Driving pile construction method

Abstract

To provide a creative driving pile construction method.SOLUTION: There is provided a method for driving a pile 30, which is configured to be non-concrete and does not have a node part in at least an axial central part of itself, into the ground. The method drives the pile into the ground and thereby establishes a vertical hole 140 in the ground, charges sand as a filler into the vertical hole 140 appearing by pulling out the pile without adding cement thereto, expands the sand and peripheral soil thereof which are charged into the vertical hole by driving the pile, outward and compacts the sand and the soil, embeds the pile into the ground after having completed the compaction, and thereby fixes the pile into the ground.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention provides a technique that simplifies the work required to install and remove posts and piles. 、 Techniques for improving the accuracy of the position and orientation of piles when they are driven into the ground and / or driven pile construction This is regarding. [Background technology]

[0002] Columns fixed to the ground may be used to support a structure at an elevated position (high or low) above ground level.

[0003] Here, in one example, "high place" means a place that is 2 m or more above the foundation surface (e.g., the ground surface, a scaffolding on the ground that is the earth's surface), while "low place" means a place that is lower than that high place.

[0004] The above-mentioned "support" is also called, for example, a pole or a post, and is formed, for example, of a steel or plastic round pipe, square pipe, etc. Supports may be delivered to the site as prefabricated products, or may be constructed on site.

[0005] Examples of the above-mentioned "structures" include structures that display information, such as signs (e.g., display boards for commercial advertising), guide boards or signs (e.g., traffic signs, traffic signals, etc.) (see, for example, Patent Documents 1 and 3), and enclosures such as protective fences and temporary enclosures (see, for example, Patent Documents 2 and 4).

[0006] Furthermore, the term "structure" includes structures that are installed outdoors and exposed to wind, rain, and snow (for example, outdoor signs) and structures that are installed indoors.

[0007] Furthermore, the types of support for a "structure" by pillars include a type supported by one pillar (single-legged type), a type supported by multiple pillars extending parallel to each other (multi-legged type), etc. A multi-legged type has the advantage that it has higher torsional rigidity around the vertical axis than a single-legged type, and that even if an abnormality occurs in one of the pillars, as long as the other pillars are normal, the pillars can be prevented from tilting or falling over.

[0008] There is a precast pile method as a method for fixing piles to the ground. The precast pile method is a method in which precast piles (e.g., steel or concrete, solid or hollow structure) are driven into the ground.

[0009] There are two types of prefabricated pile construction methods: the driving pile construction method and the buried pile construction method.

[0010] The driving pile method is a method in which a prefabricated pile (e.g., steel or concrete) is driven into the ground by the striking force of a hammer, without having to dig pilot holes in the soil beforehand.

[0011] Here, "hammer" refers to a manual hammer, a pile driver (e.g., an air hammer) as construction machinery (automatic hammer), etc. Manual hammers are large hammers with a metal lump attached to the tip of a long handle held by the worker, and are used by being swung down by the worker, or are lifted by the worker's hand against gravity and then allowed to fall freely to strike a pile.

[0012] In contrast, the buried pile method is a process in which the ground is excavated to a specified depth to create a pilot hole, and a prefabricated pile is inserted into the pilot hole. One such buried pile method is called the root wrapping method (see, for example, Patent Document 3). This root wrapping method is, for example, a method in which an enlarged bulb made of concrete is created at the bottom end of the pile.

[0013] According to this method, a pilot hole is excavated in the ground, crushed stone is poured into the bottom of the hole, and then the crushed stone is tamped down. A post is then inserted into the hole, and temporary braces are used to keep the post upright so that it does not tip over. Ready-mixed concrete is then poured into the hole so that it surrounds the post. The ready-mixed concrete is then allowed to harden, thereby fixing the post in place.

[0014] By using this root wrapping method, there is no need to replace the pillars during the long lifespan of a concrete foundation, which usually lasts 20-30 years.

[0015] However, this root-wrapping method requires processes such as digging the ground to create pilot holes, temporarily supporting the posts, and constructing a concrete foundation, which results in increased costs and extended construction time, so it is not suitable in cases where the posts and piles are used for a short period of time and therefore need to be removed frequently.

[0016] Patent Document 1 discloses a technique for driving a pile into the ground and using the driven pile to fix a support. However, this document only discloses using the pile to press the support against the ground surface (ground surface) after the support is installed, and does not disclose connecting the pile to the support after the pile is driven into the ground, or connecting the pile to the support coaxially. Furthermore, this document does not disclose driving the pile into the ground while guiding it so that it can move up and down.

[0017] Patent Document 2 discloses a technique for repeatedly applying impact force to a pile to drive the pile deeper into the ground in stages. However, this document only discloses that after driving the pile into the ground, a pilot hole is excavated in the ground by pulling it out, and a support is inserted into the pilot hole, but does not disclose that the pile driven into the ground is retained in the ground and the upper end of the retained pile is connected to the lower end of the support.

[0018] Furthermore, this document, like Patent Document 1, does not disclose driving a pile straight into the ground using a pile guide that guides the pile itself so that it can move up and down. Specifically, this document discloses driving a pile using a tool called a guide rod, but to be precise, the guide rod is used to guide the air hammer so that it can slide up and down, and is not used to guide the pile itself so that it can slide up and down.

[0019] Patent Document 3 is primarily concerned with the aforementioned root wrapping method, and is silent on the driving pile method. This document discloses that if a vertical hole is excavated in the ground at an unplanned incline, the pile is also erected in the vertical hole at an incline accordingly, resulting in a decrease in the verticality of the support inserted into the pile. Furthermore, this document discloses that the pile is coaxially connected to the support after it is root wrapped in concrete in the ground. However, this document does not disclose that the support is fixed directly using a pile fixed in the ground, nor that the pile fixed in the ground and the support are connected in a state of mutual contact.

[0020] Patent Document 4 discloses a technique for driving a pile into the ground. Furthermore, this document discloses driving the pile into the ground while guiding the pile itself so that it can move up and down. However, this document does not disclose connecting the pile to a support after the pile is driven into the ground, connecting the pile to the support coaxially, or connecting the pile to the support in a state where the piles are in contact with each other.

[0021] Patent Document 5 discloses a buried pile method as a pile construction method, but is silent about a driven pile method. Furthermore, this document does not disclose that a support is divided into a part that exists above ground and a part that exists underground and acts as a foundation, and that the latter part is treated as a pile.

[0022] Furthermore, this document points out that a disadvantage of using the buried pile method is that if a large wind pressure acts on a structure supported on the ground by the upper ends of pillars whose lower ends are buried in the ground, the pillars may not be strong enough.

[0023] Furthermore, this document points out that if the cast-in-place pile method, in which the ground is first excavated to create a pilot hole, then a cylindrical rebar assembled on-site is dropped into the hole, and then fresh concrete is poured into the hole and the concrete is allowed to harden to create the pile, is used, it is true that the pile is stronger and more stable than the buried pile method, but there are problems with this method, such as the great effort (man-hours, construction time, etc.) and cost required to remove the posts. [Prior art documents] [Patent documents]

[0024] [Patent Document 1] Japanese Utility Model Application Publication No. 58-21177 [Patent Document 2] Japanese Patent Application Publication No. 7-189529 [Patent Document 3] JP 2004-190241 A [Patent Document 4] Japanese Patent Application Publication No. 10-37194 [Patent Document 5] JP 2014-001542 A Summary of the Invention [Problem to be solved by the invention]

[0025] As such, there are various pile construction methods, each with its own advantages and disadvantages. Therefore, it is necessary to select from among these pile construction methods the one that is most suitable for the site (e.g., topography, soil quality, natural phenomena, etc.) and use (e.g., average period of use, etc.) taking into account various factors related to the site and use, and there are various factors that must be taken into consideration when selecting a method. These factors include, for example, the size of the pillars, the average period of use of the pillars, factors related to the construction period for installing and removing the pillars, and factors related to the construction costs for installing and removing the pillars.

[0026] A support pillar is required to have certain strength requirements in order to fulfill its mission of stably supporting a structure in the air in the environment of the installation site (for example, wind pressure, rain, snow accumulation, vibration, etc.).

[0027] The strength requirements imposed on a support are determined by the weight and size (particularly the height dimension of the support) of the support and the structure supported by the support, and generally, in the structural environment in which the structure is held in a position above ground, the weight ranking of the structure depends on the ranking of the height dimension of the structure (i.e., generally comparable to the length (height dimension above ground level) of the support that supports the structure).

[0028] Furthermore, the strength requirements imposed on the supports depend on the average age of the structure in use at the same site. Therefore, if the strength requirements imposed on the supports are stronger than the corresponding strength requirements even though the average age is short, the supports will be overqualified in terms of strength, which will lead to waste.

[0029] For ease of explanation, the types of poles are classified into three types according to their length: small poles with a length of less than 2m, medium poles with a length of 2m to less than 4m, and large poles with a length of 4m or more.

[0030] Specifically, small poles include, for example, signs that are installed for a short period of time in vacant lots, while medium-sized poles include, for example, outdoor signs installed in parking lots (including bicycle parking areas), as illustrated in Figure 1, as well as pedestrian traffic lights and road signs, and large poles include, for example, traffic lights for vehicles (for example, 4.5 m or more).

[0031] If the support pillar is large, it is subject to high strength requirements, if it is medium, it is subject to moderate strength requirements, and if it is small, it is subject to low strength requirements.

[0032] Usually, to meet high strength requirements, the piles supporting the columns are fixed to the ground using concrete foundations and filler materials by the above-mentioned root-wrapping method, and usually, to meet low strength requirements, the piles supporting the columns are fixed to the ground by simply driving them into the ground without using concrete foundations or filler materials by a simple driving pile method.

[0033] Conventionally, there has been no pile construction method suitable for achieving a strength level intermediate between that achieved by the root wrapping method and that achieved by the simple driving pile construction method.

[0034] In response to this, the inventor conducted research and development into a pile construction method suitable for achieving an intermediate strength level. In doing so, the inventor assumed a structure such as the above-mentioned outdoor parking signboard used by a company that temporarily manages land on behalf of the landowner as a parking lot, which may suddenly need to be removed and whose continuous usable period is unstable, and selected the following requirements.

[0035] (1)Average number of years of use

[0036] Based on past statistics on the use of the parking lot outdoor signboards mentioned above, the inventors set the maximum usage period of the poles at about 5 years. Therefore, if the root wrapping method was adopted, the strength level achieved by the method (for example, a service life of about 20 to 30 years) would be excessive.

[0037] Therefore, the present inventors have researched and developed a new pile construction method suitable for achieving a sufficient level of strength in the pillars while keeping in relation to the maximum service life of the pillars.

[0038] (2) Bending strength

[0039] In general, a support pillar must be safe and reliable enough that it will not tilt or collapse even if the ground is weak or there is strong wind. In other words, it is necessary to ensure the necessary degree of ground compaction and the bending rigidity of the support pillar (deflection characteristics due to wind load as a lateral load). Therefore, if a simple driving pile construction method is adopted, the level of strength achieved will be insufficient.

[0040] Furthermore, when using pillars fixed to the ground, it is important to take care that the pillars do not tilt or collapse due to bending moments generated in the pillars by wind pressure acting on the structure when the structure is in use.

[0041] It is known that the bending moment acting on the support due to the wind pressure is maximized near the ground surface (for example, in the bending mode of a quasi-cantilever beam, which is a structure that can be approximated in terms of material mechanics (if the ground can be assumed to be completely rigid (the ground reaction force is maximum), it can be approximated as a cantilever beam), at the position where the bending start point of the quasi-cantilever beam (the fixed end in the case of a cantilever beam) appears).

[0042] In addition, when adopting a structure in which the support pillars are not fixed directly to the ground but are indirectly fixed to the ground by connecting them to piles fixed to the ground, it is necessary to connect multiple individual parts, namely the support pillars and piles, to each other.

[0043] The joints between the posts and piles are usually located on the ground, i.e., at the positions of the posts where the bending moment acting from the outside is maximized. Therefore, the inventors recognized that the type of structure adopted for the joints is an important factor that determines the strength of the posts' resistance to the bending moment. The maximum bending moment increases with the length of the posts.

[0044] Therefore, the inventor devised a structure connecting the pile and the support pillar that prevents a sudden change in the section modulus between the two components, thereby reducing stress concentration at the connection between the two components.

[0045] (3) Accuracy of the orientation (position and angle) of the piles fixed in the ground

[0046] The verticality of a pile fixed to the ground refers to the angle at which the center line of the pile fixed to the ground is inclined relative to the direction of gravity, i.e., the vertical direction, in other words, the angle of deviation of the center line of the pile from the vertical direction. The closer the verticality of the pile is to 0, the closer the center line of the pile is to the direction of gravity.

[0047] When a structure is supported by columns, the structure is generally placed at or near the head of the column. Therefore, when the column is installed at an angle from the vertical, the weight of the structure acts on the column as an eccentric load, and as a result, a bending moment acts on the column. This bending moment constantly applies a load to the column and, in some cases, can be a cause of fatigue failure of the column, so it should be reduced or eliminated.

[0048] On the other hand, when a support is connected to a pile fixed to the ground, that is, when the apparent support (when the support and the pile are viewed as one support) adopts a two-part structure, the verticality of the support depends on the verticality of the pile. Therefore, the inventor recognized that fixing the pile to the ground in a state where its verticality is good is essential for improving the verticality of the support.

[0049] Therefore, the inventors have devised a method to improve the verticality of piles fixed to the ground regardless of the number of pillars supporting a single structure, thereby improving the verticality of the pillars connected to those piles, and ultimately preventing unexpected bending moments from occurring at the pillars, particularly at the bending start points of the pillars.

[0050] Furthermore, when a structure is supported by multiple parallel pillars which are in turn connected to multiple piles, during the process of fixing the multiple piles to the ground, it is necessary to improve the accuracy of the pile spacing, the perpendicularity of each pile, and ultimately the parallelism of the multiple piles.

[0051] The reason for this will be specifically explained below by taking as an example the case where, after the assembly of a signboard is complete, its multiple posts are attached to multiple piles fixed to the ground, i.e., the case where multiple piles whose relative positions are fixed (constrained to each other) are attached to multiple posts whose relative positions are fixed (constrained to each other).

[0052] In this case, if a connecting structure is adopted in which the multiple posts are coaxially connected to the multiple piles (for example, a structure in which one member is inserted into a hollow hole in the other member), it will be impossible to assemble the multiple posts, i.e., for example, a signboard, to the multiple piles, unless the post and the pile to be connected to each other are arranged in a straight line so that they match in both position and orientation.

[0053] More specifically, when multiple piles are fixed to the ground, if there is an error in the pile spacing and / or pile verticality, the top end of the part of the pile protruding from the ground surface (i.e., the part of the pile that should be connected to the bottom end of the support) will shift sideways from the target position. At this time, the position error of the connection point of the pile with the ground tends to appear at the top end of the part of the pile protruding from the ground surface as an amplified error depending on the error Δθ in the verticality of the pile and the length L of the part of the pile protruding from the ground surface.

[0054] Therefore, if multiple posts are forcibly attached to multiple piles, they will be twisted and unexpected residual stress will be generated in each structural member. If the residual stress is tensile stress, it may cause cracks in each structural member.

[0055] Therefore, the inventors have devised a method for reducing errors in the position and orientation of piles fixed to the ground when multiple pillars support a single structure, thereby making it possible to effortlessly assemble multiple pillars to multiple piles.

[0056] Furthermore, when the pillars are fixed to the ground using the aforementioned root wrapping method, a single continuous pillar exists both underground and in the air, so it is assumed that there is no risk of orientation errors in multiple pillars fixed to the ground causing problems when assembling the pillars, or if there are any, they will be minimal.

[0057] In particular, as described below, when a pair of posts are inserted into their respective pilot holes with their relative positions fixed (for example, when the assembly of the signboard is complete) and before their respective concrete foundations have solidified, the geometric error between the pair of posts will not cause any new serious problems.

[0058] (4) Construction period and costs

[0059] As mentioned above, the maximum period of use of the pillars in the category that the inventor is concerned with is short. Therefore, the construction period for installing and removing the pillars is long, and the construction cost increases, which reduces the net profit obtained from the use of the pillars. As a result, in some cases, the construction cost puts pressure on the net profit, and the business related to the pillars may go bankrupt.

[0060] Therefore, in order to shorten the construction time required for installing and removing the pillars, the inventors have devised a method that allows workers to install and remove the pillars as simple manual work using simple tools instead of heavy machinery.

[0061] Incidentally, according to the inventor's past experience, the above-mentioned root wrapping method is expected to allow the strength of the support to be managed without worry. However, this root wrapping method requires the installation of a support by bringing in and taking out heavy machinery, digging the ground to create pilot holes using the heavy machinery, temporarily supporting the support, and creating a concrete foundation. As a result, the removal of the support also requires the bringing in and taking out of heavy machinery, digging the ground using the heavy machinery, and removing the concrete foundation using the heavy machinery. As a result, the construction period tends to be extended and the construction costs tend to increase.

[0062] Therefore, this root wrapping method was not suitable for the supports that the inventors were currently focusing on, in terms of both construction time and construction costs.

[0063] In short, the inventor has researched and developed a method of fixing supports that allows a worker to manually install and remove the supports easily and quickly, without sacrificing the strength that has been achieved so far for medium-sized supports.

[0064] However, the pillar fixing method as the result of this research and development can be applied not only to medium-sized pillars but also to small and large pillars. Furthermore, the pillar fixing method as the result of this research and development can be applied when fixing a pillar to soft ground or when fixing a pillar to hard ground (for example, hard ground, good ground, solid ground, dense solid ground).

[0065] In view of the above-described background, the present invention provides a technique for simplifying the work required for the installation and removal of posts and piles. 、 Techniques for improving the accuracy of the position and orientation of piles when they are driven into the ground and / or creative driving pile construction methods This was undertaken with the objective of providing the following: [Means for solving the problem]

[0066] In order to solve the problem, according to one aspect of the present invention, A method for driving a round bar-shaped pile into the ground, the round bar-shaped pile being made of non-concrete and configured to have no nodes at least at a central portion in an axial direction of the pile, comprising the steps of: This provides a pile driving method in which a vertical hole is created in the ground by driving the pile into the ground, and then the vertical hole that appears when the pile is pulled out is filled with sand as a filler without the addition of cement, and then the sand and the surrounding soil that have been poured into the vertical hole are pushed outward and compacted by driving the pile, and when compaction is complete, the pile is left in the ground, thereby fixing the pile to the ground.

[0067] The present invention provides the following embodiments. Each embodiment is divided into clauses, each clause is numbered, and other clause numbers are cited as necessary. This is to facilitate understanding of some of the technical features that the present invention may employ and their combinations, and should not be construed as limiting the technical features and combinations that the present invention may employ to the following embodiments. In other words, it should be construed that technical features that are not described in the following embodiments but are described in this specification may be appropriately extracted and employed as technical features of the present invention.

[0068] Furthermore, describing each section in a form that refers to the number of other sections does not necessarily mean that the technical features described in each section are prevented from being separated and made independent from the technical features described in other sections, and it should be interpreted that the technical features described in each section can be made independent as appropriate depending on their nature.

[0069] (1) A method in which, instead of using a concrete foundation, workers manually drive at least one pile into the ground and use the pile as a foundation to fix at least one support to the ground, a pile driving process in which the pile is repeatedly driven into and pulled out of the ground, and after each pullout, sand is poured into a vertical hole created in the ground as a filler, and the same pile is then repeatedly driven into the ground each time, gradually expanding and compacting the sand and surrounding soil that have been poured into the vertical hole, and when compaction is complete, the pile is left in the ground with its upper end protruding from the ground surface, thereby fixing the pile to the ground; a post connecting step of connecting the support to the pile coaxially and in contact with each other using a portion of the pile protruding from the ground surface after the pile is fixed to the ground; A post fixing method including:

[0070] (2) Furthermore, The post fixing method described in item (1) includes a guide installation step in which, prior to the first driving, an operator installs a pile guide device that guides the pile so that it can move up and down while in contact with its outer circumferential surface, and a pile positioning device that positions the pile horizontally on the ground surface and has a through hole for the pile to pass through.

[0071] (3) The pile guide includes a guide pipe into which the pile is axially slidably fitted, The method for fixing a post according to claim 2, wherein the guide installation step includes a step of installing the pile guide device relative to the pile positioning device so that the guide pipe passes through the through hole.

[0072] (4) A pillar fixing method as described in (2) or (3), wherein the guide installation step includes a step in which, after the pile positioning device is installed on or near the ground surface, an operator positions the pile guide device using the through hole of the installed pile positioning device as a visual target.

[0073] (5) The pile guide device is A guide pipe into which the pile is fitted so as to be axially slidable; A direction adjustment mechanism for adjusting the direction of the guide pipe and Including, The method for fixing a post according to any one of items (2) to (4), wherein the guide installation process includes a process in which an operator uses the orientation adjustment mechanism to adjust the orientation of the pile guide device so that the guide pipe extends in a vertical direction.

[0074] (6) Furthermore, Prior to the pillar connecting step, a guide removal step is included in which an operator removes the pile guide tool from the ground surface while leaving the pile positioning tool on the ground surface, The pillar connecting process includes, after the pile guide device is removed from the ground surface, (a) a process in which an operator coaxially covers a reinforcing sleeve on the portion of the pile protruding from the ground surface, and (b) a process in which an operator further coaxially covers the hollow hole of the lower end of the pillar on the reinforcing sleeve, thereby connecting the pile and the pillar to each other in a triple-cylinder structure via the reinforcing sleeve. The pillar fixing method described in (3) or (5).

[0075] (7) Furthermore, Prior to the pillar connecting step, a guide removal step is included in which an operator removes the pile guide tool from the ground surface while leaving the pile positioning tool on the ground surface, The pillar connecting step includes, after the pile guide device is removed from the ground, (a) a step in which an operator coaxially covers the hollow hole at the lower end of the pillar over the part of the pile protruding from the ground, thereby coaxially inserting the protruding part into the hollow hole, and (b) a step in which the lower end is fixed, joined or fastened to the protruding part, thereby coaxially connecting the pile and the pillar to each other in a double-tube structure. The pillar fixing method described in (3) or (5).

[0076] (8) A method for fixing a post described in any of (1) to (7), wherein the at least one post is used to display an information-displaying structure, including a signboard, guide board or sign, or to fix a protective fence.

[0077] (11) A method in which, instead of using a concrete foundation, an operator manually drives at least one pile into the ground and uses the pile as a foundation to fix at least one support to the ground, comprising the steps of: a driving step in which an operator manually drives the pile into the original ground without a shaft being pre-drilled by striking the pile at its upper end with a hammer, so that the upper end of the pile protrudes above the ground surface; After the first driving is completed, a worker manually pulls out the driven pile from the ground using a pile puller, thereby creating a vertical hole in the ground; After the first extraction is completed, an operator manually pours sand into the vertical hole as a filler. After the first sand is poured, the worker uses the same pile to repeat the driving step, the pulling step, and the pouring step in sequence, thereby compacting the sand poured into the vertical hole and the surrounding soil while gradually expanding them outward. once the desired compaction characteristics have been achieved for the sand and surrounding soil, placing the pile in the ground with its upper end protruding above the ground surface, thereby anchoring the pile in the ground; a connecting process in which, after the pile is fixed to the ground, a worker inserts the part of the pile fixed to the ground that protrudes from the ground surface into the hollow hole at the lower end of the support, thereby connecting the two. A post fixing method including:

[0078] (12) Furthermore, A preparation process in which, prior to the first driving, a worker manually installs a pile guide tool that guides the pile so that it can move up and down, in accordance with a target portion of the ground surface where the lower end of the pile should start to enter; a removal process in which, after the pile is fixed to the ground, a worker manually removes the pile guide tool; The method for fixing a support pole according to claim 11, further comprising:

[0079] (13) The linking step comprises: After removing the pile guide tool, an operator manually inserts a portion of the pile fixed to the ground that protrudes from the ground surface into a hollow hole at the lower end of the support pillar until the end face of the lower end of the support pillar is buried in the ground; After the insertion, a fastening process is performed in which an operator fastens the support and the pile using a fastening tool. of include The method for fixing a support pole according to claim 12.

[0080] (14) A method for fixing a support pillar according to any one of items (11) to (13), in which the pile guide device is constructed by connecting a plurality of pipes that intersect with each other at a three-dimensional intersection using a plurality of orthogonal clamps so as to form a roughly rectangular prism shape, and the plurality of pipes have the same number of guide pipes as the at least one pile, and each pile is slidably inserted into each guide pipe.

[0081] (15) The method for fixing a support pillar as described in (14), wherein the plurality of pipes include three or more support pipes which are erected on the ground surface in a parallel posture to each other, and each of the support pipes has a height adjustment mechanism independent of each other, thereby adjusting the orientation of the pile guide device in three dimensions and adjusting the verticality of the guide pipes.

[0082] (16) The at least one pile includes a plurality of piles; The at least one support includes a number of supports equal to the number of piles; The pile guide device is configured to guide the plurality of piles so as to be movable up and down along a plurality of center lines parallel to each other, The method for fixing the support pole further comprises: Prior to the first driving, a worker manually installs a pile spacing regulation tool that regulates the target pile spacing between the piles in a plan view, the pile spacing regulation tool being placed on the ground surface or at least partially buried in the ground, in accordance with the target sites on the ground surface into which the piles are to be driven; After the support and the pile are fastened, the pile interval regulation device is buried in the ground and left in place without being removed. The method for fixing a support pole according to any one of (11) to (15) above,

[0083] (17) The pile spacing regulation device has a plurality of through holes through which each pile should penetrate at intervals equal to the target pile spacing, The post fixing method described in (16) above, wherein the preparation step includes a step in which, after the pile spacing regulation devices are installed, an operator positions the pile guide devices using each of the through holes of the installed pile spacing regulation devices as visual targets.

[0084] (18) A pile guide device according to any one of items (12) to (15).

[0085] (19) A pile spacing regulation device as described in paragraph (16).

[0086] (20) The pile spacing regulation device is placed on or near the ground surface with the piles fixed to the ground, The pile spacing regulator described in paragraph (19) acts as a tie bar that connects the plurality of piles to each other in the horizontal direction, thereby mechanically restraining the piles so that the piles are substantially prevented from moving toward or away from each other.

[0087] (31) A method in which, instead of using a concrete foundation, an operator manually drives at least one pile into the ground and uses the pile as a foundation to fix at least one support to the ground, comprising the steps of: A pile driving process of driving the pile into the ground to fix the pile to the ground; a post connecting step of connecting the support to the pile coaxially and in contact with each other using a portion of the pile protruding from the ground surface after the pile is fixed to the ground; A post fixing method including:

[0088] (32) Furthermore, The post fixing method described in item (31) includes a guide installation step in which, prior to driving the pile, an operator installs a pile guide device that guides the pile so that it can move up and down while in contact with its outer circumferential surface, and a pile positioning device that positions the pile horizontally on the ground surface and has a through hole for the pile to pass through.

[0089] (33) The pile guide device includes a guide pipe into which the pile is axially slidably fitted, The method for fixing a post according to claim 32, wherein the guide installation step includes a step of installing the pile guide device relative to the pile positioning device so that the guide pipe passes through the through hole.

[0090] (34) The pillar fixing method according to claim 32 or 33, wherein the guide installation step includes a step of an operator positioning the pile guide device by using the through hole of the installed pile positioning device as a visual target after the pile positioning device is installed on or near the ground surface.

[0091] (35) The pile guide device is A guide pipe into which the pile is fitted so as to be axially slidable; A direction adjustment mechanism for adjusting the direction of the guide pipe and Including, The pillar fixing method according to any one of items (32) to (34), wherein the guide installation step includes a step in which an operator uses the orientation adjustment mechanism to adjust the orientation of the pile guide device so that the guide pipe extends in a vertical direction.

[0092] (36) Furthermore, Prior to the pillar connecting step, a guide removal step is included in which an operator removes the pile guide tool from the ground surface while leaving the pile positioning tool on the ground surface, The pillar connecting step includes, after the pile guide device is removed from the ground surface, (a) a step in which an operator coaxially covers a portion of the pile protruding from the ground surface with a reinforcing sleeve, and (b) a step in which an operator further coaxially covers the hollow hole at the lower end of the pillar over the reinforcing sleeve, thereby connecting the pile and the pillar to each other in a triple-cylinder structure via the reinforcing sleeve. The pillar fixing method described in (33) or (35). [Brief description of the drawings]

[0093] [Figure 1]FIG. 1 is a front view showing an example of a signboard installed on a site by using a pole fixing method according to an exemplary embodiment of the present invention, together with a pole and a stake. [Diagram 2] FIG. 2 is a perspective view showing an example of how the signboard shown in FIG. 1 is installed in an area adjacent to a sidewalk on a site. [Diagram 3] FIG. 3 is a perspective view exemplarily showing the pile shown in FIGS. 1 and 2. FIG. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a fastener for fastening the pile shown in FIG. 2 to the support pole shown in the same figure. [Diagram 5] FIG. 5 is a perspective view showing an example of a post fixing system used by an operator to carry out the post fixing method, the system including a pile guide for vertically guiding the pile shown in FIG. 2 as it is driven into the ground, and a base plate for determining the horizontal position of the pile on the ground surface. [Figure 6] FIG. 6(a) is a side view showing the support pipe, the main horizontal pipe, and the guide pipe of the pile guide device shown in FIG. 5, and FIG. 6(b) is a plan view. [Figure 7] FIG. 7 is a side cross-sectional view for explaining how the pile shown in FIG. 2 is guided vertically by the guide pipe and base plate, both of which are shown in FIG. 5, when the pile is driven into the ground. [Figure 8] FIG. 8 is a process diagram showing an example of an installation work in which a worker installs the signboard shown in FIG. 1 as an operation in which the post fixing method is carried out. [Figure 9] FIG. 9 is a side cross-sectional view illustrating how the base plate shown in FIG. 5 can be installed horizontally despite the inherent slope of the ground as part of the topsoil preparation step shown in FIG. [Figure 10] Figure 10 shows multiple vertical cross-sectional views for explaining in chronological order the pile driving process shown in Figure 8, in which piles are repeatedly driven into and pulled out of the ground, and after each removal, sand is poured into the vertical hole created in the ground as filler. [Figure 11] FIG. 11 is a perspective view showing an example of a pile driving hammer used by an operator to drive a pile into the ground in the pile driving step shown in FIG. [Figure 12] FIG. 12 is a perspective view showing an example of a pile extractor used by an operator to extract piles from the ground in the pile driving step shown in FIG. [Figure 13] Figure 13(a) is a side cross-sectional view for explaining the relative positional relationship between the pile, guide pipe and base plate in the pile driving process shown in Figure 8, and Figure 13(b) is a side cross-sectional view for explaining the relative positional relationship between the pile, pillar, reinforcing sleeve and base plate in the pillar connection process shown in Figure 8. [Figure 14] FIG. 14 is a cross-sectional view for explaining the relative positional relationship between the pile, the post, and the reinforcing sleeve in the post connecting step shown in FIG. [Figure 15] FIG. 15 is a process diagram illustrating an example of a removal operation in which a worker removes the signboard shown in FIG. [Figure 16] FIG. 16 is a perspective view showing an example of how a plurality of types of accessories are detachably attached to a signboard according to another exemplary embodiment of the present invention using one type of clamp. [Figure 17] FIG. 17 is an enlarged plan view showing a clamp for detachably mounting the accessory shown in FIG. 16 to the signboard shown in the same figure, in a locked position and an unlocked position. [Figure 18] FIG. 18(a) is a plan view conceptually showing the clamp shown in FIG. 17 together with a first adapter attached thereto, and FIG. 18(b) is a plan view conceptually showing the same clamp together with a second adapter attached thereto. [Figure 19] FIG. 19(a) is a partial cross-sectional plan view showing a coaxial connection structure between a pile and a support pole connected to it after driving, and FIG. 19(b) is a cross-sectional side view showing the coaxial connection structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0094] Hereinafter, some of more specific exemplary embodiments of the present invention will be described in detail with reference to the drawings.

[0095] <One embodiment>

[0096] The pole fixing method according to the exemplary embodiment of the present invention is carried out by an operator using a pole fixing system 10, which will be described in detail later with reference to Fig. 5. Fig. 1 is a front view showing a signboard 20 installed on a site by carrying out this pole fixing method, together with a pair of poles 22, 22 and a pair of stakes 30, 30.

[0097] The signboard 20 is of a free-standing or fixed installation type, and has a display board 40 as a structure supported by posts 22, 22 at a position above the ground surface (ground surface, ground surface, supporting surface, etc.).

[0098] In other words, the signboard 20 is configured to include a pair of posts 22, 22 that are fixed vertically to the ground of a site (one example of an area), and a display board 40 that is supported by the posts 22, 22 on both sides.

[0099] Each of the posts 22 is made of a square pipe with a side length of 75 mm, whereas each of the piles 30 is made of a round bar with an outside diameter of about 50 mm. The round bar may, for example, be solid or at least partially hollow.

[0100] The signboard 40 may be long horizontally or long vertically. In the example shown in Fig. 1, the signboard 30 is long horizontally. Specifically, the signboard 20 has a height of about 3000 to about 4000 mm and a width of about 2000 to about 3000 mm.

[0101] The signboard 20 is a double-sided display type, and therefore the display board 40 has a front (front side) display surface and a rear (rear side) display surface. The display surfaces on both sides can display the same or different information.

[0102] The information is expressed, for example, by letters, numbers, figures, etc. Numbers, for example, may be composed of one number or multiple digits.

[0103] 2 shows an example of a signboard 20 installed in an area adjacent to a sidewalk on a site. In this example, the signboard 20 is classified as an outdoor signboard, which is installed outdoors.

[0104] 3 is a perspective view showing a pile 30. This pile 30 is, of course, classified as a prefabricated pile. This pile 30 is made of, for example, steel, and is made of a hollow pipe closed at the head (upper end or uppermost end when driven into the ground) 50 and the tip (lower end or lowermost end when driven into the ground) 52.

[0105] The total length of the pile 30 is about 1100 to about 1600 mm, and the diameter is about 50 mm. The pile 30 has a parallel portion (a portion extending straight with the same cross section) 54 in the axial center thereof, and has tapered portions 56, 58 at the front and rear thereof.

[0106] <Outline of the coaxial insertion type connection structure between piles and supports>

[0107] 2, the corresponding posts 22 are inserted into each pile 30 driven into the ground and are connected coaxially and in contact with each other. This connection structure is called a "coaxial insertion type connection structure."

[0108] This coaxial insertion type connection structure can be replaced with a connection structure in which the upper end face of each pile 30 and the lower end face of each pillar 22 are butted together and bolted together. However, the coaxial insertion type connection structure shown in the figure has a larger contact surface area between both components than the latter connection structure, and cross-sectional forces are transmitted between the two components over a wider area.

[0109] Therefore, the coaxial insertion type connection structure is more suitable for dispersing the stress generated at the connection between the pile 30 and the support column 22 due to the lateral load acting on the display board 40 in the axial direction, thereby reducing the stress concentration. This coaxial insertion type connection structure will be described in detail later with reference to Figure 13(b).

[0110] 4 is a cross-sectional view showing an example of a fastener 60 for fastening and fixing the pile 30 to the support 22. In the fastener 60, a U-bolt 62 is attached to the support 22 so as to partially surround the pile 30 inside the support 22, and a plurality of nuts 64 are screwed from the outside into the portion of the U-bolt 62 exposed from the outer surface of the support 22. Inside the support 22, a spacer 66 is appropriately interposed between the inner surface of the support 22 and the outer surface of the pile 30.

[0111] <Support post fixing system>

[0112] 5, an operator uses a pole fixing system 10 to carry out the pole step method. The pole fixing system 10 has a pile guide 70 for vertically guiding the pile 30 when the operator drives the pile 30 into the ground, and a base plate (anchor plate) 72 for defining the horizontal position of the pile 30 on the ground surface.

[0113] <Pile guide tool>

[0114] Generally speaking, the pile guide device 70 constitutes an example of a pile guide device that guides the pile 30 so that the pile 30 can move up and down while being in contact with the outer circumferential surface of the pile 30. In addition, the pile guide device 70 is also called an "upper guide" because it guides the portion of the pile 30 excluding the lower end portion.

[0115] Specifically, the pile guide 70 is configured by connecting multiple pipes that cross each other at two levels using multiple orthogonal clamps (not shown) to form a roughly rectangular parallelepiped shape. These pipes have the same number of guide pipes 80 as the number of piles 30 (two in the illustrated example). Each pile 30 is slidably fitted or inserted into each guide pipe 80. Each orthogonal clamp may be commercially available.

[0116] The plurality of pipes include three or more support pipes 90 (in the illustrated example, four support pipes are arranged at the four vertices of a rectangle) that are erected on the ground in a parallel posture to one another.

[0117] Each of the support pipes 90 has a height adjustment mechanism independent of the others. Three or more height adjustment mechanisms work together for one pile guide tool 70, so that the orientation (particularly the direction) of the pile guide tool 70 is manually adjusted three-dimensionally by an operator so that the verticality of the guide pipe 80 (the angle θ of the center line of the guide pipe 80 from the vertical direction) becomes 0 degrees.

[0118] As the height adjustment mechanism, as shown in Fig. 6(a), each support pipe 90 has a jack base 92. The jack base 92 is attached to the lower end of each support pipe 90 and has a grounded base 94, a male thread 96 inserted into the support pipe 90, a nut 98 screwed into the male thread 96, and a plurality of operating parts 100 extending radially outward from the nut 98.

[0119] While relative rotation between the base 94 and the male thread 96 is prevented, relative rotation and relative axial movement between the support pipes 90 and the male thread 96 are permitted. Thus, by rotating the nut 98 via the operating unit 100, the operator can raise and lower the nut 98, thereby extending and contracting the entire length of each support pipe 90.

[0120] In order for an operator to visually and accurately determine whether the guide pipe 80 is facing vertically, at least one spirit level (not shown) is attached to the guide pipe 80 or to at least one other pipe whose relative positional relationship is fixed thereto.

[0121] 5, the plurality of pipes further includes a plurality of main horizontal pipes 110 and a plurality of sub-horizontal pipes 112. The main horizontal pipes 110 and the sub-horizontal pipes 112 intersect at right angles.

[0122] As shown in FIG. 6(a) which is a side view and FIG. 6(b) which is a plan view, the guide pipe 80 and the support pipe 90 are erected on the ground in a position extending parallel to each other, and the main cross pipe 110 is sandwiched between the pipes 80, 90 on both sides so as to intersect at right angles to the pipes 80, 90 in a multi-level crossing manner.

[0123] As shown in Figures 6(a) and 6(b), the guide pipe 80 is connected to the main cross pipe 110 by multiple orthogonal clamps (not shown) so as to intersect at right angles, and each orthogonal clamp can be individually switched between a locked and unlocked state by the operator.

[0124] In the locked state, the guide pipe 80 is firmly (inseparably) fixed to the main horizontal pipe 110, whereas in the unlocked state, an operator can separate the guide pipe 80 from the main horizontal pipe 110. In other words, the guide pipe 80 is detachably attached to the pile guide device 70.

[0125] <Base plate>

[0126] 5, the base plate 72 generally constitutes an example of a pile positioning tool that horizontally positions the pile 30 on the ground surface and has a through hole 74 through which the pile 30 penetrates. The base plate 72 also constitutes an example of a pile spacing regulator that simultaneously regulates a target pile spacing that the pair of piles 30, 30 should be spaced apart from each other in a plan view.

[0127] In addition, the base plate 72 is also referred to as a "lower guide" because it guides the lower end of the pile 30. In addition, the pile guide device 70 and the base plate 72 are collectively referred to as the "upper and lower guides."

[0128] The base plate 72 further acts as a tie bar that connects a pair of piles 30,30 to each other horizontally, thereby mechanically restraining (e.g., holding together from a material mechanics perspective) the piles 30,30 so that they are substantially prevented from moving toward or away from each other.

[0129] As a result, the actual pile spacing is encouraged to continually match the target value, compared to when the base plate 72 is divided into separate piles 30 and installed discretely, and the piles 30 are prevented from tilting independently at their positions on the ground surface even if the ground is soft.

[0130] Specifically, the base plate 72 is mainly made of, for example, a single steel plate 120 that extends linearly and does not deform when placed on the ground (for example, with a plate thickness of about 3 mm). The steel plate 120 has one through hole 74 at each end, for a total of two through holes 74.

[0131] In the illustrated example, the base plate 72 has, in addition to the steel plate 120, two short steel plates 122 stacked and fixed on both sides of the steel plate 120 in a direction intersecting at right angles. Each steel plate 122 has one through hole 74 at each end, and the base plate 72 has a total of six through holes 74. As a result, by using the base plate 72, it is possible to simultaneously drive two piles 30 into the ground with a specified pile spacing between them.

[0132] <How to install the pile guide and base plate>

[0133] To install the pile guide device 70 and the base plate 72 on the ground surface, a worker first installs the base plate 72 on or near the ground surface. Then, using each through-hole 74 of the installed base plate 72 as a visual target, the worker installs the pile guide device 70 by positioning it so that each guide pipe 80 and each through-hole (guide hole, positioning hole, etc.) 74 are aligned in a straight line.

[0134] <How to guide the pile during driving>

[0135] FIG. 7 is a side cross-sectional view illustrating how the pile 30 is guided vertically by the guide pipe 80 and the base plate 72 as the pile 30 is driven into the ground.

[0136] In this embodiment, one pile 30 is guided by being slidably fitted into two guides, the base plate 72 and the guide pipe 80, at two different positions in the axial direction. However, the present invention may be embodied in an embodiment in which one pile 30 is guided at only one position in the axial direction. This embodiment may be embodied as an embodiment in which only the guide pipe 80 is used, or an embodiment in which only the base plate 72 is used.

[0137] In this embodiment, when the pile 30 passes through the through hole 74 of the base plate 72, the guide pipe 80 also passes through the same through hole 74. As a result, at the position of the base plate 72, i.e., for example, at or near the ground surface, the outer peripheral surface of the guide pipe 80 contacts the inner peripheral surface of the through hole 74, and at the same time, the inner peripheral surface of the same guide pipe 80 contacts the outer peripheral surface of the pile 30.

[0138] As a result, the base plate 72, the guide pipe 80 and the pile 30 are stacked in three layers in the diametric direction. The structure is a triple structure consisting of the pile 30 as the innermost cylinder or innermost layer, the guide pipe 80 as the middle cylinder or middle layer, and the base plate 72 as the outermost cylinder or outermost layer. This prevents the center line of the pile 30 from shifting laterally parallel to the center line of the through hole 74 of the base plate 72, and also prevents the center line of the pile 30 from tilting relative to the center line of the through hole 74.

[0139] In this embodiment, the lower end of the guide pipe 80 is buried in the ground protruding from the lower surface of the base plate 72 so as to prevent the lower end of the guide pipe 80 from coming off the base plate 72 upward during driving of the pile 30. However, the initial value of the protruding length may be sufficient for about 20 mm.

[0140] <Signboard installation work>

[0141] FIG. 8 shows an example of a process diagram of an installation work in which a worker installs the signboard 20 shown in FIG. 1 on a site prior to use, as a work in which the post fixing method is carried out.

[0142] 1. Topsoil preparation process

[0143] When the installation work is started, a topsoil preparation process is carried out as the first step, as shown in Fig. 8. Specifically, a worker conducts a topographical survey (e.g., a survey of the slope of the ground surface) and a soil survey (e.g., a survey of the softness of the ground) for the area of ​​the site where the signboard 20 is to be installed. After that, the worker decides on the planned installation location of the signboard 20.

[0144] Next, if the ground surface of the original ground in the area where the signboard 20 is planned to be installed is not horizontal, workers excavate at least the topsoil of the planned installation location, i.e., the topsoil of an area that includes the silhouette of the signboard 20 when installed if projected from directly above, as illustrated in the side cross-sectional view of Figure 9 (wherein the base plate 72 is composed only of a single steel plate 120), thereby creating a horizontal excavation surface, i.e., a construction base, for the installation of the signboard 20.

[0145] 2. Upper and lower guide installation process

[0146] Next, as a second step, a top and bottom guide installation process is performed as shown in Fig. 8. Specifically, as shown in Fig. 9, a worker installs a base plate 72 as a bottom guide on the construction base surface.

[0147] After installing the base plate 72, the worker positions and installs the pile guide device 70 on the construction base surface using the two through holes 74, 74 of the previously installed base plate 72 as visual targets relative to the two guide pipes 80, 80 of the pile guide device 70 to be installed.

[0148] Furthermore, as illustrated in FIG. 13( a ), the worker installs the pile guide tool 70 on the construction base surface relative to the base plate 72 so that the guide pipe 80 passes through the through hole 74 of the base plate 72 .

[0149] Furthermore, the worker adjusts the length of at least one of the four support pipes 90 of the installed pile guide device 70 by operating the corresponding jack base 92, so that all the guide pipes 80 extend vertically and at the same time, the guide pipes 80 extend parallel to each other. As a result, as shown in FIG. 7, the center lines of the guide pipes 80 and the center lines of the corresponding through holes 74 coincide with each other.

[0150] 3. Pile driving process

[0151] Next, as shown in FIG. 8, a pile driving process is carried out as the third step.

[0152] Specifically, the worker repeatedly drives the pile 30 into the ground and pulls it out. After each pull, the worker pours sand as a filler into the vertical hole 140 (see FIG. 7) created in the ground.

[0153] With each subsequent repeated driving, the same pile 30 compacts the sand layer 150 (see FIG. 7) and the surrounding soil that were placed in the vertical hole 140 while gradually expanding them outward. When the compaction is completed, the worker leaves the pile 30 in the ground with its top end protruding from the ground surface, thereby fixing the pile 30 to the ground.

[0154] FIG. 10 shows multiple vertical cross-sectional views for explaining in chronological order the pile driving process, in which piles are repeatedly driven into and pulled out of the ground, and after each removal, sand is poured into the vertical hole 140 created in the ground as filler material.

[0155] The figure shows the chronological changes in the ground cross-section for the first (n=1) cycle, the nth cycle, and the final cycle out of the multiple cycles that make up one pile driving process.

[0156] In the final cycle, after driving the pile 30 into the ground, the worker applies rotational force, axial force, vibration (e.g., sound waves) to the pile 30 and subjectively or objectively using a sensor to evaluate whether the degree of compaction (e.g., earth pressure) of the sand layer 150 and the surrounding soil has reached a target value.

[0157] Once the desired degree of soil compaction has been achieved, the operator places the stake 30 in the ground.

[0158] In each cycle, the pile 30 is driven in step by step by, for example, an operator repeatedly allowing a pile driving hammer 200 shown in Fig. 11 to freely fall. The pile driving hammer 200 has, for example, a generally cylindrical weight portion 202 having a bottomed hole extending upward from its lower end, and a pair of grip portions 204, 204 extending from the outer circumferential surface of the weight portion 202.

[0159] 7, the total length of the pile 30 is longer than the total length of the guide pipe 80. Therefore, when the pile 30 is driven into the ground to a position where its top end is approximately aligned with the top end of the guide pipe 80, the top end position of the pile 30, i.e., the pile head level, approximately corresponds to a position raised from the ground surface into the air to a height approximately equal to the total length of the guide pipe 80. At this time, the pile tip depth, which is the depth of the tip 52, i.e., the tip of the pile 30 driven into the ground, approximately corresponds to a position lowered from the ground surface into the ground by the length of the part obtained by subtracting the total length of the guide pipe 80 from the total length of the pile 30.

[0160] The appropriate depth of the pile tip depends on the softness of the soil into which the pile 30 is to be driven, but the depth of the pile tip is selected to be, for example, about 700 mm or more, as shown in FIG. 13(b).

[0161] In contrast, in each cycle, the extraction of the pile 30 is performed step by step, for example, by an operator repeatedly operating a pile extractor 300, for example as shown in FIG.

[0162] The pile puller 300 has, for example, a base 302 that is grounded, a lever 304, and an engaging tool 306 that detachably engages with the pile 30. The lever 304 has a force point operated by an operator, a fulcrum supported by the base 302, and a point of action that is swingably connected to the engaging tool (for example, a metal fitting having a U-shaped gripping portion that matches the diameter of the pipe to be pulled out) 306.

[0163] When the worker repeatedly tilts the lever 304 in a direction pulling it toward himself, the operating force applied by the worker to the force point of the lever 304 is multiplied by the principle of leverage. The multiplied operating force is transmitted to the pile 30 via the engaging device 306 as a pulling force.

[0164] When using this pile puller 300 to pull out the pile 30, the guide pipe 80 prevents the pile puller 300 from directly accessing the outer circumferential surface of the pile 30, as shown in FIG. 7, so that before each extraction, the worker must temporarily pull out the guide pipe 80 from the pile 30 driven into the ground.

[0165] Therefore, the worker first unlocks the orthogonal clamp related to the guide pipe 80 in the pile guide tool 70, thereby making the guide pipe 80 separable from the pile guide tool 70. In this state, the worker pulls out the guide pipe 80 from the ground. After that, the worker attaches the pile puller 300 to the pile 30.

[0166] Once the pile 30 has been pulled out, the worker attaches the removed guide pipe 80 to the pile guide tool 70 in its original position, and then the next driving is performed using the same guide pipe 80.

[0167] 4. Pile guide removal process

[0168] 8, a pile guide tool removal step is carried out as a fourth step. Specifically, the worker removes and recovers the pile guide tool 70 from the ground surface. At that time, the worker leaves the base plate 72 on the ground surface.

[0169] As a result, after the signboard 20 is installed, the base plate 72 will function as a member that reinforces the pair of posts 22, 22 of the signboard 20 on the ground surface or underground (for example, a tie bar that horizontally restrains the pair of posts 22, 22).

[0170] 5.Column connection process

[0171] Thereafter, as shown in Fig. 8, a post connecting step is carried out as the fifth step. Specifically, after the piles 30 are fixed to the ground as described above, the worker connects each of the posts 22 of the signboard 20 to the piles 30 coaxially and in contact with each other using the parts of the piles 30 fixed to the ground that protrude above the ground surface, as shown in Fig. 13(b).

[0172] Fig. 13(b) is a side cross-sectional view for explaining the relative positional relationship between the pile 30, the post 22, the reinforcing sleeve 400, and the base plate 72 in this post connecting process. Also, Fig. 14 is a cross-sectional view for explaining the relative positional relationship between the pile 30, the post 22, and the reinforcing sleeve 400 in this post connecting process.

[0173] Specifically, in this pillar connecting process, a worker first coaxially covers the portion of the pile 30 protruding from the ground surface with a reinforcing sleeve 400 (made of a round pipe in the illustrated example, but it can also be made of a square pipe).

[0174] Next, the worker coaxially covers the hollow hole at the lower end of the support 22 (made of a square pipe in the illustrated example, but it can also be made of a round pipe) onto the reinforcing sleeve 400. As a result, the worker connects the pile 30 and the support 22 to each other in a triple-cylinder type connecting structure by using the reinforcing sleeve 400 as an intermediary between them.

[0175] 13(b), the worker embeds the reinforcing sleeve 400 in the ground so that its lower end penetrates the through-hole 74 of the base plate 72 and then sinks deeper, for example, to a tip depth of about 100 to about 200 mm. The worker may embed the reinforcing sleeve 400 by hitting the upper end surface of the reinforcing sleeve 400 with a hammer.

[0176] As shown in Fig. 13(b), the reinforcing sleeve 400 is embedded in the ground, completely penetrating the through-hole 74 of the base plate 72. This realizes a layout that reduces the gap between the outer peripheral surface of the pile 30 and the inner peripheral surface of the through-hole 74 of the base plate 72. This layout prevents the pile 30 and the support column 22 from wobbling sideways within the through-hole 74, and the reinforcing sleeve 400 embedded in the ground strengthens the ground, improving the posture stability of the pile 30 and the support column 22.

[0177] In this post connecting step, the worker further fastens and fixes the post 22 to the pile 30 using a fastener 60, as illustrated in Fig. 4. This prevents the post 22 from coming axially out of the pile 30. The fastening and fixing using the fastener 60 is performed, for example, at least one axial position of the post 22 that is not covered by the reinforcing sleeve 400, as shown in Fig. 13(b).

[0178] Incidentally, prior to carrying out this post connecting step, there are two options: each post 22 is already attached to the signboard 40 together with the other posts 22 that make up a pair, and therefore cannot move freely on its own, i.e., the signboard 20 is in a completed state except for the stakes 30, or each post 22 has not yet been attached to the signboard 40, and therefore can be separated from the other parts and move freely, i.e., the signboard 20 is in an incomplete state. This embodiment is applicable under either option.

[0179] However, in one example of this embodiment, the former option is adopted, which has the advantage that the work of attaching each of the posts 22 to the display board 40 can be performed on flat ground and in parallel with the construction of the piles 30, thereby improving work efficiency.

[0180] On the other hand, when the main body of the signboard 20 is completed, it is necessary to connect the pair of posts 22, 22 whose relative positions are fixed to a pair of piles 30, 30 driven into the ground whose relative positions are also fixed. Therefore, there is a need for almost perfect geometric coincidence between the center lines of the pair of posts 22, 22 and the center lines of the pair of piles 30, 30.

[0181] Here, "nearly perfect geometric consistency" means that a pair of posts 22, 22 are almost perfectly parallel to each other, a pair of piles 30, 30 are almost perfectly parallel to each other, and the spacing between the pair of posts 22, 22 and the spacing between the pair of piles 30, 30 almost perfectly match each other.

[0182] Thus, in order to meet the requirement of almost perfect geometric alignment between a pair of posts 22, 22 and a pair of piles 30, 30, this embodiment uses in combination a pile guide device 70 that adjusts the orientation of the upper part of each pile 30 and a base plate 72 that adjusts the orientation of the lower part of each pile 30 so that the actual orientation of each pile 30 accurately matches the target orientation.

[0183] 6. Backfilling process with topsoil

[0184] Thereafter, as shown in Fig. 8, a topsoil backfilling step is carried out as the sixth step. Specifically, as shown in Fig. 13(b), a worker buries the base plate 72 in the ground by piling up soil. If the original ground surface was a slope, the soil is piled up on the base plate 72 to match the original ground surface, and the initially excavated portion is backfilled and restored.

[0185] Thus, one signboard installation work is completed without using heavy machinery and without excavating the ground, by simple manual work by a worker, which does not require advanced techniques or many years of experience.

[0186] <Signboard removal work>

[0187] FIG. 15 is a process diagram showing an example of removal work in which a worker removes the signboard 20 after use has been completed.

[0188] <1.Disassembly process>

[0189] First, as shown in the figure, a dismantling process is carried out as a first step. Specifically, a worker separates each support 22 from the pile 30 to which it is connected by loosening the fastener 60. As a result, the pair of piles 30, 30, covered with their respective reinforcing sleeves 400, protrude from the ground surface.

[0190] <2. Pile removal process>

[0191] Next, as shown in the figure, a pile removal process is carried out as a second step.

[0192] Specifically, first, an operator manually pulls out each reinforcing sleeve 400 from each pile 30 using a first pile puller 300 having an engaging tool 306 that fits the diameter of the reinforcing sleeve 400 .

[0193] Next, the worker manually pulls out each pile 30 from the ground by using a second pile puller 300 (which may be the same as the one used in the pile driving step during the above-mentioned installation work) having an engagement tool 306 that fits the diameter of the pile 30. As a result, a pair of vertical holes 140, 140 created by the pair of piles 30, 30 remains in the ground.

[0194] <3. Base plate removal process>

[0195] Thereafter, as shown in the figure, a base plate removal process is carried out as the third step. Specifically, first, workers remove the soil covering the buried base plate 72, thereby exposing the base plate 72. Next, workers remove and recover the base plate 72 from the ground surface.

[0196] <4. Topsoil restoration process>

[0197] Next, as shown in the figure, a topsoil restoration process is carried out as the fourth step. Specifically, the worker fills in and levels the parts of the site where the topsoil has not been leveled because the winning signboard 20 was removed by appropriately piling up soil.

[0198] Thus, one signboard removal operation is completed without using heavy machinery and without excavating the ground, by simple manual work by a worker that does not require advanced techniques or many years of experience.

[0199] In this embodiment, in the pile driving process shown in Figure 8, the driving and pulling out of the pile 30 and the pouring of sand are repeated; however, for example, if the ground on which the signboard 20 is to be installed is not weak, the pile 30 may be driven only once and the pouring of sand into the vertical hole 140 may be omitted.

[0200] However, even in this case, by using the pile guide device 70 and the base plate 72 and / or the aforementioned triple-tube type connecting structure between the pile 30 and the support 22, the reliability of the assembly of the support 22 (pile spacing and verticality / parallelism) can be ensured and / or the connecting strength of the support 22 (e.g., bending rigidity) can be ensured.

[0201] The above describes an exemplary scenario in which the posts 22, 22 of a signboard 20 are fixed to the ground of a site (e.g., used as a parking lot) using the ingenious pile driving method according to this embodiment, but the same pile construction method can be used to install other equipment used together with the signboard 20 on a similar site, such as box-shaped bodies such as ticket vending machines, ticket issuing machines, and payment machines, and posts (e.g., hollow cylindrical bodies) to which equipment such as security lights can be attached.

[0202] For example, when a ticket machine having a hollow box-shaped frame (e.g., a hollow box-shaped body) is to be installed on a site, one or more piles 30 driven into the ground using the same pile construction method are inserted into the central hole in the bottom plate of the box-shaped frame described above, thereby firmly connecting the ticket machine to the piles 30.

[0203] <Advantages of the driving pile method according to this embodiment over the root-wrapping pile method>

[0204] 1. The advantage of shortening construction time

[0205] The applicant conducted a test construction in which one signboard 20, one ticket machine, and five security lights were installed together on the same site. During the test construction, the time spent installing multiple piles 30 using the ingenious pile driving method according to this embodiment was approximately four hours.

[0206] In contrast, when constructing multiple posts 22 (including a pair of posts for a signboard 20, multiple posts for a ticket machine, and multiple posts for multiple security lights) using the aforementioned root-wrapping pile method, a worker will, for example, carry out the following multiple steps in order.

[0207] (1) A step of drilling pilot holes into the ground in the same number as the number of supports 22.

[0208] (2) preparing ready mixed concrete (or mortar) for all the columns 22

[0209] (3) A process of inserting all the posts 22 into the respective prepared holes and installing them on the site (however, the pair of posts 22, 22 for the signboard 20 are inserted into their respective prepared holes and installed on the site in a state where both posts are attached to the display board 30, i.e., in the completed state of the signboard 20).

[0210] (4) pouring the prepared ready-mix concrete into a plurality of pilot holes;

[0211] (5) A step of aligning the installed signboard 20 so that its lateral direction almost completely coincides with the horizontal direction.

[0212] (6) A process of installing reinforcing diagonal members (braces) at the lower ends (e.g., the parts protruding from the ground surface) of the pillars 22 so that the pillars 22 do not tilt or fall unintentionally before the ready-mixed concrete in each pilot hole is completely solidified.

[0213] (7) A step of waiting until the fresh concrete solidifies

[0214] As a comparative test to the above-mentioned test construction, the applicant used the root-wrapping pile method to drive the same number of posts 22 into the ground as the multiple piles 30 used in the above-mentioned test construction, and the work took two days.

[0215] As is self-evident from the above explanation, according to this embodiment, the construction of the pile 30 can be completed in a significantly shorter time than when the root-wrapping pile method is used, thereby shortening the construction period required for pile construction and, accordingly, reducing the construction costs required for pile construction.

[0216] Furthermore, according to this embodiment, while a plurality of piles 30 are usually constructed in sequence, not all at once, once the construction of a certain pile 30 is completed in a few hours, another worker can carry out another work related to that pile 30. As a result, according to this embodiment, construction of another pile 30 can be carried out in parallel with the work related to a completed pile 30. Here, "another work" is, for example, electrical work carried out on the signboard 20. The electrical work includes the work of attaching a signboard light for night lighting to the top of the signboard 20 and wiring work for supplying power to the signboard light.

[0217] Therefore, according to this embodiment, multiple types of work required on the same site can be performed at least partially simultaneously in parallel, thereby improving overall work efficiency.

[0218] In contrast, when using the root-wrapping pile construction method, work associated with any of the pillars 22 (such as necessary electrical work) cannot be carried out until the concrete has hardened for all of the pillars 22. Therefore, the concrete foundations of all the pillars 22 must be completed before work associated with those pillars 22 can begin as serial work rather than parallel work.

[0219] As a result, when using the root-wrapping pile construction method, multiple types of work can only be carried out with efficiency significantly lower than the work efficiency in this embodiment.

[0220] 2. The advantage is that the underground installation space for piles is reduced.

[0221] As is clear from the above explanation, in this embodiment, prior to fixing the support 22 to the ground, the pile 30 is driven into the ground, and at this time, the pile 30 functions as a hole-drilling tool, thereby creating a vertical hole 140 in the ground having a diameter approximately the same as that of the pile 30.

[0222] According to the above-mentioned root-wrap pile method, a pilot hole is drilled in the ground before the pillar is buried in the ground. The pilot hole is drilled to have a cross section larger than the outer diameter of the pillar, taking into account the size of the concrete foundation that will surround the lower end of the pillar when it is buried in the pilot hole.

[0223] Furthermore, according to this root-wrap pile method, as mentioned above, before the concrete foundation solidifies, the reinforcing diagonal members are attached to the lower ends of each pillar so that they extend laterally from each pillar, and therefore extra space is required at the ground surface to be occupied by the reinforcing diagonal members.

[0224] Therefore, when this root-wrap pile method is adopted, when the pile is installed on the site near the boundary line with the neighboring land, it is necessary to move the support pillar away from the boundary line toward the site so that the pilot hole, concrete foundation, and reinforcing diagonal material do not enter the neighboring land. Therefore, when this root-wrap pile method is adopted, it is difficult to install the support pillar as close as possible to the boundary line within the site, thereby minimizing the possibility that the support pillar will become an obstacle within the site.

[0225] In contrast, according to this embodiment, the vertical hole 140 is constructed in the ground at the same position as the pile 30 and with approximately the same diameter, and the depth of each pile 30 is deep enough (for example, 700 mm, 800 mm or 900 mm or more) that the reinforcing diagonal members required in the case of the root-wrap pile method are not required, making it easy to install the piles 30 and the supports 22 connected to them as close as possible to the boundary line within the site.

[0226] In the embodiment described above, the support pillar 22 and the pile 30 are coaxially connected to each other in a triple-cylinder structure via the reinforcing sleeve 400 serving as a third member or intermediate member.

[0227] In contrast, in one modified example, as illustrated in Figs. 19(a) and (b), a pile 30 and a support column 22 are coaxially connected to each other in a double-tube structure without using a third member or an intermediate member.

[0228] FIG. 1A is a partial cross-sectional plan view showing the coaxial connection structure between a pile 30 and a support 22 connected to it after driving, and FIG. 1B is a cross-sectional side view showing the coaxial connection structure.

[0229] The coaxial connection structure has a plurality of guide plates 600 fixed discretely in the axial direction within the central hole 22b of the lower end 22a of the support 22. The number of guide plates 600 may be two as shown in the figure, or may be more than that, for example, three or four.

[0230] At the lower end 22a of the pillar 22 (the portion of the pillar 22 that is connected to the upper end of the pile 30), the greater the number of guide plates 600 per given axial length (the higher the density), the smaller the load acting on the connection point between the pillar 22 and the pile 30 via each guide plate 600. Therefore, the higher the density of the guide plates 600, the more widely the load is distributed in the axial direction at the connection between the pillar 22 and the pile 30, and the stress is distributed over a wide area without being concentrated in a local area. As a result, stress concentration is mitigated.

[0231] Each guide plate 600 is generally plate-shaped, and in one example, has a support portion 602 having an outer shape smaller than the cross-sectional shape of the central hole 22b (for example, an outer shape that allows the guide plate 600 to pass through the central hole 22b in a predetermined posture), and an attachment portion 604 bent at one end of the support portion 602. The support portion 602 and the attachment portion 604 may be configured as an integrated part or as separate parts.

[0232] The support portion 602 has a through hole 603 through which the peg 300 passes, thereby fixing the radial position of the peg 300 .

[0233] On the other hand, the mounting portion 604 is attached to the central hole 22b at a predetermined axial position thereof by, for example, screwing or welding to the side wall of the support 22.

[0234] Furthermore, this mounting portion 604 is used to fix the support 22 and the pile 30 in a predetermined axial direction using a fastener 610 such as a set screw (a male screw for pressing its tip against a mating component to fix the mating component).

[0235] The fastener 610 is screwed into an internal thread formed in a penetrating state in the side wall of the support 22 (in this case, a through hole is formed in the mounting portion 604) or into an internal thread formed in the mounting portion 604 (in this case, a through hole is formed in the side wall of the support 22). In this screwed state, the fastener 610 engages with the outer surface of the pile 30 at its tip. This engagement presses the pile 30 against the inner peripheral surface of the through hole 603 of the guide plate 600. This pressing position the support 22 with respect to the pile 30 in both the axial and radial directions, and prevents the support 22 from coming off the pile 30 in the axial direction.

[0236] When this coaxial connection structure is adopted, the pillar connection process includes, for example, after the pile guide device 70 is removed from the ground surface, (a) a process in which an operator coaxially covers the hollow hole 22b of the lower end 22a of the pillar 22 over the portion of the pile 30 protruding from the ground surface, thereby coaxially inserting the protruding portion into the hollow hole 22b, and (b) a process of fixing, joining or fastening the lower end 22a to the protruding portion, thereby coaxially connecting the pile 30 and the pillar 22 to each other using a double-tube structure.

[0237] <Another embodiment>

[0238] Next, a signboard according to another exemplary embodiment of the present invention will be described with reference to Figures 16 to 18. However, elements common to the previous embodiment will be referred to using the same reference numerals or names to omit redundant explanations, and only different elements will be described in detail.

[0239] As shown in FIG. 1, the signboard 20 has a pair of posts 22, 22, and in one example, each post 22 is configured as a square pipe.

[0240] Incidentally, in cases where the signboard 20 is used, for example, as a parking lot signboard, a light (e.g., a security light) for illuminating the display panel 30 of the signboard 20 at night and a surveillance camera for photographing and monitoring the parking lot at all times of the day and night are detachably attached to a high point on the support pole 22, for example, near the top end.

[0241] 16, in order to detachably mount the accessories 520, 522 such as the electric lights (e.g., security lights) and the surveillance cameras to the pole 22, a clamp 500 such as the above-mentioned orthogonal clamp is used as a commercially available (standard) product. This clamp 500 is known as a mounting bracket that straddles two parts, a bracket that fastens and fixes two parts, etc.

[0242] In the figure, a perspective view is shown as an example of how a plurality of types of accessories 520, 522 are detachably attached to a standing signboard 20 using one type of clamp 500.

[0243] Fig. 17 is an enlarged plan view of clamp 500, which is detachably attached to support 22 made of square pipe, showing the locked and unlocked positions. The example shown is a parallel clamp (or a flexible clamp) that clamps two pipes parallel to each other, but it is also possible to use an orthogonal clamp (or a fixed clamp) that clamps two pipes in a position where they intersect at a right angle, as shown in Figs. 16 and 18.

[0244] As shown in Fig. 17, regardless of the type, clamp 500 has a first holding part 504 for detachably holding a first pipe 502 (e.g., a support 22 made of a square pipe) and a second holding part 508 for detachably holding a second pipe 506 (e.g., a round pipe 506 of adapters 530, 532 (described in detail later with reference to Fig. 18) used to attach accessories 520, 522). These holding parts 504, 508 are connected by a connecting part 510 so that they cannot be displaced relative to each other if the clamp is fixed, or so that they can be displaced relative to each other if the clamp is flexible.

[0245] The first holding portion 504 switches between a locked position shown by a dotted line in the same figure, i.e., a position where the first pipe 502 is fixed to the clamp 500, and an unlocked position shown by a solid line in the same figure, i.e., a position where the first pipe 502 can be released from the clamp 500.

[0246] Similarly, the second holding portion 508 switches between a locked position shown by a dotted line in the same figure, i.e., a position in which the second pipe 506 is fixed to the clamp 500, and an unlocked position shown by a solid line in the same figure, i.e., a position in which the second pipe 506 can be released from the clamp 500.

[0247] FIG. 18(a) is a plan view conceptually showing a clamp 500 with a first adaptor 530 attached thereto, and FIG. 18(b) is a plan view conceptually showing the same clamp 500 with a second adaptor 532 attached thereto.

[0248] In this embodiment, first and second adapters 530, 532 made to match the geometric characteristics of the fittings 520, 522, respectively, are used to attach the fittings 520, 522 to the first pipe 502 by the clamp 500. Specifically, the first adapter 530 is used to attach the first fitting 520 to the clamp 500, while the second adapter 532 is used to attach the second fitting 522 to the same clamp 500.

[0249] Each of the adapters 530, 532 is configured as a two-part structure, specifically including an attachment 550 as a first part that is attached to a mounting bracket 540 of the equipment 520, 522, and a second pipe 506 as a second part that is held by a second holding portion 508.

[0250] The attachment 550 is a dedicated product for the accessories 520, 522 to be attached at least in terms of mounting specifications (e.g., the number and arrangement of screw holes), whereas the second pipe 506 corresponds one-to-one to the type of the corresponding clamp 500 and is a common product for the accessories 520, 522 to be attached. Usually, the attachment 550 and the second pipe 506 are manufactured separately, and then the two are combined to form the adapters 530, 532 as a single completed product.

[0251] When the mounting bracket 540 and the attachment 550 are screwed together, the same number of screw holes 560, 562 are formed in the same arrangement (e.g., pitch and direction) in both the mounting bracket 540 and the attachment 550. However, the mounting specifications of the mounting bracket 540 (the number and arrangement of the screw holes 560) differ depending on the type of the accessories 520, 522.

[0252] Therefore, the adapters 530, 532 exist for each type (type of installation specification) of the accessories 520, 522. However, in the adapters 530, 532, the second pipe 506 is common regardless of the type of the accessories 520, 522, whereas the attachment 550 differs depending on the type (type of installation specification) of the accessories 520, 522.

[0253] Therefore, the adapters 530, 532 are common to each other regardless of the type of the second pipe 506, so that only one type of clamp 500 is required. On the other hand, the adapters 530, 532 are dedicated to each of the accessories 520, 522 because the attachment 550 differs depending on the type of the accessories 520, 522.

[0254] Incidentally, in the past, in order for a worker to install equipment 520, 522 at a high spot on a pillar 22 at a work site (e.g., a parking lot), the worker would drill holes in the wall of the pillar 22 according to the installation specifications of the equipment 520, 522 while working at the high spot.

[0255] In contrast, according to this embodiment, the same drilling work can be performed not on-site, but at a production site such as a factory before the attachment is transported to the site, by the same worker who will be going to the installation site or a different worker who will not be going to the installation site, as work on flat ground or at a low altitude. Therefore, according to this embodiment, it is no longer necessary to perform the drilling work at a high altitude, and the burden on the worker is reduced.

[0256] Furthermore, according to this embodiment, the multiple types of accessories 520, 522 are not directly attached to the clamp 500, but are indirectly attached to the clamp 500 via the corresponding adapters 530, 532. Therefore, according to this embodiment, regardless of the types of accessories 520, 522 to be attached, the type of clamp 500 is unified to one type as long as the type of support 22 is the same. As a result, storage and management of the clamp 500 before use is easy.

[0257] That is, according to this embodiment, the compatibility or versatility of the clamp 500 with respect to the types of accessories 520, 522 is expanded thanks to the presence of the adapters 530, 532.

[0258] Furthermore, according to this embodiment, the clamp 500 that arrived at the site is not genuine and therefore does not match the equipment 520, 522 that arrived at the site together with the clamp 500, so there is no need to take the extra effort of transporting a different genuine clamp 500 to the same site.

[0259] As is clear from the above explanation, this embodiment has been made to solve the problem of wanting to reduce the burden on an operator who is attaching a second object (e.g., equipment 520, 522) to a first object (e.g., support 22) using a commercially available clamp (e.g., a two-component connecting type) as the number of types of second objects that may be attached to a first object of the same type increases.

[0260] In order to solve the problem, the present embodiment employs the following technical idea.

[0261] That is, based on (a) a first technical idea of ​​using a commercially available or standardized clamp to attach a second object (e.g., equipment 520, 522) to a first object (e.g., support 22), and (b) a second technical idea of ​​having the clamp indirectly hold the second object via an adapter, configuring the adapter as a connection between a first part that is attached to the second object and a second part that is held by the clamp, and manufacturing the first part to have different geometry depending on the type of second object, while manufacturing the second part to have a geometry that exists only once as long as there is only one type of clamp, an adapter-interposed object mounting method or an adapter for a clamp is adopted as a means for solving the problem.

[0262] Furthermore, as is self-evident from the above explanation, this embodiment enables a worker to use only one type of clamp at any of a number of work sites to detachably attach any type of second object to one type of first object (e.g., working at height), while also achieving the effect of simplifying associated work (e.g., storing and managing the clamps).

[0263] In this embodiment, the "adapter" is interposed between the clamp and the second object, as exemplified above, but instead, it may be interposed between the clamp and the first object, or it may be embodied as a combination of a first adapter interposed between the clamp and the first object and a second adapter interposed between the clamp and the second object.

[0264] Incidentally, as a prior art document relating to a clamp as a tool for connecting multiple components to each other so as to form a three-dimensional intersection, there is, for example, JP 2017-127272 A.

[0265] Although some exemplary embodiments of the present invention have been described in detail above with reference to the drawings, these are merely examples, and the present invention can be embodied in other forms that incorporate various modifications and improvements based on the knowledge of those skilled in the art, including the forms described in the [Summary of the Invention] section above.

Claims

1. A method for driving a round bar-shaped pile into the ground, the round bar-shaped pile being made of non-concrete and configured to have no nodes at least at a central portion in an axial direction of the pile, comprising the steps of: This pile driving method involves driving the pile into the ground to create a vertical hole in the ground, then pouring sand as a filler without adding cement into the vertical hole that appears when the pile is pulled out, and then driving the pile into the ground to spread and compact the sand and the surrounding soil outward, and when compaction is complete, leaving the pile in the ground, thereby fixing the pile to the ground.

2. The pile is transferred from an installation stage in which the pile is fixed to the ground and installed by the pile driving method according to claim 1 to a removal stage in which the pile is pulled out from the ground and removed, The pile driving method according to claim 1, wherein in the installation stage, the pile is driven into the ground so that when the pile is pulled out in the removal stage, the vertical hole created in the installation stage can appear in the ground.

3. 3. The pile driving method according to claim 1, wherein the vertical hole is constructed in the ground so as to have a diameter substantially the same as that of the pile.

4. 3. The pile driving method according to claim 1, wherein the pile is manually pulled out of the ground.

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