JP2005098050A - Pile head joint structure by simple joint female die method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a satisfactory pile head joint structure which has an enough stress resistance, excellent reliability and workability is not developed, although there is a tendency in recent designs that an ultimate design for prevention of destruction of a building upon a big earthquake is adopted, for which a number of reinforced piles wound by steel pipes or the like are designed. <P>SOLUTION: To realize the design which is resistant against an ultimate design stress, the pile head joint structure is developed, in which joint processing of a reinforcement to be settled in a foundation slab is structured, and after a female die joint metal to be fitted to an upper end of the pile of the steel pipe outer diameter by reliable butt welding, a thick plate having a hole for a lower part wedge, or a hole-in joint metal to be embedded in the pile head part is attached at a factory, each pile is delivered to a construction site. Then, the pile having excellent workability is constructed rapidly and economically at the site without the expertise. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pile head joint structure by a simple joint female mold method.

  Conventionally, a pile has a basic configuration of manufacturing a single pile and construction by the manufacturer. When a pile is constructed and then joined to a concrete footing foundation of an upper structure, there are portions that are not always satisfied. At present, the pile and the footing foundation slab constructed on the top of the pile use a pile with an end plate of the same diameter attached to the outer steel pipe of the pile head, and weld or mechanically join a rebar to this end plate, Alternatively, a reinforcing bar is welded and fixed to the side surface of the pile head outer peripheral steel pipe, and the other end of the reinforcing bar is fixed in the footing foundation slab.

  However, the conventional technique has the following problems.

  Recent designs tend to adopt ultimate strength design that prevents building destruction in the event of a large earthquake. Cast-in-place concrete pile and PC (PHC) pile strengthened cast-in-place concrete that can cope with this in the foundation field. Production of piles and steel pipe wound PC (PHC) piles and steel pipe piles specially processed at the tip of piles and development of construction methods are actively conducted. However, with regard to the connection between the pile and the footing foundation slab constructed on top of it, the concrete strength of the footing foundation slab is only about 30% to 40% compressive strength of the pile. In addition, it is difficult to support the bending moment only with the support pressure of the foundation slab of the same area as the pile. Not in the current situation.

  Recently, there is a method in which a reinforcing bar that has been fixed in the footing foundation slab is grooved and welded to the upper end of the pile of the outer diameter of the steel pipe and fixed, but this method is welding in the field, Due to vertical welding, it is not reliable. Although welding inspection by color check is possible, it takes a lot of time, and there remains a problem that it is difficult to ensure sufficient quality as compared with ultrasonic deep scratches. In rainy weather, construction is impossible.

  The method (flare welding) of welding a deformed reinforcing bar directly to the pile upper end of the steel pipe outer diameter part requires 10 times or more of the reinforcing bar diameter, and 290 mm or more is necessary when using reinforcing bar D29. Generally, the height of the pile head and embedding in the footing foundation slab is designed to be 100 mm, which lowers the footing foundation slab by 290 mm or more, which is uneconomical. Further, this welding method (flare welding) generally has a drawback that the quality of the welded portion is not sufficiently ensured.

  There is a method in which a fixing plate having a female screw hole is attached to a PC steel rod portion installed inside a pile head of a PC (PHC) pile, and a fixing rebar in a footing foundation slab that has been male threaded is screwed and fixed. There is also a method of direct stat welding to the fixing plate of the PC steel bar. Either method corresponds to the strength of the joint, and the use of the maximum deformed reinforcing bar is D29 or less. As a result, it is often impossible to line up within the reinforcing bar diameter pitch determined for the steel pipe wound pile maximum proof stress.

  In the present invention, a pile with a simple joint female thick plate (upper / lower nut tightening / simple joint method, screwed with nut / simple joint method) attached to the upper end of the pile at the outer diameter of the steel pipe, and a thickness with a lower wedge hole Development of plate pile (wedge / simple joint method), PC (PHC) pile and cast-in-place concrete pile head hole-in / simple joint pile (hole-in / simple joint method) and its pile head joint structure Thus, the above problem is solved.

  The pile and pile head joint structure by the simple joint female mold method according to the present invention has the following unique effects.

  The latest design adopts the ultimate design that prevents the destruction of the building in the event of a large earthquake, but the pile head joint structure that can withstand the stress sufficiently, has excellent reliability and workability, and can fully demonstrate economic efficiency. Can be built.

  Leg length designed with a female plate thick plate 7 attached to the top of the pile at the outer diameter of the steel pipe and a plate 14 with a lower wedge hole in order to uniformly distribute the axial force and bending moment generated in the pile And perform reliable butt-welding and set the number corresponding to the designed stress, or set the number of female hole-in joint hardware 17 corresponding to the designed stress to set each pile. After carrying in the field, the male threaded rebar 10 that has been screwed into the base slab and fixed to the foundation slab, or the upper wedged thick plate 15 with the anchoring anchor reinforcing bar 10, or the male hole-in with the anchoring reinforcing bar 10 The joint hardware 18 can be easily and quickly constructed on site, and an economical and highly reliable pile head joint can be constructed.

  It is possible to perform construction quickly after loading the pile site without being influenced by the weather. Moreover, it becomes possible to construct the beard anchor muscle in the basic slab very easily without using a professional technique.

The designed leg length can be freely increased in terms of construction and effective in design, and a large-diameter bar such as D32 can be designed as an anchor bar in the foundation slab. As a result, it is possible to design the number that can cope with the axial force and bending moment stress generated in the pile, and to arrange the beard anchor bars at the standard pitch determined by the standard within the range of pile diameter designed by construction. Become. As a result, it is possible to construct a pile head joint that is economical and suitable for design stress.
In addition, in the factory, the highly reliable butt welding 11 that sufficiently satisfies the design stress is performed in the factory with the designed leg length, or the female hole-in joint hardware 17 that sufficiently satisfies the design stress is embedded. This makes it possible to construct a pile head joint structure that sufficiently satisfies the required design stress.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  Here, a pile with a simple joint female thick plate (upper / lower nut tightening / simple joint method, screwed with nut / simple joint method) attached to the top of the pile of the outer diameter part of the steel pipe of the present invention, steel pipe winding PC (PHC) ) An example of a hole-in / simple joint pile (hole-in / simple joint method) embedded in a pile and steel pipe winding cast-in-place concrete pile head and its pile head joint structure will be described with reference to the drawings.

  1, FIG. 2 and FIG. 3 are bird's-eye views showing a state in which the female thick plate 7 according to the invention of claim 1 is attached.

4, 5, and 6 are explanatory views of an embodiment according to the first aspect of the present invention.
A thick plate 7 with a female hole is welded in the factory at the upper end position of the pre-designed steel pipe, and after the pile is brought into the field, a male screw rebar 10 that has been threaded and fixed in the foundation slab is manufactured in advance at the factory. It is inserted into a hole 9 thicker than the reinforcing bar diameter of the thick plate 7 with a female hole set by welding and tightened from above and below with upper and lower nuts 8. 4, 5, and 6 show a male threaded rebar 10 having a threaded end 12 threaded in the factory after being welded together at the factory with leg lengths designed in advance and fixed in the foundation slab. It is a figure, a longitudinal cross-sectional view, and a welding detail in which the upper and lower nuts 8 are tightened by being inserted and set in the hole 9 of the thick plate 7 with female holes.

  FIG. 7 is a cross-sectional view taken along line AA of FIG. 6 and a cross-section of the butt weld.

  1, FIG. 2 and FIG. 3 are bird's-eye views showing a state in which the thick plate 7 with a female hole according to the invention of claim 2 is attached.

FIGS. 8, 9, and 10 are explanatory views of an embodiment according to the second aspect of the present invention.
At the factory, a thick plate 7 with a female hole is welded at the factory with the designed leg length, and the pile 12 is threaded into the foundation slab after the pile is brought into the field. A male threaded reinforcing bar 10 is screwed into a female threaded portion 13 of a thick plate 7 with a female hole that has been dug in advance, and an upper nut 8 is tightened. Figs. 8, 9, and 10 are factory-made steel plate 7 with a female hole in advance, butt-welded with the designed leg length, and then carried into the field and machined into the foundation slab to be threaded with the tip of the reinforcing bar. 5 is a figure, a longitudinal cross-sectional view, and welding details formed by screwing a male threaded reinforcing bar 10 having a groove 12 into a female threaded portion 13 of a thick plate 7 with a female hole.

  FIG. 11 is a cross-sectional view taken along line AA in FIG. 10 and a cross-section of the butt weld.

  FIG. 12 is a bird's-eye view showing a state in which a thick plate 14 with a lower wedge hole is attached to a steel pipe upper end position of a pile head according to the invention of claim 3.

FIG. 13, FIG. 14 and FIG. 15 are explanatory views of an embodiment according to the third aspect of the present invention.
The upper wedge with the reinforcing bar 10 is fixed to the foundation slab after welding the pile with the designed leg length at the factory at the upper end position of the pre-designed steel pipe. The thick plate 15 with holes for use is set close to the thick plate 14 with holes for lower wedges, and a specially-made wedge (special H-shaped steel) 16 is pushed in from the side surface by light striking and fixed tightly. 13, 14, and 15 show a thick plate 14 with a lower wedge hole in a factory, after butt welding with a designed leg length in advance, and then carried to the pile site. Figure and longitudinal section of a wedge and specially-made wedge (special H-shaped steel) 16 pressed into the base slab with a reinforcing bar 10 fixed in the foundation slab by lightly striking from the side. Figure and welding details.

  FIG. 16 is a BB cross-sectional view of FIG. 15 and a cross-section of the butt weld.

  FIGS. 17 and 18 show anchor anchor bars 19 that can sufficiently withstand pulling stress on the heads of steel pipe winding PC piles (PHC piles) or steel pipe winding cast-in-place concrete piles (with steel plate) according to the invention of claim 4. It is a bird's-eye view of the state which attached and attached the female type | mold hole-in simple joint metal fitting 17.

19 and 20 are explanatory views of an embodiment according to the fourth aspect of the present invention.
A female hole-in / simple joint hardware 17 with anchoring reinforcing bars 19 that can withstand the pulling stress of the number designed on the head of steel pipe winding cast-in-place concrete pile or steel pipe winding PC pile (PHC pile) is embedded and set at the factory. After the pile is brought into the field, the male hole-in / simple joint hardware 18 having the reinforcing bar 10 fixed in the foundation slab is pressed and fixed. At this time, the screw type lid 20 is set in advance on the female hole-in-joint hardware 17 at the factory before loading the pile, and when the male hole-in / simple joint is installed, the screw-type lid is removed and the female type hole-in joint is removed.・ Push into simple joint hardware.
FIGS. 19 and 20 show the reinforcing bar 10 that is carried in the pile and fixed in the foundation slab after the female hole-in / simple joint hardware 17 with anchoring anchor bars 19 that can withstand pulling stress is set in advance at the factory. It is the figure, the longitudinal cross-sectional view, and the welding details which were fastened and fixed by pushing in the male type | mold hole-in simple joint metal object 18 which has it.

  FIG. 21 is a cross-sectional view taken along the line CC of FIG.

  FIG. 22 is a longitudinal cross-sectional view that takes advantage of each feature in the description related to the invention of claim 1, claim 2, claim 3, and claim 4, details of the cross section of welding, and anchoring reinforcing bar 19 for fixing. The details of the cross section of the embedded portion of the attached hole-in joint hardware 17 are shown.

  In the present invention, all the fields that require specialized technology are manufactured and installed in factories, and little technology is required after delivery to the site, enabling simple and quick installation without being influenced by the weather. As a pile head joint structure, it is considered that there is a great potential for demand at civil engineering and construction sites.

It is a bird's-eye view of the pile which attached the thick plate with a female type | mold hole concerning invention of Claim 1 and Claim 2 to the pile upper end of the steel pipe outer diameter part of a steel pipe winding precast pile. It is a bird's-eye view of the pile which attached the thick plate with a female type | mold hole concerning the invention of Claim 1 and Claim 2 to the pile upper end of the steel pipe outer diameter part of a steel pipe winding cast-in-place concrete pile. It is a bird's-eye view of the pile which attached the thick plate with a female type | mold hole concerning invention of Claim 1 and Claim 2 to the pile upper end of the steel pipe outer diameter part of a steel pipe pile. It is the figure which inserted the whisker anchor bar | burr after attaching the thick plate with a female type | mold hole concerning the invention of Claim 1 to the pile upper end of a steel pipe outer diameter part, and fastened with the upper and lower nut. FIG. 5 is a view from the side of FIG. 4. The longitudinal cross-sectional view of FIG. 4 which attached the whisker anchor reinforcement to the thick plate with a female top hole of a pile upper end of a steel pipe outer diameter part, and fastened with the up-and-down nut, and the detail of a welding part are represented. The cross-sectional view by the AA line of longitudinal cross-sectional view 6 and the leg long cross section of butt welding are represented. It is the figure which tightened the whisker anchor muscle with the screwing attachment upper nut, after attaching the thick plate with a female type | mold hole concerning invention of Claim 2 to the pile upper end of a steel pipe outer diameter part. It is the figure seen from the side of FIG. The longitudinal cross-sectional view which screwed and attached the whisker anchor reinforcing bar to the thick plate with a female hole attached to the upper end of the pile of the outer diameter part of the steel pipe and the details of the welded part are shown. The cross-sectional view by the AA line of longitudinal cross-sectional view 10 and the leg long cross section of butt welding are represented. It is a bird's-eye view which attached the thick board with a lower wedge hole concerning the invention of Claim 3, and a butt welding figure. After attaching the thick plate with holes for the lower wedge according to the invention of claim 3 to the upper end of the pile of the outer diameter portion of the steel pipe, the upper wedge thick plate with the whisker anchor bars is brought close to the wedge and It is a figure which pushed in (H-shaped steel). It is a figure seen from the side of FIG. Detail of the welded part and longitudinal section with the wedge (special H-shaped steel) specially made from the side set with the plate with holes for the lower wedge and the upper wedge plate with the whisker anchor reinforcement set close to each other Represent. The cross-sectional view by the BB line of longitudinal cross-sectional view 15 and the leg long cross section of butt welding are represented. It is the figure which embedded the female hole-in-joint metal fitting in the pile head of the steel pipe winding PC pile (PHC pile) concerning the invention of Claim 4. It is a figure which embedded the female type | mold hole-in joint metal fitting in the pile head of the steel pipe winding cast-in-place concrete pile concerning the invention of Claim 4. It is a longitudinal cross-sectional view of a state in which a male type hole-in joint hardware having a beard anchor reinforcing bar is pushed into a female type hole-in joint hardware attached to a pile head. FIG. 20 is a longitudinal sectional view showing a state where the pushing is completed from the pushed state in FIG. 19. It is a transverse cross section by CC line of longitudinal section 20. In the description concerning invention of Claim 1, Claim 2, Claim 3, and Claim 4, it is a longitudinal cross-sectional view which utilized each characteristic.

Explanation of symbols

1. Steel pipe piles2. Steel pipe wound precast concrete (PC or PHC pile) piles 3. Steel pipe winding cast-in-place concrete piles4. 4. Steel pipe PC part of steel pipe winding PC pile (or PHC pile) 6. 6. Concrete part of steel pipe winding cast-in-place concrete pile 7. Thick plate with female holes Nut 9. 10. Hole part of thick plate with female hole Reinforcing bar for anchoring concrete (bearing anchor) (D32 or higher can be used)
11. Butt weld 12. (Beard anchor) Rebar thread cutting male part (rebar end threaded male threaded rebar)
13. (Beard anchor) female part for rebar screw (female thread part processed into thick plate with female hole)
14 Plate with holes for lower wedge 15. Plate with holes for upper wedge 16. Wedge (special H-shaped steel)
17. Female hole-in joint hardware 18. Male hole-in joint hardware19. Anchor reinforcing bar for pile head fixing20. Threaded lid (factory installation)
21. Steel plate for anchoring, attached to the pile head of steel pipe-wrapped PC pile (PHC pile) and steel pipe-wrapped concrete pile

Claims (4)

  To join the pile and the foundation slab constructed on the top of the pile, to have a thick plate with a female hole with a hole larger than the threaded part at the top of the steel pipe at the top of the pile, and to insert the male screw of the reinforcing bar A thick plate with a female hole is welded and fixed. A pile head joint between a pile and a foundation slab, characterized by inserting a male threaded reinforcing bar that has been threaded into the foundation slab into the female slab and screwed into the foundation slab. Structure-Upper / lower nut tightening / Simple joint method   In joining the pile and the foundation slab constructed on the top of the pile, there is a female-threaded thick plate at the top of the steel pipe at the top of the pile, and a female-threaded thick plate for screwing the male screw of the reinforcing bar is welded and fixed To do. A pile head joint structure between a pile and a foundation slab, characterized in that a male threaded steel bar threaded with a rebar tip fixed to the foundation slab is screwed to this female threaded thick plate and fastened with an upper nut Screwed with nuts / Simple joint method   In joining the pile and the foundation slab constructed at the top of the pile, there is a thick plate with holes for lower wedges at the upper end of the steel pipe at the top of the pile, and a thick plate with holes for lower wedges is fixed by welding. Tightening by pushing specially made wedges (special H-shaped steel) from the sides into the wedge holes on both sides of the thick plate with holes for use and the thick plate with holes for upper wedges that have reinforcing bars fixed in the foundation slab Pile head joint structure between pile and foundation slab characterized by being fixed-wedge and simple joint method   In joining the pile and the foundation slab constructed on top of it, a steel-hole pre-cast concrete pile (hereinafter referred to as PC pile or PHC pile) and a steel-hole-wound cast-in-place concrete pile head at the pile head A female hole-in joint hardware with anchor rebar that has sufficient resistance to pull-out stress is embedded and fixed, and a male hole-in joint hardware with a rebar fixed in the base slab is fixed to this hole-in joint hardware. Pile head joint structure between pile and foundation slab characterized by being tightly fixed by pushing

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