Pole construction method

Abstract

To provide a pole construction method which reduces construction costs, facilitates construction management, and contributes to construction within a construction period.SOLUTION: The pile construction method includes a pile driving step of driving a pile into the ground, and a joining step of joining a support column erected from an upper end of the pile to the pile to form a pole, wherein the pile driving step includes an all-round rotary excavator installing step of installing an all-round rotary excavator mounted with the pile on a ground surface, a pile penetration step of penetrating the pile into the ground by rotation and press-in force of the all-round rotary excavator, and a concrete filling step of filling concrete into a tip side of a hollow portion formed by removing earth and sand inside the pile in the pile penetration step to construct tip closed concrete.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pole construction method for constructing a pole consisting of a stake and a support. [Background technology]

[0002] Patent Document 1 discloses a technique for constructing large-diameter piles, which involves drilling a hole in the ground with an earth drill or the like, removing the soil and sand from inside to create a pile hole, inserting a prefabricated pile (made of concrete, steel pipe, etc.) into the hole, and then filling the space between the outer surface of the prefabricated pile and the hole wall with soil and sand or a filler material (mortar, cement milk, etc.) to secure the prefabricated pile to the ground. Patent Document 2 discloses a technique for cases in which, when the ground is relatively soft, a biodegradable plastic casing with an outer diameter slightly larger than the outer diameter of the pile is used to drill a hole, and the casing is rock-pressed in with a rocking device while the soil inside the casing is excavated and removed using a hammergraf, forming a pile hole while the hole wall is held in place by the casing. In Patent Document 2, after the hole has been drilled, concrete is poured into the casing to create a pile foundation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-150433 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-274745 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Documents 1 and 2 require three steps: drilling a pile hole in the ground, inserting a steel pipe pile into the drilled hole, and filling the gap between the outer surface of the steel pipe pile and the hole wall with a filler (soil, mortar, cement milk, etc.) to secure the steel pipe pile. This lengthens the construction period and may not be completed in time for the construction of poles that are manufactured by attaching supports to the piles. Furthermore, the construction requires a large amount of heavy machinery and labor, resulting in high construction costs. Furthermore, a filler must be filled between the steel pipe pile and the hole wall, which requires material costs for the filler and proper construction management to ensure sufficient filling.

[0005] The present invention has been made to solve the above-mentioned problems, and provides a pole construction method that reduces construction costs, simplifies construction management, and allows construction to be completed on time. [Means for solving the problem]

[0006] The pole construction method of the present invention comprises a pile driving process of driving a pile into the ground, and a joining process of joining a support pillar erected from the top end of the pile to the pile to form a pole. The pile driving process comprises a full-circle rotary excavator installation process of installing a full-circle rotary excavator equipped with the pile on the ground surface, a pile penetration process of penetrating the pile into the ground by rotating and pressing the full-circle rotary excavator, and a concrete filling process of removing soil and sand from inside the pile during the pile penetration process and filling concrete into the tip side of the hollow part to form a tip-blocking concrete. [Effects of the Invention]

[0007] According to the present invention, piles are driven directly into the ground. This eliminates the three steps of pile hole excavation, pile insertion, and gap filling for pile fixation. This reduces construction costs, simplifies construction management, and allows construction to be completed on time. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic diagram showing a pole according to the first embodiment. [Figure 2]3 is a flowchart showing a pole construction method according to the first embodiment. [Figure 3] FIG. 3 is a schematic diagram showing a process for installing the full-circle rotary excavator according to the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing a pile penetration step according to the first embodiment. [Figure 5] 1 is a schematic diagram showing a cutting blade according to a first embodiment. FIG. [Figure 6] FIG. 10 is a schematic diagram showing the upper pile connection penetration step according to the first embodiment. [Figure 7] FIG. 4 is a schematic diagram showing a piling process according to the first embodiment. [Figure 8] 3 is a schematic diagram showing a stopping member according to the first embodiment. FIG. [Figure 9] FIG. 4 is a schematic diagram showing a removal step according to the first embodiment. [Figure 10] FIG. 3 is a schematic diagram showing a concrete filling step according to the first embodiment. [Figure 11] 3 is a schematic diagram showing a displacement preventing member according to the first embodiment. FIG. [Figure 12] FIG. 4 is a schematic diagram showing a backfilling step according to the first embodiment. [Figure 13] 5A to 5C are schematic diagrams illustrating a joining step according to the first embodiment. [Figure 14] 5 is a schematic diagram showing a step of joining upper and lower supports according to the first embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below. Each figure is a schematic illustration, and the relative size and thickness of each member are not limited to the dimensions shown. Furthermore, the size relationships between each component member in the following drawings may differ from the actual ones.

[0010] Embodiment 1 FIG. 1 is a schematic diagram showing a pole 1 according to a first embodiment. As shown in FIG. 1, the pole 1 stands upright on the ground 3 and supports a net 2. The net 2 is, for example, a ball net or a dust net, and is connected to a net mounting member attached to the pole 1 by wire or the like. The pole 1 has stakes 10 and supports 20, and a plurality of poles 1 are provided adjacent to each other, for example. The net 2 is fixed by being attached to a plurality of adjacent poles 1. Note that the pole 1 is not limited to one for fixing the net 2, and may also be used as a pole consisting of stakes 10 and supports 20, such as a lighting pole or a steel tower.

[0011] The pile 10 is, for example, a steel pipe buried in the ground and includes a lower pile 11 (see FIG. 6) located at the bottom and an upper pile 12 (see FIG. 6) connected to the lower pile 11 and located above. If the length of the pile 10 can be short, the upper pile 12 can be omitted, leaving only the lower pile 11. The pile 10 is not limited to being made of steel pipe, but may also be made of concrete. Furthermore, the pile 10 may be a steel pipe concrete pile, which is a concrete pile made by injecting high-strength concrete into the hollow portion of a steel pipe and then centrifugal compaction. The support pillar 20 is, for example, a steel pipe provided at the top of the pile 10 and includes a lower support pillar 21 located at the bottom and an upper support pillar 22 connected to the lower support pillar 21 and located above. If the length of the support pillar 20 can be short, the upper support pillar 22 can be omitted, leaving only the lower support pillar 21. The support pillar 20 is not limited to being made of steel pipe, but may also be made of concrete.

[0012] FIG. 2 is a flowchart showing a pole erecting method according to the first embodiment. Next, the pole erecting method will be described. As shown in FIG. 2, the pole erecting method is carried out by a plurality of steps. The pole erecting method includes a pile driving step (step ST0), a joining step (step ST8), an upper and lower support joining step (step ST9), and an extension step (step ST10). Of these, the pile driving step is a step of driving a pile 10 into the ground, and includes a full-circle rotary excavator installation step (step ST1), a pile penetration step (step ST2), an upper pile connection and penetration step (step ST3), a pile driving and securing step (step ST4), a removal step (step ST5), a concrete filling step (step ST6), and a backfilling step (step ST7).

[0013] (Step ST1, full-circle rotary excavator installation process) FIG. 3 is a schematic diagram showing the all-around rotary excavator installation process according to the first embodiment. As shown in step ST1 in FIG. 2, first, the all-around rotary excavator 30 is installed in the pile driving process (all-around rotary excavator installation process). The pole 1 to be constructed supports structures such as ball nets, dust nets, and lighting. Although these structures are relatively light in weight, they are subject to extremely large wind loads during strong winds, placing a significant horizontal load on the pole 1. Therefore, the external force acting on the pile 10 supporting the pole 1 is small in vertical load, but generates an extremely large bending moment due to the horizontal load of the pole 1. Therefore, the pile 10 must be able to resist large bending moments. For example, in the case of a steel pipe pile, a pile with an extremely large diameter, approximately 1000 mm to 2000 mm in outer diameter, is used. Since it is difficult to drive such a large-diameter pile 10 using a normal pile driver, we have devised a method to facilitate construction by utilizing the all-around rotary excavator 30 used for excavating the ground. Thus, in the full-circle rotary excavator installation process, a full-circle rotary excavator 30 capable of applying a large torque is used to drive a very large diameter pile 10. The full-circle rotary excavator 30 applies rotation, swinging, and press-fitting force to drive the pile 10. As shown in Figure 3, the full-circle rotary excavator 30 is installed at a predetermined position on the ground surface 4. Using a crane, the lower pile 11 is inserted into the chuck device of the full-circle rotary excavator 30 and gripped.

[0014] If the embedded length of the pile 10 exceeds approximately 7 m, it is divided into an upper pile 12 and a lower pile 11, and the upper pile 12 and the lower pile 11 are welded together in the pile penetration process. On the other hand, if the embedded length of the pile 10 is approximately 7 m or less, it is not necessary to divide it into the upper pile 12 and the lower pile 11. If the embedded length of the pile 10 is significantly longer than 7 m, the number of divisions of the pile 10 is appropriately increased and they are welded together in the pile penetration process. Note that the full-circle rotary excavator 30 generally has the capacity to excavate a casing with an outer diameter of 800 mm to 3000 mm, and is therefore fully capable of penetrating the pile 10 with an outer diameter of 1000 mm to 2000 mm used for the pole 1. Note that the height of the pole 1 is, for example, 30 m to 60 m.

[0015] (Step ST2, pile penetration process) FIG. 4 is a schematic diagram showing a pile penetration process according to the first embodiment. As shown in step ST2 of FIG. 2, the lower pile 11 is penetrated into the ground (pile penetration process). As shown in FIG. 4, in the pile penetration process, the pile 10 is penetrated into the ground by the rotation and press-in force of the full-circle rotary excavator 30. The full-circle rotary excavator 30 grips the lower pile 11, and rotation and press-in force are applied. At the same time, the hammer grab 31 is used to excavate and remove the soil 70 inside the pile 10. Here, the hammer grab 31 is an excavation device that drops into and penetrates the ground 3, and grabs and discharges the soil 70. The soil 70 inside the tip of the pile 10 is excavated and discharged, thereby releasing the blockage at the tip of the pile 10. This makes it easier to penetrate the pile 10, and the lower pile 11 is penetrated.

[0016] (cutting blade 40) FIG. 5 is a schematic diagram showing a cutting blade 40 according to the first embodiment. As shown in FIG. 5, the cutting blade 40 is attached to the tip of the lower pile 11 along the circumferential direction of the pile 10. FIG. 5(a) is a bottom view, and FIG. 5(b) is a side view. FIG. 5(c) is an enlarged view of the cutting blade in FIG. 5(a). FIGS. 5(d) and 5(e) are enlarged views of the cutting blade in FIG. 5(b). The cutting blade 40 is a plurality of plate-shaped members attached to the inner and outer surfaces of the lower end of the pile 10 along the circumferential direction of the pile 10. While the cutting blade 40 is a straight plate, the lower pile 11 is arc-shaped, and gaps on the outer periphery are welded together to form welded joints 40a. The cutting blade 40 protrudes downward from the tip of the pile 10 and forms an acute angle in the rotational direction of the pile 10. The cutting blade 40 is fixed to the inner and outer surfaces of the pile 10 by, for example, welding. It is preferable that eight or more cutting blades 40 are attached around the periphery of the pile 10. The cutting blades 40 are shaped to have an angle from the bottom end of the pile 10, so they can dig into the ground 3 located at the tip of the pile 10 and cut it efficiently. The thickness of the cutting blades 40 is preferably 20 mm or more. Because the pile 10 has an extremely large diameter, the soil 70 on the inner surface of the tip is not compressed and blocked during penetration. Therefore, penetration is possible by simply cutting through the thickness of the pile 10.

[0017] (Step ST3, upper pile connection penetration process) Fig. 6 is a schematic diagram showing the upper pile connection penetration step according to the first embodiment. As shown in step ST3 of Fig. 2, the upper pile 12 is connected to the lower pile 11 and then penetrated into the ground (upper pile connection penetration step). As shown in Fig. 6, in the upper pile connection penetration step, after the penetration of the lower pile 11 is completed, the upper pile 12 is hoisted by a crane, installed on the upper end of the lower pile 11, and welded together to form an integrated structure. Thereafter, the integrated upper pile 12 and lower pile 11 are penetrated in the same manner as in step ST2.

[0018] (Step ST4, piling process) FIG. 7 is a schematic diagram showing a pile driving process according to the first embodiment. As shown in step ST4 of FIG. 2, after the upper pile 12 and the lower pile 11 are driven, the pile 10 is driven (pile driving process). As shown in FIG. 7, in the pile driving process, a driving member 50 is attached to the upper end of the pile 10, and then the pile 10 and the driving member 50 are driven into the ground together by the 360° rotary excavator 30. The driving is completed when the upper end of the pile 10 reaches the same height as the ground surface 4. Here, the pile 10 refers to the upper pile 12. As the driving of the pile 10 progresses, if the upper end of the upper pile 12 falls below the gripping device of the 360° rotary excavator 30, the 360° rotary excavator 30 will no longer be able to grip the pile 10. In this state, the pile 10 is driven into the ground using the driving member 50. A stop member 50 is attached to the top of the pile 10, and then, as in the pile penetration process, the full-circle rotary excavator 30 grips the stop member 50 and penetration proceeds. After penetration is complete, the stop member 50 is removed. Note that when driving the pile 10 within the gripping range of the full-circle rotary excavator 30, construction using the stop member 50 is not necessary.

[0019] (Stopping member 50) FIG. 8 is a schematic diagram showing a stop member 50 according to the first embodiment. As shown in FIG. 8, the stop member 50 has a stop pipe 51 and a connecting pipe 52. The stop pipe 51 has the same cross-sectional shape as the pile 10. The connecting pipe 52 is inserted into and fixed to the inside of the stop pipe 51, and has a locking groove 52a formed at its lower end in the circumferential direction. The connecting pipe 52 is attached concentrically to the inner surface of the stop pipe 51 by welding or the like. Because the pile 10 and the stop member 50 have the same outer diameter, the stop member 50 can be smoothly inserted into the gripping device of the full-circle rotary excavator 30 and can be securely gripped by the gripping device.

[0020] The pile 10 also has a locking protrusion 10a provided on the inner surface of its upper portion. As shown in FIG. 8(a), the upper end of the pile 10 faces the connecting pipe 52. Then, as shown in FIG. 8(b), the connecting pipe 52 is inserted into the pile 10, and the locking protrusion 10a is inserted into the locking groove 52a. The locking pipe 51 is then rotated, and the locking protrusion 10a engages with the end of the locking groove 52a, thereby integrating the pile 10 and the locking member 50, as shown in FIG. 8(c). The locking grooves 52a are formed at two opposing locations in the circumferential direction of the connecting pipe 52, and are designed to have a depth that allows the locking protrusions 10a to enter in both directions around the connecting pipe 52. This allows for bidirectional rotation of the 360° rotary excavator 30 and ensures reliable transmission of torque in both directions. The pile 10 can be pulled out with the locking protrusions 10a engaged with the locking groove 52a.

[0021] (Step ST5, removal process) Fig. 9 is a schematic diagram showing the removal step according to the first embodiment. As shown in step ST5 of Fig. 2, after the anchoring is performed, the members and construction equipment are removed (removal step). As shown in Fig. 9, in the removal step, after the anchoring step, the anchoring member 50 is removed, and then the full-circle rotary excavator 30 is removed.

[0022] (Step ST6, concrete filling process) FIG. 10 is a schematic diagram showing a concrete filling process according to the first embodiment. As shown in step ST6 of FIG. 2, concrete is filled into the tip of the interior of the pile 10 (concrete filling process). As shown in FIG. 10, in the concrete filling process, after the pile driving and securing process, soil 70 inside the pile 10 is removed in the pile penetration process, and concrete is filled into the tip side of the hollow portion, thereby constructing a tip-blocking concrete 60. A mixer truck 5 is driven to the construction site, and a tremie pipe is inserted up to the tip of the interior of the pile 10, and concrete is filled into the tip of the pile 10 and solidified. This blocks the tip of the pile 10, ensuring a ground bearing capacity equivalent to the area of ​​the underside of the tip of the pile 10. If concrete is not filled, the bearing capacity of the tip of the pile 10 will be reduced because only the area equivalent to the plate thickness of the pile 10 is ensured. The height of the tip-blocking concrete 60 is preferably approximately one to two times the outer diameter of the pile 10. In addition, if the vertical load is small and the tip bearing capacity is secured in the cross section of the pile 10, the tip blocking concrete 60 is not necessary.

[0023] (Slip prevention member 80) FIG. 11 is a schematic diagram showing a shear stopper member 80 according to the first embodiment. FIG. 11(a) is a perspective view showing a pile 10 provided with the shear stopper member 80, and FIG. 11(b) is a cross-sectional view showing the pile 10 provided with the shear stopper member 80. As shown in FIGS. 11(a) and 11(b), the shear stopper member 80 is made of a steel bar or a steel plate and is installed on the inner surface of the pile 10. This increases the adhesive force between the end-blocking concrete 60 and the pile 10. Therefore, even if the height of the end-blocking concrete 60 is low, sufficient ground bearing capacity can be obtained. This allows for a reduction in the amount of concrete used.

[0024] (Step ST7, backfilling process) FIG. 12 is a schematic diagram showing a backfilling step according to the first embodiment. As shown in step ST7 of FIG. 2, soil 70 is backfilled inside the pile 10 (backfilling step). As shown in FIG. 12, after the concrete filling step, soil 70 removed from inside the pile 10 is poured onto the top of the tip-blocking concrete 60, and backfilling is performed up to the bottom surface of the filled concrete to be filled in the joining step. The soil 70 removed by excavation is used to backfill the inside of the pile 10. The top of the pile 10 is backfilled to a position lower than the top end of the pile 10 by the length required for inserting and joining the pole 1. The length required for joining the pole 1 is approximately 1.5 to 2.5 times the outer diameter of the base of the pole 1. In the backfilling step, the soil 70 removed during drilling the pile hole is backfilled inside the pile 10, thereby reducing the generation of surplus soil waste and contributing to environmental conservation. Note that if the soil excavated from inside the pile 10 is used for banking or the like, the backfilling step can be omitted.

[0025] (Step ST8, joining process) FIG. 13 is a schematic diagram showing a joining step according to the first embodiment. As shown in step ST8 of FIG. 2, the pile 10 and the support pillar 20 are joined (joining step). As shown in FIG. 13, in the joining step, the support pillar 20 erected from the upper end of the pile 10 is joined to the pile 10 to form the pole 1. In the first embodiment, the support pillar 20 is a lower support pillar 21. The support pillar 20 is installed at the upper end of a support member 90 which is installed by welding on the inner surface of the upper part of the pile 10. The support members 90 are provided at three or more locations on the inner surface of the pile 10. By using the support members 90, the height of the support pillar 20 can be adjusted to a predetermined position. The lower support pillar 21 is lifted by a crane, and the lower end of the support pillar 20 is installed above the support member 90.

[0026] At this time, the core of the support 20 is aligned to a predetermined position. The inner diameter of the pile 10 is preferably approximately 200 mm larger than the outer diameter of the pole 1. This allows the support 20 to be adjusted to a predetermined position and installed even if there is a horizontal error in the installation core of the pile 10. Alternatively, the support 20 may be adjusted to a predetermined position and temporarily fixed using a wedge 93. Thereafter, joining concrete 91 is filled into the gap between the outer surface of the support 20 and the inner surface of the pile 10, and solidified to firmly join them. Furthermore, if a shear stopper 80 is provided on the outer surface of the support 20 and the inner surface of the pile 10, a firm connection can be achieved by the interlocking of the concrete. Finally, a concrete lining 92 is installed to protect the support 20 and prevent corrosion. The height of the joining concrete is approximately 1.5 to 2.0 times the outer diameter of the support 20.

[0027] (Step ST9, upper and lower support joining process) FIG. 14 is a schematic diagram showing the upper and lower pillar joining step according to the first embodiment. As shown in step ST9 of FIG. 2, the lower pillar 21 and the upper pillar 22 are joined (upper and lower pillar joining step). As shown in FIG. 14, after the pile 10 and the lower pillar 21 are joined, the lower pillar 21 and the upper pillar 22 are joined. The upper pillar 22 is lifted by a crane and joined to the lower pillar 21. Examples of joining methods include bolt joining, welding, or joining by inserting concrete into the upper pillar 22. Note that the lower pillar 21 and the upper pillar 22 may be joined and integrated in advance in a construction yard. In this case, once the joining of the pile 10 and the pillar 20 is completed, the upper and lower pillar joining step can be omitted.

[0028] (Step ST10, expansion process) As shown in step ST10 in Fig. 2, after the upper and lower support joining step, the net 2 is stretched (stretching step). The net 2 is, for example, a ball-proof net or a dust-proof net, and is connected by wire or the like to a net mounting member installed on the pole 1. Note that if the pole 1 is not for the net 2, the stretching step can be omitted.

[0029] According to the first embodiment, the pile 10 is driven directly into the ground. This eliminates the three steps of pile hole excavation, pile insertion, and gap filling for pile fixation. This reduces construction costs, simplifies construction management, and allows construction to be completed on time.

[0030] A conventional method for installing steel pipe piles directly into the ground without drilling pile holes has been known. This method involves using a rotary penetration machine to drive steel pipe piles equipped with cutting blades, spiral expansion blades, friction cutters, etc. at the tip of the pile. This eliminates the three steps of drilling the pile hole, inserting the pile, and filling the gap to secure the pile. Instead, the installation process is completed with only the pile installation step. However, while this method uses a rotary penetration machine, which is used for steel pipe earth retaining wall structures, the steel pipe piles used in baseball net poles have extremely large outer diameters. This makes installation difficult with conventional construction machines due to insufficient rotational torque and press-fitting force. Furthermore, the need to process and attach cutting blades, expansion blades, friction cutters, etc. to the steel pipe piles increases the material costs of the steel pipe piles. Furthermore, because the steel pipe piles have extremely large outer diameters, simply mixing and solidifying cement milk or other materials at the tip of the piles does not provide sufficient strength to seal the pile tips, potentially resulting in insufficient vertical bearing capacity.

[0031] Also known is a pile that is driven into the ground by rotating it. The tip of this pile is provided with an expansion wing. By rotating the spiral expansion wing, the pile is screwed into the ground at the tip and penetrated. The wing protruding from the outer periphery of the pile increases the pressure-receiving area at the tip of the pile, ensuring high bearing capacity. The wing protruding from the inner surface of the pile ensures a blocking effect inside the steel pipe, ensuring high bearing capacity. However, in the case of pole-support piles, the pole piles have an extremely large diameter, so the expansion wing is also large, resulting in significant material and processing costs. In particular, to achieve a blocking effect inside a steel pipe pile, it is necessary to block the inner surface of the steel pipe pile as much as possible, but the larger the blocking area, the more difficult it becomes to penetrate.

[0032] In addition, a technique for constructing steel pipe piles with tip wings using a full-circle rotary excavator is known. This technique allows for the construction of large-diameter steel pipe piles, but requires the installation of wings at the tip, which increases the material and processing costs of the steel pipe piles and is therefore uneconomical.

[0033] Furthermore, a full-circle rotary excavator for constructing steel pipe piles with wings has been known. Since wings are installed on the outer periphery of the steel pipe pile, the gripping part of the full-circle rotary excavator is designed to engage with the wings. However, in this case, the full-circle rotary excavator needs to be specially equipped with a wing-compatible member, which increases the manufacturing cost of the full-circle rotary excavator. Furthermore, since a general full-circle rotary excavator cannot be used, it is difficult to obtain a full-circle rotary excavator commercially, and it is not possible to obtain one that meets the process requirements, which increases the procurement cost.

[0034] In contrast, in the first embodiment, a large-diameter steel pipe pile 10 is installed using a full-circle rotary excavator 30, which is used to install large-diameter cast-in-place piles. This eliminates the insufficient torque and press-in force that are present in the prior art. Furthermore, because concrete is filled into the space within the pile at the tip of the pile 10 to create a tip-blocking concrete 60, even a large-diameter steel pipe pile can fully demonstrate the tip-blocking effect, ensuring sufficient bearing capacity for the pile 10. Therefore, there is no need to fabricate components, such as wings at the tip of the pile 10, to ensure tip bearing capacity. This reduces the material cost of the pile 10. Furthermore, because the pile 10 has no wings, there is little resistance to rotary penetration, allowing the pile 10 to be driven efficiently.

[0035] In addition, while large wings were conventionally attached to ensure the tip bearing capacity of a pile after penetration, in the present embodiment 1, the tip bearing capacity is provided by filling the inner surface with concrete. Therefore, wings are not required at the tip of the pile 10, and only the cutting blade 40 needs to be attached. This reduces the material costs and processing and installation costs of the tip blade. Furthermore, since the pile 10 does not have wings on its outer periphery and only the thin cutting blade 40 is attached at the tip of the pile 10, there is no need to equip the full-circle rotary excavator 30 with a mechanism for inserting wings. This reduces the manufacturing costs of the full-circle rotary excavator 30 and the lease fee. Furthermore, since it is sufficient to arrange a general full-circle rotary excavator 30, arrangements are easy, there is no delay in meeting process requirements, and arrangement costs are saved, making this economical.

[0036] Conventionally, a technique for driving a pile using a locking member has been known. A steel pipe cap with a diameter slightly larger than that of the steel pipe pile is placed over the head of the steel pipe pile. The joint is joined by engaging a protrusion on the outer periphery of the steel pipe pile with a notch at the bottom end of the cap. Because the outer diameter of this locking member is larger than that of the pile, there is a risk that when gripped by a full-circle rotary excavator, the step may prevent smooth gripping. In contrast, in the first embodiment, the pile 10 is driven in by the locking protrusion 10a and the locking groove 52a, so no step occurs on the pile 10. As a result, the pile can be smoothly gripped by the full-circle rotary excavator 30.

[0037] The pole construction method described above may also include combinations of the following features, which are described below: [Appendix 1] A pile driving process in which piles are driven into the ground; A joining process is provided in which a support erected from the upper end of the pile is joined to the pile to form a pole, The pile driving step includes: an all-around rotary excavator installation process of installing the all-around rotary excavator equipped with the piles on the ground surface; A pile penetration process in which the pile is penetrated into the ground by rotation and press-fitting of the full-circle rotary excavator; In the pile penetration process, a concrete filling process is performed to fill concrete into the tip side of the hollow portion by removing soil and sand from inside the pile to construct a tip blocking concrete; have Pole construction methods. [Appendix 2] The height of the tip blocking concrete is 1 to 2 times the outer diameter of the pile. Pole construction method described in Appendix 1. [Appendix 3] A shear stopper is provided on the inner surface of the pile that contacts the tip blocking concrete. Pole construction method described in Appendix 2. [Appendix 4] The pile penetration step includes: The full-circle rotary excavator with a cutting blade attached to the lower end of the pile is rotated in the circumferential direction of the pile, and the soil inside the pile is excavated and removed using a hammer grab. A pole construction method according to any one of appendices 1 to 3. [Appendix 5] The cutting blade is A plurality of plate-shaped members are attached to the inner and outer surfaces of the lower end of the pile in the circumferential direction of the pile, protruding downward from the tip of the pile and forming an acute angle in the rotation direction of the pile. Pole construction method described in Appendix 4. [Appendix 6] The pile driving step includes: A pile driving step of driving the pile in after the pile penetration step is included. 6. A pole construction method according to claim 4 or 5. [Appendix 7] The pile driving step includes: The pile and the stopper member are integrally driven into the ground by the full-circle rotary excavator with the stopper member attached to the top end of the pile, and the driving is completed when the top end of the pile is flush with the ground surface. Pole construction method described in Appendix 6. [Appendix 8] The pile is A locking projection is provided on the inner surface of the upper portion, The stop member is A stop pipe having the same cross-sectional shape as the pile; a connecting pipe that is inserted into the stopper pipe and has a locking groove formed at its lower end in the circumferential direction, The locking projection is engaged with the locking groove, thereby integrating the pile and the anchoring member. Pole construction method described in Appendix 7. [Appendix 9] The pile driving step includes: After the concrete filling step, a backfilling step is performed in which the soil removed from the inside of the pile is poured onto the top of the tip-blocking concrete to fill it up to the bottom surface of the filled concrete filled in the joining step. A pole construction method according to any one of appendices 1 to 8. [Appendix 10] The pole is It supports the network. A pole construction method according to any one of appendices 1 to 9. [Explanation of symbols]

[0038] 1 pole, 2 net, 3 ground, 4 ground surface, 5 mixer truck, 10 pile, 10a locking projection, 11 lower pile, 12 upper pile, 20 support, 21 lower support, 22 upper support, 30 full-circle rotary excavator, 31 hammer grab, 40 cutting blade, 40a welded part, 50 stop member, 51 stop pipe, 52 connecting pipe, 52a locking groove, 60 tip blocking concrete, 70 soil, 80 slip stop member, 90 support member, 91 joining concrete, 92 root wrapping concrete, 93 wedge material.

Claims

1. A pile driving process in which piles are driven into the ground; A joining process is provided in which a support erected from the upper end of the pile is joined to the pile to form a pole, The pile driving step includes: an all-around rotary excavator installation process of installing the all-around rotary excavator equipped with the piles on the ground surface; A pile penetration process in which the pile is penetrated into the ground by rotation and press-fitting of the full-circle rotary excavator; In the pile penetration process, a concrete filling process is performed to fill concrete into the tip side of the hollow portion by removing soil and sand from inside the pile to construct a tip blocking concrete; have Pole construction methods.

2. The height of the tip blocking concrete is 1 to 2 times the outer diameter of the pile. The pole construction method of claim 1.

3. A shear stopper is provided on the inner surface of the pile that contacts the tip blocking concrete.

3. The pole construction method of claim 2.

4. The pile penetration step includes: The full-circle rotary excavator with a cutting blade attached to the lower end of the pile is rotated in the circumferential direction of the pile, and the soil inside the pile is excavated and removed using a hammer grab. A pole construction method according to any one of claims 1 to 3.

5. The cutting blade is A plurality of plate-shaped members are attached to the inner and outer surfaces of the lower end of the pile in the circumferential direction of the pile, protruding downward from the tip of the pile and forming an acute angle in the rotation direction of the pile.

5. The pole construction method of claim 4.

6. The pile driving step includes: A pile driving step of driving the pile in after the pile penetration step is included.

5. The pole construction method of claim 4.

7. The pile driving step includes: The pile and the stopper member are integrally driven into the ground by the full-circle rotary excavator with the stopper member attached to the top end of the pile, and the driving is completed when the top end of the pile is flush with the ground surface.

7. The pole construction method of claim 6.

8. The pile is A locking projection is provided on the inner surface of the upper portion, The stop member is A stop pipe having the same cross-sectional shape as the pile; a connecting pipe that is inserted into the stopper pipe and has a locking groove formed at its lower end in the circumferential direction, The locking projection is engaged with the locking groove, thereby integrating the pile and the anchoring member.

8. The pole construction method of claim 7.

9. The pile driving step includes: After the concrete filling step, a backfilling step is performed in which the soil removed from the inside of the pile is poured onto the top of the tip-blocking concrete to fill it up to the bottom surface of the filled concrete filled in the joining step. A pole construction method according to any one of claims 1 to 3.

10. The pole is It supports the network. A pole construction method according to any one of claims 1 to 3.

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