JP7557118B2 - Driven pile and pile driving method - Google Patents

Description

The present invention relates to a driven pile and a pile driving method.

One example of a conventional sheet-like material holding down stake used to hold down and secure sheet-like materials, such as weed control sheets, shading sheets, agricultural sheets such as mulch, greening sheets, and vegetation mats for cultivating plants, to the ground is disclosed in Patent Document 1.

Figures 2 and 3 of Patent Document 1 show, as an example of a sheet-like material holding down pile, a support pile with a smooth peripheral surface protruding downward from the underside of a holding plate in the form of a disk or cross plate that holds down the sheet-like material, and the support pile is pushed into the ground so that the holding plate holds down the sheet-like material and secures it to the ground. However, because the peripheral surface of the support pile is smooth and the attempt is made to obtain pull-out resistance through friction between the smooth peripheral surface and the soil, the sheet-like material has the disadvantage that it is easily pulled out, resulting in the sheet-like material being torn off by the wind.

The pile disclosed in Figure 4 of Patent Document 1 is intended to increase the pull-out resistance of the pile, and is, for example, a flat pile body that is driven into the ground in the shape of an inverted triangular plate, with anti-pull-out pieces protruding from the opposing sides of the front and back of the pile body, and the top surface of the anti-pull-out piece is formed as a horizontal surface. When a pile having such a configuration is buried in the ground and an upward pull-out force is applied to the pile, the horizontal top surface of the anti-pull-out piece acts to press upward and lift the soil above it, and the anti-pull-out piece can increase the pull-out resistance of the pile.

However, because the pile only served to lift the soil above the retaining piece, there was a limit to the amount of pull-out resistance that could be obtained.

As shown in Figure 17, one example of a sheet-like object holding down pile in Patent Document 2 (hereinafter referred to as a first type pile) is configured to further increase the pull-out resistance force by providing zigzag-shaped bent protrusions that bend in a zigzag pattern in the vertical direction on the side surfaces facing each other in the front-to-rear direction of a vertically long base. A triangular recess with the side surface as its base surface is formed between the inclined upper surface and inclined lower surface formed by the zigzag-shaped bent protrusions.

When a sheet-like material holding down pile of this configuration is used, when the pile is buried in the ground and the soil that has entered the triangular recess becomes integrated with the surrounding soil, when a pull-out load is applied to the fixing device, the inclined upper surface presses the surrounding soil diagonally upwards through the soil that is held in the triangular recess, and a force acts that tries to lift the surrounding soil diagonally upwards, so that the pull-out resistance of the sheet-like material holding down pile is increased compared to the pile described in Patent Document 1.

Another example of a sheet-like object holding down pile according to Patent Document 2 (hereinafter referred to as a second type pile) is, as shown in FIG. 22, formed long in the vertical direction and arranged between two opposing flat plate-like base bodies spaced apart, with a zigzag-shaped bent protrusion that is bent in a zigzag pattern in the vertical direction interposed therebetween. The zigzag-shaped bent protrusion is configured to protrude from the side surfaces of both base bodies.

The pile body having such a configuration has a triangular recess formed between the flat base plates, and unlike the sheet-like material holding down pile described in FIG. 17 of Patent Document 2, it is difficult to expect soil to gradually enter the triangular recess as the pile body is driven. Therefore, it is undeniable that the increase in pull-out resistance is not immediate and takes a certain number of days, but soil may eventually enter the triangular recess due to the influence of rainfall after the pile body is driven. The soil that has entered in this way is held in the triangular recess. The amount of soil held in the triangular recess is greater than the amount of soil held in the triangular recess of the sheet-like material holding down pile described in FIG. 17 of Patent Document 2.

When the soil that has penetrated in this way becomes integrated with the surrounding soil, if a pulling action is applied to the sheet-like material holding down pile, as shown by the arrow in Figure 23 of Patent Document 2, a force acts through the soil held in the triangular recess, causing the upwardly inclined upper surface to press the surrounding soil diagonally upward and lift the surrounding soil diagonally upward. As a result, the pulling resistance force of the sheet-like material holding down pile increases, effectively preventing the sheet-like material holding down pile from floating up.

In this way, when using the second type of pile, the amount of soil that is held in the triangular recess is greater than that of the first type of pile, so there is an advantage in that the force that tends to lift the surrounding soil diagonally upwards is greater.

However, both the first and second type piles are designed to apply a force that tries to lift the surrounding soil diagonally upwards by using a zigzag-shaped bent protrusion that protrudes a relatively small amount from the side of the vertically long base, so the increase in pull-out resistance caused by the force that tries to lift the soil diagonally upwards was not that great. Furthermore, particularly with the second type pile, it is difficult to expect soil to gradually fill the triangular recess as the pile body is driven in, so the increase in pull-out resistance was not immediate.

Let us now assume that the stake with a cross-shaped cross section (a stake for fixing a cylindrical marker) described in Patent Document 3 is used to press and fix a sheet-like material, such as a weed control sheet, to the ground. The sides of each rib of the stake are formed smoothly, and as the stake is driven in, soil can be allowed to gradually fill in between adjacent ribs.

Therefore, there is an advantage in that, as soon as driving is completed, a pull-out resistance force is obtained due to the friction between the smooth side and the soil. However, since the obtained pull-out resistance force is only due to the friction between the smooth side and the soil, it is easy to pull out, which results in the problem of the sheet-like material being torn off by the wind. The pile with a cross-shaped cross section is intended to obtain pull-out resistance force only due to the friction between the smooth side and the soil, and it is not expected to produce much of a pull-out resistance force that pushes the surrounding soil diagonally upwards and lifts the surrounding soil diagonally upwards.

Japanese Utility Model Application Publication No. 6-86442 JP 2015-154760 A Japanese Utility Model Publication No. 57-28486

The present invention was developed in consideration of the above-mentioned problems with the conventional method, and aims to provide a driven pile that can exert a large pull-out resistance force as soon as the pile is driven into the ground, and also aims to provide a pile driving method that can exert a large pull-out resistance force as soon as the pile is driven into the ground.

In order to solve the above problems, the present invention employs the following means.
That is, a first aspect of the driven-in pile of the present invention is a driven-in pile having a pile body of a required length extending from the base end of the pile, which is the driving part, to the tip of the pile, which is the entry part into the ground, and a soil holding part having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other on the left and right at a required interval in the circumferential direction of the pile body is integrally provided at a required interval in the circumferential direction of the pile body, and when the axial direction is viewed as the up-down direction, the soil holding part is provided in one stage or in multiple stages at a required interval when viewed in the axial direction of the pile body. The soil holding portion has upper and lower open ends between the pair of soil holding pieces, and has a soil inflow end at the lower end and a soil outflow end at the upper end, and the outer tips of the pair of soil holding pieces are open to form an open side end, and the upper edge of the outer end portion of both soil holding pieces when viewed from the side is inclined inward toward the upper end and toward the axis, and when the soil holding portion is buried in the ground by driving the pile body, the upper end of the soil holding portion closest to the ground is located the required distance from the ground. The soil holding portion is capable of sequentially allowing soil that has flowed between the pair of soil holding pieces through the soil inflow end as the pile body is driven into the ground to flow out from the soil outflow end, and the open side end serves as a soil connecting portion that connects and integrates the soil in the soil holding portion with the soil surrounding the pile body when the pile body is driven into the ground as required, and the soil holding portion is characterized in that it has a soil compression means for compressing the soil that has flowed into the soil holding portion through the soil inflow end.

The second aspect of the driven pile according to the present invention is the first aspect, and is provided with the pile body and a soil holding member formed separately from the pile body and having the soil holding portion provided on the peripheral surface of a central shaft portion extending in the axial direction of the pile body, and the soil holding portion is configured by the soil holding member being provided in an integrated state with the pile body. The central shaft portion of the soil holding member is provided with a hole portion through which the pile body can be inserted or inserted, and when the pile body is inserted into the hole portion or the pile body is inserted into the hole portion, the soil holding member is provided in the integrated state with the pile body, thereby the soil holding portion is provided in an integrated state with the peripheral surface of the pile body.

The third aspect of the driven pile according to the present invention is characterized in that, in the second aspect, the central shaft of the soil holding member is configured as a central shaft that allows a screw shaft provided on the pile body to be inserted axially into the hole, and when the screw shaft is inserted into the central shaft, upper and lower clamping nuts that are screwed into the screw shaft so as to clamp the central shaft from above and below are tightened, so that the soil holding member is provided integrally with the pile body, and thus the soil holding portion is provided integrally with the peripheral surface of the pile body.

The fourth aspect of the driven pile according to the present invention is characterized in that in the second aspect, the central shaft portion of the soil holding member is configured as a central shaft portion in which a female thread portion is provided in the hole portion into which a screw shaft portion provided in the lower part of the pile body can be screwed, and the soil holding member is provided in an integrated state with the pile body when the screw shaft portion is screwed into the female thread portion of the central shaft portion, thereby the soil holding portion is provided in an integrated state with the peripheral portion of the pile body.

The fifth aspect of the driven pile according to the present invention is characterized in that, in the first or second aspect, each of the opposing inner surfaces of the pair of soil-holding pieces has a biting projection having a protruding amount of 0.1 to 3 mm that is dispersed and bites into the compressed soil mass compressed by the soil compression means between the soil-holding pieces.

The sixth aspect of the driven pile according to the present invention is the first or second aspect, wherein the soil compression means is constituted by the pair of soil holding pieces, and the outer edge of both soil holding pieces, when viewed from the side, consists of an intermediate edge, an upper edge, and a lower edge when viewed in the direction of the axis, the intermediate edge extends in the direction of the axis, the upper edge is inclined inward toward the upper end and toward the axis, the lower edge is inclined inward toward the lower end and toward the axis, and the lower edge is a sharp blade-like portion, and the blade-like portion is formed in a mountain shape with an inclined surface that slopes in the opposite direction from its apex.

The seventh aspect of the driven pile according to the present invention is characterized in that in the first or second aspect, the soil compression means is composed of the pair of soil holding pieces, and the thickness of both or either one of the soil holding pieces in a plan view is gradually increased from the inner end, which is the connection part to the pile body, toward the outer end.

The eighth aspect of the driven pile according to the present invention is characterized in that in the first or second aspect, the soil compression means is constituted by the pair of soil holding pieces, and both or either one of the opposing inner surfaces of the soil holding pieces is formed so as to slope inwardly of the soil holding portion from the lower end to the upper end, and the interior of the soil holding portion narrows from the lower end to the upper end.

The ninth aspect of the driven pile according to the present invention is characterized in that in the first or second aspect, the soil compression means is composed of the pair of soil holding pieces, and a soil runoff suppression protrusion is provided on the upper end portion of the opposing inner surface of both or either of the two soil holding pieces.

The tenth aspect of the driven pile according to the present invention is the first or second aspect, characterized in that the soil holding portion is composed of a pair of soil holding pieces facing each other on the left and right, which are 4 to 8 soil holding pieces protruding radially at a required angular pitch around the circumference of the pile body.

The eleventh aspect of the driven pile according to the present invention is characterized in that, in the first or second aspect, when the soil holding portion is provided in multiple upper and lower tiers at a required interval when viewed in the axial direction of the pile body, each pair of soil holding pieces constituting the multiple upper and lower tiers of soil holding portions is arranged in a row in the axial direction, and the thickness of the soil holding pieces arranged in the row is formed so that the thickness of the soil holding pieces in the upper tier is thicker than the thickness of the soil holding pieces in the lower tier.

The first aspect of the pile driving method according to the present invention is a pile driving method using the driven-in pile according to the first aspect, characterized in that the soil that flows into the soil holding pieces through the soil inflow end as the driven-in pile is driven into the ground is compressed as the soil flows out through the soil outflow end to form a compressed soil mass, and when the pile has been driven to the required depth into the ground, the compressed soil mass in the soil holding pieces and the soil around the pile body are integrated via the open end.

The second aspect of the pile driving method according to the present invention is a pile driving method using the driven-in pile according to the fifth aspect, characterized in that the soil that flows into the soil holding pieces through the soil inflow end as the driven-in pile is driven into the ground is compressed as the soil flows out through the soil outflow end to form a compressed soil mass, and when the pile has been driven to the required depth into the ground, the biting protrusions are caused to bite into the compressed soil mass in the soil holding parts, and the compressed soil mass in the soil holding parts and the soil around the pile body are integrated via the open end.

The present invention provides a driven pile that can exert a large pull-out resistance force as soon as the pile is driven into the ground. It also provides a pile driving method that can obtain a large pull-out resistance force as soon as the pile is driven into the ground.

FIG. 1 is a side view showing a driven-in stake according to the present invention with a weed control sheet pressed down and secured to the ground. FIG. 4 is a side view illustrating the configuration of the soil holding portion of the driven-in pile according to the present invention. FIG. 2 is a perspective view illustrating the configuration of the soil holding portion of the driven pile according to the present invention. FIG. 2 is a cross-sectional view illustrating the configuration of the soil holding portion of the driven pile according to the present invention. 1 is an explanatory diagram illustrating the configuration of the biting protrusions provided on the opposing inner surfaces of the soil-holding pieces of the driven-in pile of the present invention, together with the state in which the biting protrusions are bitten into the compressed soil mass. FIG. 2 is an explanatory diagram illustrating a soil compression means according to the present invention. FIG. 2 is an explanatory diagram illustrating a state in which the driven pile according to the present invention is being driven into the ground. This is a cross-sectional view showing the state in which the compressed soil mass formed in the soil holding portion is integrated with the soil surrounding the pile body. FIG. 2 is an explanatory diagram illustrating a bulbous object formed by driving the driven pile according to the present invention to a required depth. This is an explanatory diagram showing the state in which a pull-out force is applied within a certain limit to a driven pile driven into the ground, together with the state of the ground in the surrounding area. FIG. 13 is an explanatory diagram showing a state in which, as a result of further increasing the pulling force, the ground has risen over a somewhat wide area and some cracks have appeared in the ground. This is a perspective view showing a state in which a large crack has appeared over a wide area in the ground as a result of further increasing the pulling force. 1 is a perspective view showing the state of the soil-holding portion of a pile immediately after it has been pulled out of the ground. FIG. FIG. 1 is an explanatory diagram showing a state in which a solar panel stand is fixed to the ground using a driven pile according to the present invention. FIG. 2 is a cross-sectional view showing the driven pile. FIG. 2 is an explanatory diagram showing the state in which the driven-in pile has been driven into the ground and bulb-like objects have formed. This is a side view showing a driven-in pile in which soil-holding portions are provided in two levels, one above the other, with a required distance between them. This is a cross-sectional view explaining the configuration of a soil holding section having eight soil holding pieces arranged at an angle pitch of 45 degrees. FIG. 13 is an explanatory diagram illustrating the use of a driven pile to fix a slope protection material to a slope via a wire to prevent the slope from collapsing. FIG. 2 is an explanatory diagram illustrating the driving-in pile together with the driving means. FIG. 2 is an explanatory diagram showing the state in which the driven pile is driven into the slope so as to be approximately perpendicular to the slope, forming a bulbous object. This is an exploded side view showing a penetration type driven pile that uses a separate pile body and soil holding member. This is a side view and a cross-sectional view showing a penetrating type driven pile in which the pile body and the soil holding member are integrated. FIG. 4 is a cross-sectional view illustrating the configuration of the soil holding member. This is an exploded side view and cross-sectional view of a screw-in type driven pile that uses a separate pile body and soil-holding member. This is a side view and a cross-sectional view showing a screw-in type driven pile in which the pile body and the soil holding member are integrated. FIG. 1 is an explanatory diagram illustrating the use of driven piles to prevent the collapse of a slope. This is a cross-sectional view showing the state in which the compressed soil mass formed in the soil holding portion is integrated with the soil surrounding the pile body. FIG. 13 is an explanatory diagram illustrating the state in which a driven pile is driven into the ground so as to be approximately perpendicular to the slope and a bulb-shaped object is formed. FIG. 1 is a partial side view illustrating a driven pile suitable for use in fixing a mounting such as a solar panel to the ground. This is a cross-sectional view. FIG. 2 is an explanatory diagram showing the state in which the driven-in pile has been driven into the ground and bulb-like objects have formed. FIG. 2 is a side view illustrating a driven pile used in construction to prevent the collapse of a slope. This is a side view showing a driven-in pile in which soil-holding portions are provided in two levels, one above the other, with a required distance between them. FIG. 11 is a cross-sectional view illustrating another embodiment of the soil compression means. FIG. 11 is a cross-sectional view illustrating another embodiment of the soil compression means. FIG. 11 is a cross-sectional view illustrating another embodiment of the soil compression means.

In Figures 1 to 4 and 8, the driven-in pile (hereinafter also referred to as pile) 1 according to the present invention has a pile body 5 of a required length that extends from the pile base end 2, which is the driving part, to the pile tip 3, which is the part that enters the ground, and is used to press and secure a sheet-like material 7, such as a weed control sheet 7a, laid on the ground 6 to the ground 6. The driven-in pile 1 is formed as a single unit entirely from a synthetic resin, such as ABS resin, AES resin, polycarbonate, etc.

The driven pile 1 is provided on the peripheral surface 9 of the pile body 5 with a soil holding portion 11 having a pair of soil holding pieces 10, 10 extending in the direction of the axis L of the pile body 5 (hereinafter referred to as the axial direction) F and facing each other at a required interval around the circumference of the pile body 5, and is integrally provided at a required interval around the circumference of the pile body 5.

When the axial direction F is viewed as the up-down direction, the soil holding portion 11 is provided in one stage as viewed in the axial direction F, and as shown in Figs. 1-3, the upper and lower ends between the pair of soil holding pieces 10, 10 are open to have a soil inflow end 12 at the lower end and a soil outflow end 13 at the upper end, and the outer ends between the pair of soil holding pieces 10, 10 are open to have an open side end 15 (Figs. 3-4, 8). As shown in Fig. 2, the upper end side edge 17 of the outer end edge 16 in both soil holding pieces 10, 10 in a side view is inclined inward toward the upper end and toward the axis L. Then, when the soil holding portion 11 is buried in the ground by driving the pile main body 5 (Fig. 1), the upper end 19 of the soil holding portion 11a closest to the ground surface 6 is located a required distance away from the ground surface 6. In this embodiment, the soil holding portion 11 is provided in one step on the peripheral portion 9 of the pile body 5, and the soil holding portion 11 is the soil holding portion 11a that is closest to the ground surface 6.

As shown in Fig. 7, the soil holding portion 11 can sequentially discharge the soil that has flowed between the pair of soil holding pieces 10, 10 through the soil inflow end 12 as the pile body 5 is driven into the ground from the soil outflow end 13. As shown in Fig. 8, the open end 15 becomes a soil connecting portion 21 that connects and integrates the soil 20a (compressed soil mass 25 described below) present in the soil holding portion 11 and the soil 20b around the pile 1 when the pile body 5 is driven into the ground as required. As shown in Figures 1 to 3 and 6, the soil holding portion 11 has a soil compression means 22 that compresses the soil that has flowed into the soil holding portion 11, and each of the opposing inner surfaces 23, 23 of the two soil holding pieces 10, 10 has biting protrusions 26 (Figures 1 to 3 and 5) that are distributed between the soil holding pieces 10, 10 and bite into the compressed soil mass 25 compressed by the soil compression means 22. This will be explained in detail below.

In this embodiment, the pile body 5 is rod-shaped as shown in FIG. 1, and the portion on the pile tip 3 side is a tapered portion 27 that becomes thinner toward the pile tip 3. In this embodiment, the pile base end 2 is configured as a disk-shaped pressing plate 29 that presses and secures the sheet-like material 7 (weed control sheet 7a) to the ground. The overall length of the pile body 5 is set to, for example, about 300 to 400 mm, and its diameter is set to about 10 mm.

As shown in Figs. 1 and 4, the four soil-holding pieces 10 are radially protruding from the peripheral surface 9 of the lower part 30 of the pile body 5 to form a cross shape in plan view, and four soil-holding parts 11 consisting of a pair of soil-holding pieces 10, 10 arranged opposite each other at a required interval in the circumferential direction of the pile body 5 are provided at an angle pitch of 90 degrees in the circumferential direction of the pile body 6. The diameter D1 (Fig. 4) of the driven pile in plan view at the part where the soil-holding parts 11 are protruding is set to about 34 mm, which is about three times the diameter of the pile body 5 (about 10 mm). The diameter is set taking into consideration the required size of the bulbous object 57 (Fig. 9) described later.

As shown in Figures 1 to 4, the soil holding portion 11 is provided on the peripheral portion 9 of the lower portion 30 of the pile body 5, and the distance L1 (Figure 1) between the upper end 19 of the soil holding portion 11 and the lower surface portion 32 of the pressure plate 29 is set to approximately 170 mm.

In this embodiment, the soil holding piece 10 has a trapezoidal shape in side view extending in the axial direction F of the pile body 5, has a thickness of about 3 mm, and the length of the soil holding piece 10 as viewed in the axial direction F can be set to 100 to 150 mm, and is set to about 130 mm in this embodiment. As shown in Figure 2, the outer edge portion 16 of both soil holding pieces 10, 10 in side view consists of an intermediate edge portion 33, the upper end edge portion 17, and a lower end edge portion 35 as viewed in the axial direction F of the pile body 5. The upper end 19 of the upper end edge 17 is connected to the lower end 39 of a reinforcing ridge 37 (a ridge that reinforces the pile body 5) that protrudes from the peripheral surface 9 of the pile body 5 and whose upper end 36 (Figure 1) is connected to the lower surface 32 of the pressure plate 29 and extends in the axial direction F, and the height of the reinforcing ridge 37 is set to about 2 mm.

The intermediate edge portion 33 extends in the axial direction F and has a length in the axial direction F of about 65 mm, and the amount of protrusion from the peripheral surface portion 9 of the pile body 5 is set to about 12 mm.

The length of the lower edge 35 is set to about 40 mm. The lower edge 35 is inclined, for example, linearly, toward the pile tip 3 of the pile body 5 and inward toward the axis L. The portion 35a of the lower edge 35 that intersects with the pile body 5 is located about 10 mm above the pile tip 3. The lower edge 35 is configured as a sharp blade-like portion 40, which is formed in a mountain shape with inclined surfaces 42, 42 that incline in the opposite direction from the apex line 41, as shown in Figure 2 (B).

The upper edge 17 has a length of about 18 mm and is inclined inward toward the upper end and toward the axis L. The inclination angle θ (FIG. 2) is 45 to 60 degrees with respect to the horizontal plane, for example, about 60. Both ends of the upper edge 17 are formed as arcuate edges 43, 45, and the connection portion with the upper end of the intermediate edge portion 33 is formed as a convex arcuate edge, and the connection portion with the lower end of the reinforcing protrusion 37 is formed as a concave arcuate edge. In this embodiment, the distance L1 (FIG. 1) between the upper end 19 of the upper edge 17 and the lower surface 32 of the pressing plate 29 is set to about 170 mm as described above. In other words, when the driven pile 1 is driven so that the soil holding portion 11 is buried in the ground as required (i.e., when driving is complete), the upper end 19 of the soil holding portion 11 is positioned a required distance (approximately 17 cm) from the ground surface 6.

The biting protrusions 26 provided on the opposing inner surfaces 23, 23 of both soil holding pieces 10, 10 are configured as sawtooth protrusions having a first inclined surface 46 that is gently inclined toward the lower end and a second inclined surface 47 that is strongly inclined toward the upper end, as shown in Figure 5 in this embodiment. The biting protrusions 26 configured in this manner are arranged in parallel in the vertical direction, with the base ends 49 of the first inclined surfaces 46 and the base ends 50 of the second inclined surfaces 47 of the biting protrusions 26, 26 adjacent to each other in the vertical direction coinciding with each other. The length L3 of the biting protrusion 26 in the axial direction is set to about 5.5 mm, the height (protrusion amount) L4 from the opposing inner side surfaces 23, 23 is set to 0.5 to 2 mm, for example, about 1 mm, the angle (first angle θ1) of the first inclined surface 46 with respect to the opposing inner side surface 23 (i.e., with respect to the axial direction F) is set to about 15 degrees, for example, and the angle (second angle θ2) of the second inclined surface 47 with respect to the opposing inner side surface 23 (i.e., with respect to the axial direction F) is set to 30 to 45 degrees, for example, about 30 degrees.

The first angle θ1 and the second angle θ2 are set in this manner in order to improve the bite of the biting protrusion 26 into the compressed soil mass 25 (Figures 5 and 8) and to further increase the integrated strength between the biting protrusion 26 and the compressed soil mass 25.

The protrusion amount of the biting protrusion 26 is set to 0.5 to 2 mm, for example, about 1 mm, in order to improve the biting of the biting protrusion 26 into the compressed soil mass 25, further increasing the integrated strength between the biting protrusion 26 and the compressed soil mass 25, and to prevent the resistance to pile driving from increasing.

In this embodiment, as shown in Figures 1 and 2, the biting protrusions 26 are not provided on the lower end portions 51, 51 (Figure 2) of the opposing inner surfaces 23, 23 of each of the soil holding pieces 10, 10, but this is to reduce resistance when driving the pile. The state in which the biting protrusions 26 are provided in this manner also corresponds to the biting protrusions 26 being provided in a dispersed state on the opposing inner surfaces 23.

However, in order to increase the integration strength between the compressed soil mass 25 in the soil holding portion 11 and the opposing inner surfaces 23, 23, and to further increase the strength of the bulb-shaped object 57 (Figure 9) described below, it is preferable to provide the biting protrusions 26 on the lower end portions 51, 51 as well.

As shown in Figures 2-3 and 6, the soil compression means 22 is composed of a pair of soil holding pieces 10, 10 of the above-mentioned configuration, and compresses the soil that flows into the soil holding part 11 through the soil inflow end part 12 and rises relatively within the soil holding part 11 as the pile is driven.

The amount of soil that rises relative to the ground is the soil that rises relative to the ground in the space inside the soil-holding portion 11 formed by the opposing inner surfaces 23, 23 of the soil-holding pieces 10, 10 and the peripheral portion 9 of the pile body 5 (the space inside the outline shown by the thick line in Figure 6), as shown in Figure 6, plus any surplus soil.

In this embodiment, the amount of surplus soil is approximately the sum of approximately 1/2 of the amount of soil displaced by each of the lower ends 54 (the lower end edges 35) of the soil holding pieces 10, 10 as the driven pile 1 is driven, and approximately 1/4 of the amount of soil displaced by the lower end 52 of the pile body 5. In this embodiment, the lower end edge 35 is formed as a sharp blade portion 40 as described above, so that the soil is cut by the blade portion 40 as the pile 1 is driven, and the soil is smoothly displaced by the soil holding pieces 10, 10, and the soil enters the soil holding portions 11 adjacent to each other in the circumferential direction of the pile body 5 approximately evenly through the soil inflow end portion 12.

The soil that rises relatively inside the soil holding section 11 (between the soil holding pieces 10, 10) through the soil inflow end 12 is compressed as required by the soil compression means 22 and then flows out sequentially from the soil outflow end 13. The soil that flows out is then slightly released from the compression. In particular, in this embodiment, a biting protrusion 26 is provided on the opposing inner surfaces 23, 23 of both soil holding pieces 10, 10, and the biting protrusion 26 also compresses the soil inside the soil holding section 11 according to its volume.

Next, a pile driving method using the driven-in pile 1 having the above-mentioned configuration will be described with reference to Figures 1, 5, and 7. In this pile driving method, the soil that flows into the soil holding portion 11 (between the soil holding pieces 10, 10) through the soil inflow end 12 (Figure 7) as the driven-in pile 1 is driven into the ground is compressed while the soil flows out through the soil outflow end 13 (Figure 7) to form a compressed soil mass 25 (Figures 5, 8). When the pile has been driven to the required depth into the ground, the biting protrusion 26 is bitten into the compressed soil mass 25 in the soil holding portion 11, and as shown in Figure 8, the soil 20a (compressed soil mass 25) in the soil holding portion 11 and the soil 20b around the pile body 5 are integrated through the open side end 15.

The pile driving method will be described in terms of the case where the sheet-like object 7, which is a weed-control sheet 7a (Fig. 1) laid on the ground 6, is pressed down to the ground 6. First, the driven-in pile 1 is placed in an upright position with the pile tip 3 in contact with a required portion of the upper surface 55 of the weed-control sheet 7a. In this state, as shown in Fig. 7, when the pile base end 2 (upper surface of the pressing plate 29) of the pile main body 5 is struck with a hammer, the tapered portion 27 penetrates the weed-control sheet 7a, forms a hole, and is stuck into the ground 6, and the blade portions 40 (Fig. 2) of the four soil-holding pieces 10 make cross-shaped cuts on the edge of the hole. Subsequent striking pressure causes the driven-in pile 1 to be embedded in the ground one by one, and finally, as shown in Fig. 1, the pressing plate 29 presses down the upper surface 55 of the weed-control sheet 7a to the ground 6.

During this pile driving process, as shown in FIG. 7, the soil displaced by the lower end 54 (the lower edge 35) of the soil holding piece 10 and the lower end 52 of the pile body 5 flows into the soil holding part 11 through the soil inflow end 12. The soil that has flowed in is compressed by the soil compression means 22 to form a compressed soil lump 25 (FIGS. 5 and 8), and the compressed soil lump 25 and the soil holding part 11 are integrated to form a bulb-shaped object 57 (FIG. 9).

The bulb-shaped object 57 is a combination of the compressed soil mass 25, all the soil holding parts 11, and the pile body 5, which is formed by filling all the soil holding parts 11 with soil 2a as shown by the dashed lines in Figures 5 and 8 and as shown in Figure 13.

The integration of the compressed soil mass 25 and the soil holding portion 11 is achieved mainly by the frictional force caused by the pressure of the compressed soil mass 25 against the opposing inner surface 23 of the soil holding piece 10 and the frictional force caused by the biting protrusion 26 biting into the compressed soil mass 25. As a result, immediately after the driving-in pile 1 is driven, the bulbous object 57 (Figures 9 and 13) in which the compressed soil mass 25 and the soil holding portion 11 are integrated is obtained. The bulbous object 57 is then integrated with the soil 20b around the pile body 5 via the open end 15 (Figures 5 and 8).

Therefore, when a pull-out force acts on the driven pile 1 buried in the ground, the pull-out force acts on the bulbous object 57 formed in the ground. When a pull-out force acts on the bulbous object 57 as shown by the arrow in Figure 10, a large pull-out resistance force is exerted.

To explain this in more detail, first, the bulb-shaped object 57 exists in the ground as a large mass; second, the bulb-shaped object 57 is integrated with the soil surrounding the pile body 5 via the open end 15; third, the soil 58 (Figure 1) covering the upper end of the bulb-shaped object 57 acts as a resistance to the bulb-shaped object 57 floating up (in this embodiment, as shown in Figure 1, the upper end 19 of the soil holding part 11 is located a required distance (e.g., about 17 cm) from the ground 6, and there is sufficient covering soil above the bulb-shaped object 57); and fourth, the soil holding part 1 The upper end of the bulbous object 57 is open with the soil spill end 13, and the upper edge 19 (Fig. 2, Fig. 9) is inclined inward toward the upper end and toward the axis L. Therefore, the upper end portion 57a (Fig. 9) of the bulbous object 57 presents an inclined surface 64 (Fig. 9, Fig. 13) that is inclined in the inclination direction of the upper edge 17. Therefore, when the pulling force acts on the driven pile 1, the bulbous object 57 pushes the surrounding soil diagonally upward, as shown by the diagonal arrow in Fig. 9, and a force acts to lift the surrounding soil diagonally upward.

Figures 10 to 13 show the driven pile 1 that has been driven into the ground as described above being forcibly pulled out by applying a large pulling force of, for example, about 40 to 50 kg, as shown by the arrows in Figures 10 to 12. Note that in Figures 10 to 12, the base end (upper end) 2 of the pile is shown slightly elevated above the ground 6 in order to make it easier to see the changes in the ground 6 around the pile 1.

Even if a large pulling force is applied to the pile 1, as long as the pulling force is within a certain limit, no change is observed in the ground 6 around the entire circumference of the pile 1, as shown in Figure 10. If the pulling force becomes even larger, as shown in Figure 11, a rise occurs over a somewhat wide area in the ground 6 around the entire circumference of the pile 1, and some cracks 44 appear in the ground 6. If the pulling force becomes even larger, as shown in Figure 12, large cracks appear over a wide area in the ground 6 around the surrounding area, and immediately after that, the pile 1 is easily pulled out.

From this, it can be seen that the compressed soil masses 25 (Figure 8) in the four soil-holding portions 11 and the soil 20b (Figure 8) around the pile body 5 are integrated via the open end portion 15, and that the bulb-shaped object 57 exerts a force that presses the surrounding soil diagonally upward and lifts the surrounding soil diagonally upward, as shown by the diagonal arrow in Figure 9.

Figure 13 shows a pile 1 that has been pulled out of the ground, with the four soil-holding portions 31 of the pile 1 filled with compressed soil lumps 25. The state in which the compressed soil lumps 25 are filled can be said to be the state of the bulb-shaped object 57 that had formed in the ground. The side end surface portion 59 of the compressed soil lumps 25 is a fracture surface with the surrounding soil 20b that was integrated with it.

In this way, the driven pile 1 exerts a large pull-out resistance force, which is exerted as soon as the pile is completely driven into the ground. This immediate effect is a feature of the present invention.

Figures 14 and 15 show another embodiment of the driven pile 1 according to the present invention, which is an example of a case where it is used to fix a base 60 of a workpiece, such as a base 60 of a solar panel, to the ground 6.

The driven pile 1 is entirely made of metal, for example, iron, and a soil holding section 11 having a pair of soil holding pieces 10, 10 facing each other at a required interval in the circumferential direction is provided on the peripheral surface 9 of the pile body 5 at a required interval in the circumferential direction of the pile body 5. The soil holding section 11 has an open upper and lower ends between the pair of soil holding pieces 10, 10, a soil inflow end 12 at the lower end and a soil outflow end 13 at the upper end, and the outer tips of the pair of soil holding pieces 10, 10 are open to form an open side end 15. When the axial direction F of the pile body 5 is viewed as the up-down direction, the soil holding section 11 is provided in one stage as viewed in the axial direction F.

In this embodiment, the pile body 5 is made of an iron pipe with a diameter of 40 to 100 mm, for example 70 mm, and its overall length is set to, for example, about 1.5 m. Four soil holding pieces 10 are provided on the peripheral surface 9 of the pile body 5 at an angular pitch of, for example, 90 degrees in the circumferential direction of the pile body 5. The soil holding pieces 10 are made of, for example, checkered steel plate, and are connected to the peripheral surface 9 of the pile body 5 by welding. Four soil holding parts 11, each consisting of a pair of opposing soil holding pieces 10 adjacent to each other in the circumferential direction of the pile body 5, are provided at an angular pitch of 90 degrees in the circumferential direction of the pile body 5.

The soil holding piece 10 is, for example, a trapezoidal plate extending in the axial direction F of the pile body 5, and in this embodiment, its thickness is set to 6 mm, and the length of the soil holding piece 10 as viewed in the axial direction F is set to about 400 mm. The diameter of the part of the driven pile 1 where the soil holding piece 10 protrudes is about 130 mm in plan view. The outer edge 16 of both soil holding pieces 10, 10 in a side view consists of an intermediate edge 33, an upper edge 17, and a lower edge 35 as viewed in the axial direction F of the pile body 5.

The intermediate edge portion 33 extends in the axial direction F, and its length in the axial direction F is set to about 190 mm, and the amount of protrusion from the peripheral surface portion 9 of the pile body 5 is set to about 35 mm, for example.

The length of the lower edge 35 is set to about 120 mm, and the lower edge 35 is inclined, for example linearly, toward the pile tip 3 of the pile body 5 and inward toward the axis L. The portion where the lower edge 35 intersects with the pile body 5 is located about 45 mm above the pile tip 3. The lower edge 35 is configured as a sharp blade portion 40, as in Example 1.

The upper edge 17 has a length of approximately 105 mm and is inclined inward toward the upper end and toward the axis L. The angle of inclination is approximately 60 degrees with respect to the horizontal plane.

In this embodiment, the distance between the upper end 19 of the soil holding part 11 and the ground surface 6 is set to about 110 cm. In other words, when the soil holding part 1 is buried in the ground by driving the driving-in pile, the upper end 19 of the soil holding part 11 is located a required distance (about 110 cm) from the ground surface 6.

In this embodiment, each of the soil-holding pieces 10, 10 is made of two pieces of the checkered steel plate of the required shape, with a thickness of, for example, about 3 mm, which are welded back-to-back with their striped convex portions facing outwards, and the thickness of the soil-holding piece 10 is set to about 6 mm. The biting convex portions 26 provided on each of the opposing inner surfaces 23, 23 are formed by the striped convex portions of the checkered steel plate. Note that the striped convex portions are not shown in Figures 14 and 15.

The soil compression means 22 is composed of the pair of soil holding pieces 10, 10 and has the same configuration as in Example 1.

When using the driven pile 1 according to this embodiment, during the pile driving process, the required amount of soil (the surplus soil) displaced sequentially by the lower end 54 (the edge 35 on the lower end side) of the soil holding piece 10 and the lower end 52 of the pile body 5 flows into the soil holding part 11 (between the soil holding pieces 10, 10) through the soil inflow end 12. The soil that flows into the soil holding part 11 rises relatively within the soil holding part 11. The relatively rising soil is compressed as required by the soil compression means 22 and then flows out from the soil outflow end 13. The flowed out soil is then in a state in which the compression is slightly released.

The compressed soil mass 25 thus compressed exerts pressure on the opposing inner surfaces 23, 23 of the soil-holding pieces 10, 10, creating friction between the two, and friction caused by the biting protrusions 26 biting into the compressed soil mass 25, forming a bulbous object 57 in which the compressed soil mass 25 and the soil-holding portion 11 are integrated. This is the same as in Example 1, and the bulbous object 57 is not shown in the figure. The bulbous object 57 is then integrated with the soil 20b around the pile body 5 via the open end 15.

Next, a method for fixing the mount 60 of the photovoltaic panel to the ground 6 using the driven-in pile 1 having the above-mentioned configuration will be described. Figure 14 shows a case where an upper connecting plate 63 provided at the lower end 62 of a support 61 supporting the mount 60 is bolted to a lower connecting plate 65 provided at the pile base end 2 of the pile body 5 of the driven-in pile 1. The pile 1 is driven into the ground so that the lower connecting plate 65 of the pile body 5 protrudes slightly from the ground 6. With the pile 1 driven into the ground, a bulb-shaped object 57 (Figure 16) is formed by the soil holding portion 11.

When a pull-out force acts on the driven pile 1, as explained in the first embodiment, each bulbous object 57 pushes the surrounding soil diagonally upward, as shown by the diagonally upward arrow in FIG. 16, and a force acts to lift the surrounding soil diagonally upward. This is possible because, as mentioned above, the upper end 19 of the soil holding part 11 is sufficiently far from the ground 6 (about 130 cm in this embodiment), so there is sufficient covering soil on the upper side of the bulbous object 57. This provides a large pull-out resistance. In addition, when a downward load acts on the bulbous object 57, the bulbous object 57 pushes the surrounding soil diagonally downward, as shown by the diagonally downward arrow in FIG. 16, and a force acts to push the surrounding soil diagonally downward, so the bulbous object 57 also provides an increase in the supporting force.

The pull-out resistance and support force are exerted as soon as the piles are driven into the ground. This means that the solar panel stand 60 can be firmly fixed to the ground 6 as soon as it is installed.

Figure 17 shows an example of the driving pile 1 according to the present invention being used to fix a workpiece heavier than the solar panel stand 60 to the ground. The basic difference from the above is that the soil holding portion 11 is provided in multiple levels, for example two levels, one above the other, spaced about 600 mm apart. This further increases the pull-out resistance and the support force.

In this case, to meet the objective of fixing a heavy workpiece to the ground, the diameter of the pile body 5, which is made of a metal, for example, an iron pipe, is set to 70 to 180 mm, and as the diameter increases, the number of soil-holding pieces 10 can be increased, for example to 8 pieces at an angle pitch of 45 degrees as shown in Figure 18, and the number of soil-holding parts 11 can be increased by increasing the number of pieces.

The thickness of the soil holding pieces 10 constituting the soil holding parts 11, 11 provided in multiple upper and lower stages (two upper and lower stages in the above example) can all be set to the same value, but in this embodiment, the soil holding parts 11 in the upper stage are configured as follows to more reliably compress the soil that has flowed into the soil holding parts 11 through the soil inflow end 12 and to increase the strength of the bulb-shaped objects 57 (not shown). That is, each of the pair of soil holding pieces 10, 10 constituting the soil holding parts 11, 11 provided in the two stages is arranged in a row in the axial direction F, and the thickness of the soil holding pieces 10, 10 arranged in a row is formed so that the thickness of the soil holding piece 10a in the upper stage is thicker than the thickness of the soil holding piece 10b in the lower stage, as shown in Figure 17 (B).

When the driven pile 1 is driven, the soil holding piece 10b forms a linear groove in the axial direction F with a groove width that is approximately equivalent to the thickness of the soil holding piece 10b plus the protruding amount of the biting protrusion 26, accompanied by compression of the soil. Note that the biting protrusion 26 is not shown in Figures 17 and 18.

However, the width of this groove becomes slightly smaller after the soil holding piece 10 is removed from the groove due to the progressive advancement of the driven pile 1 into the ground, as the compression of the soil is slightly released, and because the thickness of the soil holding piece 10a of the upper tier is thicker than the thickness of the soil holding piece 10b of the lower tier, even though the groove is formed, a certain amount of soil can be displaced by the soil holding piece 10a of the upper tier. This allows soil to flow into the soil holding part 11a of the upper tier, and the soil that has flowed in can be compressed by the soil compression means 22. As an example of a case in which the thickness of the soil holding piece 10a in the upper tier is made thicker than the thickness of the soil holding piece 10b in the lower tier, when the soil holding part 11 is provided in two tiers as shown in FIG. 17(B), the thicknesses are set to, for example, 6 mm and 12 mm from the bottom.

Figure 19 shows another embodiment of the driven pile 1 according to the present invention, which is used to fix a slope protection material 67, such as a protective net or a protection block that covers the slope 66 to prevent the slope 66 from collapsing, to the slope 66 (ground 6) via a pressing member 69. The driven piles 1 are driven into the slope 66 at the required intervals and in the required number, taking into account the pull-out resistance force required to fix the slope protection material 67 to the slope 66.

The driven pile 1 shown in Figures 19 and 20 has a configuration described below, and is driven into the ground, for example, 2 to 10 m, for example, about 5 m, in a direction approximately perpendicular to the slope 66, via a pile driving pipe 70 (a steel pipe or the like shown by a dashed line in Figure 19). After the pile has been driven, only the pile driving pipe 70 is pulled out, and the driven pile 1 is left in the ground.

20, one end portion 73 of the wire 72 is connected to the pile base end portion 71 of the driven pile 1. The wire 72 is inserted into the pile driving pipe 70 and drawn out at the pipe base end 75. With the wire 72 inserted into the pile driving pipe 70 in this manner, the pipe tip portion 76 of the pile driving pipe 70 is detachably attached to the pile base end portion 71 of the pile body 5 described below. Then, the pile tip 3 of the driven pile 1 is brought into contact with a predetermined portion of the slope 66 with the pile 1 in a direction approximately perpendicular to the slope 66, and in this state, the pipe base end 75 of the pile driving pipe 70 is hammered. As a result, the pile 1 is driven into a predetermined position in the ground as shown in FIG. 19. Then, when the pile driving pipe 70 is pulled out, the driven pile 1 remains in the ground, and the other end portion 77 of the wire 72 is positioned on the slope 66. Then, when the other end portion 77 is connected as required to the pressing member 69 that presses down the slope protection material 67, it is firmly fixed to the slope 66 by the pull-out resistance of the driven pile 1 and the pressing action of the pressing member 69. This effectively prevents the slope from collapsing. This will be explained in detail below.

In this embodiment, as shown in FIG. 20, the soil holding portion 11 is provided in one stage on the pile body 5 when viewed in the axial direction F. The soil holding portion 11 is open at the upper and lower ends between the pair of soil holding pieces 10, 10, and has a soil inflow end portion 12 at the lower end and a soil outflow end portion 13 at the upper end, and the outer tips of the pair of soil holding pieces 10, 10 are open to form an open side end portion 15.

The driven pile 1 is entirely made of metal, for example iron, and a soil holding portion 11 consisting of a pair of soil holding pieces 10, 10 arranged at a required interval around the circumferential direction of the pile body 5 is arranged at a required interval around the pile body 5.

The pile body 5 is made of a deformed rebar with a diameter of 19 to 22 mm, for example 19 mm, and its overall length is set to 500 to 1000 mm, for example 600 mm, with the upper end of the pile body having a length of 100 mm serving as a connecting shaft 79 (the pile base end portion 71) that is detachably inserted into the tip portion 76 of the pile driving pipe 70.

Four soil holding pieces 10 are provided at an angle pitch of, for example, 90 degrees in the circumferential direction of the pile body 5 over the entire length of the portion of the pile body 5 below the connecting shaft 79. The soil holding pieces 10 are made of, for example, checkered steel plate and are connected to the peripheral surface portion 9 of the pile body 5 by welding. Four soil holding parts 11 consisting of a pair of soil holding pieces 10, 10 that are adjacent to each other in the circumferential direction of the pile body 5 and face each other on the left and right are provided at an angle pitch of 90 degrees in the circumferential direction of the pile body 5. In this embodiment, the biting convex parts 26 consisting of the striped convex parts having a protrusion amount of about 1 to 2 mm are provided in a dispersed state on the opposing inner surfaces 23, 23 of the soil holding pieces 10, 10.

In this embodiment, each of the soil-holding pieces 10, 10 is made of two pieces of the checkered steel plate, each about 3 mm thick, welded back-to-back with their striped convex portions facing outwards, and the thickness of the soil-holding piece 10 is set to about 6 mm. In this embodiment, the biting convex portions 26 provided on each of the opposing inner surfaces 23, 23 are formed by the striped convex portions of the checkered steel plate. Note that the striped convex portions are not shown in Figures 19 and 20.

The soil holding piece 10 is, for example, a trapezoidal plate shape extending in the axial direction F of the pile body 5, and the length of the soil holding piece 10 viewed in the axial direction is set to, for example, 400 mm. The outer edge portion 16 of each soil holding piece 10 in a side view consists of an intermediate edge portion 33, an upper edge portion 17, and a lower edge portion 35 when viewed in the axial direction F of the pile body 5.

The intermediate edge 33 extends in the axial direction F of the pile body 5, and its length in the axial direction F is set to about 200 mm, and its protrusion from the peripheral surface 9 of the pile body 5 is set to about 55 mm.

The length of the lower edge 35 is set to about 130 mm. The lower edge 35 is inclined, for example linearly, inward toward the pile tip 3 of the pile body 5 and toward the axis L. The lower edge 35 is also configured as a sharp blade-like portion, as in Example 1.

The upper edge 17 has a length of about 120 mm and is inclined inward toward the upper end and toward the axis L. The inclination angle is about 60 degrees with respect to the horizontal plane.

The soil compression means 22 is a means for compressing the soil that flows into the soil holding section 11 through the soil inflow end 12 and rises relatively within the soil holding section 11, and has the same configuration as in Example 1, and is composed of the pair of soil holding pieces 10, 10.

When using the driven pile 1 according to this embodiment, during the pile driving process, soil flows into the soil holding portion 11 (between the soil holding pieces 10, 10) through the soil inflow end 12, including the required amount of soil displaced sequentially by the lower end 54 (the edge 35 on the lower end side) of the soil holding pieces 10, 10 and the lower end 52 of the pile body 5. The soil that has flowed into the soil holding portion 11 rises relatively within the soil holding portion 11 as the pile is driven. The rising soil is compressed as required by the soil compression means 22 and then flows out from the soil outflow end 13.

The soil that has flowed in is compressed by the soil compression means 22 to form a compressed soil mass 25, and the compressed soil mass 25 and the soil holding portion 11 are integrated to form a bulbous object 57 (Figure 21). The integration of the compressed soil mass 25 and the soil holding portion 11 is achieved by the frictional force caused by the compressed soil mass 25 exerting pressure on the opposing inner surface 23 of the soil holding piece 10 and the frictional force caused by the biting protrusion 26 biting into the compressed soil mass 25. The bulbous object 57 is integrated with the soil 20b around the pile body 5 via the open end 15.

When a pulling force acts on the driven pile 1 through the wire 72, the bulbous object 57 presses the surrounding soil in a diagonal direction relative to the extension direction of the axis L (extension direction of the wire 72) as shown by the arrow in Figure 21, as in Example 1, and a force acts to press the surrounding soil toward the slope 66 on the left and right sides of the axis L. This is possible because, as described above, the upper end 19 of the soil holding part 11 is sufficiently separated from the ground 6 (slope 66), and there is sufficient covering soil above the bulbous object 57 when viewed in the axial direction F. This produces a large pulling resistance force, which is exerted simultaneously with the completion of driving the pile into the ground.

Since each of the numerous driven piles 1 exerts such a large pull-out resistance force, the slope protection material 67 is firmly fixed to the slope 66 by the pull-out resistance force of the driven piles 1 and the pressing action of the pressing member 69. This effectively prevents the slope 66 from collapsing.

In this embodiment, if a further increase in the pull-out resistance is required, the soil-holding portion 11 may be provided in multiple stages, for example two stages, at required intervals (for example 600 mm) in the axial direction F of the pile body 5.

As the driven pile 1 for fixing the slope protection material 67 to the slope 66, a pile with the same configuration as the driven pile 1 described in Example 2, in which the soil holding portion 11 is provided in multiple stages, can be used. In this case, the overall length of the pile body 5 (in this example, made of deformed reinforcing bars or steel pipes) can be set to 2 to 10 m, for example 5 m. The driven pile 1 is driven in a direction approximately perpendicular to the slope 66, and the base end portion of the driven pile 1 is passed through the mesh of, for example, a protective net as the slope protection material 67 and connected to the pressing member 69 as required.

When a pull-out force acts on the driven pile 1, as explained in Example 1, each bulbous object 57 presses the surrounding soil diagonally upward relative to the axial direction of the pile 1, and a force acts to lift the surrounding soil diagonally upward relative to the axial direction. This is possible because, as described above, the upper end 19 of the soil holding portion 11 is sufficiently far from the ground 6 (slope 66), so that there is sufficient covering soil above the bulbous object 57 as viewed in the axial direction. This produces a large pull-out resistance force, which is exerted simultaneously with the completion of driving the pile into the ground.

The slope protection material 67 is then firmly fixed to the slope 66 by the pull-out resistance of the driven pile 1 and the holding down action of the holding down member 69. This effectively prevents the slope 66 from collapsing.

Figures 22 to 24 and 25 to 26 show another embodiment of the driven pile 1 according to the present invention, which includes a pile body 5 and a soil holding member 80 formed separately from the pile body 5 and having the soil holding portion 11 provided on the outer peripheral surface portion 85 of a central shaft portion 84 extending in the extension direction of the pile body 5. The soil holding member 80 is provided in an integrated state with the pile body 5 to form the soil holding portion 11. The central shaft portion 84 of the soil holding member 80 is provided with a hole portion 88 through which the pile body 5 can be inserted or inserted. With the pile body 5 inserted into the hole portion 88 or the pile body 5 inserted into the hole portion 88, the soil holding member 80 is provided in the integrated state with the pile body 5, whereby the soil holding portion 11 is provided in an integrated state with the peripheral surface portion 9 of the pile body 5.

Figures 22 to 24 show a first embodiment of the driven pile 1 according to the present invention, which includes a pile body 5 and a soil holding member 80 formed separately from the pile body 5, and the soil holding member 80 is provided integrally with the pile body 5 as shown in Figures 23 (A) and (B), thereby forming the soil holding portion 11. As shown in Figures 24 (A) and (B), the soil holding member 80 is provided with the soil holding portion 11 on the outer peripheral surface portion 85 of the central shaft portion 84 extending in the extension direction of the axis of the pile body 5, and the central shaft portion 84 is provided with a hole portion 88 through which the pile body 5 is inserted. The soil holding member 80 is provided integrally with the pile body 5 when the pile body 5 is inserted into the hole portion 88 as shown in Figures 24 (B) and 23 (A).

25-26 show a second embodiment of the driven pile 1 according to the present invention, which includes a soil holding member 80 formed separately from the pile main body 5, and the soil holding member 80 is provided integrally with the pile main body 5 as shown in FIG. 26, thereby forming the soil holding portion 11. As shown in FIG. 25(A), the soil holding member 80 is provided on the outer peripheral surface portion 85 of the central shaft portion 84, and the central shaft portion 84 is provided with a bottomed hole portion 88 that can insert the pile main body 5. When the pile main body 5 is inserted into the hole portion 88 as shown in FIGS. 26(A) and (B), the soil holding member 80 is provided integrally with the pile main body 5, thereby forming the soil holding portion 11 integrally with the peripheral surface portion 9 of the pile main body 5.
The first and second aspects will now be described in detail.

[Regarding the first aspect]
22 to 24 and 27, the driven-in pile 1 according to the first embodiment of the present invention is used to fix, via a pressing member 69, a slope protection material 67 such as a protective net, protective reinforcing bar, or protective block that covers a slope 66 to prevent the slope 66 from collapsing. Below, the basic configuration and action of the driven-in pile 1 will be described, and then the usage state and action of the driven-in pile 1 when used to prevent the slope 66 from collapsing will be described.

A. Basic structure of the driven-in pile and explanation of its action The pile body 5 constituting the driven-in pile 1 is configured as a steel screw shaft 5a (in this embodiment, a male screw portion is provided along its entire length) having a diameter of about 9 to 13 mm, for example about 10 mm, and a total length of about 1000 to 5000 mm, for example about 1500 mm, and when the pile body 5 is viewed in the vertical direction, its lower end portion 82 is a tapered portion 83 (FIG. 22) that becomes thinner toward the lower end.

The soil holding member 80 is formed as a single unit from, for example, polycarbonate, AES resin, or ASA resin, which has excellent strength and weather resistance, and as shown in FIG. 24(B), the soil holding portion 11 (FIG. 24(A)) is provided on the outer surface 85 of the central shaft portion 84, which is provided with a hole portion 88 through which the screw shaft (the pile main body) 5a can be inserted in a substantially tight fit. The overall length of the central shaft portion 84 is set to about 200 to 300 mm, for example about 200 mm, and in this embodiment, the soil holding portion 11 is provided in one step when viewed in the axial direction of the central shaft portion 83.

The soil holding portion 11 is formed by providing a pair of soil holding pieces 10, 10 on the outer peripheral surface 85 of the central shaft portion 84, which extend in the direction of the axis L1 of the central shaft portion 84 (hereinafter referred to as the axial direction) F1 (Figure 24) and face each other at a required distance in the circumferential direction of the pile body 5.

In this embodiment, the soil holding portion 11 is provided such that the four soil holding pieces 10 are radially protruding from the outer peripheral surface portion 85 of the central shaft portion 84 so as to form a cross shape in a plan view. As a result, four soil holding portions 11 consisting of a pair of soil holding pieces 10, 10 facing each other on the left and right are provided at an angle pitch of 90 degrees around the circumference of the pile body 5.

The diameter D2 (Fig. 24(A)) in a plan view of the portion where the soil holding portion 11 is provided is set to, for example, about 50 mm, which is about three times the diameter (about 16 mm) of the central shaft portion 84. The diameter D2 is set taking into consideration the required size of the bulb-shaped object 57 (Fig. 29) described later.

As shown in FIG. 23, the soil holding portion 11 is provided on the outer peripheral surface 85 of the central shaft portion 84 over the entire length. Therefore, the overall length of the soil holding piece 10 constituting the soil holding portion 11 is about 200 mm. The soil holding piece 10 has a thickness of about 5 mm and is trapezoidal in side view, and its outer edge portion 16 in side view consists of an intermediate edge portion 33, the upper edge portion 17, and the lower edge portion 35 when viewed in the axial direction F1 (FIG. 24) of the soil holding member 80.

The intermediate edge portion 33 extends in the axial direction F1 and has a length of approximately 100 mm as viewed in the axial direction F1, and the amount of protrusion from the peripheral surface portion 9 of the central shaft portion is set to approximately 16 mm.

The upper edge 17 is inclined, for example linearly, inwardly toward the upper end of the central shaft 84 and toward the axis L1, and the upper end of the upper edge 17 coincides with the upper end of the central shaft 84. The length of the upper edge 17 is set to about 36 mm.

The lower edge 35 is inclined, for example, linearly inward toward the lower end of the central shaft 84 and toward the axis F1, and the lower end of the lower edge 35 coincides with the lower end of the central shaft 84. The lower edge 35 is configured as a sharp blade 40 (Fig. 22), and the blade 40 is formed in a mountain shape having inclined surfaces 42, 42 that incline in the opposite direction from the apex 41, as shown in Fig. 2 (B). The length of the lower edge 35 is set to about 45 mm. The opposing inner surfaces 23, 23 (Fig. 24 (A)) of both soil holding pieces 10, 10 are each provided with a biting protrusion 26 in a distributed state in the same configuration as in the driven pile 1 of Example 1. The configuration of the biting protrusion 26 is the same as that described in Example 1 based on Figs. 2-3 and 5, so a detailed description thereof will be omitted.

To provide the soil holding member 80 having such a configuration in an integrated state with the lower portion 81 (Figs. 22-23) of the pile body 5, as shown in Fig. 24, the lower end portion 86 (Fig. 22) of the screw shaft 5a is inserted into the hole portion (in this embodiment, a hole portion as a through hole with a smooth inner surface) 88 of the central shaft portion 84 of the soil holding member 80 from its upper end 88a (Fig. 24(B)), and then, as shown in Fig. 23(A), the central shaft portion 84 is clamped by upper and lower clamping nuts (in this embodiment, metal nuts) 87, 89 that screw onto the screw shaft 5a. For this purpose, prior to inserting the lower end portion 86 (Figs. 22 and 24) into the hole portion 88, the upper clamping nut 87 is screwed into the required portion of the screw shaft 5a. In this embodiment, in order to make it easier to drive the pile by escaping any gravel present in the soil, the lower clamping nut 89 is a conical nut with a conical surface 94 whose lower outer diameter becomes smaller toward the bottom. By clamping and clamping the upper and lower clamping nuts 87, 89, the soil holding portion 11 is fixed to the lower portion 81 of the pile body 5 (Figure 23), and the driven-in pile 1 is formed.

The upper and lower clamping nuts 87, 89 are clamped together to form the driven pile 1, which has a pile body 5 of the required length extending from the pile base end (upper end of the pile) 2, which is the driving part, to the pile tip (lower end of the pile) 3, which is the part that enters the ground, and has an earth holding part 11 integrally provided to the lower part 81 of the pile body 5 (Figures 23 and 27).

Here, the soil compression means 22 of the soil holding portion 11 will be described in relation to the driving of the driven-in pile 1. That is, the soil compression means 22 has a configuration similar to that of the soil compression means 22 described in the first embodiment, and is composed of a pair of soil holding pieces 10, 10 as shown in Figures 2 to 3, 6, and 23, and compresses the soil that flows into the soil holding portion 11 through the soil inflow end portion 12 and rises relatively within the soil holding portion 11 as the pile is driven.

The amount of soil that rises relatively is the same as that described in Example 1, and referring to Figures 2-3, 6-8, 23, and 24(A), it is the soil that rises relatively in the space within the soil-holding portion 11 formed by the opposing inner surfaces 23, 23 of the soil-holding pieces 10, 10 and the peripheral portion 9 of the pile main body 5 (the space inside the outline shown by the thick line in Figure 6), plus surplus soil.

In this embodiment, the amount of surplus soil is approximately the sum of approximately 1/2 of the amount of soil displaced by each of the lower ends 54 (the lower end edges 35) (FIG. 3) of the two soil-holding pieces 10, 10 as the driven pile 1 is driven, and approximately 1/4 of the amount of soil displaced by the lower end 52 of the pile body 5. In this embodiment, the lower end edges 35 are formed as sharp blades 40 (FIG. 2(B)) as described above, so that the soil is cut by the blades 40 as the pile 1 is driven, and the soil is smoothly displaced by the soil-holding pieces 10, 10, and the soil enters the soil holding parts 11 adjacent to each other in the circumferential direction of the pile body 5 approximately evenly through the soil inflow end 12.

The soil that rises relatively inside the soil holding section 11 (between the soil holding pieces 10, 10) through the soil inflow end 12 is compressed as required by the soil compression means 22 and then flows out sequentially from the soil outflow end 13 (Figure 7). In particular, in this embodiment, the biting protrusions 26 are provided on the opposing inner surfaces 23, 23 of both soil holding pieces 10, 10, so the biting protrusions 26 also compress the soil inside the soil holding section 11 according to their volume.

The soil that flows into the soil holding portion 11 is compressed as required by the soil compression means 22 (Fig. 23(B)) to form a compressed soil mass. The frictional force between the compressed soil mass 25 exerted by pressure on the opposing inner surfaces 23, 23 of the soil holding pieces 10, 10 and the frictional force caused by the biting protrusions 26 biting into the compressed soil mass 25 forms a bulbous object 57 in which the compressed soil mass 25 and the soil holding portion 11 are integrated, as shown in Figs. 28-29. The bulbous object 57 is then integrated with the soil 20b around the pile body 5 via the open end portion 15 (Fig. 28).

B. Explanation of the Use State and Action of the Driven-in Pile When Used to Prevent the Collapse of a Slope Figure 24 and Figures 27 to 29 show the case where the driven-in pile 1 according to this embodiment is used to prevent the collapse of a slope 66. As shown in Figures 22 to 23, the driven-in pile 1 has a retainer member 69, such as a hook member 92 having a hook 91, which is engaged with a slope protection material 67 such as a protection net, protection rebar, or protection block that covers the slope 66, and is connected to the upper end side of the screw shaft 5a (the pile main body 5) by screwing a female screw portion 95 provided on a base 93 of the retainer member 69. The hook member 92 is connected after the pile main body 5 is driven into the ground as required.

As shown in Figure 27, for example, the driven pile 1 is set in a state in which its axis L is approximately perpendicular to the slope 66, and in this state, the upper end 96 (pile base end 2) (Figure 22) is struck with a hammer and driven into the ground about 1.5 m. After the driving is completed, the base 93 of the hook member 92 is connected by screwing its female threaded portion 95 into the upper end portion 5a1 of the screw shaft 5a (pile body 5).

The required number of driven piles 1 are driven into the slope 66 at required intervals, taking into consideration the pull-out resistance force required to secure the slope protection material 67 to the slope 66.

In this way, the pile is driven, and during this pile driving process, as described above, soil flows into the soil holding portion 11 (between the soil holding pieces 10, 10) through the soil inflow end 12 (Figure 23), including the required amount of soil displaced sequentially by the lower end 54 (the lower end edge 35) (Figure 23) of the soil holding pieces 10, 10 and the lower end 52 of the pile body 5. The soil that has flowed into the soil holding portion 11 rises relatively within the soil holding portion 11 as the pile is driven. The rising soil is compressed as required by the soil compression means 22 and then flows out from the soil outflow end 13.

The soil that has flowed in is compressed by the soil compression means 22 to form a compressed soil mass 25, and the compressed soil mass 25 and the soil holding portion 11 are integrated to form the bulbous object 57 (Figs. 28-29). The integration of the compressed soil mass 25 and the soil holding portion 11 is achieved by the frictional force caused by the compressed soil mass 25 exerting pressure on the opposing inner surface 23 (Fig. 24(A)) of the soil holding piece 10, and the frictional force caused by the biting protrusion 26 (Fig. 24(A)) biting into the compressed soil mass 25. The bulbous object 57 is integrated with the soil 20b around the pile body 5 via the open end portion 15 (Fig. 28).

When a pull-out force acts on the driven pile 1, as explained in Example 1, each bulbous object 57 exerts a force that presses the surrounding soil toward the slope 66 on the left and right sides of the axis L, as shown by the diagonally upward arrow in Figure 29. This is possible because, as shown in Figure 27, the upper end 19 of the soil holding portion 11 is sufficiently far from the slope 66 (about 80 cm away in this example), so there is sufficient covering soil above the bulbous object 57 in the axial direction. This provides a large pull-out resistance force. This pull-out resistance force is exerted as soon as the pile is driven into the ground.

Since each of the numerous driven piles 1 exerts such a large pull-out resistance force, the slope protection material 67 is firmly fixed to the slope 66 by the pull-out resistance force of the driven piles 1 and the holding action of the holding member 69 (the hook member 92 in this embodiment). This effectively prevents the slope 66 from collapsing.

[Regarding the second aspect]
25 to 26, the second embodiment of the driven pile 1 of the present invention is used, like the first embodiment, to fix a slope protection material 67 such as a protective net, protective reinforcing bars, protective blocks, etc., which covers a slope 66 to prevent the slope 66 from collapsing, to the slope 66 (ground 6) via a pressing member 69.

The difference between the driven-in pile 1 according to the second embodiment and the driven-in pile 1 according to the first embodiment is that the central shaft portion 84 constituting the soil holding member 80 is not configured as a hole portion 88 that is a through hole through which the screw shaft 5a (the pile body 5) is inserted as in the first embodiment, but rather, for example, approximately 1/2 to 2/3 of the length of the central shaft portion 84 on the upper side is configured as a bottomed hole portion 88 provided with a female screw portion 97 into which the screw shaft 5a can be screwed. In the driven-in pile 1, the lower end portion 86 of the screw shaft 5a is inserted into the female screw portion 97 by screwing, as shown in FIG. 26 (A), and the screw shaft 5a is tightened in the final stage. As a result, the driven-in pile 1 is configured in which the soil holding member 80 is fixed to the lower portion 81 of the pile body 5 and the soil holding portion 11 is integrally provided on the peripheral surface portion 9 of the pile body 5. In order to make the fixed state stronger, it is advisable to screw a fixing nut 99 onto the lower end portion 86 of the screw shaft 5a as shown by the dashed line in FIG. 26(A) before screwing the lower end portion 86 into the female threaded portion 97. This makes it possible to make the fixed state stronger by screwing the lower end portion 86 into the female threaded portion 97 and then tightening the fixing nut 99.

In Figures 25-26, the lower end portion 86 of the soil holding member 80 is a tapered portion 83 that narrows downward.

The function of the driven pile 1 in preventing the slope 66 from collapsing is the same as that described in the first embodiment above, so a description thereof will be omitted.

[Other aspects of the driven pile according to Example 4]
(1) The first embodiment in which the driven pile 1 according to the present invention is used to prevent the collapse of a slope 66.
When the pile main body 5 is configured as the screw shaft 5a as in the second embodiment, the screw shaft 5a may be made into the screw shaft portion only in the range necessary for attaching the soil retaining member 80, the pressure member 69, etc. by screwing them together.

(2) The driven pile 1 according to the present invention can also be used to fix the base of a photovoltaic power generation panel, advertising tower, monument, or other structure described in Example 2 described based on Figures 14 and 16 to the ground. Figures 30-31 are partial views of one example, in which the pile body 5 is made of a single-tube pipe (e.g., with an outer diameter of 50 mm). The soil holding member 80 is formed by providing the soil holding portion 11 on the outer peripheral surface 102 of the central shaft portion (e.g., a steel cylinder 101 with an outer diameter of 60 mm) 84 through which the single-tube pipe 100 can be inserted in a substantially tightly packed state. The soil holding portion 11 has a pair of soil holding pieces 10, 10 facing each other at a required interval in the circumferential direction of the central shaft portion 84, and is provided at a required interval in the circumferential direction of the pile body 5, for example, in a configuration similar to that shown in Figures 14-15. In FIG. 30, when the axial direction of the central shaft portion 84 is viewed as the up-down direction, the soil holding member 80 is provided in one stage when viewed in the axial direction.

Examples of a means for integrally attaching the soil-holding member 80 to the lower portion 81 of the pile body 5 include, for example, pressing in a fixing pin 105 as shown by the dashed line in Figure 31, or welding.

When a pull-out force acts on the driven pile 1, as explained in Example 1, the bulbous object 57 exerts a force that pushes the surrounding soil diagonally upward, as shown by the diagonally upward arrow in Figure 32, to lift the surrounding soil diagonally upward. In addition, when a downward load acts on the bulbous object 57, the bulbous object 57 exerts a force that pushes the surrounding soil diagonally downward, as shown by the diagonally downward arrow in Figure 32, to push the surrounding soil diagonally downward, and the bulbous object 57 also exerts an increase in the bearing capacity.

(3) The driven pile 1 according to the present invention can also be applied to the construction of preventing the collapse of the slope 66 using the wire 72 described in Example 3. The soil holding member 80 used in this case can be configured in the same manner as in the first and second embodiments, as shown in FIG. 33, for example, and the soil holding portion 11 is provided in one stage when viewed in the axial direction of the central shaft portion 84. The steel screw shaft 5a (the pile body 5) combined with the soil holding member 80 has a short overall length, and the protruding length from the upper end 103 of the soil holding member 80 is, for example, about 100 mm. A connection hole 104 for connecting one end portion 73 of the wire 72 is provided at the upper end portion of the screw shaft 5a.

(4) The soil holding members 80 may be arranged in multiple tiers, one above the other, on the pile body 5. In this case, the distance between adjacent soil holding members 80, 80 is set so that each bulb-shaped object 57 formed in the soil effectively exerts a force to press the surrounding soil toward the slope 66. For example, it is set to about 600 mm.

(5) As described above, the soil-holding member 80 can be constructed by integrally molding the entire member out of resin, or by connecting the central shaft portion 84 and the pile body 5 by welding. Alternatively, the entire member can be made of cast iron. In particular, when the entire member is integrally molded out of resin, the resin to be selected should have the strength and weather resistance required to continuously exert the required pull-out resistance force required for the application. For example, ABS resin, AES resin, polycarbonate resin, ASA resin, etc. can be selected.

(6) As a means for integrating the soil holding member 80 with the pile body 5, the above-mentioned screwing means, the means for pressing in a fixing pin, the means for welding, etc. can be used. The screwing means also includes a means for screwing and tightening a screw shaft portion provided at the upper end of the soil holding member 80 into a female screw portion provided at the lower end portion of the pile body 5. Also included is a means for providing a screw shaft portion at the end of the pile body 5 and the soil holding member 80, and connecting the screw shaft portions to each other using a long connecting nut (long nut).

(7) The means for integrating the soil holding member 80 with the pile body 5 is to insert the pile body 5 into the hole 88 provided in the central shaft 84 of the soil holding member 80, but the pile body may be made of deformed steel bars or reinforcing bars with smooth surfaces. In this case, the integrated state can be obtained by the welding means, the pin fixing means, etc.

(8) The driven pile 1 according to the fourth embodiment has a pile body 5 of a required length extending from the pile base end 2, which is a driving portion, to the pile tip 3, which is an entry portion into the ground, and the pile body 5
The driven-in pile 1 is an attachment type pile in which a soil holding member 80 formed separately from the pile body 5 is integrally provided on a lower portion 81 of the pile body 5, and a soil holding portion 11 having a soil compression means 22 is provided on an outer peripheral surface portion 85 of the pile body 5. The driven-in pile 1 can be appropriately selected, preferably within the following ranges, for the diameter of the pile body, the overall length of the pile body, the vertical length of the soil holding member, and the maximum diameter in plan view of the soil holding member, depending on construction conditions such as pull-out resistance required at various construction sites (civil engineering construction sites, installation sites of various racks, etc.).
Diameter of pile body 5: 9 to 50 mm
Total length of pile body 5: 1 to 20 m
Vertical length of soil holding member 80: 100 to 2000 mm
Maximum diameter of soil holding member 80 in plan view: 30 to 250 mm

[Remarkable effect of the driven pile according to Example 4]
In the driven pile 1 according to Example 4, the pile body 5 and the soil holding member 80 are separate bodies, and the driven pile can be constructed by integrating the soil holding member 80 with the pile body 5. For this reason, when using the driven pile 1 according to this example, by preparing in advance a variety of soil holding members 80 configured as required based on construction data, the optimal driven pile 1 can be easily configured according to the construction site.

More specifically, by selecting an appropriate soil-holding member (attachment) 80 from the many types of soil-holding members according to the soil quality at the construction site and the pull-out resistance required at the construction site, and combining and integrating this with a pile body 5 of the required diameter and length, it is possible to easily configure the optimal driven pile 1 required at the construction site.

Furthermore, the work of integrating the pile body 5 and the soil holding member 80 can be performed at the construction site or in a factory, but if the integration is easily performed using a screw-on method or a fixed pin connection method as exemplified in the first and second embodiments, the integration at the construction site is easy, and the pile body 5 and the soil holding member 80, which are separate bodies, can be transported individually and together. This has the advantage that the pile body 5 and the soil holding member 80 can be transported with a reduced bulk, reducing transportation costs. In addition, when transporting the pile body 5 and the soil holding member 80 to the desired location at the construction site, they can be handled individually, reducing labor.

The present invention is by no means limited to the above examples, and it goes without saying that various design modifications are possible within the scope of the claims. One example is as follows.

(1) Figure 35 shows another embodiment of the soil compression means 22, which is composed of the pair of soil holding pieces 10, 10, and the thickness of both soil holding pieces 10, 10 in plan view is gradually increased from the inner end 80, which is the connection part to the peripheral portion 9 of the pile main body 5, toward the outer end 81. In the figure, four of the soil holding pieces 10, 10 are radially protruded to form a cross shape on the peripheral portion 9 of the pile main body 5, and the soil holding portion 11 is composed of a pair of adjacent soil holding pieces 10, 10. Each soil holding piece 10, 10 is configured in a dovetail shape in which the thickness in plan view gradually increases symmetrically from the inner end 80 toward the outer end 81. For example, when the driven-in stake 1 is used to attach the weed control sheet 7a, the protruding length of the soil holding piece 10 is set to 10 to 15 mm, for example, about 12 mm, the thickness of the inner end 106 is set to about 3 mm, and the thickness of the outer end 107 is set to about 5 mm. In this embodiment, as explained based on Figures 1 and 2, the upper edge 17 of each soil holding piece 11 is inclined inward toward the upper end and toward the axis. In addition, it is preferable that the lower edge 35 of the soil holding piece 10 is inclined inward toward the lower end and toward the axis L, and that the lower edge is a sharp blade-like portion 40.

For example, when a sheet-like material 7 as a weed control sheet 7a laid on the ground is pressed down and fixed to the ground 6, the base end 2 of the driven-in pile 1 standing upright on the ground 6 is struck with a hammer, and the soil that flows into the space between the soil holding pieces 10, 10 through the soil inflow end 12 as the pile is driven in is compressed well while flowing out through the soil outflow end 13, forming a compressed soil mass 25.

This soil compression effect is achieved because the thickness of the soil-holding piece 10 in the plan view is formed to be thick in the dovetail shape, so that the amount of soil that is pushed aside during the pile driving process and flows into the soil-holding portion 12 can be increased on the open end portion 15 side 108, which has a larger opening width, within the soil-holding portion 12.

In this embodiment, one of the two opposing soil-holding pieces 10, 10 may be configured in a dovetail shape, and the other soil-holding piece may be configured as a plate of the same thickness. Also, instead of configuring the soil-holding piece 10 to gradually become thicker in a symmetrical manner as described above, the soil-holding piece 10 may be configured to gradually become thicker in an asymmetrical manner by making only the opposing inner surfaces 23, 23 that constitute the soil-holding portion 11 a surface that slopes inward from the inner end 106 to the outer end 108 of the soil-holding portion 11.

(2) Figure 36 shows another embodiment of the soil compression means 22. The configuration of the soil compression means 22 is as follows, but in Figure 36, for the sake of convenience, the two soil holding pieces 10, 10 are shown facing each other and as rectangular pieces.

The soil compression means 22 is composed of the pair of soil holding pieces 10, 10, and the opposing inner surfaces 23, 23 of both soil holding pieces 10, 10 are formed so as to slope from their lower ends 109 toward their upper ends 110 toward the inside of the soil holding portion 11, and the interior 111 of the soil holding portion 11 is configured so as to narrow from its lower end 112 toward its upper end 113.

In the figure, four of the soil holding pieces 10 are radially protruding from the peripheral surface 9 of the pile body 5 to form a cross shape, and the soil holding portion 11 is composed of a pair of adjacent soil holding pieces 10, 10. Each soil holding piece 10 is formed in a dovetail shape in which the thickness in a front view gradually increases symmetrically from the lower end to the upper end, so that the opposing inner surfaces 23, 23 of both soil holding pieces 10, 10 are both formed so as to slope inward of the soil holding portion 11 from their lower end 112 to their upper end 113. For example, when the driven-in pile 1 is used to fasten the weed control sheet 7a, the vertical length of the soil holding piece 10 is set to, for example, about 100 mm, the lower end thickness to about 3 mm, and the upper end thickness to about 5 mm.

In this embodiment, as explained based on Figures 1 and 2, the upper edge 17 of each soil holding piece 10 is inclined inward toward the upper end and toward the axis. In addition, it is preferable that the lower edge 35 of the soil holding piece 10 is inclined inward toward the lower end and toward the axis L, and that the lower edge is a sharp blade-like portion 40.

For example, when a sheet-like material 7 as a weed control sheet 7a laid on the ground 6 is pressed down and fixed to the ground 6, the base end 2 of the driven-in pile 1 standing upright in the ground is struck with a hammer, and the soil that flows into the space between the soil holding pieces 10, 10 through the soil inflow end 12 as the pile is driven in is compressed as it flows out through the soil outflow end 13, forming a compressed soil mass 25.

This soil compression effect is achieved because the opposing inner surfaces 23, 23 of both soil-holding pieces 10, 10 are both formed as inclined surfaces that slope inwardly of the soil-holding portion 11 from their lower ends 115 to their upper ends 116, and the interior of the soil-holding portion 11 is configured to narrow from its lower end 87 to its upper end 89, thereby compressing the soil that flows between the soil-holding pieces 10, 10.

In this embodiment, only one of the opposing inner surfaces 23, 23 of the soil-holding pieces 10, 10 may be configured as the inclined surface.

(3) Figure 37 shows another embodiment of the soil compression means 22. The configuration of the soil compression means 22 is as follows, but in Figure 37, for the sake of convenience, the two soil holding pieces 10, 10 are shown facing each other and as rectangular pieces. The soil compression means 22 is composed of the pair of soil holding pieces 10, 10, and a soil runoff suppression protrusion 117 is provided on the upper end portion of the opposing inner surface 23 of both or either of the two soil holding pieces 10, 10.

In the figure, for example, four of the soil holding pieces 10 are radially protruding to form a cross shape on the peripheral surface 9 of the pile body 5, and the soil holding portion 11 is composed of a pair of adjacent soil holding pieces 10, 10. Each soil holding piece 10 has a soil runoff suppression protrusion 117 as a protrusion along the edge 17 of the upper end side at the upper end portion of the opposing inner surface 23. The amount of protrusion of the soil runoff suppression protrusion 117 from the opposing inner surface 23 is set to, for example, about 3 mm.

In this embodiment, as explained based on Figures 1 and 2, the upper edge 17 of each soil holding piece 11 is inclined inward toward the upper end and toward the axis L. In addition, it is preferable that the lower edge 35 of the soil holding piece 10 is inclined inward toward the lower end and toward the axis L, and that the lower edge 35 is a sharp blade-like portion 40.

For example, when a sheet-like material 7 as a weed control sheet 7a laid on the ground 6 is pressed down and fixed to the ground 6, the base end 3 of the driven-in pile 1 standing upright on the ground 6 is struck with a hammer, and the soil that flows into the space between the soil holding pieces 10, 10 through the soil inflow end 12 as the pile is driven in is compressed as it flows out through the soil outflow end 13, forming a compressed soil mass 25.

This soil compression effect is achieved because the soil that flows between the soil holding pieces 10, 10 is squeezed by the soil outflow suppression protrusion 117 as it flows out through the soil outflow end 13.

In this embodiment, the soil runoff suppression protrusion 117 may be provided on only one of the pair of soil holding pieces 10, 10. In this case, it is preferable to make the protrusion amount of the soil runoff suppression protrusion 117 larger than that described above, or to make the length of the soil runoff suppression protrusion 117 longer than that described above.

(4) The soil compression means 22 described in (1), (2), (3) and in Example 1 may be used alone or in combination. The blade portion 40 may not be formed on the lower edge 35 of the soil holding piece 10. The lower edge 35 may be configured horizontally.

(5) The soil holding pieces 10, 10, which are arranged opposite each other at a required interval in the circumferential direction of the pile main body 5 to form the soil holding portion 11, may be protruded radially from the peripheral surface portion 9 of the pile main body 5, or may be protruded in a parallel state at a required interval from the peripheral surface portion 9, for example. When the soil holding pieces 10, 10 are protruded radially, they do not need to be protruded at equal angular pitches. In addition, the number of soil holding pieces 10 that constitute the soil holding portion 11 is set as required according to the diameter of the pile main body 5, and the number of protruding soil holding pieces 10 can be increased to ensure soil holding. However, if the number of protruding soil-holding pieces 10 is large compared to the diameter of the pile body 5, the volume of soil held by the soil-holding parts 11 will be small, and the bulb-shaped object 57 formed will be divided into small pieces by the soil-holding pieces 10, weakening the strength of the bulb-shaped object 57, and as a result, it will not be able to exert the required pull-out resistance.

The diameter of the part of the driven pile 1 where the soil holding part 11 protrudes from the pile body 5, as viewed from above, should be set to, for example, 3 to 5 times the diameter of the pile body, taking into account the required size of the bulbous object 57.

(6) In order for the bulbous object 57 formed in the ground when the driven-in pile is driven in as required to effectively exert the pull-out resistance force, that is, in order for the bulbous object 57 to effectively exert a force that pushes the surrounding soil diagonally upward and lifts the surrounding soil diagonally upward when a pull-out force acts on the driven-in pile 1 buried in the ground, a certain thickness of soil must cover the top of the bulbous object 57. A minimum thickness of soil of about 30 mm is required.

(7) In order for the bulbous object 31 to exert the pull-out resistance force more effectively, it is preferable to place the soil holding portion 11 at the bottom of the pile body 5, but the placement is not limited to this.

The number of stages in which the soil-holding parts 11 are arranged is set taking into consideration the magnitude of the required pull-out resistance force, and the spacing between adjacent soil-holding parts 11, 11 above and below is set as required (at least about 30 mm) so that the bulb-shaped objects 31 in each stage can exert the required pull-out resistance force.

(8) The biting protrusions 26, which are provided in a distributed state on each of the opposing inner surfaces 23, 23 of both soil holding pieces 10, 10, generate a good frictional effect by biting into the compressed soil mass 25 compressed by the soil compression means 22, thereby forming a bulb-shaped object 57 in which the compressed soil mass 25 and the soil holding part 11 are integrated, but the shape of the biting protrusions 26 is not limited to the sawtooth protrusions or the striped protrusions of the checkered steel plate as long as it exhibits the above-mentioned effect. In addition, it can be configured as a protrusion of various shapes that can generate the effective frictional force by biting into the compressed soil mass 25, such as a hemispherical protrusion, a trapezoidal protrusion, a conical protrusion, a pyramidal protrusion, a linear protrusion, a zigzag protrusion, a wavy protrusion, etc. The amount by which these biting protrusions 26 protrude from the opposing inner surface 23 should be set to 0.1 to 3 mm, preferably 1 to 2 mm, in order to improve the biting of the biting protrusions 26 into the compressed soil mass 25 and to further increase the integrated strength between the biting protrusions 26 and the compressed soil mass 25.

(9) If the pressure exerted by the compressed soil mass 25 on the opposing inner surface 23 of the soil-holding piece 10 is large, and therefore the required frictional force can be obtained between the compressed soil mass 25 and the soil-holding piece 10, the biting protrusion 26 may be omitted.

(10) When the driven-in pile 1 according to the present invention is used to press and secure a sheet-like material 7, such as a weed control sheet 7a, laid on the ground to the ground 6, the total length of the driven-in pile is 100 to 500 mm, and typically 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, 350 mm, or 400 mm.

(11) When the driven pile 1 is entirely made of metal, the pile body 5 can be constructed using the above-mentioned metal pipe (e.g., iron pipe) or deformed bar. When the pile body is constructed of a metal pipe, it is preferable to drive the pile without blocking the tip of the pile, since soil can flow into the pipe, thereby reducing the driving resistance.

(12) The shape of the soil holding piece 10 in a side view is not limited to a trapezoidal plate shape, so long as the upper edge 17 of the outer edge 16 is inclined inwardly toward the upper end and toward the axis L. For example, the outer edge 16 as a whole may be in the shape of a convex arc toward the outside, and the intermediate edge 33 does not need to extend in the axial direction F. Furthermore, when the upper edge 17 or the lower edge 35 is inclined with respect to the axis L, the edges 17, 35 are not limited to a straight line shape, and may be, for example, in the shape of an arc.

(13) The driving piles can be driven into the ground using various means, such as a hammer or power tools.

(14) The driven pile 1 according to the present invention can be used for various applications requiring increased pull-out resistance by setting the length and diameter of the driven pile 1, the size of each part of the soil-holding portion 11 for forming the bulbous object 57, and the number and arrangement state of the soil-holding portion 11 relative to the pile body 5 as required.

The main applications of the driven pile 1 according to the present invention are to fasten sheet-like materials such as weed control sheets and cover sheets to the ground, to fasten structures such as photovoltaic panel stands to the ground, and to fasten slope protection materials to a slope that cover the slope to prevent the slope from collapsing. However, by forming the pile base end 2 into the required shape, it can also be used to prevent outdoor installations such as tents and other various installations from floating up or sinking.

1 Driven pile 2 Pile base end 3 Pile tip 5 Pile body 6 Ground 7 Sheet-like material 9 Peripheral surface portion 10 Soil holding piece 11 Soil holding portion 12 Soil inflow end 13 Soil outflow end 15 Open side end 16 Outer end edge portion 17 Upper end side edge portion 19 Upper end 21 Soil connecting portion 22 Soil compression means 23 Opposing inner surface 25 Compressed soil mass 26 Biting convex portion 29 Pressing plate 33 Middle edge portion 35 Lower end side edge portion 40 Blade-like portion 57 Bulb-like material 66 Slope 67 Slope protection material 69 Pressing member 72 Wire 80 Soil holding member 84 Central shaft portion 85 Outer peripheral surface portion 87 Upper clamping nut 88 Hole portion 89 Lower clamping nut 93 Soil outflow suppression protrusion

Claims (8)

A driven pile having a pile body of a required length extending from the pile base end, which is the driving portion, to the pile tip, which is the entry portion into the ground,
A soil holding portion having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other at a required interval in the circumferential direction of the pile body is provided on the peripheral surface of the pile body in an integrated state at a required interval in the circumferential direction of the pile body,
When the direction of the axis is viewed as the up-down direction, the soil holding portion is provided in one stage or in multiple stages at required intervals when viewed in the direction of the axis of the pile main body,
The soil holding portion has an upper and lower ends between the pair of soil holding pieces that are open, and has a lower soil inflow end and an upper soil outflow end, and has an open side end between the outer tips of the pair of soil holding pieces that are open,
The upper end edge of each of the soil holding pieces is inclined inwardly toward the upper end and toward the axis when viewed from the side,
When the pile body is driven into the ground, the upper end of the soil holding part closest to the ground is located a required distance away from the ground,
The soil holding portion can sequentially discharge the soil that has flowed between the pair of soil holding pieces through the soil inflow end portion as the pile body is driven into the ground from the soil outflow end portion, and the pair of soil holding pieces compress the flowed-in soil,
This driven-in pile is characterized in that each of the opposing inner surfaces of the pair of soil-holding pieces has a biting convex portion with a protruding amount of 0.1 to 3 mm that bites into the compressed soil mass between the soil-holding pieces and is provided in a dispersed manner . A driven pile having a pile body of a required length extending from the pile base end, which is the driving portion, to the pile tip, which is the entry portion into the ground,
A soil holding portion having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other at a required interval in the circumferential direction of the pile body is provided on the peripheral surface of the pile body in an integrated state at a required interval in the circumferential direction of the pile body,
When the direction of the axis is viewed as the up-down direction, the soil holding portion is provided in one stage or in multiple stages at required intervals when viewed in the direction of the axis of the pile main body,
The soil holding portion has an upper and lower ends between the pair of soil holding pieces that are open, and has a lower soil inflow end and an upper soil outflow end, and has an open side end between the outer tips of the pair of soil holding pieces that are open,
The upper end edge of each of the soil holding pieces is inclined inwardly toward the upper end and toward the axis when viewed from the side,
When the pile body is driven into the ground, the upper end of the soil holding part closest to the ground is located a required distance away from the ground,
The soil holding portion can sequentially discharge the soil that has flowed between the pair of soil holding pieces through the soil inflow end portion as the pile body is driven into the ground from the soil outflow end portion, and the pair of soil holding pieces compress the flowed-in soil,
The pile body and a soil holding member formed separately from the pile body and having the soil holding portion provided on the peripheral surface of a central shaft portion extending in the axial direction of the pile body, the soil holding member being integrally provided with the pile body to form the soil holding portion,
The central axis of the soil holding member is provided with a hole portion through which the pile body can be inserted or fitted, and when the pile body is inserted into the hole portion or when the pile body is inserted into the hole portion, the soil holding member is provided in the integrated state with the pile body, thereby forming an integral state with the peripheral portion of the pile body, thereby forming a driven -in pile. A driven pile having a pile body of a required length extending from the pile base end, which is the driving portion, to the pile tip, which is the entry portion into the ground,
A soil holding portion having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other at a required interval in the circumferential direction of the pile body is provided on the peripheral surface of the pile body in an integrated state at a required interval in the circumferential direction of the pile body,
When the direction of the axis is viewed as the up-down direction, the soil holding portion is provided in one stage or in multiple stages at required intervals when viewed in the direction of the axis of the pile main body,
The soil holding portion has an upper and lower ends between the pair of soil holding pieces that are open, and has a lower soil inflow end and an upper soil outflow end, and has an open side end between the outer tips of the pair of soil holding pieces that are open,
The upper end edge of each of the soil holding pieces is inclined inwardly toward the upper end and toward the axis when viewed from the side,
When the pile body is driven into the ground, the upper end of the soil holding part closest to the ground is located a required distance away from the ground,
The soil holding portion can sequentially discharge the soil that has flowed between the pair of soil holding pieces through the soil inflow end portion as the pile body is driven into the ground from the soil outflow end portion, and the pair of soil holding pieces compress the flowed-in soil,
A driven-in pile characterized in that the outer edge portions of both of the pair of soil-holding pieces, when viewed from the side, consist of an intermediate edge portion, an upper edge portion and a lower edge portion when viewed in the direction of the axis, the intermediate edge portion extending in the direction of the axis, the upper edge portion sloping inward toward the upper end and toward the axis, the lower edge portion sloping inward toward the lower end and toward the axis, and the lower edge portion being a sharp blade-like portion, the blade-like portion being formed in a mountain shape having an inclined surface sloping in the opposite direction from its apex line. A driven pile having a pile body of a required length extending from the pile base end, which is the driving portion, to the pile tip, which is the entry portion into the ground,
A soil holding portion having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other at a required interval in the circumferential direction of the pile body is provided on the peripheral surface of the pile body in an integrated state at a required interval in the circumferential direction of the pile body,
When the direction of the axis is viewed as the up-down direction, the soil holding portion is provided in one stage or in multiple stages at required intervals when viewed in the direction of the axis of the pile main body,
The soil holding portion has an upper and lower ends between the pair of soil holding pieces that are open, and has a lower soil inflow end and an upper soil outflow end, and has an open side end between the outer tips of the pair of soil holding pieces that are open,
The upper end edge of each of the soil holding pieces is inclined inwardly toward the upper end and toward the axis when viewed from the side,
When the pile body is driven into the ground, the upper end of the soil holding part closest to the ground is located a required distance away from the ground,
The soil holding portion can sequentially discharge the soil that has flowed between the pair of soil holding pieces through the soil inflow end portion as the pile body is driven into the ground from the soil outflow end portion, and the pair of soil holding pieces compress the flowed-in soil,
This is a driven-in pile, characterized in that both or either one of the pair of soil-holding pieces has a thickness in a plan view that gradually increases from the inner end, which is the connection part to the pile body, toward the outer end. A driven pile having a pile body of a required length extending from the pile base end, which is the driving portion, to the pile tip, which is the entry portion into the ground,
A soil holding portion having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other at a required interval in the circumferential direction of the pile body is provided on the peripheral surface of the pile body in an integrated state at a required interval in the circumferential direction of the pile body,
When the direction of the axis is viewed as the up-down direction, the soil holding portion is provided in one stage or in multiple stages at required intervals when viewed in the direction of the axis of the pile main body,
The soil holding portion has an upper and lower ends between the pair of soil holding pieces that are open, and has a lower soil inflow end and an upper soil outflow end, and has an open side end between the outer tips of the pair of soil holding pieces that are open,
The upper end edge of each of the soil holding pieces is inclined inwardly toward the upper end and toward the axis when viewed from the side,
When the pile body is driven into the ground, the upper end of the soil holding part closest to the ground is located a required distance away from the ground,
The soil holding portion can sequentially discharge the soil that has flowed between the pair of soil holding pieces through the soil inflow end portion as the pile body is driven into the ground from the soil outflow end portion, and the pair of soil holding pieces compress the flowed-in soil,
A driven-in pile characterized in that both or either of the opposing inner surfaces of the pair of soil-holding pieces are formed so as to slope inwardly toward the soil-holding portion from the lower end to the upper end, and the interior of the soil- holding portion narrows from the lower end to the upper end. A driven pile having a pile body of a required length extending from the pile base end, which is the driving portion, to the pile tip, which is the entry portion into the ground,
A soil holding portion having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other at a required interval in the circumferential direction of the pile body is provided on the peripheral surface of the pile body in an integrated state at a required interval in the circumferential direction of the pile body,
When the direction of the axis is viewed as the up-down direction, the soil holding portion is provided in one stage or in multiple stages at required intervals when viewed in the direction of the axis of the pile main body,
The soil holding portion has an upper and lower ends between the pair of soil holding pieces that are open, and has a lower soil inflow end and an upper soil outflow end, and has an open side end between the outer tips of the pair of soil holding pieces that are open,
The upper end edge of each of the soil holding pieces is inclined inwardly toward the upper end and toward the axis when viewed from the side,
When the pile body is driven into the ground, the upper end of the soil holding part closest to the ground is located a required distance away from the ground,
The soil holding portion can sequentially discharge the soil that has flowed between the pair of soil holding pieces through the soil inflow end portion as the pile body is driven into the ground from the soil outflow end portion, and the pair of soil holding pieces compress the flowed-in soil,
A driven -in pile, characterized in that a soil erosion prevention protrusion is provided on the upper end portion of the opposing inner surface of both or either of the pair of soil-holding pieces. A driven pile having a pile body of a required length extending from the pile base end, which is the driving portion, to the pile tip, which is the entry portion into the ground,
A soil holding portion having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other at a required interval in the circumferential direction of the pile body is provided on the peripheral surface of the pile body in an integrated state at a required interval in the circumferential direction of the pile body,
When the direction of the axis is viewed as the up-down direction, the soil holding portion is provided in one stage or in multiple stages at required intervals when viewed in the direction of the axis of the pile main body,
The soil holding portion has an upper and lower ends between the pair of soil holding pieces that are open, and has a lower soil inflow end and an upper soil outflow end, and has an open side end between the outer tips of the pair of soil holding pieces that are open,
The upper end edge of each of the soil holding pieces is inclined inwardly toward the upper end and toward the axis when viewed from the side,
When the pile body is driven into the ground, the upper end of the soil holding part closest to the ground is located a required distance away from the ground,
The soil holding portion can sequentially discharge the soil that has flowed between the pair of soil holding pieces through the soil inflow end portion as the pile body is driven into the ground from the soil outflow end portion, and the pair of soil holding pieces compress the flowed-in soil,
This driven-in pile is characterized in that the soil holding portion is composed of a pair of soil holding pieces facing each other on the left and right, which are 4 to 8 soil holding pieces radially protruding at a required angular pitch in the circumferential direction of the pile body. A driven pile having a pile body of a required length extending from the pile base end, which is the driving portion, to the pile tip, which is the entry portion into the ground,
A soil holding portion having a pair of soil holding pieces extending in the axial direction of the pile body and facing each other at a required interval in the circumferential direction of the pile body is provided on the peripheral surface of the pile body in an integrated state at a required interval in the circumferential direction of the pile body,
When the direction of the axis is viewed as the up-down direction, the soil holding portion is provided in one stage or in multiple stages at required intervals when viewed in the direction of the axis of the pile main body,
The soil holding portion has an upper and lower ends between the pair of soil holding pieces that are open, and has a lower soil inflow end and an upper soil outflow end, and has an open side end between the outer tips of the pair of soil holding pieces that are open,
The upper end edge of each of the soil holding pieces is inclined inwardly toward the upper end and toward the axis when viewed from the side,
When the pile body is driven into the ground, the upper end of the soil holding part closest to the ground is located a required distance away from the ground,
The soil holding portion can sequentially discharge the soil that has flowed between the pair of soil holding pieces through the soil inflow end portion as the pile body is driven into the ground from the soil outflow end portion, and the pair of soil holding pieces compress the flowed-in soil,
When the soil holding portion is arranged in multiple upper and lower tiers at a required interval when viewed in the direction of the axis of the pile body, each of the pairs of soil holding pieces that make up the multiple upper and lower tiers of soil holding portions is arranged in a row in the direction of the axis, and the thickness of the soil holding pieces arranged in the row is formed so that the thickness of the soil holding pieces in the upper tier is thicker than the thickness of the soil holding pieces in the lower tier.This is a driven-in pile characterized in that

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