Steel pipe connection jig

Abstract

To reduce a workload of a worker when connecting steel pipes driven into the ground in a straight line by a push-fit method in an auxiliary method for tunnel construction.SOLUTION: A movable steel pipe receiver 33 of a steel pipe connection jig 30 is provided in a guide cell 23 of a driving drill jumbo 20. The movable steel pipe receiver 33 is advanced and retreated by an advance / retract drive unit 50. The movable steel pipe receiver 33 is provided with a receiving portion 33c that receives a steel pipe 10B to be spliced, and a holding portion 32. The holding portion 32 is advanced together with the movable steel pipe receiver 33 when advanced by the advance / retract drive unit 50, while being kept immovable relative to the steel pipe 10B, and is released from the steel pipe 10B after being pushed in and fitted by the advance.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a jig for connecting steel pipes in a straight line in an auxiliary method for mountain tunnel construction, and particularly to a steel pipe connection jig applied to steel pipes connected by push-fit instead of screw connection.

Background Art

[0002] When constructing a mountain tunnel by the NATM (New Australian Tunneling Method), in order to reinforce the ground being excavated, auxiliary methods such as the AGF (all ground fasting) method and the mirror bolt method may be implemented. In this type of auxiliary method, for example, a machine such as a drill jumbo is used to drive steel pipes into the ground. A plurality of steel pipes are sequentially connected in a straight line to make them longer. Generally, steel pipes are connected by screw connection (see Patent Document 1, etc.). The newly added steel pipe is mounted on the guide cell of the drill jumbo and arranged so as to be aligned in a straight line with the already driven steel pipe. Then, an operator uses tools such as a pipe wrench or a chain tong to manually pull out and rotate the added steel pipe to screw-connect it to the end of the already driven steel pipe. Such a screw connection method takes time because it is necessary to rotate the added steel pipe. In addition, the screw connection part becomes structurally weak.

[0003] Therefore, it has been proposed to connect steel pipes by push-fit instead of screw connection (see Patent Document 2, etc.). A plurality of locking claws arranged annularly are formed at the end of one steel pipe of the push-fit method. An annular locking groove is formed at the end of the other steel pipe. When the added steel pipe is pushed straight along the pipe axis toward the already driven steel pipe, the locking claws are elastically deformed and fitted into the locking groove to be locked. Thereby, the steel pipes can be connected with one touch by only linear movement.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the above - mentioned push - fit method, the steel pipe on the added side has to be strongly pushed in to elastically deform the locking claws, and for example, a force of about 1 kN is required. Therefore, even when using tools such as pipe wrenches and chain tongs, the workload is excessive with only manual labor. In addition, since the work is usually carried out on a high - altitude work platform such as the man - cage of a drill jumbo, the footing is poor and it is difficult to brace and obtain reaction force, and the working conditions are often more difficult. It was not easy to join using the existing mechanism of the drill jumbo as it was. In view of such circumstances, an object of the present invention is to reduce the workload of workers when connecting steel pipes driven into the ground in a straight line by a push - fit method in an auxiliary method for tunnel construction.

Means for Solving the Problems

[0006] To solve the above problems, the inventor conceived of applying a pushing force to the steel pipe on the added side on behalf of the worker using a steel pipe connection jig. The present invention is made based on such a concept, and is a steel pipe connection jig used in an auxiliary method for tunnel construction in which a plurality of steel pipes connected in a straight line by push - fit are driven into the ground, and It has a slide receiver that slidably receives the steel pipe to be added in the pipe axis direction, and a fixed steel pipe receiver fixed to the tip of the guide cell of the driving drill jumbo for driving, and A holding part that is provided in the front - rear direction of the fixed steel pipe receiver so as to be able to move forward and backward, and holds the steel pipe to be added in a non - relative - movement and releasable manner, and A forward - backward drive part that moves the holding part forward and backward. characterized by comprising

[0007] Furthermore, the present invention is a steel pipe connection jig used in a tunnel auxiliary construction method for driving a plurality of steel pipes connected in a straight line by push-fit into the ground, a moving steel pipe receiver provided in a guide cell of the drilling jumbo for driving, and a forward and backward drive unit for advancing and retracting the moving steel pipe receiver, comprising, wherein the moving steel pipe receiver is provided with a receiving portion for receiving a steel pipe to be added and a holding portion, and the holding portion is advanced together with the moving steel pipe receiver during forward movement by the forward and backward drive unit while maintaining a state in which it cannot move relative to the steel pipe to be added, and is separated from the steel pipe after the push-fit by the forward movement. The holding portion may be provided integrally with the moving steel pipe receiver. Preferably, the holding portion includes a clamp for clamping the steel pipe to be added.

Advantages of the Invention

[0008] According to the present invention, in an auxiliary construction method for tunnel construction, the work load of an operator when connecting steel pipes driven into the ground in a straight line by a push-fit method can be reduced.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Best Mode for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a tunnel 1 under construction by the NATM method. The natural ground 2 is being excavated to construct the tunnel 1. In the construction, as an auxiliary method for ground reinforcement, for example, a large number (only one is shown in the figure) of long front bearing steel pipes 9 (ground reinforcement pipes) are driven into the natural ground in front of the face by the AGF method. A drill jumbo 20 is used for driving. The long front bearing steel pipe 9 is composed of a plurality (for example, about four) of steel pipes 10. These steel pipes 10 are connected in a straight line.

[0011] As shown in FIG. 1, one-touch connection parts 11 are formed at the end 10e of the steel pipe on the tip side (left in FIG. 1) and the tip 10f of the steel pipe on the rear end side (right in FIG. 1) in two adjacent steel pipes 10. As shown in FIG. 2(a), the one-touch connection part 11 includes an annular locking groove 12 formed on the inner peripheral surface of the end 10e of the steel pipe on the tip side and a locking claw 13 formed on the tip 10f of the steel pipe on the rear end side. For example, the locking groove 12 is formed in a wedge-shaped concave cross-sectional shape. The locking claw 13 is formed in a wedge-shaped convex cross-sectional shape (see Patent Document 2). The locking claw 13 forms an annulus and is divided into a plurality of locking claw parts 13a by a slit 14. The locking claw part 13a and thus the locking claw 13 are locked in the locking groove 12. By inserting the tip 10f of the steel pipe on the rear end side into the inside of the end 10e of the steel pipe on the tip side, the locking claw 13 is fitted into the locking groove 12.

[0012] The end 10e and the tip 10f including the locking groove 12 and the locking claw 13 in the steel pipe 10 are preferably composed of high-tensile steel. The intermediate portion excluding the end 10e and the tip 10f of the steel pipe 10 may be composed of ordinary steel.

[0013] Note that a drilling rod 24 (shown only in FIG. 1) is inserted into the inner part of the previously received steel pipe 9. A drilling bit 25 is provided at the tip of the drilling rod 24. The rear end of the drilling rod 24 is connected to a drifter 26 on a guide cell 23 of a drill jumbo 20.

[0014] As shown in FIG. 1, a steel pipe connection jig 30 is prepared for connecting the steel pipes 10 to each other. The steel pipe connection jig 30 is incorporated in the drill jumbo 20. A boom 22 extends from the body 21 of the drill jumbo 20, and a guide cell 23 is provided at the tip of the boom 22. The steel pipe connection jig 30 is attached to the tip of the guide cell 23. Preferably, the steel pipe connection jig 30 is attachable and detachable with respect to the guide cell 23.

[0015] As shown in FIGS. 2(a) and 2(b), the steel pipe connection jig 30 includes a fixed steel pipe receiver 31, a movable steel pipe receiver 33, a telescopic guide 40 (guide member), and a reciprocating drive unit 50. The fixed steel pipe receiver 31 is composed of a thick steel plate. The fixed steel pipe receiver 31 is oriented so as to be orthogonal to the longitudinal direction (front-rear direction) of the guide cell 23 and is abutted against and fixed to the front end surface of the guide cell 23. As shown in FIG. 3, the fixed steel pipe receiver 31 has a pair of convex plate portions 31a, 31b. The convex plate portions 31a, 31b protrude upward from the left and right sides of the bottom of the fixed steel pipe receiver 31. The upper end heights of the left and right convex plate portions 31a, 31b are different from each other. A slide receiving portion 31c is formed between these convex plate portions 31a, 31b. The slide receiving portion 31c penetrates the fixed steel pipe receiver 31 in the front-rear direction and has a U-shaped hole shape opened at the upper end of the fixed steel pipe receiver 31, and receives the steel pipe 10B to be butt-welded so as to be slidable in the longitudinal direction of the guide cell 23. The pipe axis direction of the steel pipe 10B is oriented in the longitudinal direction of the guide cell 23. A steel pipe centralizer provided in the guide cell 23 may be used as the fixed steel pipe receiver 31.

[0016] As shown in FIG. 3, a telescopic guide 40 protrudes forward from the tip of the guide cell 23. The telescopic guide 40 includes a cylindrical fixed guide portion 41 and a cylindrical movable guide portion 42 that is smaller in diameter than the fixed guide portion 41, and has a double cylinder structure. The axial direction of the telescopic guide 40 is oriented in the longitudinal direction of the guide cell 23. The cross-sections of the fixed guide portion 41 and the movable guide portion 42 are square, but are not limited thereto and may be circular. The rear end portion of the fixed guide portion 41 is fixed to the fixed steel pipe receiver 31. As shown in FIGS. 2(b) and 4(a), the movable guide portion 42 is axially slidably accommodated inside the fixed guide portion 41. By the forward and backward movement of the movable guide portion 42, the telescopic guide 40 is telescoped in the axial direction (front-rear direction).

[0017] A moving steel pipe receiver 33 and a clamp 34 are disposed in front of the fixed steel pipe receiver 31 (leftward in FIG. 2(b)) via the telescopic guide 40. The moving steel pipe receiver 33 is movable back and forth in the front-rear direction by the telescoping of the telescopic guide 40. Further, the clamp 34 is included in a holding portion 32 that holds the steel pipe 10B in a non-relative movable and releasable manner with respect to the clamp 34.

[0018] Specifically, as shown in FIG. 2(a), the moving steel pipe receiver 33 is composed of a thick steel plate, similar to the fixed steel pipe receiver 31. The moving steel pipe receiver 33 is oriented so as to be orthogonal to the longitudinal direction (front-rear direction) of the guide cell 23 and is abutted against and fixed to the front end surface of the movable guide portion 42. As shown in FIG. 3, the moving steel pipe receiver 33 has a pair of convex plate portions 33a, 33b. The convex plate portions 33a, 33b protrude upward from the left and right sides of the bottom of the moving steel pipe receiver 33. The upper end heights of the left and right convex plate portions 33a, 33b are different from each other, and moreover, the height differences are opposite left and right to the convex plate portions 31a, 31b of the fixed steel pipe receiver 31. A receiving portion 33c is formed between the convex plate portions 33a, 33b. The receiving portion 33c penetrates the moving steel pipe receiver 33 back and forth and has a U-shaped hole shape that reaches the upper end of the moving steel pipe receiver 33. The receiving portion 33c receives the steel pipe 10B. The moving steel pipe receiver 33 and the fixed steel pipe receiver 31 face each other in the front-rear direction and are connected via the telescopic guide 40 so as to be able to approach and separate from each other.

[0019] As shown in FIGS. 2(a) and (b), a clamp 34 is disposed in front of the moving steel pipe receiver 33. Preferably, the clamp 34 abuts against the front surface of the moving steel pipe receiver 33. The clamp 34 is detachably attached to the outer periphery of the front portion of the steel pipe 10B that is ahead of the moving steel pipe receiver 33.

[0020] As shown by the solid line in FIG. 3, the clamp 34 includes a pair of clamp members 34a and a tightening tool 34b. Each clamp member 34a is formed in a semi-circular shape. The pair of clamp members 34a are rotatably connected via a hinge 34c. As shown by the two-dot chain line in FIG. 3, these clamp members 34a sandwich the steel pipe 10B from both sides. The ends of the clamp members 34a that are 180 degrees opposite to the hinge 34c are separably connected by the tightening tool 34b. The tightening tool 34b includes, for example, a bolt or the like. When the tightening tool 34b is tightened, the clamp 34 is fixed to the outer periphery of the steel pipe 10B. By loosening and removing the tightening tool 34b, the clamp 34 is separated from the steel pipe 10B.

[0021] As shown in FIG. 2(a), the reciprocating drive unit 50 includes a pair of hydraulic cylinders 51. The pair of hydraulic cylinders 51 are disposed on the left and right sides (upper and lower in FIG. 2(a)) with the telescopic guide 40 interposed therebetween. The cylinder portion 52 of each hydraulic cylinder 51 is connected to and supported by the side of the guide cell 23. The tip of the piston rod 53 of the hydraulic cylinder 51 is connected to the moving steel pipe receiver 33 directly or via a bracket (not shown). Although not shown, some hydraulic hoses of the drill jumbo 20 are connected to the hydraulic cylinders 51. Thereby, the hydraulic driving force of the hydraulic cylinders 51 is supplied from the drill jumbo 20. By the telescopic drive of the reciprocating drive unit 50 composed of the pair of hydraulic cylinders 51, the telescopic guide 40 is telescoped and the moving steel pipe receiver 33 is reciprocated.

[0022] The steel pipe connecting jig 30 is used as follows. <Driving-in process> As shown in Fig. 1, the pilot pipe 9 is driven into the ground 2 by the drill jumbo 20. Before the last pipe 10A of the pilot pipe 9 is completely buried in the ground 2, the driving is stopped, and the end 10e is projected into the tunnel 1.

[0023] <Steel pipe installation process> Subsequently, as shown in Fig. 3, the steel pipe 10B to be added is installed so as to straddle from the movable pipe receiver 33 to the fixed pipe receiver 31 of the pipe connection jig 30. The pipe connection jig 30 is inserted into and supported by the receiving portion 33c of the movable pipe receiver 33, and is inserted into and supported by the slide receiving portion 31c of the fixed pipe receiver 31. <Drilling rod addition process> Before and after the above steel pipe installation process, the drilling rod 24 (Fig. 1) is added by the length of the steel pipe 10B.

[0024] <Clamp mounting process> As shown in Figs. 2(a) and 2(b), a clamp 34 is mounted and clamped on the front portion of the movable pipe receiver 33 of the steel pipe 10B. The steel pipe 10B is clamped from both sides by a pair of clamp members 34a, and the clamp 34 is fixed to the steel pipe 10B by tightening the tightening tool 34b. Preferably, the clamp 34 is abutted against the front surface of the movable pipe receiver 33.

[0025] <Positioning process> Subsequently, as shown in Figs. 2(a) and 2(b), by operating the boom 22 of the drill jumbo 20, the pipe axis of the steel pipe 10B is aligned with the pipe axis of the pilot pipe 9 previously driven, and the tip 10f of the steel pipe 10B is brought close to the end 10e of the immediately preceding steel pipe 10A. Preferably, a worker A different from the operator (not shown) of the drill jumbo 20 is arranged near the connection planned portion of the steel pipes 10A and 10B on the elevated work platform 27, and the positioning is performed while the worker A confirms.

[0026] <Pushing-in process> Next, the hydraulic cylinder 51 of the forward and backward drive unit 50 is extended to drive the movable steel pipe receiver 33 forward. Then, as shown in Fig. 4(a), together with the movable steel pipe receiver 33, the clamp 34 abutting against the movable steel pipe receiver 33 moves forward, and the steel pipe 10B fixed to the clamp 34 moves forward. The steel pipe 10B slides on the slide receiving portion 31c. The telescopic guide 40 is extended.

[0027] The tip 10f of the advancing steel pipe 10B is pushed into the end 10e of the steel pipe 10A, and the locking claw 13 is elastically deformed and engaged with the locking groove 12 to be locked. As a result, the tip 10f of the steel pipe 10B is connected to the end 10e of the steel pipe 10A with one touch, and the steel pipe 10B can be added to the front receiving steel pipe 9 during the casting. The pushing force can be obtained by the forward and backward drive unit 50, and it is not necessary for the operator A to push it manually. Therefore, the operator A only needs to perform the positioning process. As a result, the burden on the operator A can be significantly reduced.

[0028] <Retraction process> Thereafter, by loosening the tightening tool 34b, the steel pipe 10B is released from the clamp 34. Preferably, the clamp 34 is removed from the steel pipe 10B. Further, as shown in Fig. 4(b), by contracting the hydraulic cylinder 51, the movable steel pipe receiver 33 is retracted (retreated), and the telescopic guide 40 is contracted. At this time, the receiving portion 33c is slid along the steel pipe 10B.

[0029] <Resumption of driving process> Subsequently, the drifter 26 (Fig. 1) is advanced along the guide cell 23 and connected to the end of the steel pipe 10B, and the driving of the front receiving steel pipe 9 by the drill jumbo 20 is resumed. By retracting (retreating) the movable steel pipe receiver 33 (Fig. 4(b)), it is possible to avoid the steel pipe connection jig 30 from becoming an obstacle to the steel pipe driving. Therefore, when resuming driving, it is not necessary to remove the entire steel pipe connection jig 30 from the guide cell 23 as long as only the clamp 34 is removed.

[0030] Repeat the above operation for the number of steel pipes 10 that make up the leading steel pipe 9. As a result, the leading steel pipe 9 of a predetermined length can be driven into the natural ground 2.

[0031] The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the movable steel pipe receiver 33 may integrally have a clamp for fixing the steel pipe 10B. The receiving portion 33c of the movable steel pipe receiver 33 may be a clamp that releasably clamps the steel pipe 10B. In this case, in the steel pipe installation process, when supporting the steel pipe 10B to be added to the movable steel pipe receiver 33, the steel pipe 10B is clamped by the clamp integral with the movable steel pipe receiver 33. Subsequently, in the pushing-in process by the advancing / retreating drive unit 50, the movable steel pipe receiver 33 and the clamp integral therewith are advanced, so that the steel pipe 10B is advanced and connected to the steel pipe 10A. Thereafter, in the retracting process, the clamp integral with the movable steel pipe receiver 33 is loosened, the clamp is released from the steel pipe 10B, and then the movable steel pipe receiver 33 and the clamp integral therewith are retracted. The telescopic guide 40 may integrally have the advancing / retreating drive unit 50.

Industrial Applicability

[0032] The present invention is applicable to an auxiliary construction method for ground reinforcement in the construction of mountain tunnels.

Explanation of Reference Numerals

[0033] 1 Tunnel 2 Natural ground 9 Long leading steel pipe 10 Steel pipe 10B Steel pipe to be added 10e End 10f Tip 11 One-touch connection part 12 Locking groove 13 Locking claw 13a Locking claw part 14 Slit 20 Drill jumbo 21 Machine body 22 Boom 23 Guide cell 24 Excavation rod 25 Excavation bit 26 Drifter 30 Steel pipe connection jig 31 Fixed steel pipe receiver 1c Slide receiving part 32 Holding part 33 Movable steel pipe receiver 33c Receiving part 34 Clamp 34a Clamp member 34b Tightening tool 34c Hinge 40 Telescopic guide 50 Forward and backward drive part 51 Hydraulic cylinder 52 Cylinder part 53 Piston rod

Claims

1. A steel pipe connection jig used in a tunnel auxiliary construction method for driving a plurality of steel pipes linearly connected by push-fit into the ground, comprising: a moving steel pipe receiver provided in a guide cell of the drilling jumbo for driving; a forward and backward drive unit for moving the moving steel pipe receiver forward and backward; The moving steel pipe receiver is provided with a receiving portion for receiving a steel pipe to be added and a holding portion. The holding portion is advanced together with the moving steel pipe receiver during forward movement by the forward and backward drive unit while maintaining a state of being immovable relative to the steel pipe to be added, and is separated from the steel pipe after the push-fit by the forward movement. A steel pipe connection jig characterized by this.

2. The steel pipe connection jig according to claim 1, wherein the holding portion is provided integrally with the moving steel pipe receiver.

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