double steel pipe grouting method for reinforcing an excavated tunnel comprises the steps of perforating the ground using a direct-boring apparatus and inserting an outer steel pipe to the ground, separating a perforation bit and a rod from the direct-boring apparatus and removing the rod, inserting an inner steel pipe(50) having the outside diameter smaller than the inside diameter of the outer steel pipe to the inside of the outer steel pipe, installing a caulking material to a gap between the outer steel pipe and the perforated surface, and consolidating the ground.

Description

Grooving method by direct-boring using the duplicate steel pipe}

1A and 1B show a conventional direct drilling apparatus.

Figure 2 illustrates one embodiment of a direct drilling apparatus used in the present invention.

Figure 3 illustrates a lumen pipe used in the present invention.

Figures 4a to 4e is shown in each step of the perforated double steel pipe grouting method according to the present invention.

5 is a schematic diagram of a state in which the grout material is injected in a spiral motion.

<Description of the symbols for the main parts of the drawings>

10: outer steel pipe 11: strainer

20: Steel Shoe 21: Stuck

30: rod 31: section enlargement

40: punched bit 50: lumen

51: spacer material 70: caulking material

80: grout material 90: spray nozzle

100: ground

The present invention relates to a direct hole double steel pipe grouting method, and more particularly, in the direct hole grouting method in which the outer steel pipe is inserted at the same time as the ground drilling, the rod is removed by separating the bits for drilling the ground. After the lumen pipe is inserted, the construction method for grouting between the outer lumen and lumen.

The conventional underground excavation assistance method, which is a steel pipe grouting method, improves the order while reinforcing the ground, installs a steel pipe on the ground, and installs a packer inside the steel pipe to inject the grout material into the ground so that the steel pipe It is characterized by increasing the shear strength of soil and rock, and by integrating the ground. The steel pipe grouting method is widely used as a part of the tunnel reinforcing method in recognition of its effect.

In general, the steel pipe grouting method comprises the steps of drilling the ground; Inserting a steel pipe having a strainer installed in the drilling hole; Injecting a sealing material between the steel pipe and the drilling hole; Injecting cement while installing the packer; was made. Since this method proceeds to insert the steel pipe after drilling, in the soft soil ground where the drilling hole is not naturally maintained, it is difficult to insert the steel pipe due to the collapse of the drilling hole or the mixing of foreign substances, thereby reducing its applicability.

In order to improve the above problems, a direct drilling apparatus for enabling steel pipe insertion and ground drilling at the same time has been developed, which is an example of the direct drilling apparatus of Patent Registration No. 166423 of FIG. 1A and Utility Model Registration No. 300881 of FIG. 1B. The direct drilling device of the patent No. 166423 is a female thread processing on the inner circumferential surface of the distal end of the steel pipe (1) equipped with the strainer and is screwed with the drill bit (4), which is externally threaded on the outer circumferential surface, the steel pipe and the drilling bit is directly coupled It can be seen that. In addition, it can be seen that the direct drilling device of the Utility Model No. 300881 has a structure in which the steel pipe 1 and the drilling bit 4 are screwed together and the power transmission rod 3 is integrally coupled. This configuration required bits of the same size as the inner circumferential surface of the steel pipe, making it difficult to apply ordinary bits as they are, and increasing the material cost by not reusing the power transmission rods. Since the applied power is transferred directly to the steel pipe, the strainer mounted on the steel pipe is easily detached or causes a problem in the steel pipe.

 Accordingly, the inventors of the present application are formed with a plurality of injection holes for injecting grout material, the injection hole is a steel pipe equipped with a strainer; A steel pipe shoe connected to the end portion of the steel pipe and having an inner diameter smaller than that of the steel pipe tip portion; A rod coupling portion having a smaller size than the inner diameter of the steel pipe shoe and a cross-sectional enlargement portion extending from the bit coupling portion and having a size larger than the inner diameter of the steel pipe shoe. ; And a body extending from the head in a size smaller than the inner diameter of the steel pipe shoe and a size smaller than the inner diameter of the steel pipe shoe, the body being connected to the bit coupling part of the rod and into the steel pipe shoe. A drill bit for inserting and drilling the ground with the power received by being exposed to the outside of the head; By developing a separate bit perforated steel pipe grouting device characterized in that it comprises a, by allowing the ground reinforcement by the direct-hole steel pipe grouting method without combining the perforated bits and steel pipes, regardless of the size of the steel pipes conventional perforated bits Can be used in a direct drilling device while allowing the reuse of rods and the technology has been patented. (Patent registration No. 04697537, filed on April 30, 2004, registered on January 13, 2005)

Patent registration No. 0,67537 greatly improves the ease of construction of the perforated steel pipe grouting, thereby reducing the amount of work. However, due to the hardening of the grout material, the injection length is limited, and the amount of grout material to be injected is required. Therefore, a packer must be inserted before the grout material is injected into the steel pipe. .

The present invention can be applied to the soft ground by drilling the reinforcement directly, but also by applying a double steel pipe structure, by injecting grout material efficiently, even if a small amount of grout material is injected, the reinforcement area is further expanded, and the rigidity of the double steel pipe structure itself The purpose of the present invention is to provide a direct perforated double steel pipe grouting method that can improve the shear stress of the reinforcement part.

The present invention is a drill pipe reinforcing steel pipe grouting method, (a) a plurality of injection holes are formed in the injection hole is a strainer equipped with an outer steel pipe; A steel pipe shoe connected to the outer steel pipe tip and having an inner diameter smaller than that of the outer steel pipe tip; A bit coupling part having a smaller size than an inner diameter of the steel pipe shoe and a cross-sectional enlargement part extending from the bit coupling part and having a size larger than an inner diameter of the steel pipe shoe, which is disposed inside the outer steel pipe to transmit power applied from outside road; And a body extending from the head with a size larger than the inner diameter of the steel pipe shoe and a size smaller than the inner diameter of the steel pipe shoe, the body being connected to the bit coupling portion of the rod and inserted into the steel pipe shoe. And the head portion is exposed to the outside and drilled bits for drilling the ground with the received power; Inserting the outer steel pipe into the ground while drilling the ground using a jikcheon factory configured to include; (b) removing the rod by separating the punch bit and the rod from the direct drilling apparatus; (c) inserting the inner lumen of the outer lumen in which the outer diameter is smaller than the inner diameter of the outer lumen; (d) installing a caulking material in the gap between the outer steel pipe and the perforated surface; And (e) injecting a grout material between the outer steel pipe and the lumen pipe to solidify the ground by filling the grout material between the outer steel pipe and the ground through a strainer of the outer steel pipe. It provides a straight hole double steel pipe grouting method comprising a.

Hereinafter, the present invention will be described for each construction step according to the accompanying drawings.

1.step (a)

This step is a step of inserting the outer steel pipe 10 into the ground while drilling the ground (100) using jikcheon factory. (See Figure 4A)

In order to apply the straight hole double steel pipe grouting method according to the present invention, the inner lumen 50 must be inserted into the outer lumen 10 as described below.

Therefore, the direct mill factory should be able to separate the drill bit 40 for ground drilling and the rod 30 for transmitting power to the drill bit 40, as shown in FIG. The factory device is formed with a plurality of inlets, the inlet of the outer steel tube 10 is equipped with a strainer (11); A steel pipe shoe 20 connected to the distal end of the outer steel pipe 10 and having an inner diameter smaller than the inner diameter of the outer steel pipe distal end portion; To include a bit coupling portion 32 having a size smaller than the inner diameter of the steel pipe shoe 20 and the cross-sectional enlarged portion 31 extending from the bit coupling portion 32 and larger than the inner diameter of the steel pipe shoe 20. A rod 30 disposed inside the outer steel tube 10 to transfer power applied from the outside; And a body 41 extending from the head 42 with a size smaller than the inner diameter of the steel pipe shoe 20 and a size larger than the inner diameter of the steel pipe shoe 20, the body 41 is connected to the bit coupling portion 32 of the rod 30 is inserted into the steel pipe shoe 20, the head portion 42 is exposed to the outside and punched bit 40 for drilling the ground with the power received ); It is to use the configured including.

The outer steel pipe 10 is a structural steel pipe generally applied in a steel pipe grouting method for reinforcement and order, the outer peripheral surface is formed with a plurality of injection holes for injection of the grout material, the injection hole as shown in Figure 2a It prevents the backflow of the injection material (grout material). In addition, it may be processed so that the threaded portion is formed at both ends in case the connection of the outer steel pipe is required to insert to a predetermined depth. That is, one end of the male thread is processed on the outer peripheral surface and the other end of the female thread is processed on the inner peripheral surface so that the outer steel pipe can be extended by screwing.

The steel shoe (Steel Shoe, 20) is connected to the distal end of the outer steel pipe 10, the inner diameter is formed smaller than the inner diameter of the outer steel pipe 10 distal end portion while acting as a protrusion to separate the rod and the punch bit described later At the same time, the insertion of the outer steel tube is an important component to complete the present invention. That is, since the inner diameter of the steel pipe shoe 20 is smaller than the inner diameter of the distal end portion of the outer steel pipe 10, the cross-sectional enlarged portion 31 of the rod, which will be described later, is caught, and the rod 30 is drilled while drilling the ground 100. As the cross-section enlarged portion 31 of the rod pushes the steel pipe shoe 20, the outer steel pipe 10 also proceeds in accordance with the progress of the rod 30, thereby enabling the outer steel pipe to be inserted into the hole. At this time, it is preferable to further form an engaging protrusion 21 inward at the end of the steel pipe shoe 20 which is connected to the distal end of the outer steel pipe 10. This widens the area where the cross-section enlarged portion 31 of the rod is engaged with the steel pipe shoe 20 so that the propagating force of the rod 30 is transmitted to the steel pipe shoe 20 so that the steel pipe 10 is inserted into the hole. This is to facilitate the operation.

Steel Shoe (Steel Shoe) 20 may be configured to surround the outer end of the outer tube 10, or may be integrally combined or included in one configuration of the outer end of the outer tube (10). 2, the steel pipe shoe 20 is manufactured to wrap the outer steel pipe tip, and the steel pipe shoe 20 is more effective in protecting the outer steel pipe 10. The steel pipe shoe 20 does not directly contact the outer steel pipe 10 and the drilling bit 40 to be described later, the power applied from the outside (usually applied by the drifter of the perforator) is not directly transmitted to the outer steel pipe 10. By not allowing the outer steel pipe 10 to maintain a stable shape. That is, in the conventional direct drilling device, since the steel pipe 1 and the drilling bit 4 are directly screwed together, the power transmitted to the drilling bit 4 directly affects the steel pipe 1, and thus is formed on the outer circumferential surface of the steel pipe 1. The strainer mounted on the injection port is separated or caused the deformation of the steel pipe, but by connecting the steel pipe shoe 20 to the distal end of the outer steel pipe 10 to block the direct coupling of the steel pipe 10 and the punch bit 40 to the outer steel pipe 10 By protecting the steel pipe shoe 20 to act as a buffer to prevent direct power transmission to the outer steel pipe 10 to improve the conventional problem. The steel pipe shoe 20 is preferably higher in strength than the outer steel pipe 10 because it serves as a buffer for protecting the outer steel pipe 10 while being in direct contact with the perforated bit 40 at the tip of the outer steel pipe 10.

The rod 30 extends from the bit coupling portion 32 and the bit coupling portion 32 having a smaller size than the inner diameter of the steel pipe shoe 20, and has a cross-sectional enlargement portion larger than the inner diameter of the steel pipe shoe 20 ( 31), which is disposed inside the steel pipe 10 to transmit power applied from the outside to the punch bit 40. The cross section enlarged portion 31 extending from the bit coupling portion 32 of the rod is larger than the inner diameter of the steel pipe shoe 20 so that the force propagated by the rod 30 is increased by the cross section enlarged portion 31. Is transmitted to the steel pipe 10 so that the steel pipe 10 can proceed without direct contact with the drilling bit 40 so that the outer steel pipe can be inserted at the same time as the ground drilling. The rod 30 may be a rod that is usually applied in the steel pipe grouting method.

The punch bit 40 is a body 41 extending from the head portion 42 to a size smaller than the inner diameter of the head pipe 42 and the steel pipe shoe 20 larger than the inner diameter of the steel pipe shoe 20 Including, the body 41 is coupled to the bit coupling portion 31 of the rod is inserted into the steel pipe shoe 20 and the head 42 is exposed to the outside to perforate the ground with the power received . Perforated bit 40 may be used that is usually applied to ground boring regardless of the size of the outer steel tube (10). However, if the head portion 42 of the drill bit is formed with a size larger than the outer diameter of the outer steel pipe 10 and the steel pipe shoe 20 is a hole size larger than the steel pipe 10 and steel pipe shoe 20 It is completed to facilitate the insertion of the outer steel pipe and can reduce the breakage of the strainer 11 due to the friction of the drilling hole when the outer steel pipe is inserted.

To recap this step briefly:

The rod 30 is energized and operated to drill the ground. At this time, the rod 30 receives power to transmit power to the punch bit 40 so that the punch bit 40 can drill the ground, and as the ground drilling proceeds, the cross-sectional enlargement portion 31 of the rod is steel pipe. The outer steel tube 10 is inserted into the drilling hole by pushing the shoe 20. In this step, through this operation, the ground is drilled to a predetermined depth and the outer steel tube 10 is inserted at the same time.

2. Step (b)

This step is a step of removing the rod by separating the punch bit 40 and the rod 30 in the direct drilling device after completion of the ground drilling and the outer steel tube 10.

Figure 4b is a cross-sectional view of the state of completion of the outer steel pipe insertion and removal of the rod at the same time using the ground mill factory. Since the body 41 of the drill bit 40 and the bit coupling portion 32 of the rod 30 are detachably coupled to each other, when the ground drilling and the external steel tube insertion are completed, the drill bit 40 is connected to the rod 30. It is separated and left on the ground.

3. Step (c)

This step is a step of inserting the inner lumen 50 inside the outer lumen 10 with a smaller outer diameter than the inner lumen of the outer lumen. 4C is a cross-sectional view of the lumen inserted into the outer lumen.

Since the lumen 50 is inserted to reduce the injection amount of the grout material to be described later, it is preferable that both ends are blocked so that the grout material is not injected into the lumen 10. In addition, as shown in FIG. 3, when both ends are protruded in a conical shape, a space between the outer lumen 10 and the lumen 50 is formed like a funnel at the side where the grout is injected, so that the grout injection operation can be efficiently performed. In the perforated bit 40 side, it is possible to reduce the injection of the grout material by the protruding portion of the lumen.

In addition, a plurality of spacers 51 may be mounted on the outer circumferential surface of the lumen pipe 50 to maintain a constant distance from the outer lumen pipe 10. As shown in FIG. 3, the spacer 51 may freely adjust a gap between the lumen 50 and the outer lumen 10 by using a bolt having a thread formed on an outer circumferential surface thereof.

4. Step (d)

This step is to install the caulking material 70 in the gap between the outer steel tube 10 and the perforated surface. 3D is a sectional view of a state in which a caulking material 70 is installed. (See FIG. 5D)

The caulking material 70 is preferably completed to complete the installation work immediately when the insertion of the steel pipe is completed to prevent leakage and leakage of earth and sand, the required strength to withstand the grout material injection pressure is required.

5. Step (e)

In this step, the grout material 80 is injected between the outer steel pipe 10 and the inner steel pipe 50, and the grout material 80 is connected to the outer steel pipe 10 through the strainer 11 of the outer steel pipe 10. The step of solidifying the ground by allowing it to be filled between the ground. 5E is a cross-sectional view of the injection and solidification of the grout material 80 completed.

It is preferable to use a urethane chemical as the grout material 80. Urethane chemical solution saves construction time due to the fast gel-time, and is high strength, so it is more effective in strengthening the ground than when used as cement alone, and it has excellent characteristics in terms of ordering effect and early strength and limited injection.

In the conventional steel pipe grouting method, when urethane chemical is injected, the urethane chemical injected into the steel pipe passes through the strainer of the steel pipe inlet and reaches the gap between the steel pipe and the hole. Since the hardening, it was difficult to add a tight grout material, the steel pipe construction length was limited. However, when the double steel pipe structure is applied as in the present invention, the space in which the urethane chemical solution is injected becomes small, so even if the steel pipe reinforcement portion is extended, the urethane chemical solution is tightly spaced between the outer steel pipe and the lumen pipe and between the outer steel pipe and the ground before the solidification of the urethane chemical liquid. It can be injected to solidify the ground.

In addition, as the grout material 80, it is also possible to inject cement with a late gel time together with the urethane chemical.

On the other hand, during the grouting operation by injecting grout material through the injection nozzle 90 configured to continue along the center line of the drilling hole and bent in one direction, and performs a spiral rotational movement between the outer steel pipe 10 and the lumen pipe 50. It can be charged evenly. (See Fig. 5)

5 shows the injection nozzle 90 bent in the right direction, the injection nozzle 90 is provided with a cap 91 that can cover the outer steel pipe 10 during the grouting operation.

The grout material 80 injected between the outer steel pipe 10 and the inner steel pipe 50 through the injection nozzle 90 hits the inner circumferential surface of the outer steel pipe 50, which is curved, and is bent at the same reflection angle as the incident angle. The grout material movement is repeated and the spiral injection is carried out as a whole. As such, when the grout material is filled with a rotary screw type, an even and tight grouting operation is performed as compared to the conventional straight injection type injection.

According to the present invention as described above has the following effects.

First, direct drilling is performed, and the shear stress of the reinforcement part is improved by the double steel pipe structure.

second. Since the grout material is injected into a narrow space between the outer steel pipe and the lumen pipe, it is possible to perform a tight grouting operation with a small amount of grout material.

Third, even when the urethane chemical solution with fast gel time is used as the grout material, the reinforcement length can be increased.

Fourth, the grout material is injected in a spiral rotational movement between the outer steel pipe and the inner steel pipe, and even and tight grouting is performed.

Claims (4)

In steel pipe grouting method for drilling tunnel reinforcement, (A) the outer steel pipe 10 is formed with a plurality of injection holes in which the strainer 11 is mounted; A steel pipe shoe 20 connected to the distal end of the outer steel pipe 10, the inner diameter of which is smaller than the inner diameter of the distal end of the outer steel pipe 10; To include a bit coupling portion 32 having a size smaller than the inner diameter of the steel pipe shoe 20 and the cross-sectional enlarged portion 31 extending from the bit coupling portion 32 and larger than the inner diameter of the steel pipe shoe 20. A rod 30 disposed inside the outer steel tube 10 to transfer power applied from the outside; And a body 41 extending from the head 42 with a size smaller than the inner diameter of the steel pipe shoe 20 and a size larger than the inner diameter of the steel pipe shoe 20, the body 41 is connected to the bit coupling portion 32 of the rod 30 is inserted into the steel pipe shoe 20, the head portion 42 is exposed to the outside and punched bit 40 for drilling the ground with the power received ); Inserting the outer steel tube (10) into the ground while drilling the ground using a jikcheon factory configured to include; (b) removing the rod 30 by separating the punch bit 40 and the rod 30 in the direct drilling apparatus; (c) inserting the inner lumen 50 formed inside the outer lumen 10 with a smaller outer diameter than the inner diameter of the outer lumen 10; (d) installing a caulking material 70 in the gap between the outer steel tube 10 and the perforated surface; And (e) The grout material 80 is injected between the outer steel pipe 10 and the inner steel pipe 50 so that the grout material 80 passes through the strainer 11 of the outer steel pipe 10 to the outer steel pipe 10. Solidifying the ground to be filled between and the ground; Straight hole double steel pipe grouting method comprising a. In claim 1, The lumen pipe 50 is a straight hole double steel pipe grouting method, characterized in that both ends are used in the form of conical protrusions. In claim 1, The outer circumferential surface of the lumen pipe 50 is a direct hole double steel pipe grouting method, characterized in that a plurality of spacers 51 for maintaining the spacing with the outer steel pipe 10 is mounted. The method according to any one of claims 1 to 3, In step (e), the grout material 80 is injected through the injection nozzle 90 configured to be connected along the center line of the drilling hole and bent in one direction, and spirally rotates between the outer steel pipe 10 and the lumen pipe 50. Direct drilling double steel pipe grouting method, characterized in that evenly charged to exercise.

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