JP2008308860A - Prefabricated pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct a high-quality foot protection section by efficiently and surely infilling a periphery-of-pile fixing fluid in the bottom section of a pile hole between an internal wall of the pile hole and an external wall of a prefabricated pile. <P>SOLUTION: A doughnut-shaped end plate 7 with an inside diameter C<SB>1</SB>, made of a steel plate, is fixed to an undersurface 2 of a concrete prefabricated pile base 1 with an outside diameter D<SB>1</SB>and an inside diameter D<SB>2</SB>(C<SB>1</SB><D<SB>2</SB>). The prefabricated pile 20 is constituted by protrusively providing three shoes 15 on the undersurface of the end plate 7 in such a rotationally-symmetrical manner as to be almost radial with respect to the axis O of the prefabricated pile base 1. A base end 16 of the shoe 15 is positioned on the side of the axis O with respect to an inner peripheral edge 6a of the end plate 7. In the prefabricated pile, X represents a point where the shoe 15 crosses the inner periphery 3 of the prefabricated pile 20; OX represents a line which connects the axis O and the point X together; and θ represents an angle which is formed between the line OX and "a line extended outward from the length-direction line of the shoe 15". The angle direction of the angle θ, which is directed toward "The line extended outward from the line OX connecting the axis O and the point X together" and "the line extended outward from the length-direction line of the shoe 15", is set as a direction opposite to the rotational direction 30 of the prefabricated pile 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention mainly relates to a ready-made pile made of concrete.

Conventionally, in a ground where a lot of gravel is expected, a combination of a vertical tip shoe and a horizontal tip shoe is used to guide the gravel at the bottom of the pile hole into the hollow part of the pre-made pile, leaving the gravel at the bottom of the pile hole. There has been a proposal to prevent this (Patent Document 1).
JP 2005-314896

  When a ready-made pile is inserted, slime (generally soft mud mixed with bentonite muddy water and excavated soil) from the bottom of the pile hole, that is, below the ready-made pile, is removed from that position. It was able to be removed by taking it into the hollow part of the ready-made pile, but at the same time, it also took in the pile periphery fixing liquid (filled cement milk and soil cement), and between the outer periphery of the ready-made pile and the pile hole wall It was also considered that the was not sufficiently filled.

  Therefore, in the present invention, the shoe is inclined and the mounting inclination direction is set with reference to the rotation direction when the ready-made pile is rotated forward, or the inner diameter of the end plate is set narrower than the inner diameter of the ready-made pile base. The problem was solved by suppressing the inflow of milk into the ready-made pile hollow.

That is, the present invention fixes a doughnut-shaped steel plate end plate to the lower end surface of a ready-made pile base having an outer diameter D ₁ and an inner diameter D ₂ , and is substantially radially with respect to the axis of the ready-made pile on the lower surface of the end plate. And in the ready-made pile formed by projecting a shoe in rotational symmetry, it is the ready-made pile characterized as follows.
(1) Let X be the point where the shoe intersects the inner circumference of the ready-made pile,
(2) The angle direction from the “extending outward line of the line connecting the axis and the point X” to the “extending outward line of the longitudinal line of the shoe” is the ready-made pile. The direction was opposite to the direction of rotation.

In another aspect of the invention, an end plate made of a steel plate in a donut shape is fixed to the lower end surface of the ready-made pile base having an outer diameter D ₁ and an inner diameter D ₂ , and the lower surface of the end plate is attached to the axis of the ready-made pile. In the ready-made pile formed by projecting the shoes in a substantially radial and rotationally symmetrical manner, the ready-made pile is configured as follows.
(1) The shoe is disposed at a predetermined angle with respect to the radial direction,
(2) The predetermined angle is set such that the inner peripheral side first advances and the outer peripheral side advances later with respect to the rotation direction of the ready-made pile.

In another aspect of the invention, an end plate made of a steel plate in a donut shape is fixed to the lower end surface of the ready-made pile base having an outer diameter D ₁ and an inner diameter D ₂ , and the lower surface of the end plate is attached to the axis of the ready-made pile. In the ready-made pile formed by projecting the shoes in a substantially radial and rotationally symmetrical manner, the ready-made pile is configured as follows.
(1) The ready-made pile is a ready-made pile made of concrete,
(2) The inner diameter C of the end plate is defined as C <D ₂
And

  Furthermore, in the above, it is the ready-made pile which made the base end of a shoe located in the axial side of the ready-made pile rather than the inner periphery of an end plate.

  The ready-made piles in the above are mainly concrete piles, but can also be applied to SC piles, steel pipe piles, etc. with the outer periphery of the concrete piles covered with steel pipes.

The shoe is inclined with respect to the radius, and the angle θ formed by the shoe and the line OX connecting the axis O and the point X with respect to the point X in the middle of the shoe is the direction opposite to the rotation direction of the ready-made pile, Alternatively, the angle θ is set so that “the inner peripheral side advances first and the outer peripheral side advances later with respect to the rotation direction of the ready-made pile” or “end plate inner diameter C <end plate inner diameter” D ₂ ”so that the pile circumference fixing liquid (root-solidifying liquid) in the bottom of the pile hole is efficiently and reliably filled between the inner wall of the pile hole and the outer wall of the ready-made pile, and the slime is expanded to the bottom. Can be removed. Therefore, it is possible to construct a high-quality solidified part with the method of burying ready-made piles, and to reliably perform the performance as designed.

(1) an outer diameter D _1, the lower surface 2 of the prefabricated pile body 1 of the concrete inside diameter D _2, to fix the steel end plate 7 at a donut shape having an inner diameter of C1. The ready-made pile 20 is configured by projecting three shoes 15, 15 projecting from the lower surface of the end plate 7 substantially radially with respect to the axis O of the ready-made pile base 1 and rotationally symmetrical.

(2) The inner diameter C _{1 of the} end plate 7 is
Inner diameter C ₁ of end plate 7 <Inner diameter D _{2 of} ready-made pile base 1
And Moreover, the base end 16 of the shoe 7 is located on the axis O side of the ready-made pile 20 (the ready-made pile main body 1) from the inner peripheral edge 6a of the end plate 7 (FIGS. 1, 2, and 3).

(3) In the above, the point where the shoe 7 intersects the inner periphery 3 of the ready-made pile 20 (the ready-made pile base 1) is X, and the line connecting the axis O and the point X is OX. The angle formed by the line OX and the “extension line extending outward in the length direction of the shoe 15” is defined as θ. The angle direction of the angle θ toward the “externally extending line OX connecting the axis O and the point X” and the “externally extending line of the lengthwise direction of the shoe 15” is ready-made. The direction of rotation 30 of the pile 20 was the opposite direction (FIG. 1 (b)).

(4) In other words, the shoes 15 and 15 are inclined at a predetermined angle with respect to the radial direction, and the proximal end 16 (inner peripheral side) of the shoe 15 is first with respect to the rotation direction 30 of the ready-made pile 20. The predetermined angle is set so that the tip 17 (outer peripheral side) advances later (FIG. 1B).

  Embodiments of the present invention will be described with reference to the drawings.

(1) Configuration of ready-made pile 20

An upper surface 9 of a doughnut-shaped end plate 7 having an outer diameter D ₁ and an inner diameter C ₁ is attached to and attached to a lower surface 2 of a ready-made pile base 1 having an outer diameter D ₁ and an inner diameter D ₂ . Here, C ₁ <D ₂ , and the outer peripheral side 6 of the hollow portion 5 of the ready-made pile base 1 is covered with the inner peripheral 10 side of the end plate 7. Further, the inner diameter C1 of the end plate 7 is preferably in order to prevent the pile hole accommodation from entering the hollow portion 11 of the end plate 7 (the hollow portion 5 of the ready-made pile base 1).
(1/2) × D ₂ <C ₁
It is as.

Three strips (rectangular) shoes 15 and 15 are fixed to the lower surface 8 of the end plate 7 substantially radially. The shoes 15 are arranged at equal intervals in the circumferential direction with respect to the axis O (center of the hollow portion) of the ready-made pile base 1. The tip 17 of the shoe 15 protrudes outward from the outer peripheral edge 10 of the end plate 7, and the base end 16 of the shoe 15 protrudes inward (on the axis O side of the ready-made pile base 1, the center side of the end plate 7). The projecting length of the base end 16 of the shoe inward is such that the base ends 16 and 16 of the shoes 15 and 15 do not touch each other, and in the embodiment, about a quarter of the inner diameter C ₁ of the end plate 7. It is as.

The heights H ₁ , H ₂ and H ₃ of the shoes 15 are about ₂ to 15 cm ₂ .

Also, when the length direction of each shoe 15, 15 has a point of intersection with the inner circumference 3 of prefabricated pile body 1 and _{X 1,} X 2, _{X 3,} virtual intersecting the axis O and _{X 1,} X 2, _{X 3} The lines are OX ₁ , OX ₂ , and OX ₃ . The imaginary lines OX ₁ , OX ₂ , OX ₃ and the shoes 15, 15 are arranged so as to be inclined with respect to the axis O rather than radially so that angles θ ₁ , θ ₂ , θ ₃ are formed. In this case, θ ₁ , θ ₂ , and θ ₃ are formed at about 5 to 30 degrees. Further, theta _1, theta _2, the direction of the theta _3, relative to the forward direction 30 of the ready-made pile, set to be backwards from the extension outward of a virtual line _{OX 1, OX 2, OX 3} To do. That is, the angle θ ₁ (θ ₂ , θ ₃ ) from the “extension line outward of OX ₁ (OX ₂ , OX ₂ )” to the “extension line outward in the length direction of the shoe 15” is It sets so that it may become a reverse direction with respect to the normal rotation direction 30 of a ready-made pile (FIG.1 (b)).

  Therefore, when the ready-made pile base 1 is rotated forward, the front surface 18 of the shoe 15 is arranged so that the proximal end 17 side precedes the distal end 16 side and the distal end 16 side rotates with respect to the radial direction. The

  The ready-made pile 20 of this invention is comprised as mentioned above (FIG. 1). In the figure, reference numeral 13 denotes a reinforcing band fixed to the end plate 7.

(2) Use of ready-made pile 20

  This ready-made pile 20 is used similarly to a normal ready-made pile.

  That is, the pile hole 22 excavated in advance is filled with cement milk or further stirred to form a soil cement. Thereafter, the ready-made pile 20 is buried in the pile hole 22.

  In this case, when the ready-made pile 20 is rotated forward in the direction indicated by arrow 30, the base end 16 (inner peripheral side) of the shoe 15 advances first with respect to the rotation direction of the ready-made pile 20 based on the radius. Since the shoe 15 moves so that the distal end 17 (outer peripheral side) advances later, the cement milk located on the proximal end 16 side (inner peripheral side) is gradually removed from the distal end 16 side (outer peripheral side) by the surface 18 of the shoe 15. Side). Therefore, cement milk can be efficiently filled between the outer periphery 3a of the ready-made pile 20 (the ready-made pile base 1) and the inner wall 23 of the pile hole 22.

  At this time, when slimes are present in the pile hole 22, the slime is generally cemented milk before being introduced from the hollow portion 11 into the hollow portion 5 of the ready-made pile 20 (the ready-made pile base 1). Since the specific gravity is lighter than the kind, the slimes are moved along the shoe 15 to the outer peripheral side 3a of the ready-made pile 10 and rise along the outer peripheral 3a side of the ready-made pile 20. Therefore, slimes are removed from the root consolidation part 25 of the pile hole 22 (namely, the position below the lower surface 2 and lower end part of the ready-made pile 20) (FIG.1 (b)).

Further, the inner diameter C ₁ of the end plate 7, and smaller than the inner diameter D ₂ of the ready-made pile substrate 1, since the narrower the hollow portion 11, than into the hollow portion 5 of the prefabricated pile body 1, ready-made pile 20 ( It can move to the outer periphery 3a side of the ready-made pile base 1).

  In this case, the root hardening portion 25 is generally a portion in a pile hole into which the lower end portion of the ready-made pile 20 is rooted, depending on the required supporting force, and a relatively rich blended cement milk or soil cement or the like. The lower end of the filled pile hole.

(3) Other embodiments

In the above embodiment, the length, angles θ ₁ , θ ₂ , θ ₃ and heights H ₁ , H ₂ , H ₃ of each shoe 15 are the same in all the shoes 15, but different in configuration. (Not shown).

Further, in the above embodiment, the inner diameter C ₁ of the end plate _7, when the inner diameter D ₂ of the ready-made pile substrate 1,
(1/2) × D ₂ <C ₁ <D ₂
It is preferable to do, but considering only the movement to the outer periphery side of the pile circumference fixing liquid,
C ₁ <D ₂
This is also possible (not shown). Further, when the length of the shoe 15, the positions of the base end 16 and the tip end 17, and the angles θ ₁ , θ ₂ , θ ₃ are adjusted, D ₂ ≈C ₁ can be set (not shown). .

Further, in the embodiment, the inclination angles θ ₁ , θ ₂ , θ ₃ of the shoe 15 are set so that the proximal end 16 (inner peripheral side) of the shoe 15 advances first and the distal end 17 (outer peripheral side) as described above. Is tilted so that the shoe 15 moves so that it proceeds later.
D ₂ <C ₁
In this case, the inclination of the shoe 15 can be arbitrarily set (FIGS. 2 and 3). That is, the direction of θ ₁ , θ ₂ , θ ₃ is set so as to be the same direction from the virtual lines OX ₁ , OX ₂ , OX _{3 with} respect to the normal rotation direction 30 of the ready-made pile.

In the lower end part of the ready-made pile of the Example of this invention, (a) is a partial longitudinal cross-sectional view, (b) is a bottom view. In the lower end part of the ready-made pile of other Example of this invention, (a) is a partial longitudinal cross-sectional view, (b) is a bottom view. In the lower end part of the ready-made pile of other Example of this invention, (a) is a partial longitudinal cross-sectional view, (b) is a bottom view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ready-made pile base 2 Lower surface of ready-made pile base 3 Inner circumference of ready-made pile base 5 Hollow part of ready-made pile base 6 Outer side of hollow part of ready-made pile base 6a Inner peripheral side of hollow part of ready-made pile base 7 End plate 8 End Lower surface 9 of the plate Upper surface 10 of the end plate Inner circumference 11 of the end plate 13 Hollow portion 13 of the end plate 13 Reinforcement band 15 Shoe 16 Shoe base 17 Shoe tip 18 Shoe surface 20 Ready-made pile 22 Pile hole 23 Pile hole bottom 25 Pile hole root consolidation

Claims (4)

An end plate made of steel plate having a donut shape is fixed to the lower end surface of a prefabricated pile base having an outer diameter D ₁ and an inner diameter D _{2, and} the surface of the end plate is substantially radial and rotationally symmetric with respect to the axis of the prefabricated pile. A ready-made pile, which is constructed as follows in a pre-made pile formed by protruding a shoe on the base.
(1) Let X be the point where the shoe intersects the inner circumference of the ready-made pile,
(2) The angle direction from the “extending outward line of the line connecting the axis and the point X” to the “extending outward line of the longitudinal line of the shoe” is the ready-made pile. The direction was opposite to the direction of rotation. An end plate made of steel plate having a donut shape is fixed to the lower end surface of a prefabricated pile base having an outer diameter D ₁ and an inner diameter D _{2, and} the surface of the end plate is substantially radial and rotationally symmetric with respect to the axis of the prefabricated pile. A ready-made pile, which is constructed as follows in a pre-made pile formed by protruding a shoe on the base.
(1) The shoe is disposed at a predetermined angle with respect to the radial direction,
(2) The predetermined angle is set such that the inner peripheral side first advances and the outer peripheral side advances later with respect to the rotation direction of the ready-made pile. An end plate made of steel plate having a donut shape is fixed to the lower end surface of a prefabricated pile base having an outer diameter D ₁ and an inner diameter D _{2, and} the surface of the end plate is substantially radial and rotationally symmetric with respect to the axis of the prefabricated pile. A ready-made pile, which is constructed as follows in a pre-made pile formed by protruding a shoe on the base.
(1) The ready-made pile is a ready-made pile made of concrete,
(2) The inner diameter C of the end plate is defined as C <D ₂
And The ready-made pile according to any one of claims 1 to 3, wherein the base end of the shoe is positioned closer to the shaft side of the ready-made pile than the inner peripheral edge of the end plate.

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