JP2007146538A - Method of treating pile head of on-site-formed pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of treating a pile head of an on-site-formed pile by which the treatment of the pile head in accordance with a designed diameter of the on-site-formed pile can be easily carried out without causing a damage like a chip accompanied by the treatment of the pile head. <P>SOLUTION: A reinforcing cage 2 is placed in an excavated vertical hole 1. A pile-diameter-forming guide ring 3 is formed to have the same or substantially the same diameter as the designed diameter of the pile 6 which is to be formed, and is provided with a projecting cap-ring mounting guide 3a to mount a cap ring 7 on the outer periphery. The guide ring 3 is concentrically mounted on an upper end part of the reinforcing cage 2 at the same position or substantially the same position as that of a designed level of the pile 6. Concrete 4 is placed in the vertical hole 1 to the level higher than that of the guide ring 3. After the concrete 4 is cured, the concrete in a part higher than the mounting level of the guide ring 3 is removed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for treating a pile head of a field-built pile, which easily secures a pile head having a design diameter, prevents damage such as chipping, and allows the pile head to be treated very easily.

  Generally, in-situ piles made of cast-in-place concrete cannot be expected to have strength as piles immediately after construction because impurities such as slime float on the pile heads when concrete is placed and solidify.

  Therefore, concrete is so-called surplus to a position that is somewhat higher than the design level of the pile, and after the surplus portion is hardened, the pile head is processed by hanging.

  Conventionally, this pile head treatment is generally performed by cutting the outer periphery of the pile head with a cutter or the like according to the design level, and then crushing and removing the excess concrete from this cut. there were. Furthermore, in order to obtain a pile head with a design diameter, it is common to hang the pile head around the design diameter.

  By the way, as a structure of the foundation pile head which joins the foundation pile constructed in this way and the upper foundation constructed on the upper part of the foundation pile, the present applicant has so far shown in FIGS. 5 (a) and 5 (b), for example. As shown in the figure, the pile head of the foundation pile 6 is covered with a ring-shaped coupling 7 made of precast concrete, and the foundation pile 6 and the upper foundation 13 are joined to each other via the coupling 7. (See Patent Document 1).

  According to the structure of the foundation pile head, the joint between the pile head of the foundation pile 6 and the upper foundation 13 is in a semi-fixed state, that is, shear force and vertical force (axial compression acting on the pile head). Force) is transmitted to the foundation pile 6 side, but the rotational force (bending force) can be prevented from being transmitted, and this can relieve the stress during the earthquake concentrated on the foundation pile 6 head. In addition to preventing damage to the pile head, the cost of piles and foundations can be reduced.

JP 2002-167776 A Japanese Examined Patent Publication No. 6-21454 JP-A-8-105041 Japanese Patent Laid-Open No. 2001-200536

  However, when crushing and removing the overlying concrete, the part inside the design diameter below the cut position is often missing due to vibrations or impacts caused by the crushing jig, and repairing that part. It required a lot of effort.

  In addition, when the pile head after staking is larger than the design diameter, it is difficult to insert a cutter into a circular shape, and if you try to lift around the design diameter without inserting a cutter, The inside part was missing and forced to repair.

  In addition, as a method to prevent damage due to vibration or impact, a jig configured to easily peel off even after the overlaid concrete has hardened is attached to the design level position of the pile immediately after placing the concrete. Although this has been done (Patent Document 2), there is a problem that the structure is complicated and the cost is increased.

  The present invention was made in order to solve the above-described problems, and provides a pile head treatment method for a field-built pile that can easily perform pile head treatment and easily secure a pile head having a design diameter. The purpose is to provide.

  The pile head processing method for a field-built pile according to claim 1 is constructed by placing a reinforcing steel cage into a drilled hole, placing concrete in the hole, and installing a cap on the upper end. A pile head treatment method for an on-site pile, wherein the pile is formed to have the same diameter as or approximately the same diameter as the pile to be created, and a pile installation guide is provided on the outer periphery of the pile. After the diameter shaping guide ring is concentrically attached to the upper end of the reinforcing bar at the same or substantially the same position as the pile design level, concrete is put into the hole to a level higher than the pile diameter shaping guide ring. After the concrete is hardened, the concrete in the upper part from the installation position of the pile diameter shaping guide ring is removed.

  The present invention is such that, before placing concrete in an excavated hole, it is formed at the upper end of a reinforcing steel cage standing in the hole with the same or substantially the same diameter as the designed diameter of the pile to be built, By attaching a pile diameter shaping guide ring with a capling installation guide for installing the ring, the so-called surplus concrete above the pile design level is crushed after the concrete has hardened. This makes it possible to easily secure the pile head of the design diameter, and to quickly install the coupling on the pile head after the pile head treatment, thus making it possible to improve the efficiency of construction. It is a thing.

  In addition, the pile diameter shaping guide ring used here can be easily formed by curving a steel plate of a predetermined thickness such as a strip steel, and the pile diameter shaping guide ring is used when assembling the rebar cage or rebar cage. It may be attached at any time after being built into the hole. The height of the pile diameter shaping guide ring (the width of the steel plate) may be determined by appropriately taking into account the design diameter of the pile to be created, the strength of the concrete used, and the like.

  The pile head processing method for an on-site formation pile according to claim 2 is the pile head processing method for an on-site formation pile according to claim 1, wherein a plurality of capping installation guides project in the circumferential direction of the pile diameter shaping guide ring. It is characterized by this. Capturing installation guides can be installed in a stable state by protruding at least three at equal intervals. The coupling installation guide may be formed integrally with the pile diameter shaping guide ring, and can be retrofitted by bolting or clipping, further welding or the like.

  The pile head processing method for a site-created pile according to claim 3 is characterized in that in the pile head treatment method for a site-created pile according to claim 1 or 2, a level adjustment piece protrudes from the coupling installation guide. It is. The level of coupling can be adjusted.

  The pile head processing method for a field-built pile according to claim 4 is a pile head processing method for a field-built pile according to any one of claims 1 to 3, wherein a pile head level confirmation block is provided in a projecting installation guide. It is characterized by that.

  In the present invention, the outer periphery of the pile head level confirmation block is exposed on the concrete surface, and by removing this block when hanging the pile head, the position of the pile head level can be easily confirmed. Can be carried out easily.

  In this case, a foam head or the like can be used for the pile head level confirmation block, and it can be easily attached by a method such as piercing a coupling installation guide.

  In particular, the present invention particularly relates to a pile diameter shaping guide ring having the same or substantially the same diameter as the designed diameter of the pile to be formed on the upper end of the reinforcing steel cage standing in the hole before placing concrete in the excavated hole. The pile head, which is important in terms of quality, is removed when the so-called surplus part of the concrete above the design level is hardened and removed by crushing it according to the design level of the pile and concentrically with the rebar cage. It has the effect of preventing damage such as staking.

  1 and 2 show the construction process of a site-built pile made of cast-in-place concrete when the pile head (the top of the pile) is shallower than the lower end of the excavation casing. A car 2 is stood up and a pile diameter shaping guide ring 3 is horizontally attached to an upper end portion of the reinforcing steel car 2.

  Further, concrete 4 is placed in the vertical hole 1, and the concrete 4 is finally piled up to a predetermined height above the pile diameter shaping guide ring 3 as shown in FIG. 2A, for example. The

  The reinforcing bar 2 is assembled in a cylindrical shape from a plurality of main bars 2a and a plurality of hoop bars 2b wound around the outside of the main bars 2a, 2a. In order to assemble the rebar cage 2, for example, a reinforcing ring 5 installed concentrically with the hoop bar 2 b of the rebar cage 2 as shown in FIGS. 3A and 3B is used. The upper ends of the main bars 2a are fixed to the reinforcing ring 5, respectively.

  The pile diameter shaping guide ring 3 is formed to have the same diameter as the designed diameter of the pile 6 to be constructed and larger than the reinforcing ring 5, and a coupling installation guide 3 a for mounting the coupling 7 is circular on the outer periphery. A plurality of protrusions are provided at equal intervals in the circumferential direction.

  Further, the pile diameter shaping guide ring 3 is installed on the upper end of the reinforcing bar 2 concentrically with the hoop bar 2b of the reinforcing bar 2 and the reinforcing ring 5 and horizontally protrudes outside the reinforcing ring 5. The connecting bar 8 is fixed to the reinforcing ring 5.

  In addition, the pile diameter shaping guide ring 3, the capping installation guide 3a of the pile diameter shaping guide ring 3, the reinforcing ring 5, and the connecting bar 8 are all formed from a steel plate having a predetermined thickness and a predetermined width. They are joined together by welding.

  Further, the pile diameter shaping guide ring 3 is attached in advance to the outside of the reinforcing ring 5, and the coupling installation guide 3 a is projected in advance on the outer periphery of the pile diameter shaping guide ring 3.

In such a configuration, the pile head processing method of the present invention will be described together with the construction procedure of the on-site creation pile.

a. First, the vertical hole 1 for creating the on-site creation pile 6 is drilled. In this case, a drilling method which is generally widely used can be used for drilling, and the drilling casing 9 is necessary for protecting the hole wall and constructing the digging start portion.

b. Next, a pile diameter shaping guide ring 3 separately formed on the upper end portion of the rebar cage 2 assembled in advance is attached using the reinforcing ring 5 and the connecting bar 8. The pile diameter shaping guide ring 3 is attached to the rebar cage 2 and concentrically according to the design level of the on-site created pile 6 to be created.

c. Next, the reinforcing bar 2 is stood in the vertical hole 1 and the reinforcing bar 2 is set at the center of the vertical hole 1. In this case, the rebar cage 2 is set so that the design level of the pile head is lower than the ground surface, and is stood so that the upper end is positioned lower than the ground surface. At this stage, the pile diameter shaping guide ring 3 may be attached to the upper end of the reinforcing bar 2.

d. Next, concrete 4 is placed in the vertical hole 1. The concrete 4 is continuously placed up to a predetermined height above the pile diameter shaping guide ring 3. So-called concrete 4 is added.

e. Next, when the placement of the concrete 4 is completed, the excavation casing 9 is pulled out and removed before the concrete 4 is hardened. Further, the ground 10 around the site-built pile 6 thus created is dug down by root cutting. Root cutting is performed to the lower side of the pile diameter shaping guide ring 3.

f. Next, an incision 6 a is made along the upper side of the pile diameter shaping ring 3 on the outer periphery of the pile head of the on-site created pile 6. And the surplus of the upper part from this notch 6a is crushed and removed.

g. The concrete surrounding outside the design diameter is suspended in accordance with the shaping guide ring 3 exposed to the pile head. By doing in this way, the pile head of a design diameter can be obtained, without putting a cutter circularly in a top end and without damaging the inner side of a design diameter.

  In FIG. 4A, the level adjustment member 11 is attached to the coupling installation guide 3a so as to be movable in the vertical direction, and the level adjustment member 11 is raised and lowered to be placed on the level adjustment member 11. The level of the coupling 7 can be easily adjusted.

  FIG. 4 (b) shows that when removing piled concrete after removing the excavating casing 9 by attaching a pile head level confirmation block 12 made of foamed polystyrene or the like to the coupling installation guide 3a. This makes it possible to confirm at a glance the pile head level of the site-built pile 6 to be used.

  In this case, the pile head level confirmation block 12 is attached to each coupling installation guide 3a before placing the concrete 4, so that when the excavating casing 9 is removed, the pile head level confirmation block 12 is exposed to the surface of the concrete 4. The pile head level of the on-site creation pile 6 can be confirmed at a glance.

  INDUSTRIAL APPLICABILITY According to the present invention, a pile head treatment of a field-built pile by cast-in-place concrete can be performed very easily by easily securing a pile head having a design diameter.

The pile head (top end of the pile) shows the construction method of the site-built pile in a position shallower than the lower end of the excavation casing, (a) is a plan view of the pile head before placing concrete, (b) It is the longitudinal cross-sectional view. The construction procedure of the pile head treatment is shown, (a) is a partial longitudinal sectional view showing the pile head after placing concrete, (b) is a pile head shaping guide by rooting the ground around the site-built pile. Partial longitudinal cross-sectional view dug down to the lower end of the ring, (c) is a partial longitudinal sectional view showing the pile head after removing the overlying portion of concrete, (d) is after removing the surrounding concrete It is a partial longitudinal cross-sectional view which shows a pile head. The method for attaching the pile diameter shaping ring is shown, (a) is a plan view of the pile head, (b) is a longitudinal sectional view taken along line II in (a). (a), (b) shows the other example of this invention, and is a longitudinal cross-sectional view of a pile head. The structure of the foundation pile head where the foundation pile and the upper foundation were joined by the coupling is shown, (a) is a longitudinal sectional view, and (b) is a roll line sectional view in (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drilled vertical hole 2 Reinforcing bar 2a Main bar 2b Hoop bar 3 Pile diameter shaping guide ring 3a Caping installation guide 4 Concrete 5 Reinforcement ring 6 Foundation pile, site-built pile 7 Capturing 8 Connection bar 9 Excavation casing 10 Ground 11 Level adjustment member 12 Pile head level confirmation block 13 Upper foundation

Claims (4)

  A pile head treatment method for a site-built pile constructed by placing a rebar cage in a drilled hole, placing concrete in the hole, and installing a cap on the upper end. A pile diameter shaping guide ring that is formed to have the same diameter as or approximately the same diameter as the design diameter of the pile and that has a coupling installation guide for projecting the cap ring installed on the outer periphery is provided at the upper end of the rebar cage. After concentrically providing at the same or substantially the same position as the pile design level, after placing concrete in the hole to a level higher than the pile diameter shaping guide ring and hardening the concrete, the pile diameter shaping A pile head processing method for a site-built pile, characterized by removing the concrete above the guide ring installation position.   The pile head processing method for a field-built pile according to claim 1, wherein a plurality of the coupling installation guides protrude in the circumferential direction of the pile diameter shaping guide ring.   The pile head processing method for a field-built pile according to claim 1 or 2, wherein a level adjusting piece projects from the coupling installation guide. The pile head processing method for a field-built pile according to any one of claims 1 to 3, wherein a block for checking a pile head level is provided on the coupling installation guide.

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