JP2004324172A - Foundation pipe pile and method of stably bearing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foundation pipe pile which has excellent load bearing capacity and can be stably erected even in soft ground, and to provide a method of stably bearing the foundation pipe pile. <P>SOLUTION: A pile main body 1 of the foundation pipe pile has a flange-like bottom reaming plate 2 having at least part thereof cut away. The bottom reaming plate 2 is formed of a horizontal plate portion 21 horizontally arranged when the pile main body 1 is vertically driven, excavating blades 22 formed at both edges of cut-away portions thereof by bending upward one of the edges and bending downward the other edge, and a plurality of earth raking projections 23 on an upper surface of the horizontal plate portion 21 in a diagonal direction with respect to a rotating direction of the bottom-reaming plate 2. The earth raking projections 23 rake up earth in the vicinity of the upper surface of the bottom-reaming plate 2 toward the inside of the bottom-reaming plate 2 upon rotation of the penetrating pile main body 1, and therefore the concentration of the earth at an excavation site is prevented from decreasing, to thereby increase the frictional resistance and the bottom-reaming plate bearing capacity of a peripheral surface of the pile main body 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in construction technology, and more particularly, to a foundation steel pipe pile that can be stably erected with excellent supporting force even on soft ground, and a method for stably supporting the pile.
[0002]
[Prior art]
As is well known, in order to support a structure, a steel pipe pile is penetrated into the ground as a foundation member. In particular, in the soft ground, since the supporting force is small only with the straight rod-shaped pile main body, there is a type in which an expanded bottom plate is fixed to the outer periphery of the pile main body for reinforcement, but this expanded bottom plate is formed in a spiral shape. Japanese Patent Application Laid-Open Publication No. H11-163,087 discloses a structure configured to be easily buried.
[0003]
However, in such a spiral bottom plate, the effective area of the bottom plate is reduced due to the inclination angle and the supporting force is reduced, and the load applied to the steel pipe pile body generates a rotational force on the entire pile. Problem.
[0004]
In addition, during the construction, the sediment is pushed one after another to the outside of the base plate as the base plate is rotated and penetrated, and the sediment density near the top surface of the base plate is reduced, and the horizontal bearing capacity is reduced. There is a problem that the pile will sink.
[0005]
On the other hand, a steel pipe pile with a bottom plate with only a horizontal part has excellent horizontal bearing capacity, but it is very difficult to bury it, and it is very difficult to pull it out when removing or reusing it. Difficult.
[0006]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2001-220939 (Page 2-3, FIG. 1-4)
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the above-described problems in the conventional steel pipe pile, and has a superior supporting force capable of stably standing even on soft ground. The technical task is to provide steel pipe piles.
[0008]
Another object of the present invention is to provide a method for stably supporting a foundation steel pipe pile, which can reliably and stably erect the foundation steel pipe pile.
[0009]
[Means for Solving the Problems]
Means adopted by the present inventor to solve the above problem will be described below with reference to the accompanying drawings.
[0010]
That is, the present invention is a steel pipe pile penetrating into the ground as the foundation of a construction structure,
On the outer periphery of the pile main body 1, a flange-shaped expanded bottom plate 2 at least partially cut is provided,
The expanded bottom plate 2 includes a horizontal plate portion 21 that is horizontal with respect to the vertically piled pile body 1, and the horizontal plate portion 21 occupies at least half or more of the entire area of the expanded bottom plate 2. While supporting the supporting force in the direction and preventing the generation of the rotational force of the pile main body 1 with respect to the load,
One of the edges of the cut portion of the expanded bottom plate 2 is bent upward and the other is bent downward to form a digging blade 22, and a plurality of sediment scraping protrusions 23 are formed on the upper surface of the horizontal plate portion 21. Arranged obliquely with respect to the direction of rotation of the bottom plate 2, the sediment scraping projections 23 cause the earth and sand near the upper surface of the bottom plate 2 to move inside the bottom plate 2 when the penetrating pile body 1 rotates. Technical means that can increase the frictional resistance of the peripheral surface of the pile main body 1 and the supporting force of the bottom plate by preventing a decrease in soil density at the excavation site. Completed the foundation steel pipe pile.
[0011]
In addition, in order to solve the above-mentioned problems, the present invention employs a technical means in which a tip excavation blade 11 is disposed on the tip head of the pile main body 1 in addition to the above means as necessary.
[0012]
Furthermore, in order to solve the above-mentioned problems, the present invention is configured such that an additional blade 22a is detachably attached to the tip of the excavating blade 22 of the bottom-enlarged plate 2 according to the ground hardness, in addition to the above-described means as necessary. Technical measures were adopted.
[0013]
Furthermore, in order to solve the above-mentioned problem, the present invention employs a technical means for fixing a reinforcing rib 24 to the lower surface of the excavating blade 22 of the expanded bottom plate 2 in addition to the above means as necessary.
[0014]
Furthermore, in order to solve the above-mentioned problems, the present invention employs technical means for projecting the reinforcing ribs 24 of the expanded bottom plate 2 to the outside of the outer periphery in addition to the above means as necessary.
[0015]
Furthermore, in order to solve the above-mentioned problem, the present invention employs a technical means in which, in addition to the above-described means, if necessary, a pressing plate 25 is protruded from the lower surface of the outer peripheral surface of the horizontal plate portion 21 of the expanded bottom plate 2. .
[0016]
Furthermore, in order to solve the above-mentioned problems, the present invention employs a technical means in which, in addition to the above means, as necessary, the expanded bottom plate 2 is formed by winding the outer periphery of the pile body 1 a plurality of times.
[0017]
Further, the present invention is a construction method for stably supporting a steel pipe pile as a foundation of a construction structure,
A steel pipe pile is formed by arranging a bottom plate 2 around the periphery of the pile body 1, while the bottom plate 2 is in the form of a flange with at least a part cut, and is horizontal with respect to the vertically piled pile body 1. A horizontal plate portion 21 occupying at least half or more of the entire area of the plate 2 is provided, and one of the edges of the cut portion is bent upward and the other is bent downward to form a digging blade 22; On the upper surface of the horizontal plate portion 21, a plurality of sediment scraping protrusions 23 are disposed obliquely with respect to the rotation direction of the bottom plate 2.
The steel pipe pile is erected, and the pile body 1 is rotated, so that the pile body 1 penetrates while excavating the ground soil with the excavating blade 22 formed on the bottom plate 2.
The pile body 1 is rotated forward, and the sediment near the upper surface of the expanded bottom plate 2 is scraped toward the pile body 1 by the sediment scraping projections 23, thereby preventing a decrease in sediment density at an excavated portion, and 1 to increase the frictional resistance with the earth and sand on the peripheral surface,
The horizontal plate portion 21 secures the vertical support force of the steel pipe pile and prevents the generation of the rotational force of the pile main body 1 with respect to the load by adopting the technical means of adopting the technical means. The stable support method for steel pipe piles was completed.
[0018]
In addition, in order to solve the above-mentioned problem, the present invention provides, in addition to the above-described means, as necessary, injecting a hydraulic hardening agent mainly composed of lightly burned magnesium into ground soil excavated by rotating the pile body 1. While mixing the excavated earth and sand with the hydraulic hardener, and penetrate the pile body 1;
Next, the mixed earth and sand and the hydraulic hardening agent are scraped in the direction of the pile body 1 by the earth and sand raking projections 23 formed on the upper surface of the expanded bottom plate 2,
After that, the hydraulic hardening agent is hardened to prevent the density from being reduced in the excavation hole, and to increase the frictional resistance on the peripheral surface of the pile body 1 to give a stable supporting force. Adopted.
[0019]
In addition, in order to solve the above-mentioned problems, the present invention, in addition to the above-described means as necessary, adds a hydraulic hardener while resolving the soil at the excavation site by repeatedly and alternately reversing the pile main body 1 alternately. We adopted the technical means of letting go.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below in more detail with reference to the drawings.
[0021]
The basic steel pipe pile according to the present embodiment will be described with reference to FIGS. In the figure, what is designated by reference numeral 1 is a pile main body, and this pile main body 1 is a straight steel pipe. Also, what is indicated by the reference numeral 2 is a bottom plate, which is a flange member which is welded or integrally formed on the outer periphery of the pile body 1 and which is at least partially cut. A horizontal plate portion 21 that is horizontal to the horizontal plate portion 21 is provided, and the horizontal plate portion 21 occupies at least half or more of the entire area of the expanded bottom plate 2. The diameter of the expanded bottom plate 2 is preferably in the range of about 1.5 to 3 times the circumference of the pile body 1.
[0022]
In addition, one of the edges in the cut portion of the bottom plate 2 is bent upward and the other edge is bent downward to form the excavating blade 22. At this time, an inclination of about 7 ° to 13 ° is preferable. In addition, a plurality of sediment scraping projections 23 are disposed on the upper surface of the horizontal plate portion 21 obliquely with respect to the rotation direction of the expanded bottom plate 2.
[0023]
On the upper surface of the horizontal plate portion 21, a plurality of sediment scraping protrusions 23 are disposed obliquely to the rotation direction of the bottom-plate 2. When the main body 1 rotates, the earth and sand near the upper surface of the bottom plate 2 is raked into the inside of the bottom plate 2 to prevent a decrease in soil density at the excavation site, and the frictional resistance of the peripheral surface of the pile body 1 and the bottom expansion The plate supporting force can be increased (see FIG. 3).
[0024]
At this time, by preventing the sediment scraping protrusion 23 from being in contact with the peripheral surface of the pile main body 1, the contact surface with the soil can be increased, the frictional force can be increased, and the compaction effect can be enhanced. In addition, since the space is formed there, it becomes a refuge for the rushed earth and sand, so that it is wrapped around the back side of the earth and sand raking projection 23 to prevent a decrease in earth and sand density.
[0025]
Further, the earth and sand scraping projection 23 can be scraped by being installed at an angle of 45 ° or more with respect to the rotation direction, and its shape may be linear, or it may be curved. It may be what you are doing.
[0026]
A specific procedure for installing the steel pipe pile configured as described above will be described below. First, the steel pipe pile is erected, and the pile head 1 of the pile body 1 is rotated by applying torque to the pile head of the pile body 1 using a construction machine to excavate the ground soil with the excavation blade 22 formed on the expanded bottom plate 2. Penetrate.
[0027]
When the pile body 1 is rotated forward, the bottom plate 2 normally pushes and removes the earth and sand when penetrating. The nearby earth and sand can be raked in the direction of the pile main body 1, and a decrease in earth and sand density at the excavation site can be prevented.
[0028]
Therefore, the frictional resistance with the earth and sand on the peripheral surface of the pile main body 1 can be enhanced, and the vertical supporting force of the steel pipe pile can be secured. Furthermore, the horizontal plate portion 21 can prevent the generation of the rotational force of the pile main body 1 with respect to the load and is very stable.
[0029]
In the present embodiment, the excavated earth and sand and the hydraulic hardener are mixed while the hydraulic hardener mainly containing light-burned magnesia is injected into the ground soil excavated by rotating the pile body 1. The pile main body 1 can be penetrated.
[0030]
The light-fired magnesia used in the present embodiment (trade name: Mag White, manufactured by Agricultural Industries Research Institute) is obtained by firing seawater magnesia and natural magnesium carbonate, and is fired at a firing temperature of 700 ° C to 900 ° C. A product crushed to 70 to 120 mesh is used.
[0031]
Then, the mixed earth and sand and the hydraulic hardening agent are raked in the direction of the pile main body 1 by the earth and sand raking projection 23 formed on the upper surface of the expanded bottom plate 2, and then the hydraulic hardening agent is hardened. Thus, it is possible to prevent a decrease in the density of the excavation hole and increase the frictional resistance on the peripheral surface of the pile body 1 to provide a stable supporting force.
[0032]
In this case, the hydraulic hardening agent can be injected while the soil at the excavation site is released by alternately reversing the pile body 1 alternately forward and backward, so that the soil can be more appropriately injected into the soil. In addition, by appropriately charging and agitating guest soil (eg, gravel of 2 mm or more) into the excavation point, it is possible to prevent a decrease in sediment density and a liquefaction phenomenon to stabilize the pile body 1. is there.
[0033]
In addition, the tip excavation blade 11 can be provided at the tip end of the pile main body 1 as necessary, and the excavation strength can be increased. Furthermore, an additional blade 22a can be detachably attached to the tip of the excavating blade 22 of the expanded bottom plate 2 according to the ground hardness (see FIG. 4).
[0034]
Further, as shown in FIG. 5, a reinforcing rib 24 can be fixed to the lower surface of the excavating blade 22 of the expanded bottom plate 2, and furthermore, the reinforcing rib 24 can be protruded outside the outer periphery, so that the soil is disintegrated. be able to.
[0035]
Furthermore, a pressing plate 25 can be protruded from the outer peripheral lower surface of the horizontal plate portion 21 of the expanded bottom plate 2, and can serve as a wall in the horizontal direction to increase the supporting force.
[0036]
As a modified example of the present embodiment, as shown in FIG. 6, the expanded bottom plate 2 can be formed by winding the outer periphery of the pile body 1 a plurality of times, and the horizontal plate portions 21 are provided on the upper and lower surfaces, respectively, so that the vertical direction can be obtained. The supporting force can be secured.
[0037]
Although the present invention is generally configured as described above, the present invention is not limited to the illustrated embodiment, and various modifications are possible within the scope of the claims, for example, The expanded bottom plate 2 may be attached to any number of locations, and is preferably fixed to a required location corresponding to the depth of the soft ground layer.
[0038]
Further, the shape and size of the sediment scraping protrusion 23 of the expanded bottom plate 2 can be changed if the shape is inclined obliquely inward in the rotation direction. Belongs to.
[0039]
【The invention's effect】
As described above with reference to the embodiment, in the present invention, by providing the horizontal plate portion to the expanded bottom plate fixed to the pile main body, the vertical supporting force of the steel pipe pile can be secured, and the load The generation of the rotational force of the pile main body with respect to the above can be prevented.
[0040]
In addition, the formation of the sediment-raised protrusions on the upper part of the bottom plate makes it possible to effectively rake in the sediment near the upper part, so that a decrease in density can be prevented and a stable bearing force can be obtained. Therefore, during construction, it is very stable and has high reliability, and since it is easily pulled out, it is suitable for reuse, and its practical utility value in industry is extremely high.
[Brief description of the drawings]
FIG. 1 is a partial perspective view showing a foundation steel pipe pile according to an embodiment of the present invention.
FIG. 2 is a partial side view showing a foundation steel pipe pile according to the embodiment of the present invention.
FIG. 3 is a top view illustrating a foundation steel pipe pile according to the embodiment of the present invention.
FIG. 4 is a partial side view illustrating a modification of the foundation steel pipe pile according to the embodiment of the present invention.
FIG. 5 is a partial perspective view illustrating a modification of the foundation steel pipe pile according to the embodiment of the present invention.
FIG. 6 is a partial perspective view illustrating a modified example of the base steel pipe pile according to the embodiment of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 pile main body 11 tip excavating blade 2 expanded bottom plate 21 horizontal plate portion 22 excavating blade 22a additional blade 23 sediment raking projection 24 reinforcing rib 25 holding plate

Claims (10)

A steel pipe pile that penetrates into the ground as the foundation of a construction structure,
On the outer periphery of the pile body 1, a flange-shaped expanded bottom plate 2 at least partially cut is provided.
The expanded bottom plate 2 includes a horizontal plate portion 21 that is horizontal with respect to the vertically piled pile body 1, and the horizontal plate portion 21 occupies at least half or more of the entire area of the expanded bottom plate 2. While ensuring the supporting force in the direction and preventing the generation of the rotational force of the pile main body 1 with respect to the load.
One of the edges of the cut portion of the expanded bottom plate 2 is bent upward and the other is bent downward to form a digging blade 22, and a plurality of sediment scraping protrusions 23 are formed on the upper surface of the horizontal plate portion 21. Arranged obliquely with respect to the direction of rotation of the bottom plate 2, the sediment scraping projections 23 cause the earth and sand near the upper surface of the bottom plate 2 to move inside the bottom plate 2 when the penetrating pile body 1 rotates. A foundation steel pipe pile characterized by being able to increase the frictional resistance of the peripheral surface of the pile main body 1 and the support capacity of the expanded bottom plate by preventing the lowering of the sediment density at the excavation site. The foundation steel pipe pile according to claim 1, wherein a tip excavation blade (11) is provided at a tip head of the pile body (1). The foundation steel pipe pile according to claim 1 or 2, wherein an additional blade (22a) is detachably attached to a tip end of the excavating blade (22) of the expanded bottom plate (2) according to ground hardness. The foundation steel pipe pile according to any one of claims 1 to 3, wherein a reinforcing rib 24 is fixed to a lower surface of the excavating blade 22 of the expanded bottom plate 2. The foundation steel pipe pile according to claim 4, wherein the reinforcing ribs (24) of the expanded bottom plate (2) project outward from the outer periphery. The foundation steel pipe pile according to any one of claims 1 to 5, wherein a holding plate (25) protrudes from an outer lower surface of the horizontal plate portion (21) of the expanded bottom plate (2). The foundation steel pipe pile according to any one of claims 1 to 6, wherein the expanded bottom plate 2 is formed by being wound around the periphery of the pile body 1 a plurality of times. A method of stably supporting a steel pipe pile as a foundation of a construction structure,
A steel pipe pile is formed by arranging a bottom plate 2 around the periphery of the pile body 1, while the bottom plate 2 is in the form of a flange with at least a part cut, and is horizontal with respect to the vertically piled pile body 1. A horizontal plate portion 21 occupying at least half or more of the entire area of the plate 2 is provided, and one of the edges of the cut portion is bent upward and the other is bent downward to form a digging blade 22; On the upper surface of the horizontal plate portion 21, a plurality of sediment scraping protrusions 23 are disposed obliquely with respect to the rotation direction of the bottom plate 2.
The steel pipe pile is erected, and the pile body 1 is rotated, so that the pile body 1 penetrates while excavating the ground soil with the excavating blade 22 formed on the bottom plate 2.
The pile body 1 is rotated forward, and the sediment near the upper surface of the expanded bottom plate 2 is scraped toward the pile body 1 by the sediment scraping projections 23, thereby preventing a decrease in sediment density at an excavated portion, and 1 to increase the frictional resistance with the earth and sand on the peripheral surface,
A stable supporting method for a steel pipe pile, characterized in that the horizontal plate portion 21 can secure a vertical supporting force of the steel pipe pile and prevent the generation of a rotational force of the pile main body 1 with respect to a load. The excavated earth and sand and the hydraulic hardener are mixed while the hydraulic hardener mainly composed of lightly burned magnesia is injected into the ground soil excavated by rotating the pile main body 1, and the pile main body 1 is penetrated. snow,
Next, the mixed earth and sand and the hydraulic hardener are raked in the direction of the pile body 1 by the earth and sand raking projections 23 formed on the upper surface of the expanded bottom plate 2,
After that, by hardening the hydraulic hardening agent, it is possible to prevent the density from being reduced in the excavation hole and to increase the frictional resistance on the peripheral surface of the pile main body 1 to provide a stable supporting force. A method for stably supporting a steel pipe pile according to claim 8. 10. The method for stably supporting a foundation steel pipe pile according to claim 9, wherein the hydraulic hardening agent is introduced while the soil at the excavation site is released by repeatedly and alternately rotating the pile body 1 alternately.

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