Steel pipe driving equipment, steel pipe driving method

Abstract

To provide a steel pipe installation device which can efficiently and safely install a steel pipe.SOLUTION: A steel pipe installation device has: an excavation shaft member 3 having an excavation bit 2 at its tip; a rotary drive device 5 for rotating the excavation shaft member 3; and a cylindrical earth removal member 7 having substantially the same diameter as that of a steel pipe P to be installed. The cylindrical earth removal member 7 has: an earth removal port 71 for removing excavation muck blown up through the steel pipe P to be installed; a connection part 75 for attachably / detachably connecting the cylindrical earth removal member 7 to / from the upper part of the steel pipe P to be installed; and a stopper 77 for securing a rotational reaction force during operation of the rotary drive device, for the steel pipe P. The steel pipe installation device having such a structure dispenses with troublesome work such as extension and separation of a plier, dispenses with extension of the excavation shaft member associated with the extension of the plier, and can efficiently and safely install the steel pipe.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a steel pipe driving device used for driving steel pipes using an excavation shaft member, and a steel pipe driving method using this device. Specific examples of the steel pipes to be driven include steel pipe piles, steel sheet piles, casings, and the like.

Background Art

[0002] When driving steel pipes such as steel pipe piles, for example, driving work using a method such as rotary impact penetration using a down-the-hole hammer is performed. Patent Document 1 (Japanese Patent Application Laid-Open No. 2017-193930) discloses the principle of rotary impact penetration of a steel pipe pile using a down-the-hole hammer.

[0003] (Principle of Driving Steel Pipes) The principle of rotary impact penetration of a steel pipe pile by a down-the-hole hammer is shown in FIGS. 5 and 6. FIG. 5 is a schematic view showing the principle of rotary impact penetration of a steel pipe pile by a down-the-hole hammer. FIG. 6 is a detailed view (left side of FIG. 6) showing the principle of rotary impact penetration of a steel pipe pile by a down-the-hole hammer, and a plan view (right side of FIG. 6) showing the engagement relationship between the steel pipe pile to be rotationally impact penetrated and the guide material.

[0004] As shown in FIG. 5, the steel pipe driving device used for driving the steel pipe pile P mainly includes a crane suspension type rotary drive device 81 and an excavation shaft member 82 (drill rod) connected to the rotary drive device 81.

[0005] The rotary drive device 81 rotationally drives the lower excavation shaft member 82. Below this rotary drive device 81, a substantially cylindrical earth discharge cap 87 that functions as earth discharge path control means is provided. As shown in FIG. 5, this earth discharge cap 87 is fixed to the lower end of the rotary drive device 81 so as to surround the upper part of the excavation shaft member 82. A gap is provided between the outer peripheral surface of the excavation shaft member 82 of the steel pipe driving device and the inner peripheral surface of the earth discharge cap 87 for discharging the excavation chips blown up by the air lift.

[0006] As shown in Figure 6, the drilling shaft member 82 is equipped with a down-the-hole hammer 83 below it, which has a piston for generating impact pressure. This drilling shaft member 82 is operably connected to the rotary drive device 81 by passing through the inside of the cylindrical portion of the soil discharge cap 87.

[0007] On the other hand, the lower end of the drilling shaft member 82 equipped with a down-the-hole hammer 83 is provided with an expandable and retractable drilling bit 85 for excavating the ground. As shown in Figure 6, an overhang 84 (an engaging portion that strikes vertically with the casing top P1 on the steel pipe pile side) is fixed to the outer circumferential surface above the drilling bit 85 and below the down-the-hole hammer 83 for applying impact force to the lower part of the steel pipe pile P.

[0008] The drilling bit 85 at the lower end of the steel pipe driving device is configured to be displaceable (i.e., expandable and contractible) between an expanded diameter state and a contracted diameter state. When the drilling bit 85 is in the contracted diameter state, it can be freely inserted into and removed from the steel pipe pile P. In the expanded diameter state, the drilling bit 85 protrudes outward, and the rotational trajectory of its outer end exceeds the outer diameter of the steel pipe pile P.

[0009] When driving the steel pipe pile P, as shown in Figure 5, an excavation shaft member 82 is inserted into the internal part of the steel pipe pile P, and an excavation bit 85 is extended from its tip opening. The excavation bit is then set in an expanded diameter state to excavate the target ground.

[0010] When driving steel pipe piles P using the steel pipe driving device configured as described above, a rotational force is applied to the drilling shaft member 82 by the rotary drive device 81, and at the same time, compressed air is supplied to the down-the-hole hammer 83 by the compressor. When compressed air is supplied to the down-the-hole hammer 83, the piston built into the down-the-hole hammer 83 moves up and down, and the impact force of the piston is transmitted to the drilling bit 85 at the tip of the hammer. As a result, continuous impact drilling can be performed on the ground to be drilled while applying rotation.

[0011] On the other hand, the driving air (compressed air) supplied to the down-the-hole hammer 83 not only drives the down-the-hole hammer, but also generates an air-lift effect inside the steel pipe pile P, blowing up the excavated spoil (excavated soil) cut out by the drilling bit 85. In other words, the excavated spoil (excavated soil) cut out by the drilling bit 85 is blown up in an air-lift manner by riding on the airflow originating from the driving air (compressed air) of the down-the-hole hammer 83, as shown by the arrows in Figure 5.

[0012] The excavated spoil blown up by the airlift effect is discharged from the upper end opening of the steel pipe pile P through the internal cavity of the steel pipe pile P (more specifically, a path consisting of the gap between the inner circumferential surface of the steel pipe pile P and the outer circumferential surface of the excavation shaft member 82, as shown by the arrows in Figure 5), and is further discharged to the outside through the soil discharge port of the soil discharge cap 87, which is positioned to cover the steel pipe pile P from above.

[0013] As described above, the steel pipe driving device advances by rotary impact excavation of the target ground, accompanied by the ejection of excavated spoil from the upper side of the steel pipe pile. As shown in Figure 6, when the steel pipe driving device advances, the overhang 84 fixed to the outer surface above the excavation bit 85 and below the down-the-hole hammer 83, and the casing top P1 (overhang / shoe ring) fixed to the inner wall side of the lower end of the steel pipe pile P, interfere with each other (collide with each other) in the vertical direction, causing the steel pipe pile P to be driven in in the direction of excavation.

[0014] Therefore, when the ground is excavated with the excavation shaft member 82 of the steel pipe driving device inserted into the steel pipe pile P, a striking force is simultaneously applied to the lower part of the steel pipe pile, causing the steel pipe pile P to follow the steel pipe driving device, and thus the impact driving of the steel pipe pile proceeds simultaneously with the excavation.

[0015] (Guiding material used in the installation of steel pipes) In the above-described principle of driving steel pipe piles, the rotational force of a rotary drive device is utilized, so it is necessary to secure a rotational reaction force (a reaction force source for rotation) of the rotary drive device 81. If a rotational reaction force of the rotary drive device 81 cannot be secured, it is not possible to apply rotational force to the tip of the drilling shaft member 82 (drilling bit 85). Therefore, Patent Document 2 (Japanese Patent Application Publication No. 2000-080876) discloses a means for securing a rotational reaction force of a rotary drive device, as shown on the right side of Figure 6. That is, in the prior art, a guide member G (guide frame) that guides the steel pipe pile P to be driven while preventing it from rotating, and a rotation-restricting member P3 (bar-shaped engaging member) fixed to the outer circumferential surface of the steel pipe pile P are used.

[0016] In the conventional technology, the guide frame G, as shown on the right side of Figure 6, has a space that can guide the steel pipe pile P to be driven in a predetermined direction, and a recess G3 (engagement portion) into which a rotation-restricting member P3 (bar-shaped engaging member) protruding from the outer surface of the steel pipe pile P fits. The elongated rotation-restricting member P3 of the steel pipe pile P is welded to the outer surface of the steel pipe pile P along its longitudinal direction. When driving the steel pipe pile P, the steel pipe pile P is guided in the driving direction by the guide frame G while maintaining a state in which the rotation-restricting member P3 protruding from the side surface of the steel pipe pile P is fitted into the recess G3 of the guide frame G (a state in which the rotation-restricting member P3 of the steel pipe pile P slide-engages with the recess G3 of the guide frame G).

[0017] By using a guide material G with such functionality to drive steel pipe piles P, the steel pipe piles P can be guided in the driving direction without deviating from the design position (pile center), and the rotation-stopping state of the steel pipe piles P is reliably maintained during the driving process, ensuring that the rotational force of the rotary drive device 81 is reliably applied to the excavation shaft member 82. Furthermore, stoppers are provided on the upper outer circumferential surface of the steel pipe pile P to be driven and on the inner circumferential surface of the surrounding soil-removing cap 87. When the rotary drive device 81 is driven, these two stoppers collide with each other, reliably transmitting the rotational reaction force secured by the guide material to the rotary drive device 81 via the steel pipe pile P and the soil-removing cap 87.

[0018] (Construction process for steel pipes using guide materials) Figure 7 shows an example of the process for driving steel pipes using the guide material G described above. A steel pipe pile is given as an example of a steel pipe. In the process illustrated in Figure 7, it is assumed that the top of the design pile is lower than the ground level (the installation surface of the guide material G), and that the steel pipe pile to be driven P is driven so that its top reaches the design pile top shown in the figure.

[0019] As shown in Figure 7(a), in the steel pipe pile driving process, first, the drilling shaft member 82 of the steel pipe driving device is inserted into the interior of the steel pipe pile P, and the drilling bit 85 is extended from its tip opening and set in an expanded diameter state. The guide member G is installed on the ground at a position higher than the design pile top. Then, in this state, the steel pipe driving device is suspended by a crane and the steel pipe pile P is passed through the guide space of the guide member G and the drilling bit 82 is set in the center of the pile.

[0020] Next, as shown in Figure 7(b), the steel pipe pile P is driven in via the guide member G by using a combination of rotary drilling with a rotary drive device and impact driving with a down-the-hole hammer. During the rotary drilling and impact driving processes, as shown on the right side of Figure 6, the steel pipe pile P is guided by the guide member G along the pile center in the driving direction while the bar-shaped rotation restraint member P3 fixed to the outer surface of the steel pipe pile P is fitted into the recess G3 of the guide member G (sliding engagement state).

[0021] As the steel pipe pile P is driven into the ground, the top of the steel pipe pile P approaches the guide member G. If the driving of the steel pipe pile P continues in this manner, the lower end of the soil removal cap 87 surrounding the upper outer surface of the steel pipe pile P will hit the guide member G, making it impossible to drive the steel pipe pile P any further. The guide space of the guide member G is large enough for the steel pipe pile P to pass through, but the soil removal cap 87, which has a larger diameter than the steel pipe pile P, cannot pass through. Furthermore, when the top of the driven steel pipe pile P passes the guide member G and the steel pipe pile P separates from the guide member G, it becomes impossible to secure rotational reaction force in the guide member G, and it also becomes impossible to guide the steel pipe pile P with the guide member G.

[0022] Therefore, in the prior art, before the lower end of the waste soil cap 87 reaches the guide material G, as shown in Fig. 7(c), the steel pipe pile driving device is first withdrawn from the steel pipe pile P being driven, and a yatco Y is welded and added to the head of the steel pipe pile P. The yatco Y is a tubular member (dummy pipe) with the same diameter as the steel pipe pile P, and like the steel pipe pile P, it has a rotation restraining member (bar-shaped engaging member) that fits into the concave portion G3 of the guide material G. That is, the yatco Y is designed to be substantially equal to the cross-sectional shape and dimensions of the steel pipe pile P.

[0023] As shown in Fig. 7(c), when the addition of the yatco Y to the head of the steel pipe pile P being driven is completed, an excavation shaft member 82 of approximately the same length as the added yatco length is added, and then, as shown in Fig. 7(d), the excavation shaft member 82 of the steel pipe pile driving device is inserted again into the inner cavity of the steel pipe pile P, the excavation bit 85 is protruded from the tip opening, and the excavation bit is set in an expanded diameter state. Then, by using a combination of rotary excavation by a rotary drive device and impact penetration by a down-the-hole hammer, the driving of the steel pipe pile P is resumed through the guide material G.

[0024] Incidentally, if the impact penetration of the steel pipe pile P proceeds as it is, the top end of the steel pipe pile P will pass through the guide material G. However, since the yatco Y is added to the head of the steel pipe pile P, even if the top end of the steel pipe pile P passes through the guide material G, the rotation restraining member fixed to the outer peripheral surface of the yatco Y remains in a state of fitting into the concave portion G3 of the guide material G, and the guide material G guides the steel pipe pile P in the driving direction through the yatco Y.

[0025] Then, as shown in Fig. 7(e), when the top end of the steel pipe pile P reaches the designed pile top end, the steel pipe pile driving device is withdrawn from the steel pipe pile P. Subsequently, the yatco Y is separated from and removed from the head of the driven steel pipe pile P.

[0026] The driving of the steel pipe pile is completed as above.

Prior Art Documents

Patent Documents

[0027]

Patent Document 1

[0028] Generally, a yattco, which is a temporary pile made of steel pipe, is used to drive the head of a driven pile or a dug pile into the ground or underwater. In recent years, in-situ excavation construction by rotary impact excavation such as steel pipe piles and steel sheet piles using an expanded-diameter down-the-hole hammer has been carried out, and the yattco is expected to have advanced functions different from the conventional ones. For example, in order to discharge the excavated soil by air lift, it is necessary to keep the cross-sectional area of the air flow path constant in order to maintain the pressure of the compressed air that drives the down-the-hole hammer. However, when the pile head descends into loose soil or water, the air dissipates and the pressure drops, making it impossible to blow up the excavated soil to a predetermined height, which may hinder the excavation. In addition, in the case of suspension type construction by a crane or the like (construction without using the leader of a pile driver), if the head of the steel pipe pile separates from the guide member (provided above the ground surface or water surface and serving as a source of rotational reaction force) during the driving of the steel pipe pile, it becomes impossible to secure the rotational reaction force to the guide member, and it also becomes impossible to guide the steel pipe pile with the guide member. Therefore, in the prior art, as shown in Fig. 7(c), a method of adding a yattco to the head of the steel pipe pile has been adopted.

[0029] However, in the above method, one yattco is required for each steel pipe pile to substantially stop the pile head of the steel pipe pile above the ground surface, water surface, guide member, etc. in the completed pile driving state, which is uneconomical.

[0030] In addition, adding a yattco during or before the driving of the steel pipe pile and detaching the yattco after the driving requires a lot of labor and time, which lacks safety and hinders the shortening of the construction period.

[0031] Furthermore, as a measure to shorten the critical path of the process, there are methods such as making the target steel pipe pile longer by the length of the pliers to eliminate the effort of extending the pliers during the driving work (for example, forming the steel pipe pile with the length including the pliers at the ordering (procurement) stage of the steel pipe pile, or welding the length of the pliers in advance as a separate process in parallel before the driving work). However, even in these cases, there is still the problem that material is wasted by the length of the steel pipe pile, making it uneconomical. Therefore, in any case where the pliers are integrated with the pile, the process of cutting off the pliers and the associated ancillary work, which are unnecessary in the pile driving process for the original design length, is required, and there was a need for process efficiency and resource conservation.

[0032] Furthermore, in conventional steel pipe driving equipment, there is a gap between the top of the steel pipe to be driven and the surrounding soil removal cap that allows it to be exposed to the outside air. As a result, compressed air used to airlift the excavated spoil inside the steel pipe leaks out through this gap, weakening the force of the airlift and hindering the removal of the excavated spoil by the airlift.

[0033] Therefore, in view of the problems of the conventional technology described above, the object of the present invention is to provide a steel pipe driving device and a steel pipe driving method using this device that enables efficient driving of steel pipes without relying on uneconomical means such as welding or gas cutting of each individual pile, when driving piles underground or underwater, or when, for other construction reasons, objects such as guide materials, construction jigs, or parts of the structure of the construction object are positioned close to the pile in a planar manner and occupy space at a position higher than the pile head when driving steel pipes.

[0034] Another object of the present invention is to provide a steel pipe driving device that enables efficient discharge of excavated spoil when driving steel pipes using an excavation shaft member, and a steel pipe driving method using this device. [Means for solving the problem]

[0035] The above purpose is, A drilling shaft member having a length approximately equal to the length of the steel pipe plus the length of the pliers, The drilling bit provided at the tip of the drilling shaft member, A rotary drive device for rotating the drilling shaft member, It has a cylindrical soil removal member provided below the rotary drive device so as to surround the upper part of the excavation shaft member, The aforementioned cylindrical soil removal member, Having a length at least approximately equal to the length of the pliers, A connecting part for detachably connecting the cylindrical soil removal member to the upper part of the steel pipes to be driven, A discharge port for removing excavated spoil blown up through the steel pipes being driven into the ground, This is achieved by a steel pipe driving device having [specific features / features].

[0036] In the above-described steel pipe driving device, it is preferable that the cylindrical soil removal member be configured to have approximately the same diameter as the steel pipe being driven.

[0037] Furthermore, in the above-mentioned steel pipe driving device, the connection portion of the cylindrical soil discharge member only needs to be a connection between the cylindrical member and the steel pipes that realizes various functional coordinations, such as the discharge path of excavated soil and the ability to supply rotational reaction force to the driving device, in order to achieve the purpose of pile driving and the accompanying pipe excavation. Various forms such as butt joints, fitting, engagement, and joining may be appropriately selected according to the purpose. For example, it has an insert-type connection structure that can be connected to the upper part of the steel pipes to be installed.

[0038] Furthermore, in the above-mentioned steel pipe driving device, the steel pipes have a rotation-suppressing means that, for example, engages with an engaging portion of a guide member to suppress the rotation of the steel pipes. In addition, in this case, the cylindrical soil-discharging member of the steel pipe driving device has a rotation-suppressing means that, for example, engages with an engaging portion of a guide member to suppress the rotation of the cylindrical soil-discharging member.

[0039] Furthermore, the cylindrical soil removal member described above has a stopper that fixes the rotational position of the steel pipes and the rotary drive device of the steel pipe driving device when connected to the steel pipes.

[0040] Furthermore, in the above-mentioned steel pipe driving device, the stopper of the cylindrical soil removal member engages with a stopper that is pre-installed on the steel pipe to be driven, thereby ensuring that the rotational reaction force is applied to the steel pipe when the rotary drive device is in operation.

[0041] Furthermore, the aforementioned objective is Insert the excavation shaft member of the steel pipe driving device into the steel pipe to be driven. The cylindrical soil removal member of the steel pipe driving device is connected to the top of the steel pipe to be driven. With the cylindrical soil removal member connected to the top of the steel pipes, the rotary drive device is activated. Steel pipes are driven into the target ground. This is achieved by a steel pipe installation method characterized by the above.

[0042] The above method for driving steel pipes involves using a guide to drive steel pipes, wherein after the upper part of the steel pipe to be driven passes through the guide, the steel pipe is driven into the target ground while the cylindrical soil removal member connected to the upper part of the steel pipe is guided by the guide. [Effects of the Invention]

[0043] In this invention, a cylindrical soil removal member is integrally provided with the steel pipe driving device. This cylindrical soil removal member can be attached to any length. Similarly, the excavation shaft member can also be attached to any length accordingly. Due to these features, for example, in sites where the design position of the steel pipe head is underground or underwater during construction, or in sites where the finished pile head (design pile top) is lower than the installation surface of means such as guide materials (which provide rotational reaction force), the cylindrical soil removal member performs various functions as a pliers with a length appropriate to the construction conditions of each site. This eliminates the need for pliers to be attached to the top of the steel pipe by welding or other means, thus shortening the length of the steel pipe (material length) and making it more economical. Furthermore, according to this invention, the troublesome work of adding or removing pliers to the steel pipe is completely eliminated. Therefore, according to this invention, it is possible to drive steel pipes economically, efficiently, and safely.

[0044] Furthermore, in this invention, the cylindrical soil-removing member of the steel pipe driving device is configured to have approximately the same diameter (approximately the same outer diameter) as the steel pipes to be driven. This allows the cylindrical soil-removing member of the steel pipe driving device to be connected to the upper part of the steel pipes to be driven, resulting in a flush surface between the cylindrical soil-removing member and the steel pipes (a nearly flat surface with virtually no step difference between them). As a result, it is possible to create a simulated continuous appearance, as if the steel pipes were extended. Even without pliers, it is possible to drive steel pipes into the ground or underwater during construction, even if the design location of the pipe heads is underground or underwater. Furthermore, it becomes possible to guide the steel pipes with guide materials without having to perform troublesome incidental work such as rearranging guide materials to accommodate the difference in diameter between the steel pipes to be driven and the cylindrical soil removal members. Also, even in construction sites where some kind of construction jig or structure is positioned in contact with the outer circumference of the above-ground protrusion of the pile, limiting the clearance to a narrow space where conventional soil removal caps cannot pass through and construction becomes impossible, the fact that they are the same diameter allows the cylindrical soil removal members to pass through and enables the driving of steel pipes.

[0045] Furthermore, in this invention, the connection portion of the cylindrical soil removal member has an insert-type connection structure that can be connected to the upper part of the steel pipes to be driven. That is, the cylindrical soil removal member, which has the same diameter as the steel pipe and is equipped with a rotation restraint, is fitted and connected to the upper end of the steel pipe. These features allow the rotary drive unit's rotation axis to be integrated with the center (pile center) of the steel pipes via an insertable structure that can be connected to the top of the cylindrical soil removal member and the attached steel pipes. This stabilizes the excavation axis, making it easier to control the driving posture of the steel pipes that will become the piles, and thus easier to maintain verticality and straightness, resulting in a high-quality and safe construction method. Furthermore, airtightness is ensured at the connection point of the cylindrical soil removal member, preventing air leakage and resulting pressure drop at the connection point. Therefore, the excavated spoil blown up through the steel pipes being installed (reliably blown up to the top without losing momentum along the way) can be reliably discharged from the soil removal port of the cylindrical soil removal member, even if the design position of the top of the steel pipes is underground or underwater during construction.

[0046] Furthermore, in the present invention, for example, a guide material used in conjunction with a steel pipe installation device has an engaging portion (e.g., a recess) that engages with a rotation-restricting means (e.g., a protrusion) provided by the steel pipes, and the steel pipes have a rotation-restricting means (e.g., a recess) that engages with the engaging portion (e.g., a protrusion) of the guide material to suppress the rotation of the steel pipes during installation. As a result, the guide material used in conjunction with the steel pipe installation device can function not only as a steel pipe guide means but also as a means for suppressing the rotation of the steel pipes.

[0047] Furthermore, in the present invention, the cylindrical soil-removing member of the steel pipe driving device has a rotation-restricting means (e.g., a protrusion) that engages with an engagement portion (e.g., a recess) of the guide material to suppress the rotation of the steel pipes. As a result, even after the steel pipes being driven have passed the guide material, a rotational reaction force can be secured through the engagement relationship between the cylindrical soil-removing member and the guide material, and a rotational reaction force can be secured until the completion of excavation, for example, even if the design position of the head of the steel pipe is in the air, ground, or water during construction.

[0048] Furthermore, in this invention, the stopper of the cylindrical soil removal member engages with a stopper pre-installed on the steel pipes to be driven, thereby ensuring rotational reaction force on the steel pipes when the rotary drive device is operating. Due to these features, even when the top of the steel pipes is lower than means such as guide materials, the steel pipe driving device can reliably ensure the rotational reaction force required during its operation via the cylindrical soil removal member. [Brief explanation of the drawing]

[0049] [Figure 1] This figure shows an example of the steel pipe installation device of the present invention. [Figure 2]This figure shows an example of the connection configuration between the cylindrical soil removal member of a steel pipe driving device and the head of a steel pipe (separated state, in the process of fitting, or in the process of separating, fitted state). [Figure 3] These are plan views (viewed from below) of the cylindrical soil removal member of a steel pipe driving device and a plan view (viewed from above) of a steel pipe pile. [Figure 4] This is a process diagram showing the method for installing steel pipes. [Figure 5] This is a diagram showing a conventional steel pipe installation device. [Figure 6] This diagram illustrates the principle of rotary impact driving of steel pipe piles using a down-the-hole hammer. [Figure 7] This is a process diagram showing a conventional method for installing steel pipes. [Modes for carrying out the invention]

[0050] The steel pipe driving device of the present invention is a device used for driving steel pipes using an excavation shaft member. Specific examples of steel pipes include steel pipe piles, steel pipe sheet piles, and casings. Hereinafter, a specific embodiment of the present invention will be described using a steel pipe pile as a specific example of a steel pipe. The guide material used as an example in this embodiment is the same as that used in the prior art (see the right diagram in Figure 6, etc.). The right diagram in Figure 6 will be referenced in the description of this embodiment.

[0051] (Steel pipe driving device) First, the configuration of the steel pipe installation device will be explained based on Figures 1, 2, and 3.

[0052] Steel pipe installation equipment • A drilling shaft member 3 equipped with a drilling bit 2 at its tip, • A rotary drive device 5 for rotating the drilling shaft member 3, A cylindrical soil removal member 7 is provided below the rotary drive device 5 so as to surround the upper part of the excavation shaft member 3. I have it.

[0053] The rotary drive unit 5 rotates the drilling shaft member 3 connected below it. This rotary drive unit 5 is configured to be suspended by crane equipment such as a mobile crane.

[0054] The excavation shaft member 3, like the conventional technology shown in Figure 6, is equipped with a down-the-hole hammer with a built-in piston for generating impact pressure below it. This excavation shaft member 3 is operably connected to the rotary drive device 5 by passing inside the cylindrical soil removal member 7. A gap is provided between the outer circumferential surface of the excavation shaft member 3 of the steel pipe driving device and the inner circumferential surface of the cylindrical soil removal member 7 for removing the excavated spoil (excavated soil) blown up by the air lift. The basic principle of the air lift for the excavated spoil is the same as that of the conventional technology shown in Figure 5.

[0055] The cylindrical soil removal member 7 is a cylindrical member with approximately the same diameter as the steel pipe pile P to be driven. That is, the cylindrical soil removal member 7 and the steel pipe pile P below it have approximately the same outer diameter. The cylindrical soil removal member 7 is fixed below the rotary drive device 5 so as to surround the upper part of the excavation shaft member 3 and is integrated with the rotary drive device 5. The steel pipe pile P to be driven is connected to the lower end of the cylindrical soil removal member 7. This cylindrical soil removal member 7 has the same function as conventional pliers and also functions as a soil removal path that guides the excavated spoil blown up by the air lift via the steel pipe pile P toward the soil removal port 71.

[0056] This cylindrical soil removal member 7 is • A soil discharge port 71 for discharging excavated spoil blown up through the steel pipe pile P to be driven, • A soil discharge cover 73 for guiding the soil discharged from the soil discharge port 71 downwards, • A connecting portion 75 that enables connection of the cylindrical soil removal member 7 to the steel pipe pile P (see Figure 2), A stopper 77 that takes rotational reaction force on the steel pipe pile P when the steel pipe pile P is passing through the guide material G, The cylindrical soil-removing member 7 has a rotation-restricting member 78 (engaging member) that takes rotational reaction force on the guide material G when the guide material G is passing through it.

[0057] The excavation shaft member 3 and the cylindrical soil removal member 7, which are provided at approximately equal lengths to the "yattoko" (pliers), are designed to be attached at any length. In other words, the "yattoko" referred to here is a member provided at the head of a steel pipe for the purpose of meeting some construction requirement, such as through which the excavation shaft member (3) is inserted, having an internal cavity that serves as a soil removal path, or supplying rotational reaction force to the pile driving device, and is designed to extend integrally with the steel pipe pile (P) as an extension to the rotary drive device (5), and its length is optimized for each device configuration and construction method. Therefore, the "yattoko" length is not particularly limited, and as long as it can fulfill the role of a "yattoko" for the purpose of the construction according to the construction conditions, it may have a predetermined length, or it may have any length. Therefore, there may be only one type of "yattoko" length, or multiple variations may be provided depending on the construction conditions and site conditions. Furthermore, in the case of multiple construction projects where the design (finished) height of the pile head differs for each pile, it is possible to configure the device such that the excavation shaft member 3 is set to a fixed length (for example, the maximum length required on site) and the length of the cylindrical soil removal member 7 is made variable according to the conditions of the construction target.

[0058] The soil discharge cover 73 of the cylindrical soil discharge member is provided on the outer surface of the cylindrical soil discharge member 7 so as to cover the soil discharge port 71. This soil discharge cover 73 plays a role in controlling the flow of excavated spoil that is blown out from the soil discharge port 71 so that it falls downward without scattering into the surroundings.

[0059] The connecting portion 75 of the cylindrical soil removal member (see Figure 2) is a part for detachably connecting the cylindrical soil removal member 7 to the upper part of the steel pipe pile P to be driven. As shown in Figure 2, the connecting portion 75 has an insert-type connecting structure that can be connected to the upper part of the steel pipe pile P to be driven. The outer diameter of the cylindrical connecting portion 75 is slightly smaller than the inner diameter of the steel pipe pile P, and as shown in Figure 2(b), the connecting portion can be inserted into and removed from the inside of the steel pipe (with little to no gap between it and the inner circumferential surface of the steel pipe pile P). When fitted together as illustrated in Figure 2(c), the cylindrical soil removal member 7 and the steel pipe pile P become one unit.

[0060] The stopper 77 of the cylindrical soil removal member is welded to the outer surface of the cylindrical soil removal member 7 and restricts the rotational movement of the interconnected steel pipe pile P and the cylindrical soil removal member 7. The stopper 77 plays a role in ensuring that the rotational reaction force (reaction force source of rotational force) of the rotary drive device 5 is supplied to the steel pipe pile P (the steel pipe pile P to be driven) when the steel pipe pile P is passing through the guide material G.

[0061] Two parallel stoppers 77 are provided on the side surface of the cylindrical soil removal member 7 so as to protrude downward from the lower end of the cylindrical soil removal member 7. As shown in Figures 2 and 3, two pairs of stoppers P7 that engage with these two stoppers 77 are provided on the outer circumference of the top of the steel pipe pile P, at positions facing each other with the pile center in between. As shown in Figures 2(b) and 2(c), when connecting the cylindrical soil removal member 7 to the top of the steel pipe pile P, the steel pipe pile P and the cylindrical soil removal member 7 are positioned such that the stoppers P7 of the steel pipe pile P fit between the stoppers 77 of the cylindrical soil removal member 7. In this embodiment, two stoppers 77 provided on the side surface of the cylindrical soil removal member 7 and a stopper P7 provided on the outer circumference of the head of the steel pipe pile P that engages with them are given as specific examples of the rotation-preventing member 78 of the cylindrical soil removal member 7, but the shape of the rotation-preventing member is not limited to these. In other words, any type of rotation-preventing member can be used as such, as long as the stopper member provided on the cylindrical soil-removing member 7 and the stopper on the steel pipe pile P can engage with each other, and the rotation of the steel pipe pile P can be prevented through this engagement relationship (for example, by providing an engagement structure such as a notch in the connecting part 75 which forms an nested connection structure with the top of the steel pipe attached to the cylindrical soil-removing member 7, thereby making the connecting part 75 function as a stopper, and providing a stopper member that engages with the notch on the inner circumferential surface of the head of the steel pipe pile P).

[0062] The rotation-retaining member 78 of the cylindrical soil-removing member 7 is provided as a protrusion on the outer surface of the cylindrical soil-removing member 7, as shown in Figures 2 and 3, and is composed of, for example, a bar-shaped elongated member. In addition, a member similar to the rotation-retaining member 78 of the cylindrical soil-removing member 7 (rotation-retaining member P3) is provided as a protrusion on the outer surface of the steel pipe pile P. The guide material G used in driving the steel pipe pile P is provided with a recess G3 (engagement portion) that can engage with the rotation-retaining member P3 of the steel pipe pile P and the rotation-retaining member 78 of the cylindrical soil-removing member 7. See the right diagram in Figure 6.

[0063] In this embodiment, a "convex structure" is given as a specific example of the rotation-restricting member 78 of the cylindrical soil-removing member 7, and a "concave structure" is given as a specific example of the rotation-restricting member P3 of the steel pipe pile P. However, the shape of the rotation-restricting member is not limited to these. That is, any rotation-restricting member can be used as long as the rotation-restricting member 78 of the cylindrical soil-removing member 7 and the rotation-restricting member P3 of the steel pipe pile P can engage with each other and achieve rotation-restriction of the steel pipe pile P through that engagement relationship (for example, a steel member attached to a predetermined position in the longitudinal direction of the steel pipe pile P with a length exceeding the excavation length, such as a joint for a steel sheet pile).

[0064] During the installation of steel pipe piles P, when the steel pipe pile P passes through the guide material G, the rotation-restricting member P3 of the steel pipe pile P slides while engaged with the recess G3 (engaging portion) of the guide material G. On the other hand, when the steel pipe pile P passes through the guide material G and the cylindrical soil removal member 7 passes through the guide material G, the rotation-retaining member 78 of the cylindrical soil removal member 7 slides while engaged with the recess G3 (engaging portion) of the guide material G. Therefore, regardless of whether the guide material G is guiding the steel pipe pile P or the cylindrical soil removal member 7, the rotational suppression effect (anti-rotation effect) of the guide material G is exerted, and the rotational reaction force of the rotary drive device 3 is ensured through the guide material G.

[0065] (Method for installing steel pipes) Next, a method for driving steel pipes using the steel pipe driving device and guide material configured as described above will be explained based on Figure 4. A steel pipe pile will be given as an example of a steel pipe. In the process illustrated in Figure 4, it is assumed that the top of the design pile is lower than the ground level (guide material installation surface), and that the steel pipe pile to be driven is driven so that the top of the steel pipe pile reaches the design pile top shown in the figure.

[0066] As shown in Figure 4(a), in the steel pipe pile driving process, first, the drilling shaft member 3 of the steel pipe driving device is inserted into the internal cavity of the steel pipe pile P, the drilling bit 2 is extended from its tip opening, and the drilling bit is set in an expanded diameter state. Furthermore, when inserting the excavation shaft member 3 into the steel pipe pile P, the cylindrical soil removal member 7 of the steel pipe driving device is connected to the upper part of the steel pipe pile P. At this time, as shown in Figure 2(b), the connecting portion 75 of the cylindrical soil removal member 7 is fitted into the upper inside of the steel pipe pile P and secured with a spigot. Furthermore, when inserting the excavation shaft member 3 into the steel pipe pile P, the steel pipe pile P and the cylindrical soil removal member 7 are positioned such that the stopper P7 of the steel pipe pile fits between two stoppers 77 that protrude downward from the lower end of the cylindrical soil removal member 7, as shown in Figures 2(b) and (c). The rotational reaction force of the rotary drive device 5 is secured to the steel pipe pile P by the mutual engagement of the stoppers 77 and P7. Furthermore, in cases where the design location of the pile head is underground, including hard ground or bedrock, the stopper 77 should be constructed with the minimum necessary thickness in the design so as not to create resistance to penetration into the ground. As described above, when the connecting portion 75 of the cylindrical soil-removing member 7 is fitted into the upper inside of the steel pipe pile P and interlocked, the top end of the steel pipe pile P abuts against the stepped portion 79 at the base end of the connecting portion 75 of the cylindrical soil-removing member 7, and the cylindrical soil-removing member 7 and the steel pipe pile P become one. As shown in Figure 2(c), in the integrated state, the cylindrical soil-removing member 7 and the steel pipe pile P are connected in a flush state (a nearly flat state with almost no step between them). The above-described interlocking joint allows the rotational shaft of the rotary drive device 5 and the center (pile center) of the steel pipe pile P to be integrated, resulting in a robust and stable excavation shaft. This makes it easier to control the driving posture of the steel pipe pile P, which will become the pile, and helps maintain verticality and straightness, enabling safer work and ensuring high quality. Then, in this state, the steel pipe driving device is suspended by a crane, the steel pipe pile P is passed through the guide space of the guide material G, and the drilling bit 2 is set in the center of the pile. The guide material G is composed of multiple H-shaped steel beams or other steel materials arranged in a grid or lattice pattern, as illustrated in the right side of Figure 6, for example. The inner space enclosed by these steel materials functions as a space for guiding the steel pipe pile P. The configuration of the guide material G is not necessarily limited to the above; any configuration capable of guiding the steel pipes to be driven can be used.

[0067] Next, with rotational reaction force secured to the steel pipe pile P by stoppers 77 and P7, the rotary drive device 5 is activated, and as shown in Figure 4(b), the steel pipe pile P is driven in via the guide member G by using a combination of rotary excavation by the rotary drive device and impact driving by a down-the-hole hammer. During the rotary excavation and impact driving processes, the steel pipe pile P is guided in the driving direction by the guide member G while the bar-shaped rotation restraining member P3 fixed to the outer surface of the steel pipe pile P is engaged in a state (sliding engagement state) with the recess G3 of the guide member G.

[0068] As the impact driving of the steel pipe pile P progresses, the top of the steel pipe pile P approaches the guide member G. If the impact driving of the steel pipe pile P continues in this manner, the top of the steel pipe pile P being driven will pass through the guide member G and the steel pipe pile P will move away from the guide member G, but a cylindrical soil removal member 7, which has approximately the same diameter as the steel pipe pile P, is connected directly above it. Therefore, unlike conventional soil removal caps, the cylindrical soil removal member 7 in this embodiment can pass through the guide space of the guide member G, as shown in Figure 4(c). In addition, a rotational restraining member 78 (for example, a bar-shaped elongated member) is provided on the outer surface of the cylindrical soil removal member 7, similar to the steel pipe pile P, so that even if the top of the steel pipe pile P being driven passes through the guide member G and the steel pipe pile P moves away from the guide member G, a rotational reaction force can be secured to the guide member G via the cylindrical soil removal member 7.

[0069] Then, as shown in Figure 4(d), when the top of the steel pipe pile P reaches the design pile top, the connection between the cylindrical soil removal member 7 and the steel pipe pile P is released, and the steel pipe driving device is withdrawn from the steel pipe pile P, completing the driving of the steel pipe pile P.

[0070] According to the steel pipe driving device described above, even in sites where the finished pile head (design pile top) is lower than the guide material G, uneconomical pliers like those shown in Figure 7 become completely unnecessary, eliminating the troublesome work of extending or detaching pliers that was previously required. Furthermore, the extension of the excavation shaft member 82, which was necessary when extending the pliers, also becomes completely unnecessary. Therefore, according to the present invention, it is possible to drive steel pipe piles efficiently and safely. Furthermore, airtightness is ensured at the connection portion 75 of the cylindrical soil removal member 7, preventing air leakage at the connection portion. Therefore, the excavated spoil blown up through the internal cavity of the steel pipe pile P being driven (reliably blown up to the top without losing momentum along the way) is reliably discharged from the soil removal port 71 of the cylindrical soil removal member 7.

[0071] In the embodiments described above, steel pipe piles were given as an example of steel pipes, but the steel pipes that can be driven using the present invention are not limited to these, and the present invention can also be applied to the driving of, for example, steel sheet piles and casings. [Explanation of Symbols]

[0072] 2 drilling bits 3. Drilling shaft member (drill rod) 5. Rotary drive device 7 Cylindrical soil removal member 71 Soil discharge port 73 Soil removal cover 75 Connection part 77 Stopper (means for fixing the position in the circumferential direction) 78 Rotation restraining member (engaging member) 79 Step part 81 Rotary drive device 82 Drilling shaft member (drill rod) 83 Down-the-Hole Hammer 84 Overhang 85 drilling bits 87 Soil Removal Cap Y pliers (dummy tube) P Steel pipe pile (steel pipes) P7 Stopper (means for fixing the position in the circumferential direction) P1 Casing Top P3 Rotation restraint member (engaging member) G Conductor G3 Recess (engaging part)

Claims

1. A steel pipe driving device for driving steel pipes using an excavation shaft member, wherein when driving the steel pipes, the device uses a rotational drive device for the crane-suspended excavation shaft member to guide the steel pipes to be driven with a guide material, A drilling shaft member having a length approximately equal to the length of the steel pipe plus the length of the pliers, The drilling bit provided at the tip of the drilling shaft member, A rotary drive device for rotating the drilling shaft member, It has a cylindrical soil removal member provided below the rotary drive device so as to surround the upper part of the excavation shaft member, The aforementioned cylindrical soil removal member is Having a length at least approximately equal to the length of the pliers, A connecting part for detachably connecting the cylindrical soil removal member to the upper part of the steel pipes to be driven, A discharge port for removing excavated spoil blown up through the steel pipes being driven into the ground, It has, A steel pipe driving apparatus characterized in that, in the process of driving the steel pipes by guiding them with the guide material, the cylindrical soil removal member has approximately the same diameter as the steel pipes so that the cylindrical soil removal member can pass through the guide material after the steel pipes.

2. The connection portion of the cylindrical soil removal member is It has an insert-type connecting structure that can be connected to the upper part of the steel pipes to be driven into the ground. The steel pipe driving apparatus according to feature 1.

3. The aforementioned steel pipes have rotation-preventing means for preventing the rotation of the steel pipes. The steel pipe driving device according to claim 1 or 2.

4. The cylindrical soil discharge member of the steel pipe driving device has a rotation suppression means for suppressing the rotation of the cylindrical soil discharge member. The steel pipe driving device according to feature 3.

5. The aforementioned cylindrical soil removal member is The system includes a stopper that serves as a means for fixing the rotational position of the steel pipes and the rotary drive device in the steel pipe installation device when they are connected to the steel pipes. A steel pipe driving device according to any one of features 1 to 4.

6. The stopper of the aforementioned cylindrical soil removal member is By engaging with a stopper pre-installed on the steel pipes to be driven, the rotational reaction force during the operation of the rotary drive device is secured to the steel pipes. The steel pipe driving device according to feature 5.

7. A method for driving steel pipes using the apparatus described in any one of Claims 1 to 6, Insert the excavation shaft member of the steel pipe driving device into the steel pipe to be driven. The cylindrical soil removal member of the steel pipe driving device is connected to the top of the steel pipe to be driven. With the cylindrical soil removal member connected to the top of the steel pipes, the rotary drive device is activated. Steel pipes are driven into the target ground. A method for installing steel pipes, characterized by the features described above.

8. A method for driving steel pipes using guide materials, After the upper part of the steel pipe to be driven passes through the guide material, the cylindrical soil removal member connected to the upper part of the steel pipe is guided by the guide material while the steel pipe is driven into the target ground. The method for driving steel pipes according to feature 7.

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