JP2000129677A - Steel-pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel-pipe pile, which can be applied to the driving construction methods of all prefabricated piles and is transported and stored easily and by which press-in force to a hard ground can be decreased, initial settlement is lowered and stable soil bearing capacity is obtained while a consolidation effect in the periphery of the front end of a steel pipe is acquired readily. SOLUTION: Two or more of wing pieces 20, 25 rotatably supported respectively centering around two or more of shaft sections parallel with the center line of a steel-pipe pile body 10 are installed at one end of the steel-pipe pile body 10, each wing piece 20, 25 constitutes the arcuate sections of a single circle when parts of the wing pieces 20, 25 are overlapped and laminated while the diameter of the single circle is set at a value-approximately equal to the outside diameter of the steel-pipe 1 and plate edges 22, 27 having required length are projected from the partial chord sections of each wing piece 20, 25. Accordingly, the steel-pipe pile 1 can be pressed into a ground by press-in force smaller than conventional devices while ensuring a consolidation effect in the periphery of the front end of a steel pipe by single pressing-in or rotary pressing-in.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe pile used to reinforce a ground portion as part of a foundation work of civil engineering and construction work, and relates to all kinds of methods such as a hitting method, a rotary press-fitting method, a pushing method, and an embedding method. The present invention relates to a steel pipe pile which can be applied to a construction method, in particular, has a high consolidation effect around a built-in portion of a steel pipe, and can reduce initial settlement and improve a bearing capacity in soil.

[0002]

2. Description of the Related Art As a basic construction method in civil engineering construction work,
Various techniques are used for reinforcing and modifying soft ground. One of the typical technologies is the construction of piles. The method of constructing piles is to use prefabricated piles such as concrete piles and steel piles that have been produced in advance at the factory and to cast them on site. For example, drilling the ground with a rotating bucket while holding the hole wall with a surface casing and a stabilizing liquid, and installing a reinforcing steel cage in this drilling There is an earth drill method that is built in the ground, or a sand compaction pile method in which sand is dropped and pushed into the ground by a casing to form a sand pile in the ground to promote the compaction of the ground.

[0003] Of these construction methods, a large-scale facility is not required for construction around a city and noise can be avoided, and therefore, a construction method using an existing pile is often used. In particular, steel pipe piles, which have a high degree of freedom in design, provide a large horizontal resistance, are easy to cast and can be used for long construction, and are stable in price, have been increasingly used.

[0004] The casting method using the steel pipe pile includes, for example, a hammering method in which the steel pipe pile is hammered and driven into the ground, a rotary press-fitting method in which the steel pipe pile is rotationally pressed into the ground, and a static pressure applied to the steel pipe pile. Various driving methods have been adopted depending on the surrounding conditions at the time of driving, such as the press-in method of pressing into the ground, the pre-boring method of embedding steel pipe piles in the ground after excavating to a depth equal to the total length of the pile in advance with an auger, etc. I have. Further, for example, according to Japanese Patent Application Laid-Open No. 9-296446, a rotary press-fitting device for steel pipe piles and a hydraulic auger excavating mechanism for screwing an auger are arranged side by side with a leader, and the auger is first ground to a predetermined depth. A rotary press-fitting method has been proposed in which the steel pipe pile is rotary-pressed while taking a reaction force by an auger by operating the rotary press-fitting device.

On the other hand, various improvements have also been made to steel pipe piles used in these casting methods, for example, a screw steel pipe pile having a screw blade at a tip portion has been developed. There is known a method of rotationally press-fitting the steel pipe pile by press-fitting.

[0006] However, the screw steel pipe pile has a high manufacturing cost, is cumbersome to transport and store, and the stratum near the tip of the steel pipe is roughened at the time of intrusion. There is a problem that it is difficult to hold, and furthermore, the periphery of the pile is liable to sink, and an error is likely to occur in accuracy.

A steel pipe pile newly proposed to solve such a problem is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-291528. The steel pipe pile according to this proposal is closed with a circular bottom lid inside a fixed depth from the tip surface of the hollow cylindrical steel pipe, and has a width equal to the inner diameter of the steel pipe at the center of the bottom lid, The steel pipe has a configuration in which a plate blade protruding from the distal end surface by a predetermined length is fixed. According to this steel pipe pile, initial settlement does not easily occur, the bearing capacity in the soil is stable, and it can easily penetrate into hard ground.
Storage and on-site processing are easy, and furthermore, not only the formation near the tip of the steel pipe is not damaged, but also it is easy to maintain the uprightness, and it has the effect of easily obtaining the consolidation effect and accuracy.

[0008]

Problems to be Solved by the Invention
The steel pipe pile disclosed in Japanese Patent No. 528 has a consolidation effect on the ground around the steel pipe due to the presence of the bottom lid, as compared with a conventional steel pipe pile formed of a simple hollow cylinder or a steel pipe pile provided with a screw at the tip. It can be expected that the effect of suppressing some initial settlement can be expected, and the presence of the plate blade facilitates rotational press-fitting, and furthermore, it can be said that transport, storage, and on-site processing has become easier as compared with the screw steel pipe pile. .

However, the plate blade is a single blade, and the digging blade has a large digging load, a heavy load on the rotary press-fitting device, and has to increase the size of the hydraulic motor and the like. Even at the end, the bearing capacity from below the steel pipe pile is only the outer diameter of the steel pipe pile at most, and the soil bearing capacity is likely to be insufficient, and a sufficient prevention effect of initial settlement cannot be expected. In addition, according to this steel pipe pile with a plate blade, the bottom lid and the plate blade are fixed by welding to the inner wall surface of the cylinder, so there is concern about the fixing strength, and if you try to secure this Naturally, the mounting work is complicated.

The present invention has been made to solve such a conventional problem, and the object thereof is to solve the problem described in the above-mentioned JP-A-9-291.
An object of the present invention is to provide a steel pipe pile that exceeds the operational effects of the steel pipe pile disclosed in Japanese Patent Application Publication No. 528, and specifically, the manufacture of the steel pipe pile is easy without requiring special skills, and the structure is very early. Settlement can be reliably prevented, so the bearing capacity in the soil is more stable, and a large load is not required for rotary excavation on hard ground, it is easy to transport and store, and the stratum near the tip of the steel pipe is roughened. It is an object of the present invention to provide a steel pipe pile structure in which uprightness, consolidation effect, accuracy and the like are ensured.

[0011]

This object is effectively achieved by the inventions according to claims 1 to 5 of the present invention as described below. The structure of the invention according to claim 1 is a hollow steel pipe pile, and is supported at one end of a main body of the steel pipe pile so as to be rotatable around two or more shaft portions parallel to the center line thereof. Each of the wing pieces has an arc portion of a single circle when a part of each wing piece is overlapped and laminated, and the diameter of the single circle is a steel pipe pile. The steel pipe pile is characterized in that a plate blade having a required length is protruded from a part of a chord portion of each wing piece and is set to be approximately equal to the outer diameter of the wing piece.

When the bottom of the steel pipe pile having such a configuration is closed by each wing piece, that is, when the steel pipe pile is pressed into the ground with rotation or non-rotation while partially overlapping and forming a single circle, the wing piece is obtained. Prevents the intrusion of earth and sand into the steel pipe pile, and when the steel pipe pile is press-fitted, the soil around the steel pipe pile is firmly tightened by the consolidation effect, so that the press-fit is realized while ensuring an efficient and sufficient supporting force. Further, at the time of this press-fitting, the plate blade attached to the wing piece crushes the surrounding soil and rock before the steel pipe is press-fitted, so that the press-fitting can be performed efficiently.

In particular, when positively press-fitting the steel pipe pile, if the rotation is rotated in the direction in which the blade pieces close, each plate blade functions as a rotary excavating blade, so that the steel pipe pile is more press-fitted. It can be done effectively. Again, in this case,
There is no need to perform residual soil treatment because there is no discharge of sediment.

Further, in the steel pipe pile of the present invention, when each wing is opened in the direction of opening at the time of completion of the press-fitting, that is, in the direction opposite to the above-mentioned rotary press-fitting, the vertical support of the steel pipe pile with respect to the soil is achieved. The area is approximately doubled, the supporting capacity is doubled, the posture of the steel pipe pile in the ground is stabilized, and the initial settlement can be sufficiently prevented.

In addition, when the bottom opening of the steel pipe pile is closed by the wing pieces during transportation or storage, that is, when the bottom part is partially overlapped and formed into a single circle, the wing pieces do not protrude from the steel pipe pile. Therefore, the handling is easy.

The invention according to claim 2 defines one arrangement of the wing piece and the plate blade, wherein the center of rotation of each wing piece is near the circular arc portion, and the plate blade is provided with each wing piece. When the single circle is formed by the rotation of, the projections are provided at chord positions that do not interfere with each other. When the blades and the plate blades are disposed in this manner, the plate blades are independent even by the rotation of the blades, and effectively function as a plurality of crushing blades or rotating blades.

According to a third aspect of the present invention, one end of the steel pipe pile has a pivot portion for pivotally supporting a support shaft of the wing piece.
Preferably, the pivot portion is fixed to the end face of the steel pipe pile main body as defined in claim 4 and is a disk having a diameter substantially equal to the outer diameter of the steel pipe pile. It is easy to secure the strength of the bottom of the slab. Of course, it is also possible to adopt, for example, a support rod radially installed at the open end of the steel pipe pile as the pivot, or a bracket projecting from the open end toward the center. .

According to a fifth aspect of the present invention, the wing piece has stopper means for defining a rotation limit of the wing piece. A pin member that serves as a stopper and contacts the outer or inner peripheral surface of the steel pipe pile at the position where the expansion is maximized even when each wing piece rotates in the expanding direction, and regulates the rotation. It is preferable to attach a stopper means consisting of By providing such stopper means, unnecessary excessive rotation of the wing pieces can be restricted, and the wing pieces can be expanded or closed to a desired position without monitoring the rotation angle of the steel pipe pile. .

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings. 1 to 5
1 shows a first embodiment of the present invention, FIG. 1 is a structural view of a steel pipe pile main body of the present invention, and FIG. 2 is a structural description of a first wing piece rotatably attached to the steel pipe pile main body. FIG. 3 is a diagram illustrating the structure of the second blade piece, FIG. 4 is a diagram illustrating the structure of the steel pipe pile according to the present embodiment when the blade pieces are stored, and FIG. 5 is a diagram illustrating the structure of the steel pipe pile when the blade pieces are expanded. FIG.

In FIG. 1, a steel pipe pile body 10 comprises a hollow cylindrical body 11 and a disk-shaped pivot body 12 made of the same material as the steel pipe pile body 10 fixedly closed at one end opening surface thereof. The outer diameter of the disc-shaped pivot body 12 is set to be substantially equal to the outer diameter of the hollow cylindrical body 11, and a simple pin hole 13 is formed on one side near the peripheral surface of the hollow cylindrical body on the same diameter line, A boss hole 1 having a boss 14 fixed thereto is located at the other point symmetric position.
4a are formed.

FIGS. 2 and 3 show a first wing piece 20 rotatably supported via a pin member 21 in a pin hole 13 of the disc-shaped pivot body 12, and the disc-shaped pivot body. 12 boss holes 15
And a pin member 26 which is rotatably supported.
As can be understood from FIGS. 4 and 5, each of the wing pieces 20 and 25 has an outer diameter of the hollow cylindrical body 11 (disc-shaped pivot support 12) of the steel pipe pile body 10 when a part thereof is overlapped. ) Has a form such that a single circle substantially equal to the outer diameter of the circle is formed.

In the illustrated example, each of the wing pieces 20, 25 has the same shape, and has a first arc portion 20a,
25a, and has a radius of 半径 centered on a 点 point on a radial line perpendicular to the diameter line passing through one end of the arc portions 20a, 25a, and has one end at one end of the arc portion 20a, 25a.
Second arc portions 20b, 25b connected to one end of 25a
And the other ends of the second circular arc portions 20b, 25b and the other ends of the circular arc portions 20a, 25a are connected by straight lines 20c, 25c via a required radius.

The wing piece shape of the present invention is not limited to the illustrated example, and various shapes can be adopted as long as the wing piece forms a single circle when partially overlapped. In addition, the number of wing pieces is not limited to two, and it is also possible to configure three or more pieces. In this case, when a part of each wing piece is overlapped, a single circle is formed. It is necessary to be.

The first wing piece 20 and the second wing piece 25 are
Each has first and second pin members 21 and 26, and also has first and second plate blades 22 and 27. The first and second pin members 21 and 26 are attached to the wing pieces 20 and 2 respectively.
In the circular state formed when a part of 5 is overlapped,
In the vicinity of each end, they do not interfere with each other, and protrude vertically from the respective surfaces on the same side of the wing pieces 20, 25 near the outer circumference on the same diameter line. The first and second plate blades 22, 27
Has the same rectangular shape, one end of which is disposed in the vicinity of the first and second pin members 21 and 26 and extends in the chord direction, and the other ends have blade portions 27a and 28a. ing.

The form of the first wing piece 20 and the second wing piece 25 is also
First and second pin members 21, 26 and first and second pin members
The plate blades 22 and 27 are all point-symmetric with respect to the center point O of the arc portions 20a and 25a of the wing pieces 20 and 25, respectively.

On the other hand, the first pin member 21 is inserted into the pin hole 13 of the disc-shaped pivot 12 and the first wing piece 20
Is directly in contact with the disc-shaped pivoting body 12 and is pivoted, so that the distal end has a length necessary to fit the retaining ring 15 long enough to protrude from the disc-shaped pivoting body 12. , But the length of the second pin member 26 is
5 is rotated while being in contact with the surface of the first wing piece 20, so that it has a sufficient length to penetrate the boss hole 14a and to fit the stop ring 16 to its tip.

As shown in FIGS. 4 and 5, the first wing piece 20 and the second wing piece 25 having the above-described configuration are arranged so that the center points O of the arc portions 20a and 25a coincide with each other.
The respective pin members 21 and 26 and the respective plate blades 22 and 27 are arranged so as to be symmetrical with respect to the center point O, and the respective pin members 21 and 26 are disposed in the corresponding pin holes 1 of the disc-shaped pivot 12.
3 and the boss hole 14a, and are rotatably fixed and attached by retaining rings 15 and 16, respectively.

According to the steel pipe pile 1 according to the present embodiment assembled as described above, for example, a pre-boring method is used in which a conventional auger is used to excavate the steel pipe pile to a depth equal to the entire length of the pile in advance and the steel pipe pile is embedded in the excavation hole. First, an auger excavating mechanism (not shown) is operated to excavate an excavation hole having a depth substantially equal to that of the steel pipe pile 1 at a setting point of the steel pipe pile 1 by the auger. Next, the auger is pulled out, the steel pipe pile 1 is built in the excavation hole, and the press-fitting device is operated to penetrate the steel pipe pile 1 without rotating.

When the steel pipe pile 1 is inserted, the first and second wing pieces 20 and 25 are in the housed state shown in FIG. 4, and the disk-shaped pivot body 12 for closing the bottom of the steel pipe pile 1 is provided. Since the first and second wing pieces 20 and 25 are supported by the hollow cylindrical body 10, the strength at the time of introduction is ensured, and at the same time, the disk-shaped pivot body 12 and the first And the second wing piece 20,
25 not only provides a consolidation effect to the soil around the steel pipe piles, but also provides a stable bearing capacity in the soil.
The plate blades 22 and 27 projecting in the press-fitting direction from the holes allow smooth insertion.

Incidentally, using the steel pipe pile 1 according to the present embodiment,
For example, it is also possible to rotationally press-fit a steel pipe pile into the ground by taking a reaction force with an auger disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 9-296446. That is, a rotary press-fitting device for the steel pipe pile 1 and a hydraulic auger excavating mechanism (not shown) for screwing the auger are arranged side by side with a leader (not shown) interposed therebetween. First, the auger is screwed into the ground to a predetermined depth, Next, by operating the rotary press-fitting device, the steel pipe pile is rotary press-fitted while taking a reaction force by the auger.

However, at the time of this rotary press-fitting, the rotation direction of the steel pipe pile 1 is rotated in the direction in which the first and second blade pieces 20, 25 are closed, that is, in the direction of arrow B in FIG. When rotated in this manner, the base projecting end 2 of each of the pin members 21 and 26
1a, 26a is the second of the first and second wing pieces 20, 25;
The plate blades 22 and 27 are engaged with the round portions between the arc portions 20b and 25b and the linear portions 20c and 25c, and do not rotate any more. Further, the plate blades 22 and 27 function as rotary blades. , 27 is significantly reduced as compared with the case where there is no, for example, press-fitting into a steel ground or the like is facilitated.

After the steel pipe pile 1 of the present embodiment is driven into the ground in this way, the wing pieces 20, 25 can be expanded without pressing the steel pipe pile 1 on the spot (arrows in FIG. 4). A direction)
When the blades 20 and 25 are rotated by approximately 90 °,
While receiving the resistances 2 and 27, the pin members 21 and 26 are expanded as shown in FIG. Due to the widening, the substantial bottom support area of the steel pipe pile 1 is almost doubled, so that the vertical support force of the steel pipe pile 1 on the ground is almost doubled, and the initial settlement of the steel pipe pile 1 is significantly reduced. Can be.

FIGS. 6 to 10 show a second embodiment of the present invention. FIG. 6 is a structural view of a steel pipe pile body of the present invention.
7 is a structural explanatory view of a first wing piece rotatably attached to the steel pipe pile main body, FIG. 8 is a structural explanatory view of the second wing piece,
FIG. 9 is a structural explanatory view of the steel pipe pile according to the present embodiment when the wing pieces are stored, and FIG. 10 is a structural explanatory view of the steel pipe pile when the wing pieces are expanded.

As can be understood from these figures, the difference between the steel pipe pile 1 'of the present embodiment and the steel pipe pile 1 of the above embodiment is that the steel pipe pile 1' of the present embodiment has the first and second steel pipe piles. Wing piece 2
In the first embodiment, no special stopper is provided, whereas the stoppers 0 and 25 are provided with stoppers for defining the rotation limit. Therefore, in these figures, members that are substantially the same as those shown in FIGS. 1 to 5 are denoted by the same reference numerals.

That is, the member of the second embodiment having substantially the same structure as that of the first embodiment is a pin member 2
Steel pipe pile main body 10 other than 1 and 26 (hollow cylindrical body 11, disk-shaped pivot body 12, pin hole 11a, boss 14, boss hole 14)
a), the first and second wing pieces 20, 25, and the plate blade 22,
27. The stopper means according to the illustrated example utilizes the pin members 21 and 26 of the first embodiment.

That is, the pin member 2 according to the present embodiment
As shown in FIGS. 7 and 8, 1 'and 26' are bent in a crank shape. The first linear shaft portion 2
1'a and 26'a function as support shafts for rotatably supporting the wing pieces 20, 25 with respect to the steel pipe pile body 10 between the retaining rings 15 and 16, and a second linear shaft. 21 "a,
26 "a has a function as the stopper means. However, as the stopper means, for example, in FIGS. 9 and 10, the plate blades 22, 27 of the first and second wing pieces 20, 25 are used. A stopper pin may be protruded from each of the wing pieces 20 and 25 on the surface portion opposite to the side where the protruding portion is provided, and various types of stopper means in the present invention can be adopted.

In this embodiment as well, the function at the time of driving the steel pipe pile 1 'is not different from that of the first embodiment described above, but after the driving is completed, the steel pipe pile 1' is moved into the first and the second positions. Two wing pieces 20,
When the blades 25 are rotated in the expanding direction (the direction of arrow B in FIG. 9), the blade pieces 20 and 25 are connected to the second linear shaft portions 21 ″ a and 2 ″.
6 "a abuts against the inner wall surface of the cylindrical body 10, does not rotate more than shown in FIG. 10, can always be operated in the largest expansion mode, and has a stable supporting force of the steel pipe pile 1 '. Is obtained.

As is clear from the above description, according to the steel pipe pile structure of the present invention, it is needless to say that it can be applied to any existing pile driving method, but in particular, the pre-boring method and the steel pipe pile are applied to the ground. The method is suitable for a rotary press-fitting method of rotary press-fitting, and a rotary press-fitting method of rotary-press-fitting a steel pipe pile while taking a reaction force by an auger according to the above-mentioned Japanese Patent Application Laid-Open No. 9-296446. An operational effect exceeding the above-mentioned construction method can be expected, and in particular, a stable supporting force and a supporting posture at the end of the driving of the steel pipe pile, which could not be achieved conventionally, can be secured.

[Brief description of the drawings]

FIG. 1 is a structural explanatory view of a steel pipe pile main body showing a first embodiment of the present invention.

FIG. 2 is a structural explanatory view of one of a pair of wing pieces attached to the steel pipe pile main body.

FIG. 3 is another structural explanatory view of a pair of blade pieces attached to the steel pipe pile main body.

FIG. 4 is a structural explanatory view of a steel pipe pile in the present embodiment when the wing pieces are closed.

FIG. 5 is a structural explanatory view of a steel pipe pile when the wing pieces are in an expanded state.

FIG. 6 is a structural explanatory view of a steel pipe pile main body showing a second embodiment of the present invention.

FIG. 7 is a structural explanatory view of one of a pair of wing pieces attached to the steel pipe pile main body.

FIG. 8 is another structural explanatory view of a pair of blade pieces attached to the steel pipe pile main body.

FIG. 9 is a structural explanatory view of the steel pipe pile in the present embodiment when the wing pieces are closed.

FIG. 10 is a structural explanatory view of a steel pipe pile when the wing pieces are in an expanded state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1 'Steel pipe pile 10 Steel pipe pile main body 11 Hollow cylindrical body 12 Disc-shaped pivot body 13 Pin hole 14 Boss 14a Boss hole 15,16 Stop ring 17,18 Stopper means 20,25 First and second wing pieces 20a , 25a First arc portion 20b, 25b Second arc portion 20c, 25c Straight portion 21, 26 First and second pin members 21 ', 26' Pin members 21'a, 26'a First straight portion 21 "a , 26 ″ a second straight portion 22, 27 plate blade 22a, 27a blade portion 25 second wing piece 26 pin member

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hidenori Koizumi 2-3-6 Akasaka, Minato-ku, Tokyo F-term in Komatsu Manufacturing Co., Ltd. (reference) 2D041 AA02 BA21 BA32 BA33 CA01 CB06 DB02 FA02 FA14 2D050 AA06 CA01 CB01 CB23

Claims (5)

[Claims] 1. A hollow steel pipe pile having two or more blades supported at one end of a main body of the steel pipe pile so as to be rotatable around two or more shaft portions parallel to the center line thereof. Each wing piece constitutes a single circular arc portion when a part of each wing piece is overlapped and laminated, and the diameter of the single circle is substantially equal to the outer diameter of the steel pipe pile. A steel pipe pile, which is set to be equal, and has a plate blade having a required length protruding from a part of a chord of each wing piece. 2. The center of rotation of each wing piece is in the vicinity of the circular arc portion, and the plate blade projects at a chord position that does not interfere with each other when the single circle is formed by the rotation of each wing piece. The steel pipe pile according to claim 1, wherein 3. The steel pipe pile according to claim 1, wherein one end of the steel pipe pile has a pivot portion for pivotally supporting a support shaft of the wing piece. 4. The steel pipe pile according to claim 3, wherein the pivot portion is fixed to an end face of the steel pipe pile main body, and is formed of a disk having a diameter substantially equal to an outer diameter of the steel pipe pile. 5. The steel pipe pile according to claim 1, wherein said blade piece has stopper means for defining a rotation limit thereof.