JP2016003431A - Spiral pile foundation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spiral pile foundation which can be easily constructed and has a greater bearing capacity in a vertical direction.SOLUTION: The spiral pile foundation includes: a spiral pile 1 having a circumferential surface shape twisted in a spiral; and a pressure receiving member 21 which is engaged with and attached to the spiral pile 1 while protruding in a flange-like shape. The pressure receiving member 21 that protrudes from the ground G contributes to the bearing capacity of the spiral pile 1 in a vertical direction, with the spiral pile 1 buried in the ground G.

Description

  The present invention relates to a foundation using spiral piles, and relates to a technique suitable for use in a foundation for supporting a structure.

  Conventionally, when a column is erected on the ground, a method is adopted in which the foundation installed on the ground is fixed with a pile, the column is erected on the foundation, and fixed with mortar or the like. And this applicant employs the spiral pile which twisted the flat steel especially as a pile which fixes a foundation, and has put many into practical use.

  Specific examples include spiral piles that are directly screwed into the ground as shown in Patent Document 1 and used as foundations for pillars, and concrete blocks or concrete foundations that are installed on the ground as shown in Patent Documents 2 to 4. There is a method to fix the concrete block etc. by opening it and screwing it into the ground through a spiral pile. These spiral piles have the advantage that they can be embedded easily and are not easily removed due to large friction with the ground.

Spiral piles, for example, have a 45-degree torsional surface that is obtained by twisting flat steel, so they exhibit the same vertical support force for both pulling out and pushing in. Compared to the support force of the above, an improvement in the vertical support force in the pushing direction is required.
In addition, for reasons such as economy, there is a demand for a design that reduces the number of spiral piles used for the foundation (for example, by reducing the number of piles by skipping the pile pitch). There is a tendency for the supporting load to increase.
The force that the spiral pile supports the compressive force in the vertical direction (vertical support force) depends largely on the peripheral surface friction of the pile, and the support force depends on the outer diameter of the pile. However, in particular, spiral piles manufactured by twisting and forming flat steel sheets have the advantage of being easy to manufacture and inexpensive, but making large pile diameter spiral piles requires a large investment in production machinery, etc. Therefore, it may be difficult to realize sufficient vertical bearing capacity with only spiral piles.

Patent No. 4017922 Japanese Patent No. 3836745 Japanese Patent No. 4558905 Patent No. 4585757

  This invention is made | formed in view of the said conventional situation, and aims at improving the vertical direction supporting force of the foundation using a spiral pile.

The spiral pile foundation according to the present invention is a spiral pile having a circumferential shape twisted in a spiral shape, and is prepared as a separate member from the spiral pile and is engaged with the spiral pile in a state of projecting in a flange shape. A pressure receiving member fixed to the ground, and the pressure receiving member protruding from the ground contributes to a vertical supporting force of the spiral pile in a state where the spiral pile is embedded in the ground.
In the present invention, the vertical supporting force of the spiral pile generally assumes that the spiral pile is embedded in the vertical direction. However, when the spiral pile is embedded in, for example, an oblique direction, the spiral pile is spirally embedded. It means the bearing capacity in the axial direction of the pile.

According to the spiral pile foundation according to the present invention, the vertical support force by the pressure receiving member acts on the vertical compressive force applied to the spiral pile in addition to the vertical support force due to the circumferential friction of the spiral pile. Thereby, even if it is a spiral pile of comparatively small diameter, sufficient vertical direction support force is realizable with a spiral pile foundation.
The manufacturing method and material of the spiral pile are not particularly limited, but it is preferable to use a spiral steel plate formed by twisting a flat steel plate, which makes it easy to manufacture. Spiral piles can be prepared at low cost. And it can be said that spiral piles can be easily machined by twisting a relatively narrow flat steel plate, but the vertical direction is sufficient even with the foundation of a relatively small-diameter spiral pile machined in this way. Support force can be realized.

In the present invention, the pressure receiving member prepared as a separate member may be pre-engaged and fixed in a state where it is flanged over the spiral pile in manufacturing and assembling work of the pile. The state before performing the foundation construction work, such as engaging and fixing the pressure receiving member and the spiral pile at the work site, or engaging and fixing the pressure receiving member and the spiral pile in the foundation construction work. Then, it is good also considering a spiral pile and a pressure receiving member as the state of another components.
Thus, by making the spiral pile and the pressure receiving member separate parts, for example, when plating, it can be performed for each part, and the plating work becomes easy, and from the viewpoint of transportation and storage. However, it can be carried out for each part, facilitating transportation work and efficient use of space.

In this invention, although the aspect which engages and fixes a spiral pile and a pressure receiving member can be employ | adopted variously, it is preferable to set it as the following aspects, for example.
As a preferred aspect of the spiral pile foundation according to the present invention, the spiral pile includes a spiral portion having a helically twisted circumferential surface shape, and an overhang from the outer periphery of the spiral portion to the head portion of the spiral portion. The pressure receiving member has a diameter through which the spiral portion is inserted, and a hole with which the upper end engages with an edge is provided. In the state where the spiral pile through which the spiral portion is inserted is embedded in the ground, the upper end portion engages with the edge of the hole of the pressure receiving member projecting from the ground, whereby the pressure receiving member becomes the spiral pile. It is characterized by being engaged and fixed in a state of projecting in a flange shape.

According to said aspect, in the state before a foundation is constructed, a spiral pile and a pressure receiving member can be made into the state of another parts, a spiral part is inserted in the hole of a pressure receiving member, and an upper end part is the said hole. In a state where the spiral pile is embedded in the ground by being engaged with the edge of the pressure receiving member, the pressure receiving member can be sandwiched and fixed between the ground and the upper end. Typically, the upper end can be engaged with the edge of the hole by making the upper end larger than the hole, but the upper end only needs to be engaged with the edge of the hole. It can be set as various aspects, such as providing the protrusion which engages with the edge of a hole in an upper end part.
According to this aspect, if a part having a simple structure such as a spiral pile having an upper end and a pressure receiving member having a hole is prepared, a spiral pile foundation having a sufficient vertical support force can be realized.

  Moreover, as a preferable aspect of the spiral pile foundation according to the present invention, the spiral pile has a spiral portion formed by spirally twisting flat steel, and the pressure receiving member is twisted by the spiral portion. A slit to be inserted is provided, and the spiral pile that is inserted into the slit by screwing the spiral portion is buried in the ground, and the edge of the slit of the pressure receiving member that protrudes from the ground is When the spiral part is engaged, the pressure receiving member is engaged and fixed to the spiral pile in a state of projecting in a flange shape.

According to the above aspect, in a state before the foundation is constructed, the spiral pile and the pressure receiving member can be in separate parts, and when the spiral portion is screwed into the slit of the pressure receiving member and inserted, the slit The spiral part engages with the edge of the spiral part, and thereby the movement of the spiral part (spiral pile) in the longitudinal direction is restricted. That is, the pressure receiving member and the spiral pile are engaged and fixed by the engagement between the edge of the slit and the spiral portion. The slit typically has a size and shape corresponding to the cross-section of the spiral portion, but if the slit can engage with the inserted spiral portion and restrict its longitudinal displacement, the size and shape are It can be changed within the practical range.
According to this aspect, if a part having a simple structure such as a spiral pile having at least a spiral portion and a pressure receiving member having a slit is prepared, a spiral pile foundation having a sufficient vertical support force can be realized.

Here, the slit may have a long groove shape with one end opened to the side edge of the pressure receiving member, in addition to the slit provided in the pressure receiving member.
With this latter shape of slit, for example, a pressure receiving member can be inserted and engaged with a spiral pile already embedded from the side of the spiral pile, and the construction method of the spiral pile foundation is diversified. The

  Moreover, as a preferable aspect of the spiral pile foundation according to the present invention, the spiral pile includes a spiral portion having a circumferential shape twisted in a spiral shape, and an upper end portion provided at a head portion of the spiral portion. The spiral portion has a shape protruding from the outer periphery of the upper end portion, and the pressure receiving member has a diameter through which the upper end portion is inserted, and the spiral portion engages with an edge portion. And an outer member for inserting the upper end portion, the upper end portion inserted through the hole being inserted into the outer member, and the pressure receiving member by the spiral portion and the outer member. The pressure receiving member is engaged and fixed to the spiral pile in a state of projecting in a flange shape by fixing the outer member and the upper end in a state of sandwiching the pin.

According to the above aspect, in a state before the foundation is constructed, the spiral pile, the pressure receiving member, and the outer member can be in separate parts, and the pressure receiving member is sandwiched between the spiral portion and the outer member. By fixing the outer member and the upper end, the pressure receiving member and the spiral pile are engaged and fixed. Typically, the spiral portion can be engaged with the edge of the hole by setting the diameter of the spiral portion to be larger than the hole. However, the spiral portion only needs to be engaged with the edge of the hole. Therefore, it can be set as various aspects, such as providing the protruding piece engaged with the edge of a hole in a helical part, for example.
According to this aspect, a spiral pile foundation having a sufficient vertical support force can be realized by preparing parts with a simple structure such as at least a spiral pile, a pressure receiving member having a hole, and an outer member.

  Moreover, as a preferable aspect of the spiral pile foundation according to the present invention, the spiral pile includes a spiral portion having a circumferential shape twisted in a spiral shape, and an upper end portion provided at a head portion of the spiral portion. The pressure receiving member is provided with a hole through which the spiral portion or the upper end portion is inserted, and further, an outer member in which the upper end portion is inserted and a bracket is provided on the outer periphery of the lower end portion. The spiral portion or the upper end portion is inserted into the hole, the upper end portion is inserted into the outer member, the outer member and the upper end portion are fixed, and the bracket and the pressure receiving member are By adhering, the pressure receiving member is engaged and fixed to the spiral pile in a state of projecting in a flange shape.

According to said aspect, in the state before a foundation is constructed, a spiral pile, a pressure receiving member, and an outer member can be made into the state of another parts, an outer member and an upper end part are adhere | attached, a bracket, and a pressure receiving member And the pressure receiving member and the spiral pile are engaged and fixed. In addition, although the method of adhering the outer member and upper end part of the said aspect and the method of adhering the bracket and pressure receiving member of the said aspect can be employ | adopted variously, for example, both can be bolted.
According to this aspect, a spiral pile foundation having a sufficient vertical support force can be realized by preparing parts with simple structures such as at least a spiral pile, a pressure receiving member having a hole, and an outer member having a bracket. it can.

Here, in the above aspect in which the outer member and the upper end portion are fixed and the bracket and the pressure receiving member are fixed, it is possible to engage and fix the spiral pile with the pressure receiving member being prevented from rotating.
In such an embodiment, when the spiral pile is screwed into the ground and embedded, the pressure receiving member is similarly screwed into the ground and embedded, so that the pressure receiving member has a generally spiral shape. The pressure receiving member may be excavated on the ground by rotating the pressure receiving member, and the pressure receiving member may be screwed into the ground to be embedded.

Thereby, when the pressure receiving member is also embedded in the ground, it is not necessary to previously form a hole for embedding the pressure receiving member, and the working efficiency is improved.
It is preferable that the pressure receiving member has a gentle curved surface to reduce the resistance during excavation. However, in the case where the excavation resistance does not matter so much, for example, the pressure receiving member is cut to It is good also as a gentle spiral shape which bent the piece of this and made this into an excavation piece.

Moreover, as a preferable aspect of the spiral pile foundation according to the present invention, the pressure receiving member has a protruding portion, and the protruding portion fits in the ground in a state in which the pressure receiving member is installed on the ground to prevent rotation of the pressure receiving member. You may make it contribute.
According to this, in the constructed spiral pile foundation, it is possible to prevent the pressure receiving member from being displaced in the rotational direction and the spiral pile from being displaced in the vertical direction, and the pressure receiving member is displaced in the lateral direction. This prevents the spiral pile from being displaced in the lateral direction. Furthermore, in the construction work of the spiral pile foundation, for example, in the case of a pressure receiving member provided with a slit, the pressure receiving member can be prevented from turning when the spiral pile is screwed into the slit.

  According to the present invention, it is possible to provide a spiral pile foundation having an increased vertical supporting force. Moreover, according to this invention, the spiral pile foundation with which the vertical direction support force was raised can be constructed | assembled by easy construction work.

It is a figure which shows the spiral pile which concerns on 1st Example of this invention. It is a figure which shows the pressure receiving plate which concerns on 1st Example of this invention, (a) is a top view, (b) is a front view. It is a figure which shows the spiral pile foundation which concerns on 1st Example of this invention. It is a figure which shows the modification which concerns on 1st Example of this invention. It is a figure which shows the spiral pile which concerns on 2nd Example of this invention. It is a figure which shows the pressure receiving plate which concerns on 2nd Example of this invention, (a) is a top view, (b) is a front view. It is a figure which shows the spiral pile foundation based on 2nd Example of this invention. It is a figure which shows the modification which concerns on 2nd Example of this invention. It is a figure which shows 3rd Example of this invention, (a) is a spiral pile, (b) is an outer member. It is a figure which shows the pressure receiving plate which concerns on 3rd Example of this invention, (a) is a top view, (b) is a front view. It is sectional drawing which shows the adhering part which concerns on 3rd Example of this invention. It is a figure which shows the spiral pile foundation based on 3rd Example of this invention. It is a figure which shows 4th Example of this invention, (a) is a spiral pile, (b) is an outer side member. It is a figure which shows the pressure receiving plate which concerns on 4th Example of this invention, (a) is a top view, (b) is a front view. It is a figure which shows the spiral pile foundation which concerns on 4th Example of this invention. It is a figure which shows the modification of the pressure receiving member which concerns on this invention, (a) is a top view, (b) is a front view. It is a figure which shows the pressure receiving plate which concerns on 5th Example of this invention, (a) is a top view, (b) is a front view. It is a figure which shows the state which fixed the pressure receiving member to the spiral pile which concerns on 5th Example of this invention. It is a figure which shows the pressure receiving plate which concerns on 6th Example of this invention, (a) is a top view, (b) is a front view. It is a figure which shows the state which fixed the pressure receiving member to the spiral pile which concerns on 6th Example of this invention. It is a figure which shows the spiral pile foundation based on 6th Example of this invention.

The present invention will be specifically described based on the following examples.
1 to 4 show a first embodiment according to the present invention.
As shown in FIG. 3, the spiral pile foundation of this embodiment is engaged and fixed in a state where the spiral pile 1 has a circumferential shape twisted in a spiral shape and is projected in a flange shape on the spiral pile 1. The pressure receiving member 21 projecting from the ground G in a state where the spiral pile 1 is embedded in the ground G contributes to the vertical support force of the spiral pile 1.

As shown in FIG. 1, the spiral pile 1 includes a spiral portion 2 having a circumferential shape twisted in a spiral shape, and an upper end portion 3 provided at the head of the spiral portion 2. ing.
The spiral portion 2 is formed by twisting flat steel. The upper end 3 is a cylindrical pipe and is fixed to the upper end of the spiral 2 by welding or the like.

The outer diameter d2 of the upper end 3 is set to be larger than the maximum outer diameter d1 of the peripheral surface of the spiral portion 2, so that the upper end 3 is placed on the head of the spiral portion 2 from the outer periphery of the spiral portion. Overhangs.
In the present invention, the upper end portion 3 does not have to be cylindrical or columnar, and it suffices if it projects from the outer periphery of the spiral portion.

As shown in FIG. 2, the pressure receiving member 21 has a disk shape, and a hole 22 is provided in the center.
The hole 22 is a circular hole having an inner diameter d3, and the relationship with the outer diameter is d1 <d3 <d2. Therefore, when the spiral portion 2 is inserted into the hole 22, the upper end portion 3 is engaged with the edge of the hole 22.
In addition, the shape of the pressure receiving member 21 may be arbitrary and may be, for example, a block shape in addition to the plate shape. Further, the hole 22 is not necessarily the center of the pressure receiving member 21 and is not necessarily a circular hole.

The spiral pile foundation of the present embodiment can be constructed by, for example, the following method.
First, a cylindrical hole 50 into which the pressure receiving member 21 enters is formed by excavating the ground G with an auger or the like.
Next, the pressure receiving member 21 is placed in the hole 50 so that the pressure receiving member 21 is in contact with the bottom surface (ground G) of the hole 50.

  Next, the spiral portion 2 of the spiral pile 1 is screwed into the ground G through the hole 22 of the pressure receiving member 21, and the spiral portion 2 is buried in the ground. Then, by screwing in the spiral portion 2, the lower end of the upper end portion 3 is brought into contact with the hole edge portion of the pressure receiving member 21, and the pressure receiving member 21 is sandwiched between the lower end of the upper end portion 3 and the bottom surface of the hole 50. The state is fixed.

Next, the soil m is backfilled in the hole 50 and the pressure receiving member 21 is embedded in the ground G. As the backfill soil m, high-quality soil, improved soil, or the like can be used in addition to locally generated soil generated by excavation.
Here, in this embodiment, the pressure receiving member 21 is buried by excavating the hole 50, but the pressure receiving member 21 may be installed on the ground surface.
Thus, the spiral pile foundation has the upper end 3 at the edge of the hole 22 of the pressure receiving member 21 projecting from the ground G in a state where the spiral pile 1 in which the spiral portion 2 is inserted into the hole 22 is embedded in the ground G. The pressure receiving member 21 is engaged and fixed to the spiral pile 1 in a state of projecting in a flange shape.

According to this spiral pile foundation, when a downward force is applied to the spiral pile 1 as shown by an arrow in FIG. 3, in addition to the peripheral friction of the spiral pile 1 screwed into the ground G, the flange The pressure receiving member 21 protruding in a shape acts to press the ground G. As a result, the spiral pile foundation can exhibit a large vertical supporting force.
As an example of the present embodiment, the spiral portion 2 can have a diameter of about 100 mm, and the pressure receiving member 21 can have a diameter of about 500 mm. Thus, even a relatively small-diameter spiral pile 1 is sufficiently vertical to support the structure. Directional support force can be obtained.

Here, as an aspect for engaging the upper end 3 with the edge of the hole 22, for example, as shown in FIG. 4, a protruding piece 3 a protruding in a rod shape from the outer periphery of the spiral portion 2 is provided on the upper end 3. The pressure receiving member 21 can be engaged and fixed by the projecting piece 3a.
In this case, the outer diameter of the upper end portion 3 may be smaller than the inner diameter of the hole 22.

5 to 8 show a second embodiment according to the present invention.
In addition, the same code | symbol is attached | subjected to the part similar to 1st Example, and the characteristic part to a present Example is demonstrated in detail.
As shown in FIG. 7, the spiral pile foundation of this embodiment is engaged and fixed in a state where the spiral pile 1 is spirally twisted and has a circumferential shape and is projected from the spiral pile 1 in a flange shape. The pressure receiving member 21 projecting from the ground G in a state where the spiral pile 1 is embedded in the ground G contributes to the vertical support force of the spiral pile 1.

As shown in FIG. 5, the spiral pile 1 includes a spiral portion 2 having a circumferential shape twisted in a spiral shape, and an upper end portion 3 provided at the head of the spiral portion 2. ing.
The spiral portion 2 is formed by twisting flat steel.
Here, as will be described later, the upper end portion 3 of the present embodiment is not directly involved in the engagement and fixation of the pressure receiving member 21, and therefore the diameter thereof is arbitrary, and the spiral pile foundation If it is unnecessary, it can be omitted.

As shown in FIG. 6, the pressure receiving member 21 is provided with a slit 23, and the slit 23 has a shape and a size corresponding to the cross section of the spiral portion 2.
Therefore, when the spiral portion 2 is screwed into the slit 23 and inserted, when the force in the longitudinal direction acts on the spiral portion 2, the spiral portion 2 tries to rotate around the axis. 2 is engaged with the edge of the slit 23, and the spiral portion 2 is fixed so as not to move in the longitudinal direction.
The shape of the pressure receiving member 21 may be arbitrary, and the slit 23 does not necessarily have to be parallel to the side of the pressure receiving member 21 at the center of the pressure receiving member 21. However, when the slit 23 into which the spiral portion 2 is screwed is provided, the pressure receiving member 21 is not a perfect circle such as a quadrangle, a polygon, an ellipse or the like so as not to rotate due to the screwing. The shape is preferred.

The spiral pile foundation of the present embodiment can be constructed by, for example, the following method.
First, a cylindrical hole 50 into which the pressure receiving member 21 enters is formed by excavating the ground G, and the pressure receiving member 21 is placed in the hole 50 so that the pressure receiving member 21 is in contact with the bottom surface (ground G) of the hole 50. .
Next, the spiral portion 2 of the spiral pile 1 is screwed into the ground G from the slit 23 of the pressure receiving member 21, and the spiral portion 2 is buried in the ground. Thus, in a state where the spiral portion 2 is screwed into the slit 23 and inserted, the spiral portion 2 is engaged with the edge of the slit 23 so that the spiral portion 2 does not move in the longitudinal direction. Fixed to.

Next, the soil m is backfilled in the hole 50 and the pressure receiving member 21 is embedded in the ground G.
In this way, the spiral pile foundation is engaged and fixed in a state in which the spiral member 2 protrudes in a flange shape from the spiral pile 1 by engaging the spiral portion 2 with the edge of the slit 23 of the pressure member 21. The

  According to this spiral pile foundation, when a downward force is applied to the spiral pile 1 as indicated by an arrow in FIG. 7, in addition to the peripheral friction of the spiral pile 1 screwed into the ground G, the flange The pressure receiving member 21 protruding in a shape acts to press the ground G. As a result, the spiral pile foundation can exhibit a large vertical supporting force.

  Here, as a mode of engaging the spiral portion 2 with the edge of the slit 23, for example, as shown in FIG. 8, the pressure receiving member 21 may be engaged and fixed in the middle of the spiral portion 2. it can. Therefore, for example, when adjusting the height of the spiral pile 1 protruding from the ground G, the engagement position of the pressure receiving member 21 may be adjusted in this way.

9 to 12 show a third embodiment according to the present invention.
In addition, the same code | symbol is attached | subjected to the part similar to said Example, and the characteristic part to a present Example is demonstrated in detail.
As shown in FIGS. 11 and 12, the spiral pile foundation of this embodiment is engaged with a spiral pile 1 having a circumferential shape twisted in a spiral shape, and in a state where the spiral pile 1 projects in a flange shape. A pressure receiving member 21 fixed to the spiral pile 1 and an outer member 31 that engages and fixes the pressure receiving member 21 to the spiral pile 1, and the spiral pile 1 is embedded in the ground G and protrudes from the ground G. The pressure receiving member 21 contributes to the vertical support force of the spiral pile 1.

As shown in FIG. 9 (a), the spiral pile 1 includes a spiral portion 2 having a circumferential shape twisted in a spiral shape, an upper end portion 3 provided at the head of the spiral portion 2, have.
The outer diameter d4 of the upper end portion 3 is set to be smaller than the maximum outer diameter d5 of the peripheral surface of the spiral portion 2, whereby the spiral portion 2 protrudes from the outer periphery of the upper end portion 3.

As shown in FIG. 9B, the outer member 31 has a cylindrical shape, and its inner diameter d6 is set larger than the outer diameter d4 of the upper end so that the upper end 3 can be inserted.
The upper end 3 and the outer member 31 are respectively provided with holes 3a and 31a through which bolts pass. As described later, the upper member 3 is inserted into the outer member 31, and the pressure receiving member 21 is engaged and fixed. Thus, the positions of the holes 3a and 31a correspond to allow the bolts 41 to pass therethrough.
In the present invention, the upper end 3 may not be cylindrical or columnar, and the outer member 31 may not be cylindrical. In short, the outer member 31 interpolates the upper end 3 and receives pressure. What is necessary is just to engage with the edge part of the hole 22 of the member 21. FIG.

As shown in FIG. 10, the pressure receiving member 21 is provided with a hole 22. The hole 22 has a size and a shape in which the upper end portion 3 is inserted and the spiral portion 2 is engaged with the edge portion.
In this embodiment, the inner diameter d8 of the hole 22 is set larger than the outer diameter d4 of the upper end portion 3, and smaller than the outer diameter d5 of the spiral portion 2 and the outer diameter d7 of the outer member 31b.

The spiral pile foundation of the present embodiment can be constructed by, for example, the following method.
First, a cylindrical hole 50 into which the pressure receiving member 21 enters is formed by excavating the ground G, the spiral portion 2 of the spiral pile 1 is screwed into the bottom surface (ground G) of the hole 50, and the spiral portion 2 is grounded. Buried inside.
Next, the pressure receiving member 21 is inserted into the hole 22 and the upper end 3 is inserted into the hole 50 so that the pressure receiving member 21 is in contact with the bottom surface of the hole 50.

Next, the upper end portion 3 protruding from the pressure receiving member 21 is inserted into the outer member 31, and the bolt 41 is passed through the holes 3a and 31a of the upper end portion 3 and the outer member 31, as shown in FIG. Then, the outer member 31 and the upper end 3 are fixed.
In this state where the outer member 31 and the upper end portion 3 are fixed, the lower end of the outer member 31 and the upper end of the spiral portion 2 are in contact with the edge portion of the hole 22 from above and below, respectively. Thus, the pressure receiving member 21 is engaged and fixed to the spiral pile 1 in a state of projecting in a flange shape.
Next, the soil m is backfilled in the hole 50 and the pressure receiving member 21 is embedded in the ground G.

  According to this spiral pile foundation, when a downward force is applied to the spiral pile 1 as shown by an arrow in FIG. 12, in addition to the peripheral surface friction of the spiral pile 1 screwed into the ground G, it is shaped like a flange. The force by which the overhanging pressure receiving member 21 presses the ground G acts. As a result, the spiral pile foundation can exhibit a large vertical supporting force.

13 to 15 show a fourth embodiment according to the present invention.
In addition, the same code | symbol is attached | subjected to the part similar to said Example, and the characteristic part to a present Example is demonstrated in detail.
As shown in FIG. 15, the spiral pile foundation of the present embodiment is engaged and fixed in a state where the spiral pile 1 having a circumferential shape twisted in a spiral shape and the spiral pile 1 is projected in a flange shape. A pressure receiving member 21 and an outer member 31 for engaging and fixing the pressure receiving member 21 to the spiral pile 1, and the pressure receiving member 21 projecting from the ground G in a state where the spiral pile 1 is embedded in the ground G. Contributes to the vertical support force of the spiral pile 1.

As shown in FIG. 13 (a), the spiral pile 1 includes a spiral portion 2 having a circumferential shape twisted in a spiral shape, an upper end portion 3 provided on the head portion of the spiral portion 2, have.
Unlike the third embodiment, the outer diameter of the upper end 3 may be arbitrary.
As shown in FIG. 13B, the outer member 31 has a cylindrical shape, and its inner diameter is set larger than the outer diameter of the upper end so that the upper end 3 can be inserted. A bracket 32 is provided on the outer periphery of the lower end portion of the outer member 31, and a hole 32 a through which the bolt 43 is passed is provided in the bracket 32.
The upper end 3 and the outer member 31 are respectively provided with holes 3a and 31a through which bolts pass. As described later, the upper member 3 is inserted into the outer member 31, and the pressure receiving member 21 is engaged and fixed. Thus, the positions of the holes 3a and 31a correspond to allow the bolts 41 to pass therethrough.

  As shown in FIG. 14, a hole 22 is provided in the pressure receiving member 21, and the hole 22 has a shape and a size through which at least one of the spiral portion 2 or the upper end portion 3 is inserted. Further, the pressure receiving member 21 is provided with a hole 21a through which the bolt 43 passes.

The spiral pile foundation of the present embodiment can be constructed by, for example, the following method.
A cylindrical hole 50 into which the pressure receiving member 21 enters is formed by excavating the ground G.
Further, by inserting the spiral portion 2 or the upper end portion 3 into the hole 22 of the pressure receiving member 21, inserting the upper end portion 3 into the outer member 31, and fastening with the nut 42 through the bolt 41 in the holes 3 a and 31 a, the outer member 31 and the upper end 3 are fixed together, and the bracket 32 and the pressure receiving member 21 are fixed by fastening them with the nuts 44 through the bolts 43 in the holes 21a and 32a. Thereby, the pressure receiving member 21 is engaged and fixed to the spiral pile 1 in a state of projecting in a flange shape.

Next, the spiral portion 2 of the spiral pile 1 is screwed into the bottom surface (ground G) of the hole 50, and the spiral portion 2 is embedded in the ground until the pressure receiving member 21 contacts the bottom surface of the hole 50.
Next, the soil m is backfilled in the hole 50 and the pressure receiving member 21 is embedded in the ground G.

  According to this spiral pile foundation, when a downward force is applied to the spiral pile 1 as shown by an arrow in FIG. 15, in addition to the peripheral surface friction of the spiral pile 1 screwed into the ground G, a flange shape is formed. The force by which the overhanging pressure receiving member 21 presses the ground G acts. As a result, the spiral pile foundation can exhibit a large vertical supporting force.

As shown in FIG. 16, the pressure receiving member 21 is capable of excavating the ground G as shown in FIG. It may be.
That is, the pressure receiving member 21 may be a spiral plate as a whole so that the pressure receiving member 21 can excavate the ground G to form the hole 50 by rotating the pressure receiving member 21.

In this embodiment, the spiral portion 2 and the pressure-receiving member 21 are twisted in the same direction (for example, the A direction in FIG. 16), and the spiral portion 2 is screwed into the ground G, and the pressure-receiving member. When the spiral portion 2 is further screwed even if the abutment 21 contacts the ground G, the pressure receiving member 21 is screwed into the ground while being excavated on the ground G and buried.
Thereby, when the pressure receiving member 21 is also embedded in the ground, it is not necessary to previously form the hole 50 for embedding the pressure receiving member 21, and the work efficiency of constructing the foundation is improved.

17 and 18 show a fifth embodiment according to the present invention.
In addition, the same code | symbol is attached | subjected to the part similar to said Example, and the characteristic part to a present Example is demonstrated in detail.
The spiral pile foundation of the present embodiment is a modification of the second embodiment, and one end of the slit 23 is opened to the side edge of the pressure receiving member 21 as shown in FIG.
Even in the slit 23 having such a shape, as shown in FIG. 18, when the spiral portion 2 is screwed into the slit 23 and inserted, the longitudinal force is applied to the spiral portion 2. Since the spiral portion 2 tends to rotate around the axis, the spiral portion 2 engages with the edge of the slit 23, and the spiral portion 2 is fixed so as not to move in the longitudinal direction.

Although the spiral pile foundation of the present embodiment can be constructed as in the second embodiment, it can be constructed by the following method, for example, because it has a long groove shape with the slits 23 opened.
That is, the spiral portion 2 of the spiral pile 1 is screwed into the ground G, and then the pressure receiving member 21 is inserted into the spiral portion 2 of the spiral pile by the slit 23 from the side of the spiral pile 1. Engage.
Also in the spiral pile foundation of the present embodiment, when a downward force is applied to the spiral pile 1, in addition to the peripheral surface friction of the spiral pile 1 that is screwed into the ground G and embedded, the pressure receiving member 21 projecting in a flange shape. The force which presses down the ground G acts. As a result, the spiral pile foundation is able to exert a large vertical support force by adding a vertical support force of the flange portion.

19 to 21 show a sixth embodiment according to the present invention.
In addition, the same code | symbol is attached | subjected to the part similar to said Example, and the characteristic part to a present Example is demonstrated in detail.
The spiral pile foundation according to the present embodiment is obtained by modifying the pressure receiving member 21. In the following description, an example in which the aspect of the fifth embodiment is modified is shown.

Although the pressure receiving member 21 is not limited to a flat plate shape, as shown in FIGS. 19 and 20, the pressure receiving member 21 of the present embodiment has a protruding portion 21a, and as shown in FIG. In a state where the member 21 is installed on the ground, the protruding portion 21a fits in the ground and contributes to the rotation prevention of the pressure receiving member 21. For example, an angle plate can be used as the pressure receiving member 21.
In this embodiment, the protruding portion 21a is provided on one side edge of the quadrilateral pressure receiving member 21 so as to protrude downward. What is necessary is just to change arbitrarily, and, in short, the protrusion part 21a should just be provided so that it may fit in the ground and may contribute to the rotation stop of the pressure receiving member 21.

  Also in the spiral pile foundation of the present embodiment, when a downward force is applied to the spiral pile 1, in addition to the peripheral surface friction of the spiral pile 1 that is screwed into the ground G and embedded, the pressure receiving member 21 projecting in a flange shape. The force which presses down the ground G acts, and the spiral pile foundation can exhibit a large vertical direction support force. In addition, since the pressure receiving member 21 is prevented from rotating by the protruding portion 21a, the spiral pile 1 can be prevented from being displaced in the vertical direction, and the pressure receiving member 21 is positioned in the lateral direction. It is possible to prevent the spiral pile 1 from being displaced and displaced in the lateral direction.

  As mentioned above, although the Example of this invention was described, it cannot be overemphasized that this invention can perform a design change, material selection, etc. suitably in the range which does not deviate from the meaning.

  The present invention can be used for various applications known as pile foundations, and for example, can be used for foundations that support structures such as buildings and towers, foundations that support solar panels, and the like.

1: Spiral pile,
2: spiral part,
3: upper end,
3a: protrusion,
21: pressure receiving member,
21a: protrusion,
22: hole,
23: slit,
31: outer member,
32: Bracket,
50: hole,
G: Ground
m: Backfill soil (locally generated soil, high quality soil, improved soil, etc.),

Claims (8)

A spiral pile having a circumferential shape twisted in a spiral;
Prepared as a separate member from the spiral pile, and a pressure receiving member that is engaged and fixed in a state of projecting to the spiral pile in a flange shape,
The spiral pile foundation, wherein the pressure receiving member projecting from the ground contributes to the vertical support force of the spiral pile in a state where the spiral pile is embedded in the ground. In the spiral pile foundation according to claim 1,
The spiral pile includes a spiral portion having a circumferential shape twisted in a spiral shape, and an upper end portion provided on the head portion of the spiral portion so as to protrude from the outer periphery of the spiral portion,
The pressure receiving member has a diameter through which the spiral portion is inserted, and is provided with a hole in which the upper end engages with an edge,
With the spiral pile having the spiral portion inserted through the hole embedded in the ground, the upper end portion engages with the edge of the hole of the pressure receiving member projecting from the ground, whereby the pressure receiving member Is a spiral pile foundation characterized by being engaged and fixed to the spiral pile in a flange-like state. In the spiral pile foundation according to claim 1,
The spiral pile has a spiral portion formed by twisting flat steel spirally,
The pressure receiving member is provided with a slit into which the spiral portion is screwed.
By engaging the spiral portion with the edge of the slit of the pressure-receiving member projecting from the ground in a state where the spiral pile that is inserted through the spiral portion is inserted into the slit. The spiral pile foundation is characterized in that the pressure receiving member is engaged and fixed to the spiral pile in a state of protruding in a flange shape. In the spiral pile foundation according to claim 3,
The spiral pile foundation, wherein one end of the slit is open to a side edge of the pressure receiving member. In the spiral pile foundation according to claim 1,
The spiral pile includes a spiral portion having a circumferential shape twisted in a spiral shape, and an upper end portion provided on a head portion of the spiral portion, and the spiral portion is formed on the upper end portion. It is a shape that protrudes from the outer periphery,
The pressure receiving member is provided with a hole through which the upper end portion is inserted and the spiral portion is engaged with an edge portion,
Furthermore, an outer member for inserting the upper end portion is provided,
By inserting the upper end portion inserted through the hole into the outer member, and fixing the outer member and the upper end portion in a state where the pressure receiving member is sandwiched between the spiral portion and the outer member, The said pressure receiving member is engaged and fixed in the state which protruded in the flange shape to the said spiral pile, The spiral pile foundation characterized by the above-mentioned. In the spiral pile foundation according to claim 1,
The spiral pile has a spiral portion having a circumferential shape twisted in a spiral shape, and an upper end portion provided on a head portion of the spiral portion,
The pressure receiving member is provided with a hole through which the spiral portion or the upper end portion is inserted,
Further, the outer member is provided with the upper end inserted therein and a bracket provided on the outer periphery of the lower end,
The spiral portion or the upper end portion is inserted into the hole, the upper end portion is inserted into the outer member, the outer member and the upper end portion are fixed, and the bracket and the pressure receiving member are fixed. Thus, the pressure receiving member is engaged and fixed to the spiral pile in a state of protruding in a flange shape. In the spiral pile foundation according to claim 5,
The pressure receiving member has a generally disk shape, and the pressure receiving member excavates the ground by rotating the pressure receiving member, and the pressure receiving member is screwed into the ground and embedded. Spiral pile foundation characterized by. In the spiral pile foundation according to any one of claims 1 to 6,
The spiral pile foundation, wherein the pressure receiving member has a protruding portion, and the protruding portion fits into the ground and contributes to detent of the pressure receiving member in a state where the pressure receiving member is installed on the ground.

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