JP6689064B2 - Steel pipe pile - Google Patents

Description

  The present invention relates to a steel pipe pile used for civil engineering work and construction work.

  As a method for improving soft ground to strong ground, a method of pouring cement milk into an excavated bare hole to stand up a tubular steel pipe pile, adding solidifying material to the ground and stirring to increase the solidification strength of the ground A method of making the steel pipe piles stand up has been developed. Further, as a method of constructing a building on soft ground, a method is known in which a steel pipe pile is erected as it is in the ground and the steel pipe pile erected is used as a foundation pile of a building. Then, as a steel pipe pile used for these construction methods, a steel pipe pile having a tip supporting force increased by spirally fixing a band-shaped excavating blade of a constant width at the tip of a cylindrical pipe body has been developed ( Patent Document 1).

JP, 2003-27472, A

  However, the conventional steel pipe pile as in Patent Document 1 has to be welded after the long strip-shaped excavating blades are curved in a spiral shape so as to match the shape of the outer periphery of the pipe body, and therefore, it is troublesome to manufacture. It costs. In addition, when a hard ground is encountered during excavation, the spiral excavation blade may lose the force of pushing the steel pipe pile and bend. Further, there is also a problem that a sufficient tip supporting force cannot be expressed unless the spiral excavation blade is elongated to increase the bottom area.

  The object of the present invention is to solve the problems of the above-mentioned conventional steel pipe piles, can be manufactured inexpensively and easily, and even when a hard ground is encountered when setting it up in the ground, it becomes impossible to penetrate or excavation blades. The purpose of the present invention is to provide a steel pipe pile capable of exhibiting a high tip supporting force in addition to preventing the occurrence of bending.

Among the present invention, the invention described in claim 1 is a steel pipe pile used as a member for supporting a building in a state of being rotationally penetrated into the ground, and at the tip of a cylindrical pipe body. , Three fan-shaped excavating blades inclined in a predetermined direction are fixed at equal intervals so as to project outward from the outer periphery of the pipe body, and a plurality of excavating blades are provided along the tip edge of each of the excavating blades. A blade is provided, and a cylindrical reinforcing pipe having a smaller diameter than the pipe body is arranged inside the pipe body concentrically with the pipe body, and the base end of the excavation blade attached to the pipe body. Is fixed to the outer periphery of the reinforcing pipe, and the cutting tool is fixed to the lower end of the pipe body and the lower end of the reinforcing pipe .

  According to the invention described in claim 2, in the invention described in claim 1, the pipe body has a first steel pipe having a plurality of inclined sides at a lower end edge, and an upper end edge having the same diameter as the first steel pipe. A second steel pipe provided with a plurality of inclined sides that match the plurality of inclined sides provided on the first steel pipe, and the excavation blade joins the upper surface near the base end to the inclined side of the first steel pipe. In addition, the lower surface near the base end is fixed to the pipe body while being joined to the inclined side of the second steel pipe.

  According to the invention described in claim 3, in the invention described in claim 1, a cylindrical reinforcing pipe having a diameter smaller than that of the pipe body is arranged inside the pipe body concentrically with the pipe body, The base end of the excavation blade attached to the pipe body is fixed to the outer periphery of the reinforcing pipe.

  The steel pipe pile according to claim 1 can be easily manufactured because it is not necessary to bend the excavation blade so as to match the shape of the outer periphery of the pipe body when fixing the excavation blade to the pipe body. it can. Further, an extremely high excavation force can be expressed by the plurality of independent excavation blades. Furthermore, when a plurality of excavation blades are fixed at the same height on the outer circumference of the pipe body, the tip supporting force when set up on the ground will be extremely high, and high yield strength will be exhibited against the top load. It is possible (that is, the force is evenly applied to the stress from above).

  In the steel pipe pile according to claim 2, the steel pipe is cut into a saw-tooth shape, one of the steel pipes is used as the first steel pipe, and the other is used as the second steel pipe. It can be easily manufactured.

Further, in the steel pipe pile according to claim 1 , since the plurality of excavation blades are integrally fixed inside the pipe body via the reinforcing pipe, the impact resistance strength is extremely high, and the excavation blade is in the middle of excavation. The excavation wing does not bend even if it touches hard ground.

It is a front view of a steel pipe pile. It is a right view of a steel pipe pile. It is a bottom view of a steel pipe pile. It is explanatory drawing which shows a pipe main body (a is a front view of a 1st steel pipe and a 2nd steel pipe, b is a bottom view, c is a perspective view of the bite fixed to the 2nd steel pipe). It is explanatory drawing which shows an excavation blade (a is a top view, b is a front view, c is a perspective view of an excavation blade). It is explanatory drawing which shows a reinforcement pipe (a is a bottom view, b is a front view, c is a perspective view of a bite).

[Structure of steel pipe pile]
Hereinafter, the steel pipe pile according to the present invention will be described in detail with reference to the drawings. 1 to 3 show a steel pipe pile according to the present invention, in which a steel pipe pile 1 is a pipe body 2 made of steel, and three excavation blades 3, 3 ... , And a reinforcing tube 4 which is also made of steel.

  FIG. 4 shows the pipe body 2. The pipe body 2 is a short steel pipe having an outer diameter of about 165.2 mm, a thickness of 6.0 mm, and a length (height) of 500 mm, and is further serrated with a laser or the like. It has a first steel pipe 2a and a second steel pipe 2b which are formed by cutting into a shape and dividing into two. At the upper end of the first steel pipe 2a, three inclined sides 5, 5 ... Inclining to the left by about 15 ° are formed, and are adjacent to the upper ends of the respective inclined sides 5, 5 ,. Three vertical sides 9, 9 ... Are formed so as to connect the lower ends of the inclined sides 5, 5 ,. The length of these vertical sides 9, 9 ... (The height from the upper end of one inclined side 5 to the lower end of the adjacent inclined side 5) is 38.22 mm. The cut surfaces (surfaces formed in the thickness direction) forming the inclined sides 5, 5 ... And the vertical sides 9, 9. , Which is orthogonal to the tangents of the front and back surfaces of the tube body 2). Furthermore, a groove is formed on the outer edge of the cut surface to facilitate welding of the excavation blade 3.

  Further, at the upper end of the second steel pipe 2b, three inclined sides 6, 6 ... Inclining to the left by about 15 ° are formed, and are adjacent to the upper ends of the respective inclined sides 6, 6 ,. Three vertical sides 10, 10 ... Are formed so as to connect the upper ends of the inclined sides 6, 6. The length of the vertical sides 6, 6 ... (The height from the upper end of one inclined side 6 to the lower end of the adjacent inclined side 6) is 38.22 mm. The cut surfaces (the surfaces formed in the thickness direction) forming the slanted sides 6, 6 ... And the vertical sides 10, 10 ... are orthogonal to the front and back surfaces of the tube body 2. . Furthermore, a groove is formed on the outer edge of the cut surface to facilitate welding of the excavation blade 3.

  Further, at the lower end of the second steel pipe 2b, six rectangular notches 12, 12 ... Having a size of width × height = 6.0 mm × 6.0 mm are carved at equal intervals. There is. Then, the six cutting tools 11, 11, ... Are fixed at equal intervals by utilizing the notches 12, 12 ,. Each of the cutting tools 11, 11, ... Is made of a cemented carbide (a mixture of tungsten carbide (tungsten carbide) and cobalt that is a binder (sintered) and is sintered) in the shape of a vertically long rectangular parallelepiped. Width × depth × height = 6.0 mm × 6.0 mm × 20.0 mm. .. are fixed (welded) with the upper parts (approximately half) fitted in the notches 12, 12, ... At the lower end of the second steel pipe 2b. Then, three of the six cutting tools 11, 11, ... Are arranged immediately below the vertical side 10 (a state in which an extension line of the vertical side 10 is located at the center of the cutting tool 11 in the width direction). It has become.

  Further, FIG. 5 shows the excavation blade 3, and each of the excavation blades 3, 3, ... Has a hole having a radius of 54.5 mm formed in the center of a circular plate-like body having a thickness of 19 mm and a radius of 247.8 mm. The donut disc-shaped body is divided into three equal parts so that the central angle is 120 ° to form a substantially fan shape. Three notches 13a, 13b, 13c having a size of width × depth = 19.0 mm × 19.0 mm are engraved on the outer sides of the straight edges of the respective excavation blades 3, 3 ... ing. The inner cutout 13a is provided at a position approximately 86 mm from the inside of the linear end edge, and the other two cutouts 13b and 13c are the linear end outside the inner cutout 13a. They are evenly spaced so as to divide the edge into three equal parts.

  The three excavating blades 14, 14, ... Are fixed (welded) at equal intervals by utilizing the notches 13a, 13b, 13c. Each of the excavating blades 14, 14 ... Is formed of cemented carbide (the same material as the cutting tool 11) and has a shape in which a triangular prism-shaped tip portion 14b is continuously provided on the tip side of a rectangular parallelepiped base end portion 14a. (See FIG. 5 (c)). .. are fixed (welded) in the notches 13a, 13b, 13c with the base end portion 14a fitted therein.

  On the other hand, FIG. 6 shows the reinforcing pipe 4, which is a steel pipe having an outer diameter of about 101.6 mm, a thickness of 4.5 mm, and a length (height) of 80 mm, and has a width at the lower end. × Height = 6.0 mm × 6.0 mm, and four rectangular notches 15, 15 ... Are engraved at equal intervals. Using the notches 15, 15, ..., The four cutting tools 16, 16, .. The cutting tools 16, 16 ... Are made of cemented carbide (the same material as the cutting tool 11 and the drilling blade 14), and a triangular prism-shaped tip portion 16b is continuously provided on the tip side of a rectangular parallelepiped base end portion 16a. It has a curved shape (see FIG. 6C). .. are fixed (welded) in a state in which the base end portion 16a is fitted into each of the notches 15, 15 ...

[Assembling steel pipe piles]
When assembling the steel pipe pile 1, the excavation blades 3, 3, ... Are fixed (welded) to the inclined sides 5, 5, .. That is, the upper surface near the base end of each excavation blade 3, 3 ... (A portion approximately 34.1 mm outside from the inner edge) is provided with the outer edge of each inclined side 5, 5 ,. When joining. After that, the lower surface of each of the excavation blades 3, 3, ... Near the base end (a portion outside the inner edge by about 34.1 mm) is attached to the outer end of each inclined side 6, 6 ,. The three blades 3, 3 ... Are fixed to the pipe body 2 by joining them at the edges.

  Then, the reinforcing pipe 4 is fixed to the base ends (base ends arranged in a circular shape) of the three excavating blades 3, 3, ... Fixed to the pipe body 2 in this way. That is, the assembling of the steel pipe pile is completed by welding the base ends of the three excavating blades 3, 3, ... On the outer surface of the reinforcing pipe 4. Then, the base ends (base ends arranged in a circle) of the three excavating blades 3, 3, ... Fixed to the pipe body 2 are respectively welded to the outer surface of the reinforcing pipe 4, By assembling the pipe body 2, the three excavating blades 3, 3, ... And the reinforcing pipe 4, the assembly of the steel pipe pile 1 is completed.

  In the assembled steel pipe pile 1, as shown in FIGS. 1 to 3, a cylindrical reinforcing pipe 4 having a diameter smaller than that of the pipe body 2 is arranged inside the pipe body 2 concentrically with the pipe body 2. Further, the base ends of the three excavating blades 3, 3 ... Fixed to the pipe body 2 are fixed to the outer periphery of the reinforcing pipe 4.

[How to use steel pipe piles]
The steel pipe pile 1 configured as described above can be connected to a long steel pipe (having substantially the same diameter as the pipe main body 2) and can be suitably used for the uplifting work of the foundation pile during the construction work. . When the steel pipe pile 1 is to be erected on the ground in those works, the steel pipe pile 1 is pushed to the ground, and is pressed into the ground while rotating to the right (toward the right when viewed from above) while applying pressure. Penetrate). When the steel pipe pile 1 is pushed into the ground in this way, the three excavation blades 3, 3, ..., which are fixed to the outer periphery of the pipe body 2 at equal intervals, efficiently remove the earth and sand as the steel pipe pile 1 rotates. It is bitten and produces a thrust that advances the steel pipe pile 1 into the soil. After the steel pipe piles 1, 1 ... Are deeply laid in the soil in this way, it becomes possible to construct a building on the steel pipe piles 1, 1 .. Further, after being set up, the three excavation blades 3, 3 ... Fixed to the outer circumference of the pipe body 2 at equal intervals develop a very high tip support force.

[Effect of steel pile]
As described above, the steel pipe pile 1 has a plurality of fan-shaped excavating blades 3, 3 ... Inclining in a predetermined direction protruding outward from the outer periphery of the pipe body 2 at the tip of the cylindrical pipe body 2. Are fixed at equal intervals and a plurality of cutting blades 14, 14, ... Are provided along the tip edges of the cutting blades 3, 3 ,. It is not necessary to bend the excavation blades 3, 3, ... To match the shape of the outer periphery of the pipe body 2 when fixing the pipe body 2 to the pipe body 2, so that it can be easily manufactured. Further, an extremely high excavation force can be expressed by the plurality of independent excavation blades 3, 3. Further, when a plurality of excavation blades 3, 3, ... Are fixed to the outer circumference of the pipe body 2 at the same height position, the tip supporting force when standing up on the ground becomes very high, and it is against the load to be placed. And high yield strength can be expressed.

  Further, in the steel pipe pile 1, the pipe body 2 has a first steel pipe 2a having a plurality of inclined sides 5, 5 ... At the lower end edge, and a first steel pipe 2a having the same diameter as the first steel pipe 2a at the upper end edge. .. and a second steel pipe 2b provided with a plurality of inclined sides 6, 6 ... Conforming with the plurality of inclined sides 5, 5 .. In the state where the upper surface at the end is joined to the inclined sides 5, 5 ... of the first steel pipe 2a and the lower surface at the base end is joined to the inclined sides 6, 6 ... of the second steel pipe 2b. It is fixed to. Therefore, in the steel pipe pile 1, the steel pipe is cut into a sawtooth shape, one of which is used as the first steel pipe 2a and the other of which is used as the second steel pipe 2b, and the sawtooth-shaped inclined sides (inclined sides 5, 5 ... (6, 6 ...) Only by adhering the excavation blades 3, 3 ,.

  Further, in the steel pipe pile 1, a cylindrical reinforcing pipe 4 having a diameter smaller than that of the pipe body 2 is arranged inside the pipe body 2 concentrically with the pipe body 2, and an excavation blade attached to the pipe body 2 Since the base ends of the pipes 3, 3, ... Are fixed to the outer periphery of the reinforcing pipe 4, a plurality of excavation blades 3, 3, ... Are integrally fixed inside the pipe body 2 via the reinforcing pipe 4. As a result, the bending strength of each of the excavation blades 3, 3, ... Is extremely high. If the excavation blades 3, 3, .. It is possible to prevent such a situation.

[Example of changing steel pipe pile]
The structure of the steel pipe pile according to the present invention is not limited to the aspect of the above-described embodiment, and the structure of the pipe main body, the excavation blade, the excavation blade, the reinforcing pipe, and the like, the shape, the structure, etc. Modifications can be made as necessary without departing from the spirit of the invention.

  For example, the steel pipe pile is not limited to one in which three excavation blades are fixed to the outer periphery of the pipe body as in the above-described embodiment, and two or four or more excavation blades are fixed to the outer periphery of the pipe body. It is also possible to change to a different one.

  Further, the excavation blade is not limited to the one provided with three excavating blades as in the above-mentioned embodiment, and can be changed to one provided with two or less or four or more excavating blades. In addition, the shape of the excavating blade is not limited to the shape in which the tip end of the triangular prism shape is continuously provided on the tip side of the base end portion of the rectangular parallelepiped shape as in the above-described embodiment, and the tip is pointed in a triangular pyramid shape or a conical shape. It is also possible to change to a curved shape or the like.

  Further, the steel pipe pile is not limited to the one in which the base end of the excavation blade is sandwiched and fixed by the pair of steel pipes formed by cutting the steel pipe in a saw-tooth shape as in the above-described embodiment, and has a flat outer periphery. It is also possible to form rectangular penetration holes in a slanted shape at equal intervals and to change them into those in which the base ends of the excavation blades are fixedly inserted in these penetration holes.

  Further, the steel pipe pile is not limited to the one used by being fixedly attached to the long steel pipe (extension pipe) as in the above-described embodiment, and may be a long pipe itself.

  Further, the pipe body is not limited to the one in which the six rectangular parallelepiped cutting tools are provided at the tip as in the above-described embodiment, and the one in which five or less or seven or more cutting tools are provided at the tip, or the tip is sharpened. It is also possible to change to a tool provided with a cutting tool having a shape other than a rectangular parallelepiped such as a cutting tool, or one having no cutting tool.

  Further, the reinforcing pipe is not limited to one in which four cutting tools having a shape in which a triangular prism-shaped tip portion is continuously provided on the tip side of a rectangular parallelepiped base end portion are provided at the tip as in the above-described embodiment. It is also possible to change to a tool provided with at least 5 or more cutting tools at its tip, a tool provided with a tool having a rectangular parallelepiped shape at the tip, or a tool without a tool.

  Since the steel pipe pile according to the present invention has excellent effects as described above, it can be suitably used for upsetting of foundation piles during construction work, improvement work of soft ground, and the like.

1 ... Steel pipe pile 2 ... Pipe body 2a ... 1st steel pipe 2b ... 2nd steel pipe 3 ... Excavation blade 4 ... Reinforcement pipe 5 ... Inclined side 6 ... Inclined side 14 ... Excavation blade

Claims (2)

A steel pipe pile used as a member for supporting a building in a state of being rotationally penetrated into the ground,
At the end of the cylindrical pipe body, three fan-shaped excavating blades inclined in a predetermined direction are fixed at equal intervals so as to project outward from the outer periphery of the pipe body,
A plurality of drilling blades are provided along the tip edge of each of those drilling blades , and
Inside the pipe body, a cylindrical reinforcing pipe having a smaller diameter than the pipe body is arranged concentrically with the pipe body,
The base end of the excavation blade attached to the pipe body is fixed to the outer periphery of the reinforcing pipe, and
A steel pipe pile, characterized in that a bite is fixed to the lower end of the pipe body and the lower end of the reinforcing pipe . The pipe body has a first steel pipe having a plurality of inclined sides at its lower end, and a plurality of inclined sides having the same diameter as the first steel pipe and having a plurality of inclined sides provided at the upper end to match the plurality of inclined sides provided at the first steel pipe. And a second steel pipe
The excavation blade is fixed to the pipe body with the upper surface near the base end joined to the inclined side of the first steel pipe and the lower surface near the base end joined to the inclined side of the second steel pipe. The steel pipe pile according to claim 1.

Images