Hikawa Mikawa 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 relates to a technique for simplifying the work required for the installation and removal of columns and piles. 、 A technique for improving the accuracy regarding the position and orientation of the pile when the pile is driven into the ground. and / or driven pile construction method It relates to this.

Background Art

[0002] In order to support a certain structure at a position lifted from the ground (a high place or a low place), columns fixed to the ground may be used.

[0003] Here, in one example, "high place" means a place at a height of 2 m or more from the base surface (for example, a ground scaffold such as a grounding surface or the ground surface), while "low place" means a place lower than that high place.

[0004] The above-mentioned "column" is also referred to as, for example, a pole or a post, and is configured as, for example, a round pipe or a square pipe made of steel or plastic. Also, the column may be carried into the site as a ready-made product or may be constructed on site.

[0005] Examples of the above-mentioned "structure" include a structure for displaying information such as a signboard (for example, a display board for commercial advertising), a guide board or a sign (for example, a traffic sign, a traffic signal, etc.) (see, for example, Patent Documents 1 and 3), and an enclosure such as a protective fence or a temporary enclosure (see, for example, Patent Documents 2 and 4).

[0006] Also, examples of the "structure" include a structure installed outdoors and exposed to wind, rain, and snow (for example, a freestanding signboard) and a structure installed indoors.

[0007] Furthermore, there are various types of structures that support a "structure" with columns, including those supported by a single column (single-legged type) and those supported by multiple columns extending parallel to each other (double-legged type). When the columns are of the double-legged type, there are advantages such as higher torsional rigidity around the vertical axis compared to the single-legged type, and the ability to prevent the columns from tilting or falling over even if one of the columns malfunctions, as long as the other columns remain normal.

[0008] One method for fixing piles to the ground is the precast pile method. This method involves driving precast piles (for example, made of steel or concrete, with a solid or hollow structure) into the ground.

[0009] There are two types of pre-fabricated pile construction methods: driven pile construction and embedded pile construction.

[0010] The driven pile method is a construction method in which pre-fabricated piles (for example, made of steel or concrete) are driven into the ground by the force of a hammer, without the need to excavate pilot holes in the soil beforehand.

[0011] Here, "hammer" refers to both manual hammers and construction machinery (automatic hammers), such as pile drivers (e.g., air hammers). Manual hammers are large hammers with a metal block attached to the end of a long handle held by the worker, and are used by swinging them down by the worker, or by lifting them against gravity by the worker's hand and then striking the pile by free fall.

[0012] In contrast, the embedded pile method involves excavating the ground to a predetermined depth to create a pilot hole, and then inserting a prefabricated pile into that pilot hole. One such embedded pile method is called the root wrapping method (see, for example, Patent Document 3). This root wrapping method involves, for example, creating an enlarged concrete bulb at the bottom of the pile.

[0013] According to this root-wrapping method, a pilot hole is first excavated in the ground, and crushed stone is placed at the bottom of the pilot hole and compacted. Next, a support post is inserted into the pilot hole, and temporary bracing is used to keep the post upright and prevent it from tilting. After that, ready-mix concrete is poured into the pilot hole, surrounding the support post. The concrete is then allowed to harden, thereby fixing the support post in place.

[0014] Using this root wrapping method, since concrete foundations typically have a long lifespan of 20-30 years, it becomes unnecessary to replace the support columns during that time.

[0015] However, this root-wrapping method requires steps such as excavating the ground to create pilot holes, temporarily supporting the pillars, and constructing concrete foundations, which leads to increased costs and extended construction periods. Therefore, this root-wrapping method is not suitable when the pillars and piles are to be removed frequently due to their short lifespan.

[0016] Patent Document 1 discloses a technique for driving piles into the ground and using those driven piles to fix a support column. However, this document only discloses that piles are used to press the support column against the ground surface (ground surface) after it has been installed, and does not disclose that the piles are connected to the support column after they have been driven into the ground, nor does it disclose that the piles are connected to the support column coaxially. Furthermore, this document does not disclose that the piles are driven into the ground while being guided so that they can move up and down.

[0017] Patent Document 2 discloses a technique for driving piles deeper into the ground in stages by repeatedly applying impact force to the piles. However, this document only discloses the process of excavating a pilot hole in the ground by pulling out the pile after it has been driven into the ground, and then inserting a support column into that pilot hole. It does not disclose the process of leaving the driven pile in the ground and connecting the lower end of the support column to the upper end of the left-in pile.

[0018] Furthermore, this document, like Patent Document 1, does not disclose the use of a pile guide device that guides the pile itself so that it can move up and down to drive the pile straight into the ground. Specifically, this document discloses the use of a tool called a guide rod to drive piles, but to be precise, this guide rod is used to guide the air hammer so that it can slide up and down, and not 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 makes no mention of the driven pile method. This document discloses that if a vertical hole is excavated in the ground at an unexpectedly steep angle, the pile will also be erected at an angle within the vertical hole, resulting in a decrease in the verticality of the support column inserted into the pile. Furthermore, this document discloses that after the pile is root-wrapped in the ground with concrete, the pile is coaxially connected to the support column. However, this document does not disclose either directly using a pile fixed in the ground to fix the support column, nor does it disclose connecting a pile fixed in the ground and a support column in a state of mutual contact.

[0020] Patent Document 4 discloses a technique for driving piles into the ground. Furthermore, this document discloses a method of driving the pile into the ground while guiding it so that it can move up and down. However, this document does not disclose how to connect the pile to a support column after it has been driven into the ground, how to connect the pile coaxially to the support column, or how to connect the pile to the support column in a manner in which they are in contact with each other.

[0021] Patent Document 5 discloses the embedded pile method as a pile construction method, but makes no mention of the driven pile method. Furthermore, this document does not disclose that the support column 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 drawback of using the embedded pile method is that if a large wind pressure acts on a structure supported above ground by the upper end of a support column that is buried in the ground at its lower end, the column may not be structurally stable.

[0023] Furthermore, this document also points out that when the ground anchor method, that is, first excavating the ground to create a hole, then dropping a cylindrical reinforcing bar assembled on-site into the hole, and then pouring fresh concrete into the hole and solidifying the concrete to form an anchor, is adopted, although it is indeed more stable in terms of strength than when the embedded anchor method is adopted, there are problems such as requiring a great deal of labor (man-hours, construction period, etc.) and cost for the removal work of the strut.

Prior Art Documents

Patent Documents

[0024]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0025] As described above, there are various methods for the anchor method, each having its own advantages and disadvantages. Therefore, it is necessary to select a method suitable for the site (for example, terrain, soil quality, natural phenomena, etc.) and application (for example, average service life, etc.) from these anchor methods based on various circumstances related to the site and application, and there are various factors to be considered at that time. These factors include, for example, the scale of the strut, the average service life of the strut, factors related to the construction period for the installation and removal of the strut, factors related to the labor cost for the installation and removal of the strut, etc.

[0026] Support columns are subject to certain strength requirements in order to fulfill their mission of stably supporting the structure they are to support in the air, in the environment of their installation site (e.g., wind pressure, rain, snow accumulation, vibration, etc.).

[0027] The strength requirements imposed on a support column depend on the weight and size of the column and the structure it supports (particularly the height dimension of the column). Furthermore, given the structural environment in which the structure is held in a position elevated above the ground, the weight class of the structure generally depends on the height class of the structure (i.e., roughly equivalent to the length of the support column (height from the ground) that supports it).

[0028] Furthermore, the strength requirements imposed on support columns also depend on the average lifespan of the structure when it is used at the same site. Therefore, if a support column is subjected to strength requirements that are stronger than those appropriate for a short average lifespan, the column will be over-engineered in terms of strength, leading to waste.

[0029] Therefore, for the sake of explanation, we will classify the types of support posts into three categories according to their length. Specifically, we will classify the types of support posts into small posts with a length of less than 2m, medium posts with a length of 2m or more but less than 4m, and large posts with a length of 4m or more.

[0030] Specifically, small support posts include, for example, signs that are temporarily installed in vacant lots, and medium-sized support posts include, for example, roadside signs installed in parking lots (including bicycle parking areas), as illustrated in Figure 1, as well as pedestrian traffic lights and road signs. Large support posts include, for example, vehicle traffic lights (e.g., 4.5m or taller).

[0031] Large support columns are subject to high strength requirements, medium-sized columns to moderate strength requirements, and small columns to low strength requirements.

[0032] Typically, to meet high strength requirements, the piles supporting the pillars are fixed to the ground using the aforementioned root-wrapping method, employing a concrete foundation and filler material. Conversely, to meet low strength requirements, the piles supporting the pillars are typically fixed to the ground simply by being driven into the ground using a simple driven-pile method, without the use of a concrete foundation or filler material.

[0033] Traditionally, there has been no pile construction method suitable for achieving an intermediate strength level between that achieved by the root-wrapping method and that achieved by the simple driven-pile method.

[0034] In response to this, the inventors conducted research and development on a pile construction method suitable for achieving an intermediate level of strength. In doing so, the inventors considered a structure such as the aforementioned roadside parking lot sign used by a company that temporarily manages the land as a parking lot on behalf of the landowner, where it may be necessary to suddenly remove the sign and the length of continuous use is unstable, and selected the following requirements.

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

[0036] Based on past statistics regarding the usage of the aforementioned freestanding signs for parking lots, the inventors set the maximum service life of the support posts to approximately 5 years. Therefore, if the root wrapping method were adopted, the strength level achieved by it (for example, a service life of 20-30 years) would be excessive.

[0037] Therefore, the inventors have researched and developed a new pile construction method suitable for achieving a strength level in the support column that is efficient in relation to the maximum service life of the support column.

[0038] (2) Bending strength

[0039] Generally, support columns must provide sufficient safety and reliability to prevent tilting or collapse, even in soft ground or strong winds. This means ensuring the necessary degree of ground compaction and the bending stiffness of the columns (deflection characteristics due to wind load as a lateral load). Therefore, simply using a driven pile method would result in insufficient strength.

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

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

[0042] Furthermore, when adopting a structure in which the support columns are not directly fixed to the ground but are indirectly fixed to the ground by being connected to piles fixed to the ground, it is necessary to connect multiple individual components, namely the support columns and the piles, to each other.

[0043] The connection points between these posts and piles are typically located at the ground surface, that is, at the position where the externally acting bending moment on the post is maximized. Therefore, the inventors recognized that the structure adopted for these connection points is an important factor in determining the strength of the post's resistance to the aforementioned bending moment. Furthermore, the maximum bending moment increases as the length of the post increases.

[0044] Therefore, the inventors have devised a structure for connecting a pile and a support column such that abrupt changes in the section modulus between the two members are suppressed, thereby reducing stress concentration at the connection point between the two members.

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

[0046] The verticality of a pile fixed to the ground refers to the angle at which the centerline of the pile, fixed to the ground, is inclined relative to the direction in which gravity acts, i.e., the vertical direction. In other words, it is the angle of deviation of the pile's centerline from the vertical. The closer the pile's verticality is to 0, the closer its centerline is to the direction of gravity.

[0047] Incidentally, when a structure is supported by a column, the structure is generally positioned at or near the top of the column. Therefore, if the column is installed at an angle from the vertical, the weight of the structure constantly acts as an eccentric load on the column, resulting in a bending moment acting on the column. This bending moment constantly puts a load on 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 column is connected to a pile fixed to the ground, that is, when the apparent support column (when the support column and pile are viewed as a single column) employs a two-part structure, the verticality of the support column depends on the verticality of the pile. Therefore, the inventors recognized that fixing the pile to the ground in a state where its verticality is good is essential for ensuring good verticality of the support column.

[0049] Therefore, the inventors have devised a method to improve the verticality of the piles fixed to the ground, regardless of the number of support columns supporting a single structure, thereby improving the verticality of the support columns connected to those piles, and consequently preventing unexpected bending moments from occurring in the support columns, particularly at the point where the bending of the columns begins.

[0050] Furthermore, when a single structure is supported by multiple parallel pillars, and these pillars are connected to multiple piles, during the process of fixing the multiple piles to the ground, it is necessary to improve the precision of the pile spacing, the verticality of each pile, and ultimately the parallelism of the multiple piles.

[0051] The reason for this will be explained in detail later, using the example of a situation where, after the assembly of a signboard is complete, its multiple support posts are attached to multiple piles fixed to the ground; in other words, multiple piles whose relative positions are fixed (mutually constrained) are attached to multiple support posts whose relative positions are fixed (mutually constrained).

[0052] In this case, if a connection structure is adopted in which multiple support columns are coaxially connected to multiple stakes (for example, a structure in which one member is inserted into a hollow hole in the other member), then for each support column, if the support column and stake to be connected to each other are not arranged in a straight line so that they coincide in both position and orientation, it becomes impossible to assemble multiple support columns, i.e., a signboard, to multiple stakes.

[0053] More specifically, when multiple piles are fixed to the ground, if there are errors in the spacing between piles and / or the verticality of the piles, the upper end of the portion of the pile that protrudes from the ground surface (i.e., the portion of the pile that should be connected to the lower end of the support column) will be shifted laterally from the target position. In this case, the positional error of the connection point between the pile and the ground tends to appear at the upper end of the portion of the pile that protrudes from the ground surface, amplified according to the verticality error Δθ of the pile and the length L of the portion of the pile that protrudes from the ground surface.

[0054] Therefore, if multiple support columns are forcibly attached to multiple piles despite this, twisting will occur between them, resulting in unexpected residual stress in each structural member. In particular, if this residual stress is tensile stress, it can cause cracks to form in each structural member.

[0055] Therefore, the inventors have devised a method to reduce errors in the position and orientation of piles fixed to the ground when there are multiple support columns for a single structure, thereby enabling multiple support columns to be assembled to multiple piles without difficulty.

[0056] Furthermore, when the support columns are fixed to the ground using the aforementioned root-wrapping method, a single continuous support column exists both underground and in the air. Therefore, it is presumed that there is little or no risk of orientation errors between the multiple support columns fixed to the ground causing problems during the assembly of the support columns.

[0057] In particular, as will be discussed later, if a pair of support posts are inserted into their respective pilot holes before their respective concrete foundations harden, with their relative positions fixed (for example, after the assembly of the signboard is complete), then geometric errors between the pair of support posts will not lead to any new serious problems.

[0058] (4) Construction period and construction costs

[0059] As mentioned above, the support columns that fall within the category of the inventor's focus have a short maximum lifespan. Therefore, if the construction period for installing and removing the support columns is long, and consequently the construction costs increase, the net profit obtained from using the support columns will decrease. As a result, in some cases, construction costs may put pressure on net profits, and there is a risk that the business involved with the support columns may go bankrupt.

[0060] Therefore, in order to shorten the construction period for installing and removing the support columns, the inventors have devised a method that allows workers to install and remove the support columns using simple tools and manual labor instead of heavy machinery.

[0061] Incidentally, based on the inventor's past experience, the strength of the support columns can be expected to be managed without concern using the aforementioned root wrapping method. However, this root wrapping method requires the loading and unloading of heavy machinery, excavation of the ground for creating pilot holes using that heavy machinery, temporary support for the columns, and construction of concrete foundations during the installation of the columns. Consequently, the removal of the columns also requires the loading and unloading of heavy machinery, excavation of the ground using that heavy machinery, and removal of the concrete foundations using that heavy machinery. As a result, the construction period tends to be extended and construction costs tend to increase.

[0062] Therefore, this root wrapping method was unsuitable for the support columns that the inventor is focusing on, both in terms of construction time and cost.

[0063] In short, the inventors have researched and developed a method for fixing medium-sized support columns that allows for easy and quick installation and removal of the columns by manual labor, without sacrificing the strength that has been achieved to date.

[0064] However, the support column fixing method resulting from this research and development can be applied not only to medium-sized support columns but also to small and large support columns. Furthermore, this support column fixing method can be applied when fixing support columns to soft ground or when fixing support columns to hard ground (for example, hard ground, good ground, firm ground, dense ground).

[0065] Based on the circumstances described above, the present invention is a technology that simplifies the work required for the installation and removal of support columns and piles. 、 A technology to improve the accuracy of the position and orientation of piles once they have been driven into the ground. and / or innovative driven pile construction methods This project was undertaken with the objective of providing [something]. [Means for solving the problem]

[0066] To solve this problem, according to one aspect of the present invention, there is a method for driving a round rod-shaped pile made of steel and configured so as not to have any joints in at least its axial center into the ground, A vertical hole is created in the ground by driving the aforementioned pile into the ground, and sand is poured into the vertical hole that appears when the pile is subsequently withdrawn, without adding cement, and the sand and surrounding soil in the vertical hole are pushed outward and compacted by driving the aforementioned pile again. The degree of compaction of the sand placed in the vertical shaft and the surrounding soil reaches the target value. This provides a pile-driving method for fixing the pile to the ground by leaving the pile in the ground.

[0067] The present invention provides the following embodiments. Each embodiment is divided into sections, each section numbered, and the numbers of other sections are referenced as necessary. This is to facilitate understanding of some of the technical features and combinations thereof that the present invention may employ, and it should not be interpreted that the technical features and combinations thereof that the present invention may employ are limited to the embodiments below. In other words, it should be interpreted that there is no preclude from appropriately extracting and adopting technical features described in this specification that are not described in the embodiments below as technical features of the present invention.

[0068] Furthermore, the fact that each section is written in a format that references the numbering of other sections does not necessarily mean that it prevents the technical features described in each section from being separated and made independent from those described in other sections. Rather, it should be interpreted that it is possible to make the technical features described in each section independent as appropriate according to 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 that pile as a foundation to fix at least one support column to the ground, The pile driving process involves repeatedly driving and withdrawing the pile into the ground, and after each withdrawal, filling the resulting vertical hole in the ground with sand as a packing material. Through repeated driving, the same pile gradually pushes and compacts the sand and surrounding soil in the vertical hole outwards. Once the compaction is complete, the pile is left in the ground with its upper end protruding from the surface, thereby fixing the pile to the ground. After the pile is fixed to the ground, a support column connection step is performed in which the support column is connected to the pile coaxially and in mutual contact with the pile using the portion of the pile that is fixed to the ground that protrudes from the ground surface. A method for fixing support posts, including the method described above.

[0070] (2) Furthermore, The method for fixing a support column according to item (1), which includes a guide installation step in which, prior to the first driving, a worker installs a pile guide device that guides the pile so that it can move up and down while in contact with its outer 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 fitted so as to be slidable in the axial direction, The method for fixing a support column according to paragraph (2), wherein the guide installation step includes installing the pile guide device relative to the pile positioning device such that the guide pipe passes through the through hole.

[0072] (4) The method for fixing a support column according to item (2) or (3), wherein the guide installation step includes a step in which, after the pile positioning device has been installed on or near the ground surface, a worker 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 The aforementioned pile is fitted into a guide pipe that is slidable in the axial direction, A direction adjustment mechanism for adjusting the orientation of the guide pipe and Includes, The method for fixing a support column according to any one of items (2) to (4), wherein the guide installation step includes a step in which an operator adjusts the orientation of the pile guide by using the orientation adjustment mechanism so that the guide pipe extends in the vertical direction.

[0074] (6) Furthermore, Prior to the aforementioned support column connection process, the process includes a guide removal step in which a worker removes the pile guide from the ground while leaving the pile positioning device in place on the ground surface. The column connection step includes, after the pile guide is removed from the ground surface, (a) a worker coaxially placing a reinforcing sleeve over the portion of the pile that protrudes from the ground surface, and (b) a worker further coaxially placing the hollow hole at the lower end of the column over the reinforcing sleeve, thereby connecting the pile and the column to each other in a triple-cylinder structure via the reinforcing sleeve, as described in item (3) or (5).

[0075] (7) Furthermore, Prior to the aforementioned support column connection process, the process includes a guide removal step in which a worker removes the pile guide from the ground while leaving the pile positioning device in place on the ground surface. The column connection step, after the pile guide is removed from the ground surface, includes (a) a step in which a worker coaxially places the hollow hole at the lower end of the column over the portion of the pile that protrudes from the ground surface, thereby coaxially inserting the protruding portion into the hollow hole, and (b) a step in which the lower end is fixed, joined or fastened to the protruding portion, thereby coaxially connecting the pile and the column in a double-cylinder structure, as described in item (3) or (5).

[0076] (8) The method of fixing a post according to any one of paragraphs (1) to (7), wherein the at least one post is used to display an information display structure, including signs, information boards or markers, or to fix a protective fence.

[0077] (11) A method in which, instead of using a concrete foundation, workers manually drive at least one pile into the ground and use that pile as a foundation to fix at least one support column to the ground, A driving process in which a worker uses a hammer to strike the pile at its upper end, thereby manually driving the pile into the original ground where no vertical hole has been pre-excavated, so that the upper end of the pile protrudes from the ground surface. After the first pile driving is complete, the worker uses a pile extractor to manually pull the driven pile out of the ground, thereby creating a vertical hole in the ground. After the first extraction is complete, the worker manually puts sand into the vertical hole as a filler in a filling process, After the first sand is added, the worker repeats the driving process, the extraction process, and the loading process in order using the same pile, thereby compacting the sand and surrounding soil placed in the vertical shaft by the same pile in a stepwise manner. Once the target compaction characteristics are achieved for the sand and surrounding soil, the pile is placed in the ground with its upper end protruding from the surface, thereby fixing the pile to the ground in a placement process. After the pile is fixed to the ground, a worker inserts the portion of the pile that is fixed to the ground and protruding from the ground surface into the hollow hole at the lower end of the support column, thereby connecting the two. A method for fixing support posts, including the method described above.

[0078] (12) Furthermore, Prior to the first driving, a preparatory step is taken in which a worker manually installs a pile guide device, which guides the pile so that it can move up and down, at the target location on the ground surface where the lower end of the pile should begin to enter. After the pile is fixed to the ground, the removal process involves workers manually removing the pile guide device. The method of fixing the support post as described in item (11), including the method described in item (11).

[0079] (13) The coupling process is After the removal of the aforementioned pile guide device, the worker manually inserts the portion of the pile that is fixed to the ground and protruding from the ground surface into the hollow hole at the lower end of the support column until the end face of the lower end of the support column is buried in the ground. After insertion, a fastening process is performed in which the worker fastens the support column and the pile using a fastening device. of include The method of fixing the support posts as described in item (12).

[0080] (14) The method for fixing a support column according to any one of items (11) to (13), wherein the pile guide is constructed by connecting a plurality of pipes that intersect each other in three dimensions using a plurality of right-angle clamps so as to form a rectangular parallelepiped, and the plurality of pipes have the same number of guide pipes as at least one pile, and each pile is slidably inserted into each guide pipe.

[0081] (15) The method for fixing support columns according to item (14), wherein the plurality of pipes have three or more support pipes erected on the ground surface in a position parallel to each other, and each of the support pipes has a height adjustment mechanism independently of each other, thereby adjusting the orientation of the pile guide in three dimensions and adjusting the verticality of the guide pipe.

[0082] (16) The at least one pile includes multiple piles, The aforementioned at least one support column includes the same number of support columns as the aforementioned plurality of stakes, The pile guide device is configured to guide the plurality of piles so that they can move up and down along a plurality of parallel centerlines. The method of fixing the support column further includes: Prior to the first driving, the process includes a pile spacing regulating device installation step in which a worker manually installs a pile spacing regulating device, which defines the target pile spacing at which the multiple piles should be separated from each other in a plan view, either by placing it on the ground surface or by embedding it at least partially in the ground, in accordance with multiple target locations on the ground surface where the multiple piles are to be driven, After the support column and the pile are fastened together, the pile spacing guide is buried in the ground and left in place without being removed. A method for fixing a support post as described in any of items (11) to (15), including the above.

[0083] (17) The pile spacing regulating device has a plurality of through holes through which each pile should pass, spaced at the same interval as the target pile spacing, The method for fixing a support column according to item (16), wherein the preparation step includes a step in which, after the pile spacing regulating device has been installed, a worker positions the pile guide device using each through-hole of the installed pile spacing regulating device as a visual target.

[0084] (18) A pile guide device as described in any of items (12) through (15).

[0085] (19) The pile spacing guide described in item (16).

[0086] (20) The pile spacing guide is placed on or near the ground surface while the multiple piles are fixed to the ground, The pile spacing stabilizer described in paragraph (19), wherein the pile spacing stabilizer acts as a tie bar that connects the plurality of piles to each other in the horizontal direction, thereby mechanically restraining the piles such that they are substantially prevented from approaching or separating from each other.

[0087] (31) A method in which, instead of using a concrete foundation, workers manually drive at least one pile into the ground and use that pile as a foundation to fix at least one support column to the ground, A pile driving process in which the pile is driven into the ground to fix it to the ground, After the pile is fixed to the ground, a support column connection step is performed in which the support column is connected to the pile coaxially and in mutual contact with the pile using the portion of the pile that is fixed to the ground that protrudes from the ground surface. A method for fixing support posts, including the method described above.

[0088] (32) Furthermore, The method for fixing a support column according to item (31), which includes a guide installation step in which, prior to driving the pile, a worker installs a pile guide device that guides the pile so that it can move up and down while in contact with its outer 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 includes a guide pipe into which the pile is fitted so as to be slidable in the axial direction, The method for fixing a support column according to item (32), wherein the guide installation step includes the step of installing the pile guide device relative to the pile positioning device such that the guide pipe passes through the through hole.

[0090] (34) The method for fixing a support column according to paragraph (32) or (33), wherein the guide installation step includes a step of positioning the pile guide by using the through-hole of the installed pile positioning device as a visual target after the pile positioning device has been installed on or near the ground surface.

[0091] (35) The pile guide device is The aforementioned pile is fitted into a guide pipe that is slidable in the axial direction, A direction adjustment mechanism for adjusting the orientation of the guide pipe and Includes, The method for fixing a support column according to any one of items (32) to (34), wherein the guide installation step includes a step of adjusting the orientation of the pile guide by using the orientation adjustment mechanism so that the guide pipe extends in a vertical direction.

[0092] (36) Furthermore, Prior to the aforementioned support column connection process, the process includes a guide removal step in which a worker removes the pile guide from the ground while leaving the pile positioning device in place on the ground surface. The method for fixing a support column according to item (33) or (35), wherein the support column connection step includes, after the pile guide is removed from the ground surface, (a) a worker coaxially placing a reinforcing sleeve over the portion of the pile that protrudes from the ground surface, and (b) a worker further coaxially placing the hollow hole at the lower end of the support column over the reinforcing sleeve, thereby connecting the pile and the support column to each other in a triple-cylinder structure via the reinforcing sleeve. [Brief explanation of the drawing]

[0093] [Figure 1] Figure 1 is a front view illustrating a freestanding sign installed on a site using a support post fixing method according to an exemplary embodiment of the present invention, along with the support post and stake. [Figure 2] Figure 2 is a perspective view illustrating how the sign shown in Figure 1 would be installed in an area of ​​the site adjacent to the sidewalk. [Figure 3] Figure 3 is a perspective view illustrating the piles shown in Figures 1 and 2. [Figure 4] Figure 4 is a cross-sectional view illustrating an example of a fastening device used to secure the pile shown in Figure 2 to the support column shown in the same figure. [Figure 5] Figure 5 is a perspective view illustrating a support fixing system used by workers to implement the support fixing method described above, which includes a pile guide for guiding the pile shown in Figure 2 vertically when it is driven into the ground, and a base plate for defining the horizontal position of the pile on the ground surface. [Figure 6] Figure 6(a) is a side view showing the support pipe, main horizontal pipe, and guide pipe of the pile guide device shown in Figure 5, and Figure 6(b) is a plan view. [Figure 7] Figure 7 is a side cross-sectional view illustrating how the pile shown in Figure 2 is guided vertically by the guide pipe and base plate shown in Figure 5 when it is driven into the ground. [Figure 8]Figure 8 is a process diagram illustrating an example of the installation work in which the support column fixing method described above is implemented, in which a worker installs the signboard shown in Figure 1. [Figure 9] Figure 9 is a side cross-sectional view illustrating how the base plate shown in Figure 5 is installed horizontally despite the original ground being sloped, as part of the topsoil preparation process shown in Figure 8. [Figure 10] Figure 10 is a series of longitudinal cross-sectional views illustrating the pile driving process shown in Figure 8, which involves repeatedly driving piles into the ground and extracting them, and how sand is then filled into the vertical holes created in the ground after each extraction. [Figure 11] Figure 11 is a perspective view showing an example of a pile driving hammer used by workers to drive piles into the ground during the pile driving process shown in Figure 8. [Figure 12] Figure 12 is a perspective view showing an example of a pile extraction machine used by workers to pull piles out of the ground during the pile driving process shown in Figure 8. [Figure 13] Figure 13(a) is a side cross-sectional view illustrating 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 illustrating the relative positional relationship between the pile, support column, reinforcing sleeve, and base plate in the support column connection process shown in Figure 8. [Figure 14] Figure 14 is a cross-sectional view illustrating the relative positional relationship between the pile, the support column, and the reinforcing sleeve in the support column connection process shown in Figure 8. [Figure 15] Figure 15 is a process diagram illustrating the removal work performed by workers to remove the sign shown in Figure 1. [Figure 16] Figure 16 is a perspective view illustrating how multiple types of equipment are detachably attached to a signboard according to another exemplary embodiment of the present invention using one type of clamp. [Figure 17] Figure 17 is a plan view showing the locked and unlocked positions of a clamp used to detachably attach the equipment shown in Figure 16 to the signboard shown in the same figure. [Figure 18] Figure 18(a) is a conceptual plan view showing the clamp shown in Figure 17 together with a first adapter attached thereto, and Figure 18(b) is a conceptual plan view showing the same clamp together with a second adapter attached thereto. [Figure 19] Figure 19(a) is a partial plan view showing the coaxial connection structure between a driven pile and a support column connected to it, and Figure 19(b) is a side view showing the same coaxial connection structure. [Modes for carrying out the invention]

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

[0095] <One Embodiment>

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

[0097] The signboard 20 is freestanding and fixed-installation type, and has a display board 40 as a structure supported by support columns 22, 22 in a position raised above the ground surface (ground surface, ground level, support surface, etc.).

[0098] In other words, the signboard 20 is configured to include a pair of support columns 22, 22 fixed vertically to the ground of the site (an example of an area), and a display board 40 that is supported by being sandwiched between these support columns 22, 22 from both sides.

[0099] Each support column 22 is made of a square pipe with sides of 75 mm, while each stake 30 is made of a round bar with an outer diameter of approximately 50 mm. The round bar is, for example, solid or at least partially hollow.

[0100] The signboard 40 may be horizontal or vertical. In the example shown in Figure 1, the signboard 30 is horizontal. Specifically, the freestanding signboard 20 has a height dimension of approximately 3000-4000 mm and a width dimension of approximately 2000-3000 mm.

[0101] The signboard 20 is double-sided, and therefore the signboard 40 has a front display surface and a rear display surface. It is possible to display the same or different information on each of these display surfaces.

[0102] This information can be represented, for example, by letters, numbers, or shapes. Numbers, for example, may consist of a single digit or multiple digits.

[0103] Figure 2 illustrates how the signboard 20 is installed in an area adjacent to the sidewalk on the site. In this example, the signboard 20 is classified as a so-called roadside signboard, which is installed outdoors.

[0104] Figure 3 is a perspective view showing pile 30. This pile 30 is, of course, classified as a precast pile. This pile 30 is made of steel, for example, and is a hollow pipe that is closed at the top (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 pile 30 has a total length of approximately 1100-1600 mm and a diameter of approximately 50 mm. The pile 30 has a parallel section (a section extending straight with the same cross-section) 54 in its axial center and tapered sections 56 and 58 at its front and back.

[0106] <Outline explanation of the coaxial insertion type connecting structure between piles and support columns>

[0107] As shown in Figure 2, each pile 30 driven into the ground has a corresponding support column 22 inserted into it, connecting them 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 by a connection structure in which the upper end surface of each pile 30 and the lower end surface of each support column 22 are abutted together and bolted. However, the coaxial insertion type connection structure illustrated in the figure has a larger contact surface in the axial direction for both components, and the cross-sectional forces are transmitted between the two components over a wider area than the latter connection structure.

[0109] Therefore, the coaxial insertion type connection structure is more suitable because it distributes the stress generated at the connection point 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 stress concentration. This coaxial insertion type connection structure will be described in detail later with reference to Figure 13(b).

[0110] Figure 4 is a cross-sectional view illustrating a fastening device 60 for tightening and fixing a pile 30 to a support column 22. In this fastening device 60, a U-shaped bolt 62 is attached to the support column 22 so as to partially surround the pile 30 inside the support column 22, and multiple nuts 64 are screwed from the outside onto the portion of the U-shaped bolt 62 that is exposed from the outer surface of the support column 22. Within the support column 22, spacers 66 are interposed as appropriate between the inner surface of the support column 22 and the outer surface of the pile 30.

[0111] <Support post fixing system>

[0112] As shown in the perspective view in Figure 5, the worker uses the support fixing system 10 to carry out the support construction method. The support fixing system 10 includes a pile guide 70 for guiding the pile 30 vertically when the worker 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] <Stake guide tool>

[0114] In general terms, the pile guide device 70 constitutes an example of a pile guide device that guides the pile 30 so that it can move up and down while in contact with its outer surface. Furthermore, since the pile guide device 70 guides the portion of the pile 30 excluding the lower end, it is also called an "upper guide".

[0115] Specifically, the pile guide device 70 is constructed by connecting multiple pipes that intersect each other in each of the two layers using multiple orthogonal clamps (not shown) so as to form a rectangular parallelepiped. 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 aforementioned plurality of pipes have three or more support pipes 90 (in the illustrated example, four support pipes arranged at the four vertices of a rectangle) that are erected on the ground surface in a position parallel to each other.

[0117] Each of these support pipes 90 has a height adjustment mechanism that is independent of each other. With the cooperation of three or more height adjustment mechanisms for each pile guide device 70, the orientation (especially the direction) of the pile guide device 70 is manually adjusted in three dimensions 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) is 0 degrees.

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

[0119] Relative rotation between the base 94 and the male screw 96 is prevented, while relative rotation and relative axial movement between the support pipe 90 and the male screw 96 are permitted. Therefore, by rotating the nut 98 via the operating part 100, the operator can raise and lower the nut 98, and consequently extend or retract the overall length of each support pipe 90.

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

[0121] As shown in Figure 5, the plurality of pipes further comprises a plurality of main horizontal pipes 110 and a plurality of secondary horizontal pipes 112. The main horizontal pipes 110 and the secondary horizontal pipes 112 intersect at right angles in a three-dimensional manner.

[0122] As shown in Figure 6(a), a side view, and Figure 6(b), a plan view, the guide pipe 80 and the support pipe 90 are erected in the ground in a position where they extend parallel to each other, and the main horizontal pipe 110 is sandwiched between these pipes 80 and 90 from both sides so as to intersect them perpendicularly in a three-dimensional manner.

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

[0124] In the locked state, the guide pipe 80 is firmly (irremovably) fixed to the main horizontal pipe 110, while in the unlocked state, the worker 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] As shown in Figure 5, the base plate 72 schematically constitutes an example of a pile positioning device that positions the pile 30 horizontally on the ground surface and has a through hole 74 through which the pile 30 penetrates. The base plate 72 also simultaneously constitutes an example of a pile spacing defining device that defines the target pile spacing at which a pair of piles 30, 30 should be separated from each other in a plan view.

[0127] Furthermore, the base plate 72 is also called the "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 guide."

[0128] The base plate 72 also acts as a tie bar, connecting the pair of piles 30, 30 to each other horizontally, thereby mechanically restraining the piles 30, 30 so as to substantially prevent them from moving closer to or further apart from each other (for example, integrating them from a materials mechanics standpoint).

[0129] As a result, compared to when the base plate 72 is divided and installed discretely for each pile 30, the actual value of the pile spacing is promoted to continuously match the target value, and even if the ground is soft, the tilting of each pile 30 at the ground surface is suppressed.

[0130] Specifically, the base plate 72 is mainly composed of, for example, a single straight-extending steel plate 120 that does not deform when installed on the ground surface (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 a steel plate 120, as well as two short steel plates 122 that are stacked and fixed on both sides of the steel plate 120 in a direction that intersects at right angles. Each steel plate 122 has one through hole 74 at each end, so the base plate 72 has a total of six through holes 74. As a result, using the base plate 72 makes it possible to drive two piles 30 into the ground simultaneously with a specified distance between them.

[0132] <Method for installing stake guides and base plates>

[0133] To install the pile guide device 70 and base plate 72 on the ground surface, the 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 positions and installs the pile guide device 70 so that each guide pipe 80 and each through-hole (guide hole, positioning hole, etc.) 74 are aligned in a straight line.

[0134] <Method for guiding piles during driving>

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

[0136] In this embodiment, a single pile 30 is guided by being slidably fitted into two base plates 72 and guide pipes 80, which serve as guides, at two different locations in the axial direction. However, the present invention may also be implemented in a manner in which a single pile 30 is guided at only one location in the axial direction. This implementation may involve the use of only the guide pipes 80, or the use of only the base plates 72.

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

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

[0139] In this embodiment, the lower end of the guide pipe 80 is embedded in the ground with a protrusion from the underside of the base plate 72 to prevent the lower end of the guide pipe 80 from coming off upward from the base plate 72 during the driving of the pile 30. However, an initial protrusion length of about 20 mm may suffice.

[0140] <Installation of standing signs>

[0141] Figure 8 shows an example of the process in which the support column fixing method is implemented, specifically the installation work in which workers set up the signboard 20 shown in Figure 1 on the site prior to use.

[0142] 1. Topsoil preparation process

[0143] Once the installation work begins, as shown in Figure 8, the first step is the topsoil preparation process. Specifically, workers conduct a topographic 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) in the area of ​​the site where the signboard 20 is to be installed. After that, the workers determine the planned location for installing the signboard 20.

[0144] Next, if the ground surface in the area where the signboard 20 is to be installed is not a horizontal surface, the worker excavates at least the topsoil of the planned installation site, that is, the topsoil of the area including the silhouette drawn when the installed signboard 20 is projected from directly above, as illustrated in the side cross-sectional view in Figure 9 (however, the base plate 72 consists of only one steel plate 120), thereby creating a horizontal excavation surface, i.e., a construction base surface, for the installation of the signboard 20.

[0145] 2. Upper and lower guide installation process

[0146] Next, as shown in Figure 8, the second step is the installation of the upper and lower guides. Specifically, the worker installs the base plate 72, which serves as the lower guide, onto the construction base surface, as illustrated in Figure 9.

[0147] After installing the base plate 72, the worker positions and installs the pile guide 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 70 that will be installed next.

[0148] Furthermore, as illustrated in Figure 13(a), the worker places the pile guide device 70 on the construction base surface relative to the base plate 72, such that the guide pipe 80 passes through the through hole 74 in 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 each guide pipe 80 extends vertically and simultaneously extends parallel to one another. As a result, as illustrated in Figure 7, the centerlines of each guide pipe 80 and the centerlines of the corresponding through holes 74 coincide with each other.

[0150] 3. Pile driving process

[0151] Next, as shown in Figure 8, the third step is the pile driving process.

[0152] Specifically, the workers repeatedly drive piles 30 into the ground and then pull them out. After each pull-out, the workers fill the resulting vertical hole 140 (see Figure 7) in the ground with sand as a filler.

[0153] Through repeated driving attempts, the same pile 30 gradually pushes and compacts the sand layer 150 (see Figure 7) and the surrounding soil placed in the vertical shaft 140, pushing them outward in stages. Once the compaction is complete, the workers leave the pile 30 in the ground with its upper end protruding from the surface, thereby fixing the pile 30 to the ground.

[0154] Figure 10 shows multiple longitudinal cross-sectional views illustrating, in chronological order, the pile driving process, which involves repeatedly driving piles into the ground and extracting them, and how sand is then filled into the vertical holes 140 created in the ground after each extraction.

[0155] The figure shows the changes in the ground cross-section over time for the first (n=1) cycle, the nth cycle, and the final cycle, which constitute one pile-driving process.

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

[0157] Once the target degree of soil compaction is achieved, the workers will leave the piles 30 in the ground.

[0158] In each cycle, the driving of the piles 30 is carried out in stages, for example, by an operator repeatedly free-falling a pile driving hammer 200, as shown in Figure 11. 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] As shown in Figure 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 until its upper end is approximately aligned with the upper end of the guide pipe 80, the upper end of the pile 30, i.e., the pile head level, will be approximately aligned with a position that rises from the ground surface to a height approximately equal to the total length of the guide pipe 80. At this time, the depth of the tip 52 of the pile 30 driven into the ground, i.e., the pile tip depth, will be approximately aligned with a position that descends from the ground surface to a length equal to the total length of the pile 30 minus the total length of the guide pipe 80.

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

[0161] In contrast, in each cycle, the extraction of the pile 30 is carried out in stages, for example, by a worker repeatedly operating a pile extraction machine 300, as shown in Figure 12.

[0162] The pile extractor 300 includes, for example, a base 302 that is grounded, a lever 304, and an engaging device 306 that is detachably engaged with the pile 30. The lever 304 has a point of force applied by the operator, a fulcrum supported by the base 302, and a point of action that is pivotably connected to the engaging device (for example, a fitting having a U-shaped gripping portion corresponding to the diameter of the pipe to be extracted) 306.

[0163] When the worker repeatedly pushes the lever 304 in a direction that pulls it towards themselves, the operating force applied by the worker to the point of force application of the lever 304 is amplified by the lever principle. This amplified operating force is transmitted to the pile 30 as an uplift force via the engaging device 306.

[0164] When using this pile extractor 300 to pull out the pile 30, as shown in Figure 7, the guide pipe 80 prevents the pile extractor 300 from directly accessing the outer surface of the pile 30. Therefore, prior to each extraction, the worker must temporarily pull out the guide pipe 80 from the pile 30 that is driven into the ground.

[0165] Therefore, the worker first unlocks the orthogonal clamps that engage with the guide pipe 80 on the pile guide device 70, thereby making the guide pipe 80 detachable from the pile guide device 70. In this state, the worker pulls the guide pipe 80 out of the ground. After that, the worker attaches the pile extractor 300 to the pile 30.

[0166] Once the pile 30 is pulled out, the worker reattaches the removed guide pipe 80 to its original position on the pile guide device 70, and then the next driving operation is carried out using the same guide pipe 80.

[0167] 4. Pile guide removal process

[0168] Next, as shown in Figure 8, the fourth step is the removal of the pile guide device. Specifically, the worker removes and retrieves the pile guide device 70 from the ground surface. At that time, the worker leaves the base plate 72 in place 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 support columns 22, 22 of the signboard 20 on the ground surface or underground (for example, a tie bar that restrains the pair of support columns 22, 22 in the horizontal direction).

[0170] 5.Column connection process

[0171] Subsequently, as shown in Figure 8, the fifth step is the support column connection process. Specifically, after the piles 30 are fixed to the ground as described above, the workers connect each support column 22 of the signboard 20 to the piles 30 coaxially and in contact with each other, using the portion of the piles 30 that protrudes from the ground surface, as illustrated in Figure 13(b).

[0172] Figure 13(b) is a side cross-sectional view illustrating the relative positional relationship between the pile 30, the support column 22, the reinforcing sleeve 400, and the base plate 72 in this support column connection process. Figure 14 is also a side cross-sectional view illustrating the relative positional relationship between the pile 30, the support column 22, and the reinforcing sleeve 400 in this support column connection process.

[0173] Specifically, in this support column connection process, the worker first places a reinforcing sleeve 400 (in the illustrated example, it is made of a round pipe, but a square pipe is also acceptable) coaxially over the portion of the pile 30 that protrudes from the ground surface.

[0174] Next, the worker places the hollow hole at the lower end of the support column 22 (in the illustrated example, it is made of a square pipe, but a round pipe can also be used) coaxially over the reinforcing sleeve 400. In this way, the worker connects the pile 30 and the support column 22 in a triple-cylinder connecting structure by using the reinforcing sleeve 400 as an intermediary between them.

[0175] At this time, as shown in Figure 13(b), the worker embeds the reinforcing sleeve 400 into the ground so that its lower end penetrates the through hole 74 of the base plate 72 and sinks further down from there to a tip depth of, for example, about 100-200 mm. The embedding of the reinforcing sleeve 400 may also be done by the worker striking the upper end surface of the reinforcing sleeve 400 with a hammer.

[0176] As shown in Figure 13(b), the reinforcing sleeve 400 is embedded in the ground, completely penetrating the through-hole 74 of the base plate 72. This reduces the gap between the outer surface of the pile 30 and the inner surface of the through-hole 74 of the base plate 72. Thanks to this layout, the lateral wobbling of the pile 30 and, consequently, the support column 22 within the through-hole 74 is suppressed, and the postural stability of the pile 30 and the support column 22 is also improved by the strengthening of the ground by the reinforcing sleeve 400 embedded in the ground.

[0177] In this support column connection process, the worker further fastens and secures the support column 22 to the pile 30 using a fastener 60, as illustrated in Figure 4. This prevents the support column 22 from coming loose from the pile 30 in the axial direction. The fastening and securing with the fastener 60 is performed, for example, at at least one axial position of the support column 22 that is not covered by, for example, the reinforcing sleeve 400, as shown in Figure 13(b).

[0178] Incidentally, prior to the execution of this support column connection process, there are two options: one is that each support column 22 is already attached to the display board 40 together with the other support columns 22 that form a pair with it, and therefore cannot move freely on its own; that is, the signboard 20 is in a completed state except for the part of the stake 30; and the other is that each support column 22 is not yet attached to the display board 40, and therefore can be separated from the other parts and move freely; that is, 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. This makes it possible to attach each support column 22 to the display board 40 on level ground and in parallel with the construction of the piles 30, thus improving work efficiency.

[0180] On the other hand, with the signboard 20 completed in its main body, it is necessary to connect its pair of support columns 22, 22, whose relative positions are fixed, to a pair of stakes 30, 30 driven into the ground, which are similarly fixed in their relative positions. Therefore, a nearly perfect geometric coincidence is required between the centerlines of the pair of support columns 22, 22 and the centerlines of the pair of stakes 30, 30.

[0181] Here, "nearly perfect geometric agreement" means that the pair of posts 22,22 are nearly perfectly parallel to each other, the pair of stakes 30,30 are nearly perfectly parallel to each other, and the spacing between the pair of posts 22,22 and the spacing between the pair of stakes 30,30 are nearly perfectly coincide.

[0182] Thus, in order to satisfy the requirement of making the pair of support columns 22,22 and the pair of piles 30,30 geometrically almost perfectly aligned, in this embodiment, a pile guide 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 are used in combination to accurately match the actual orientation of each pile 30 to the target.

[0183] 6. Backfilling process

[0184] Subsequently, as shown in Figure 8, the sixth step is the backfilling process. Specifically, workers bury the base plate 72 in the ground by piling up soil, as illustrated in Figure 13(b). If the original ground surface was a slope, the excavated area is backfilled and restored by piling up soil on the base plate 72 to match the original ground surface.

[0185] With this, the installation of a single signpost can be completed without the use of heavy machinery or excavation of the ground, and requires only simple manual labor by workers, without requiring advanced skills or years of experience.

[0186] <Removal of standing signs>

[0187] Figure 15 shows an illustrative process diagram illustrating the removal of the signboard 20 after its use is complete.

[0188] <1.Disassembly process>

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

[0190] <2. Pile extraction process>

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

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

[0193] Next, the worker manually pulls each pile 30 out of the ground using a second pile extraction machine 300 (which may be the same one used in the pile driving process during the aforementioned installation work) having an engaging device 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 remain in the ground.

[0194] <3. Base plate removal process>

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

[0196] <4. Topsoil Restoration Process>

[0197] Next, as shown in the diagram, the fourth step is the topsoil restoration process. Specifically, the workers will work on the following areas of the site: Stand up Because sign 20 was removed, the topsoil in the area that has not been leveled will be backfilled and leveled by adding soil as needed.

[0198] With this, the removal of the signboard can be completed in one go without using heavy machinery or excavating the ground, and requires only simple manual labor by workers, without requiring advanced skills or years of experience.

[0199] In this embodiment, the pile driving process shown in Figure 8 involves repeatedly driving in and pulling out the piles 30 and filling them with sand. However, if, for example, the ground where the signboard 20 is to be installed is not soft, the piles 30 may be driven in only once, and the filling of sand into the vertical hole 140 may be omitted.

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

[0201] The above exemplifies a scenario in which the support columns 22, 22 of a signboard 20 are fixed to the ground of a site (for example, a site used as a parking lot) using the original driven pile method according to this embodiment. However, the same pile method can also be used to install support columns (for example, hollow cylindrical bodies) to which other equipment used together with the signboard 20, such as box-shaped bodies like ticket vending machines, ticket dispensers, and payment machines, or equipment like security lights, are attached, on a similar site.

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

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

[0204] 1. The advantage of a shorter construction period.

[0205] The applicant conducted a test installation in which one signboard 20, one ticket vending machine, and five security lights were installed together on the same site. Of the time spent in this test installation, approximately 4 hours were spent installing multiple piles 30 using the original driven pile method according to this embodiment.

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

[0207] (1) The process of excavating pilot holes in the ground, the same number as the number of support posts 22.

[0208] (2) The process of preparing ready-mix concrete (or mortar) for all the support posts 22.

[0209] (3) The process of inserting all the support posts 22 into their respective pilot holes and installing them on the site (however, the pair of support posts 22, 22 for the signboard 20 are inserted into their respective pilot holes and installed on the site when both are attached to the display board 30, i.e., when the signboard 20 is completed).

[0210] (4) Step of pouring the prepared ready-mix concrete into multiple pilot holes.

[0211] (5) The process of aligning the installed signboard 20 so that its horizontal direction is almost perfectly aligned with the horizontal direction.

[0212] (6) The process of installing reinforcing braces at the lower end of each support column 22 (for example, the part that protrudes from the ground surface) so that each support column 22 does not tilt or topple unexpectedly before the ready-mixed concrete has completely hardened in each pilot hole.

[0213] (7) A step of waiting until the ready-mixed concrete hardens.

[0214] As a comparative test to the aforementioned test construction, the applicant used the root-wrapping pile method to drive the same number of support columns 22 into the ground as the multiple piles 30 used in the aforementioned test construction, which took two days.

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

[0216] Furthermore, according to this embodiment, while it is common for multiple piles 30 to be constructed sequentially rather than simultaneously, once the construction of one pile 30 is completed in a few hours, another worker can perform other tasks related to that pile 30. As a result, according to this embodiment, the construction of another pile 30 can be carried out in parallel with the work related to a completed pile 30. Here, "other tasks" could include, for example, electrical work performed on a signboard 20. This electrical work could include installing signboard lights for nighttime illumination on the top of the signboard 20, or wiring work to supply power to those signboard lights.

[0217] Therefore, according to this embodiment, it becomes possible to perform multiple types of necessary tasks on the same site at least partially simultaneously, thereby improving overall work efficiency.

[0218] In contrast, when using the root-wrapping pile method, no work (such as necessary electrical work) can be performed on any of the support columns 22 until the concrete has hardened for all of them. Therefore, after the concrete foundations for all of the support columns 22 are completed, the work associated with those columns 22 is started in a series rather than parallel.

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

[0220] 2. The advantage of reduced space required for underground pile installation.

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

[0222] Incidentally, according to the aforementioned root-wrapping pile construction method, a pilot hole is excavated in the ground before embedding the support column. This pilot hole is excavated with a cross-section larger than the outer diameter of the support column, taking into account the size of the concrete foundation that will surround the lower end of the support column when it is embedded in the pilot hole.

[0223] Furthermore, according to this root-wrapping pile construction method, as mentioned above, before the concrete foundation hardens, the aforementioned reinforcing diagonal members are attached to the lower end of each support column so as to extend laterally from each column, thus requiring extra space on the ground surface to be occupied by these reinforcing diagonal members.

[0224] Therefore, when adopting this root-wrapped pile construction method, if the piles are to be installed within the site, close to the boundary line with the adjacent property, it is necessary to move the support posts closer to the site from the boundary line so that the pilot holes, concrete foundations, and reinforcing diagonal braces do not encroach on the adjacent property. Consequently, when adopting this root-wrapped pile construction method, it is difficult to install the support posts as close to the boundary line as possible within the site, thereby minimizing the possibility of the support posts becoming an obstacle within the site.

[0225] In contrast, according to this embodiment, the vertical hole 140 is constructed underground at the same location as the pile 30 and with approximately the same diameter. Furthermore, the depth of each pile 30 is so great (for example, 700 mm, 800 mm, or 900 mm or more) that the reinforcing diagonal members required in the root-wrapping pile method are unnecessary. This makes it easy to install the piles 30 and the support columns 22 connected to them as close to the boundary line as possible within the site.

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

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

[0228] Figure (a) is a partial plan cross-sectional view showing the coaxial connection structure between the driven pile 30 and the support column 22 connected to it, and Figure (b) is a side cross-sectional view showing the same coaxial connection structure.

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

[0230] At the lower end 22a of the support column 22 (the portion of the support column 22 connected to the upper end of the pile 30), the greater the number of guide plates 600 per predetermined axial length (higher density), the less load is applied to the connection point between the support column 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 axially in the connection between the support column 22 and the pile 30, and stress is distributed over a wide area without concentrating locally. As a result, stress concentration is alleviated.

[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 position), and a mounting portion 604 that is bent at one end of the support portion 602. The support portion 602 and the mounting portion 604 may be constructed as an integrated part or as separate parts.

[0232] The support portion 602 has a through hole 603 through which the pile 30 passes, thereby fixing the radial position of the pile 300.

[0233] In contrast, the mounting portion 604 is attached to a predetermined axial position in the central hole 22b. This attachment is carried out, for example, by screwing or welding to the side wall of the support column 22.

[0234] Furthermore, this mounting portion 604 is used to fix the support column 22 and the pile 30 in a predetermined axial direction using fasteners 610 such as set screws (male screws that press their tip against a mating member to fix that mating member in place).

[0235] The fastener 610 screws into a female thread formed through the side wall of the support column 22 (in this case, a through hole is formed in the mounting portion 604), or into a female thread formed in the mounting portion 604 (in this case, a through hole is formed in the side wall of the support column 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 circumferential surface of the through hole 603 in the guide plate 600. This pressing positions the support column 22 relative to the pile 30 in both the axial and radial directions, and prevents the support column 22 from detaching from the pile 30 in the axial direction.

[0236] When this coaxial connection structure is adopted, the column connection process includes, for example, after the pile guide device 70 has been removed from the ground surface, (a) a worker coaxially covers the portion of the pile 30 that protrudes from the ground surface with the hollow hole 22b of the lower end 22a of the column 22, thereby coaxially inserting the protruding portion into the hollow hole 22b, and (b) fixing, joining or fastening the lower end 22a to the protruding portion, thereby coaxially connecting the pile 30 and the column 22 in a double-cylinder structure.

[0237] <Another embodiment>

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

[0239] As shown in Figure 1, the signboard 20 has a pair of support columns 22, 22, and in one example, each support column 22 is made of a square pipe.

[0240] By the way, if the purpose of the signboard 20 is, for example, a parking lot sign, then a light (for example, a security light) to illuminate the signboard 30 of the signboard 20 at night, and a surveillance camera to film and monitor the parking lot day and night, are detachably attached to a high point on the support column 22, for example, near the top.

[0241] As illustrated in Figure 16, in order to detachably attach equipment such as electric lights (e.g., security lights) and surveillance cameras 520, 522 to the support column 22, a clamp 500 such as the aforementioned orthogonal clamp, which is a commercially available (standard) product, is used. This clamp 500 is known as a mounting bracket that spans two parts, or a bracket that fastens and secures two parts together.

[0242] The figure shows, in an illustrative perspective view, how multiple types of equipment 520 and 522 can be detachably attached to a signboard 20 using one type of clamp 500.

[0243] Figure 17 shows a magnified view of the clamp 500, which is detachably attached to the square pipe support column 22, with its locked and unlocked positions shown in plan view. The illustrated example is a parallel clamp (or swivel clamp) that clamps two pipes parallel to each other, but as illustrated in Figures 16 and 18, it is also possible to use an orthogonal clamp (or fixed clamp) that clamps two pipes in a position where they intersect at a right angle.

[0244] As shown in Figure 17, regardless of the type, the clamp 500 has a first holding part 504 for detachably holding a first pipe 502 (for example, a square pipe support 22) and a second holding part 508 for detachably holding a second pipe 506 (for example, a round pipe 506 of the adapters 530, 532 (which will be described in detail later with reference to Figure 18) used to attach equipment 520, 522). These holding parts 504 and 508 are connected by a connecting part 510 so as not to be able to move relative to each other if it is a fixed clamp, and so as to be able to move relative to each other if it is a swivel clamp.

[0245] The first retaining part 504 switches between a locked position, indicated by a dashed line in the figure, that is, a position in which the first pipe 502 is fixed to the clamp 500, and an unlocked position, indicated by a solid line in the figure, that is, a position in which the first pipe 502 can be released from the clamp 500.

[0246] Similarly, the second retaining part 508 also switches between a locked position, indicated by a dashed line in the figure, that is, a position in which the second pipe 506 is fixed to the clamp 500, and an unlocked position, indicated by a solid line in the figure, that is, a position in which the second pipe 506 can be released from the clamp 500.

[0247] Figure 18(a) is a conceptual plan view showing the clamp 500 together with a first adapter 530 attached thereto, and Figure 18(b) is a conceptual plan view showing the same clamp 500 together with a second adapter 532 attached thereto.

[0248] In this embodiment, first and second adapters 530 and 532, each manufactured to match the geometric characteristics of the equipment 520 and 522, are used to attach the equipment 520 and 522 to the first pipe 502 using the clamp 500. Specifically, the first adapter 530 is used to attach the first equipment 520 to the clamp 500, while the second adapter 532 is used to attach the second equipment 522 to the same clamp 500.

[0249] Both adapters 530 and 532 are configured as two-part structures, specifically including an attachment 550 as a first part that is mounted on the mounting bracket 540 of the equipment 520 and 522, and a second pipe 506 as a second part that is held by the second retaining part 508.

[0250] Attachment 550 is specific to the equipment 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 has a one-to-one correspondence with the corresponding clamp 500 type and is a common part for the equipment 520, 522 to be attached. Typically, attachment 550 and the second pipe 506 are manufactured separately and then joined together to form a single finished adapter 530, 532.

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

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

[0253] Therefore, regardless of their type, adapters 530 and 532 are common to each other with respect to the second pipe 506, so only one type of clamp 500 is needed. On the other hand, adapters 530 and 532 differ with respect to attachments 550 depending on the type of equipment 520 and 522, and are therefore specific to each piece of equipment 520 and 522.

[0254] Incidentally, conventionally, workers sometimes drilled holes in the wall surface of the support column 22 in accordance with the mounting specifications of the equipment 520 and 522 while working at height, in order to install the equipment 520 and 522 at a high position on the support column 22 at a work site (for example, a parking lot).

[0255] In contrast, according to this embodiment, the same drilling work can be performed not at the site, but at the manufacturing site such as a factory, before the attachment 550 is transported to the site. This can be done by the same worker who will go to the installation site, or by a different worker who will not go to the installation site, as work performed on level ground or at a low level. Therefore, according to this embodiment, it is no longer necessary to perform the drilling work at a high place, thus reducing the burden on the workers.

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

[0257] In other words, according to this embodiment, the compatibility or versatility of the clamp 500 with respect to the types of equipment 520 and 522 is expanded thanks to the intervention of the adapters 530 and 532.

[0258] Furthermore, according to this embodiment, the extra work of having to transport another genuine clamp 500 to the same site because the clamp 500 that arrived at the site was not a genuine product and therefore incompatible with the equipment 520 and 522 that arrived at the site with it is avoided.

[0259] As is clear from the above description, this embodiment was made to solve the problem of reducing the burden on workers when attaching a second object (e.g., equipment 520, 522) to a first object (e.g., support column 22) using a commercially available clamp (e.g., a two-member connecting type), as the number of types of second objects that may be attached to the first object of the same type increases.

[0260] To solve this problem, the following technical concept is adopted according to this embodiment.

[0261] That is, on the basis of (a) a first technical idea of using a commercially available or standard clamp to attach a second object (e.g., equipment 520, 522) to a first object (e.g., support column 22), and (b) a second technical idea of indirectly gripping the second object by the clamp via an adapter, and configuring the adapter as a connector of a first part attached to the second object and a second part gripped by the clamp, the first part is manufactured to have different geometries according to the type of the second object, while the second part is manufactured to have a geometry that is unique as long as there is only one type of clamp. As a means for solving the problem, an adapter-interposed object mounting method or an adapter for a clamp is adopted.

[0262] According to this embodiment, as is apparent from the above description, an operator can perform an operation (e.g., working at a height) of detachably attaching an arbitrary type of second object to a single type of first object using only one type of clamp at any of a plurality of sites, and an accompanying operation (e.g., an operation of storing and managing the clamp) is simplified.

[0263] In this embodiment, the "adapter" is interposed between the clamp and the second object as exemplified above. However, instead of this, it may be interposed between the clamp and the first object, or 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] As a prior art document regarding a clamp as a tool for connecting a plurality of members to intersect three-dimensionally with each other, for example, there is Japanese Patent Application Laid-Open No. 2017-127272.

[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 implemented in various other forms with modifications and improvements based on the knowledge of those skilled in the art, starting with the embodiments described in the [Summary of the Invention] section above.

Claims

1. A method for driving a round rod-shaped pile, made of steel and constructed so as not to have any joints in at least its axial center, into the ground, A pile driving method comprising: creating a vertical hole in the ground by driving the pile into the ground; filling the vertical hole that appears after the pile is withdrawn with sand as a filler material without adding cement; compacting the sand and surrounding soil in the vertical hole by driving the pile again, pushing and spreading it outward; and, once the degree of compaction of the sand and surrounding soil in the vertical hole reaches a target value, leaving the pile in the ground, thereby fixing the pile to the ground.

2. The pile driving method according to claim 1, wherein the degree of compaction is evaluated by applying rotational force, axial force, or vibration to the pile to determine whether the target value has been reached.

3. The pile driving method according to claim 1 or 2, wherein the pile is made of a hollow pipe that is closed at its head and tip.

4. The pile driving method according to claim 1 or 2, wherein a support column used for installing a signboard, a box-shaped body, or a security light on a site having the ground is coaxially connected to a pile fixed to the ground.

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