JP5052396B2 - Pile head joint structure and temporary tool for pile head joint used in its construction - Google Patents

Description

  The present invention relates to a pile head joint structure at a joint portion between a pile embedded in the ground and an upper structure supported by the pile, and a temporary tool for pile head joint used for the construction thereof.

  There are two types of pile foundations: a support pile type and a friction pile type. When the good quality support layer is deep underground, the former is constructed by constructing an upper structure on the pile driven to the support layer. This is a form in which the weight is stably supported by the support layer, and the latter is a basic form in which the superstructure is supported by the frictional force with the surrounding ground when there is no good support layer.

  The heads of these piles are embedded in foundation members such as foundation slabs, footings or foundation beams of the upper structure, and a compressive force acting as a long-term load acts on the foundation members. Pulling force due to the overturning moment and bending moment due to the horizontal force act.

  Therefore, when the superstructure encounters an extremely large earthquake, an excessive bending moment acts on the pile head, which may lead to an unexpected situation such as the destruction of the pile and the collapse of the superstructure.

  Therefore, recently, for example, the R & D of the semi-rigid joint method has been carried out to reduce the degree of fixation of the pile head joint by unbonding the anchor reinforcing bars standing on the end plate of the pile head. It has become.

Japanese Patent No. 3438108 Japanese Patent Laid-Open No. 2002-356861 Japanese Patent No. 3825795 JP 2004-44303 A JP 2006-193904 A

  According to such a semi-rigid joining method, since the fixing degree of the pile head joint portion is reduced, the bending moment generated at the pile head can be reduced.

  However, in the conventional semi-rigid joining method, the degree of fixation to the foundation member changes depending on the axial force acting on the pile head, and accordingly, the bending moment generated on the pile head also changes.

  On the other hand, the axial force acting on the pile head is usually different for each pile.

  Therefore, even if the fixing degree of the pile head joint can be reduced by the semi-rigid joining method, the degree of reduction will be different for each pile, resulting in a very complicated and complicated design work. It was causing the problem.

  The present invention has been made in consideration of the above-described circumstances, and a pile head joint structure capable of preventing the degree of fixing to the foundation member from depending on the axial force and a pile head joint temporary tool used for the construction thereof. The purpose is to provide.

In order to achieve the above object, the pile head joint structure according to the present invention is the pile head joint structure according to claim 1, wherein the pile head is embedded in the foundation member of the upper structure.
Of the inner surface of the embedding recessed portion of the foundation member in which the pile head connecting rod is erected on the end plate provided on the head of the pile and embedded in the foundation member, The ceiling surface is separated from the upper surface of the end plate so that a vertical load from the upper structure is transmitted to the pile only through the pile head joining rod .

  Moreover, the pile head joining structure which concerns on this invention comprises the said rod for pile head joining by the rod member standingly arranged by the said end plate, and the fixing board attached to the predetermined position of this rod member. .

  Moreover, the pile head joining structure which concerns on this invention equips the rod for pile head joining with the sheath pipe | tube through which the said rod member is penetrated.

Moreover, the temporary tool for pile head joining which concerns on this invention is as described in Claim 4, and the head of the said pile is embedded in the rod for pile head joining standingly installed in the end plate provided in the head of a pile. A pile head joining temporary tool for use in a pile head joint structure embedded in a foundation member of an upper structure, wherein the circular top plate is formed with an insertion hole through which the pile head joint rod is inserted, and the circular ceiling A crown member comprising a cylindrical body suspended from the periphery of the plate, and the crown member is inserted into the insertion hole formed in the circular top plate with the pile head joining rod inserted therethrough. The crown member is configured so that it can be put on the head of the pile, and the crown member is kept in a separated state between the circular top plate and the end plate when placing the fresh concrete when forming the foundation member. And fresh between the circular top plate and the head of the pile Nkurito together is configured so as not to flow into the foundation by so after the fresh concrete curing, vertical load from the superstructure is transferred to the pile via only rod for the pile joint It is comprised so that a member may not exert rotation restrictions on the head of the said pile.

  Moreover, the temporary installation tool for pile head joining which concerns on this invention is equipped with the concrete inflow prevention material with which it fills or arrange | positions between the said circular top plate and the head of the said pile.

  Moreover, the temporary tool for pile head joining which concerns on this invention is as described in Claim 6, The head of the said pile is embedded with the rod for pile head joining standingly installed in the end plate provided in the head of a pile. A pile head joining temporary tool for use in a pile head joint structure embedded in a foundation member of an upper structure, wherein the circular top plate is formed with an insertion hole through which the pile head joint rod is inserted, and the circular ceiling A crown member comprising a cylindrical body suspended from the periphery of the plate, and the crown member is inserted into the insertion hole formed in the circular top plate with the pile head joining rod inserted therethrough. The crown member is configured so that it can be put on the head of the pile, and the crown member is kept in a separated state between the circular top plate and the end plate when placing the fresh concrete when forming the foundation member. And fresh between the circular top plate and the head of the pile In addition, the foundation member is configured not to exert rotational restraint on the head of the pile after hardening of the fresh concrete, and the circular top plate and the head of the pile. Are provided with spacers that are interposed between the two and holding the separated state.

  As the piles are fixed to the foundation members such as foundation slabs, foundation beams, and footings, the closer to the rigid connection, the greater the rotational rigidity of the pile head and the greater the bending moment generated during an earthquake.

  Under such circumstances, as described in the prior art, many semi-rigid joining methods for reducing the fixing degree have been studied, but most of them change the fixing degree depending on the axial force. That is, when the axial force is large, the rotational rigidity of the pile head joint is increased and the generated bending moment is increased. When the axial force is small, the rotational rigidity of the pile head bonded portion is decreased and the generated bending moment is also decreased.

  In other words, the axial force acting on each pile generally varies from pile to pile, and the rotational stiffness also varies from pile to pile.Accordingly, the magnitude of the bending moment cannot be reduced generally by the semi-rigid joint method. However, the size varies from pile to pile.

  In view of this situation, the present applicant conducted research and development on how to make the rotational rigidity independent of axial force even in semi-rigid joints. Abandoning the previous design philosophy of supporting with the tensile force of anchor reinforcing bars erected on the end plate and the compressive force of foundation members made of reinforced concrete, and introducing a new design philosophy that supports compressive force with anchor reinforcing bars. Thus, the rotation rigidity at the pile head is not made dependent on the axial force.

That is, in the conventional pile head joint structure, no gap is formed between the upper surface of the pile head and the foundation member in a state embedded in the foundation member, but in the pile head joint structure according to the present invention, the pile head Of the inner surface of the embedded concave portion of the foundation member in which the portion is embedded, the concave ceiling surface is separated from the upper surface of the end plate so that the vertical load from the upper structure is transmitted only to the pile head connecting rod . As a result, a hollow space is formed between the upper surface of the pile head and the foundation member.

In this way, even if the horizontal force during the earthquake acts on the pile head from the superstructure, the pile head is not subject to rotational restraint from the foundation member, and the bending moment generated at the pile head is compressed. The pile head joint rod bears both the side and the tension side.

  In other words, the head of the pile is subjected to rotational restraint due to compressive force and tensile force via the pile head joining rod, but is not subject to rotational restraint due to compressive force transmission with the base member. The rotation constraint of the pile head is a rotation constraint that does not depend on the axial force.

  Therefore, the rotational rigidity of the pile head, that is, the relationship between the rotational deformation angle at the pile head and the bending moment generated at the pile head does not depend on the axial force, and the design process can be simplified.

  The head of the pile is embedded in a foundation member such as a foundation slab, foundation beam, or footing by a predetermined depth, but in the present invention, the recessed ceiling surface of the embedding recess formed in the foundation member is disposed away from the end plate. The embedding depth of the pile head and the embedding recess are different by the distance.

  The pile head embedding depth is such that shear force is transmitted between the foundation member of the superstructure and the pile head, while the bending moment is sufficiently smaller than the bending moment borne by the pile head connecting rod. It sets suitably so that it may become or it may not be transmitted substantially.

  As long as rotation restraint due to transmission of compressive force between the base member and the end plate does not occur, what means is adopted to separate the recessed ceiling surface from the upper surface of the end plate is arbitrary. When constructing, it is possible to use a pile head joining temporary tool provided with a crowned member that can be put on the head of the pile.

  The crowned member is composed of a circular top plate formed with an insertion hole through which the pile head joining rod is inserted, and a cylindrical body suspended from the periphery of the circular top plate, and is inserted into the insertion hole formed in the circular top plate. It is comprised so that it can cover the head of a pile in the state by which the rod for pile head joining was penetrated. It is optional to form the circular top plate and the cylindrical body integrally, or to form them separately and to join them appropriately. The joining method is also a temporary member, so it is not always necessary to join them by welding or the like. In some cases, for example, a water-resistant tape or an adhesive is sufficient.

In addition, the crown member is placed between the circular top plate and the head of the pile so that the state of separation between the circular top plate and the end plate is maintained when fresh concrete is placed when the foundation member is formed. It is configured so that fresh concrete does not flow in. After the fresh concrete is hardened , the foundation member is piled by allowing the vertical load from the superstructure to be transmitted to the pile only through the pile head joining rod. The head is not restricted rotationally.

  According to the pile head joining temporary tool provided with such a crowned member, the crowned member functions as a so-called formwork member for preventing fresh concrete from flowing between the circular top plate and the end plate of the pile head. After the fresh concrete is hardened, the crown member is integrated with the foundation member, and the inner peripheral surface of the cylindrical body constituting the crown member is a part of the side surface of the recess among the inner surfaces of the embedded recesses in the pile head joint structure or The bottom surface of the circular top plate becomes the concave ceiling surface.

  When covering the crown member on the pile head, it may be covered so that the inner peripheral surface of the cylindrical body overlaps the peripheral surface of the pile head, or the outer peripheral surface of the cylindrical body and the peripheral surface of the pile head are substantially flush. The lower end of the cylindrical body may be covered so as to be placed on the periphery of the end plate of the pile head.

  When covering the cylindrical body so as to overlap the circumferential surface of the pile head, for example, the cylindrical body and the pile head may be temporarily fixed with an adhesive to maintain the separated state between the circular top plate and the end plate. If a spacer is interposed between the circular top plate and the head of the pile, it is possible to reliably maintain the separated state of both.

  The spacer has its elasto-plastic characteristics set appropriately so that it undergoes elastic deformation or plastic deformation or brittle fracture when relative rotational deformation acts between the foundation member and the head of the pile after setting the fresh concrete. deep.

  According to this configuration, the foundation member can be prevented from exerting rotational restraint on the head of the pile.

  The form of the spacer is arbitrary, and for example, it can be a corrugated spacer or a tubular spacer through which a pile head joining rod is inserted.

  On the other hand, when the lower end of the cylindrical body is placed on the periphery of the end plate of the pile head so that the outer peripheral surface of the cylindrical body and the peripheral surface of the pile head are substantially flush, the crowned member itself supports the pressure of fresh concrete In this way, the separation between the circular top plate and the end plate is ensured, but after hardening the fresh concrete, it is elastically deformed or plastically deformed or brittle due to the relative rotational deformation of the foundation member and the head of the pile, like the spacer. The elasto-plastic characteristics of the crowned member are set as appropriate so that the foundation member does not rotationally restrain the head of the pile by breaking.

  In order to prevent fresh concrete from flowing between the circular top plate and the head of the pile, for example, a water-resistant tape may be wound so as to straddle the lower end edge of the cylindrical body and the peripheral surface of the pile head. It is also possible to adopt a configuration in which a concrete inflow prevention material is filled or arranged between the circular top plate and the head of the pile.

  The concrete inflow prevention material is a material that elastically deforms, shrinks or brittlely breaks so that the foundation member does not constrain the head of the pile after rotation of fresh concrete, such as sponge, foamed polystyrene, foamed urethane, etc. It can be made of a foam material.

  When the concrete inflow preventing material is made of a foam material, it also serves as a spacer for maintaining the separated state between the circular top plate and the end plate of the pile.

  The rod for connecting the pile head is arbitrary as long as the bending moment of the pile head can be supported by the compressive force and the tensile force, for example, a rod member such as an anchor reinforcing bar erected on the end plate It can be constituted by a fixing plate attached to a predetermined position of the rod member.

  Here, if the sheath tube through which the rod member is inserted is provided in the pile head joining rod, the rod member can be unbonded, and the rotational rigidity of the pile head can be set small.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a pile head joint structure according to the present invention and a pile head joint temporary tool used for the construction will be described with reference to the accompanying drawings. Note that components that are substantially the same as those of the prior art are assigned the same reference numerals, and descriptions thereof are omitted.

  FIG. 1 is a cross-sectional view showing a pile head joining structure according to this embodiment and a pile head joining temporary tool used for the construction, and FIG. 2 is a perspective view showing the pile head joining temporary tool. As can be seen from these drawings, the pile head joint structure 21 according to the present embodiment embeds the head 3 of the pile 2 (hereinafter, the pile head 3) in the foundation slab 6 that is the foundation member of the upper structure 5, Among the inner surfaces of the embedded recesses of the foundation slab 6 in which the anchor rebar 7 as a pile head joining rod is erected on the end plate 4 provided on the pile head 3 and embedded in the foundation slab 6 The concave ceiling surface 11 is separated from the upper surface of the end plate 4.

  The anchor rebar 7 is erected on the end plate 4 by a known fixing method such as welding or screwing.

  In order to construct such a pile head joining structure 21, the pile head joining temporary tool 1 shown in FIGS. 1 and 2 may be used. The pile head joining temporary tool 1 includes a crowned member 10 including a circular top plate 8 formed with an insertion hole 12 through which an anchor reinforcing bar 7 is inserted, and a cylindrical body 9 suspended from the periphery of the circular top plate. .

  The hole diameter of the insertion hole 12 is appropriately determined so that the circular top plate 8 and the anchor reinforcing bar 7 are not fixed, and fresh concrete described later does not flow into the crowned member 10.

  As can be clearly seen in FIG. 1, the crown member 10 is separated from the upper surface of the end plate 4 by Δh in a state where the anchor reinforcing bars 7 are inserted into the insertion holes 12 formed in the circular top plate 8. It can be put on the pile head 3 in a state.

Here, the crown member 10 is
i) When placing fresh concrete for forming the foundation slab 6, so that the separated state between the circular top plate 8 and the end plate 4 is maintained.
ii) To prevent fresh concrete from flowing between the circular top plate 8 and the pile head 3,
iii) After the fresh concrete has hardened, make sure that the foundation slab 6 does not impose rotational restraints on the pile head 3.
Configure as appropriate.

  In order to satisfy such requirements, for example, the inner diameter of the cylindrical body 9 constituting the crowned member 10 is matched with the outer diameter of the pile 2, and the inner peripheral surface of the cylindrical body is overlapped with the peripheral surface of the pile head 3. What is necessary is just to temporarily fix both with an adhesive agent.

  The type and application thickness of the adhesive are such that when the fresh concrete is placed, the pressure is supported to maintain the separation between the circular top plate 8 and the end plate 4, and after the fresh concrete is cured, What is necessary is just to determine suitably so that adhesion | attachment may be cut | disconnected by seismic motion and other relative forced deformation.

  In order to construct the pile head joining structure 21 using the temporary tool 1 for pile head joining, the anchor rebar 7 erected on the end plate 4 is inserted into the circular top plate 8 and the bottom surface of the circular top plate 8 The crown member 10 is placed on the pile head 3 so as to be separated from the upper surface of the end plate 4 by Δh, and fresh concrete is placed around the crown member 10 in this state, so that the foundation around the pile head 3 is provided. While forming the slab 6, the anchor reinforcement 7 is embed | buried in this foundation | substrate slab.

  In addition, after the fresh concrete placed around the crown member 10 is hardened, as a result, an embedded recess is formed in the foundation slab 6, and the pile head 3 is embedded in the embedded recess by a depth D. At the same time, the crowned member 10 is integrated with the basic slab 6, the inner peripheral surface of the cylindrical body 9 is a part of the side surface of the concave portion of the inner surface of the embedded concave portion, and the lower surface of the circular top plate 8 is the concave ceiling surface. 11 and spaced from the upper surface of the end plate 4 by Δh.

  Incidentally, the depth of the embedded recess is D ′ as shown in FIG. 1, and the embedded depth D is shallower than the depth D ′ of the embedded recess by Δh. What is necessary is just to set the embedding depth D suitably by the relationship with the shearing force transmission of the foundation slab 6 and the pile 2. FIG.

  Δh assumes the amount of rotation of the pile head 3 due to the design seismic motion, the circular top plate 8 and the pile head 3 are not in contact with each other, and the anchor rebar 7 is Set appropriately so as not to buckle between.

  In the pile head joining structure 21 and the pile head joining temporary tool 1 using the same according to the present embodiment, the circular top plate 8 serving as a recessed ceiling surface among the inner surfaces of the recessed recessed portions of the foundation slab 6 in which the pile heads 3 are embedded. The lower surface 11 is spaced from the upper surface of the end plate 4.

  In this way, as shown in FIG. 3, when a horizontal force during an earthquake acts on the pile head 3 from the upper structure 5, the bottom surface of the circular top plate 8 that is the recessed ceiling surface of the embedded recess formed in the foundation slab 6. 11 and the pile head 3 are in a non-contact state, the pile head 3 is not subjected to rotational restraint from the foundation slab 6, and the bending moment M generated in the pile head 3 is an anchor rebar 7 on both the compression side and the tension side. Will bear.

  That is, a compressive force C is generated in the compression-side anchor reinforcing bar 7, and a tensile force T is generated in the tensile-side anchor reinforcing bar 7, and these forces are balanced with the bending moment M. Since the bending moment shown in FIG. 3 is a moment generated at the pile head, the direction is opposite to the bending moment acting on the end plate 4 when considering the balance.

  As described above, since the lower surface 11 of the circular top plate 8 and the pile head 3 are in a non-contact state and the rotation restraint from the foundation slab 6 to the pile head 3 is eliminated, the bending moment M generated at the pile head 3 is The anchor rebar 7 bears both the compression side and the tension side. In other words, the pile head 3 is rotationally restrained by the compressive force C and the tensile force T via the anchor rebar 7, but is not subject to rotational restraint due to compressive force transmission with the foundation slab 6. This rotation constraint is a rotation constraint that does not depend on the axial force.

FIG. 4 is a schematic diagram showing a deformed state of the pile head 3 within the elastic range. First, when the axial force is relatively large ((a)), the compressive strain caused by the axial force is δ ₁ , the compressive strain due to the bending moment M is δ _c , and the tensile strain due to the bending moment M is δ _t . Then, the rotation angle R ₁ is
R ₁ = {(δ _c + δ ₁ ) + (δ _t −δ ₁ )} / (2 · r)
= (Δ _c + δ _t ) / (2 · r)
r: Distance from the center of the pile to the anchor reinforcement 7 Next, when the axial force is relatively small ((b)), assuming that the compressive strain caused by the axial force is δ ₂ , the rotation angle R ₂ is
R ₂ = {(δ _c + δ ₂ ) + (δ _t −δ ₂ )} / (2 · r)
= (Δ _c + δ _t ) / (2 · r)
It becomes. Next, when the pulling force is applied ((c)), if the tensile strain generated by the axial force is δ ₃ , the rotation angle R ₃ is
R ₃ = {(δ _t + δ ₃ ) + (δ _c −δ ₃ )} / (2 · r)
= (Δ _c + δ _t ) / (2 · r)
It becomes.

Here, if the bending moment M is the same, since δ _c and δ _t are also constant, the rotation angles R ₁ , R ₂ , and R ₃ have the same value, and the rotation angle R with respect to the predetermined bending moment M, that is, the rotation rigidity is It can be seen that it does not depend on the magnitude of the axial force.

  As described above, according to the pile head joining structure 21 and the pile head joining temporary tool 1 used for the construction according to the present embodiment, the rotational rigidity of the pile head 3 does not depend on the axial force, and the design process is simplified. Can be realized.

  In this embodiment, when covering the crowned member 10 on the pile head 3, it was covered so that the inner peripheral surface of the cylindrical body 9 overlapped with the peripheral surface of the pile head 3, but instead of this, as shown in FIG. The lower end of the cylindrical body may be placed on the periphery of the end plate 4 of the pile head 3 so that the outer peripheral surface of the cylindrical body 9 and the peripheral surface of the pile head 3 are substantially flush with each other.

  Further, in this embodiment, the example using the crowned member 10 has been described as the configuration in which the recessed ceiling surface of the embedded recessed portion formed in the base member is separated from the upper surface of the end plate, but in realizing the above-described configuration However, the present invention is not limited to such a configuration, and any configuration may be used as long as rotation restraint due to transmission of compressive force between the base member and the end plate does not occur.

  That is, the crown member 10 functions as a so-called formwork member that secures the separation between the recessed ceiling surface of the recessed recessed portion and the end plate and prevents fresh concrete from flowing between them. In terms of meaning, instead of the crowned member 10, a formwork may be appropriately arranged at the site.

  Furthermore, the formwork member is omitted, and as shown in FIG. 6, the pile head 3 is embedded in the embedded concave portion having a depth D ′ so that the embedded depth is D. 11 'may be separated from the upper surface of the end plate 4 provided on the pile head 3.

  Moreover, in this embodiment, when covering the crowned member 10 on the pile head 3, after overlapping the inner peripheral surface of the cylindrical body 9 and the peripheral surface of the pile head 3 which comprise this crowned member, both are adhesives However, instead of this, as shown in FIG. 7, the anchor rebar 7 has a tubular shape in advance. The spacer 61 may be fitted and the crown member 10 may be placed on the pile head 3 in such a state.

  In such a configuration, the pile head joining temporary tool of the present invention newly includes the spacer 61 in addition to the crowned member 10.

  The cylindrical spacer 61 is manufactured so that the height thereof is Δh, and when placing the concrete, the pressure of the fresh concrete is supported and the separation state between the circular top plate 8 and the end plate 4 is set to Δh. On the other hand, after the concrete is hardened, its elasto-plastic characteristics are appropriately set so that the foundation slab 6 does not constrain the pile head 3 from rotating.

  For example, the pressure of fresh concrete is supported, but the brittle fracture may be caused by the forced rotational deformation of the foundation slab 6 and the pile head 3 generated during an earthquake.

  The spacer is not limited to the cylindrical spacer 61, and the configuration thereof is arbitrary as long as it has the above-described function. For example, an annular spacer formed in a corrugated plate shape may be arranged between the upper surface of the end plate 4 and the circular top plate 8.

  Although not particularly mentioned in the present embodiment, if there is a concern that the fresh concrete may still flow between the circular top plate 8 and the end plate 4 even with the above-described configuration, as shown in FIG. You may make it block | close the clearance gap with the pile head 3 by sticking the water-resistant tape 71 along the lower edge part of the cylindrical body 9 which comprises the crown member 10. FIG.

  Further, instead of the water-resistant tape 71, as shown in FIG. 9, a concrete inflow prevention material 81 may be filled or disposed between the circular top plate 8 and the pile head 3.

  The concrete inflow preventing material 81 is a material that elastically deforms, contracts, or brittlely breaks so that the foundation slab 6 does not restrain the rotation of the pile head 3 after the fresh concrete is cured, for example, sponge, foamed polystyrene, foamed urethane. It can be composed of other foam materials.

  When the concrete inflow prevention material 81 is made of a foam material, it also serves as a spacer for maintaining a separated state between the circular top plate 8 and the end plate 4 of the pile 2.

  In this configuration, the pile head joining temporary tool of the present invention newly includes the concrete inflow preventing material 81 in addition to the crowned member 10.

  Moreover, in this embodiment, the pile head joining rod was comprised with the anchor reinforcing bar 7, However, As long as the pile head joining rod which concerns on this invention can support the bending moment of a pile head with a compressive force and a tensile force, how It may be configured as follows.

  10 and 11 show a rod head joint rod comprising a rod member 93 erected on the end plate 4, a fixing plate 92 attached in the vicinity of the upper end of the rod member, and a sheath tube 91 through which the rod member 93 is inserted. 94 is constructed.

  The sheath tube 91 is preferably composed of a flexible tube so as not to restrain the deformation of the rod member 93.

  The fixing plate 92 can be formed in a circular shape or a polygonal shape, and is configured to support the pulling force with a margin with respect to the pulling force in the assumed earthquake motion.

  The rod member 93 employs a screw rebar in which a male screw for screwing the fixing plate 92 is cut at the upper end, but a normal deformed rebar may be employed instead. In such a case, a screw may be cut into the deformed reinforcing bar, or the fixing plate 92 may be welded to the deformed reinforcing bar.

  According to such a modification, since the rod member 93 is unbonded, the elongation of the rod member 93 is increased, and the rotational rigidity of the pile head 3 can be set small, and the fixing degree of the pile head is reduced. be able to.

  10 and 11, since almost the entire length of the rod member 93 is covered with the sheath tube 91, only the fixing plate 92 serves as a fixing portion, and the rod member 93 serves as a non-fixing portion. If the length of the sheath tube 91 is shortened and a part of the rod member 93 is exposed, the exposed portion of the rod member 93 becomes a new fixing portion.

  Furthermore, the sheath tube 91 may be omitted. According to such a modification, not only the fixing plate 92 functions as a fixing unit, but also the rod member 93 functions as a fixing unit over the entire length thereof.

Sectional drawing of the pile head joining structure used for the pile head joining structure which concerns on this embodiment, and its construction. The perspective view of the temporary tool for pile head joining which concerns on this embodiment. The conceptual diagram which shows the effect | action of this embodiment. The schematic diagram which similarly shows an effect | action. Sectional drawing which showed the pile head junction structure which concerns on a modification. Sectional drawing of the pile head junction structure which abbreviate | omitted the crowned member. Sectional drawing of the pile head joining structure using the temporary tool for pile head joining provided with the spacer. Sectional drawing of the pile head joint structure which aimed at the inflow prevention of concrete with water-resistant tape. Sectional drawing of the temporary tool for pile head joining provided with the shrinkable filler, and a pile head joined structure using the same. The perspective view of the temporary tool for pile head joining which concerns on the modification which comprised the rod for pile head joining with the rod member, the fixing board, and the sheath pipe | tube. Sectional drawing which similarly showed the temporary tool for pile head joining, and the pile head joint structure using the same.

Explanation of symbols

1 Temporary tool for pile head joint 2 Pile 3 Head, pile head 4 End plate 5 Upper structure 6 Foundation slab (foundation member)
7 Anchor rebar (Pile head joint rod)
8 Circular top plate (crown member)
9 Cylindrical body (crown member)
DESCRIPTION OF SYMBOLS 10 Crowned member 11, 11 'Recessed ceiling surface 21 Pile head joining structure 61 Spacer 81 Concrete inflow prevention material 91 Sheath pipe 92 Fixing plate 93 Rod member 94 Pile head joining rod

Claims (6)

In the pile head joint structure in which the head of the pile is embedded in the foundation member of the superstructure,
Of the inner surface of the embedding recessed portion of the foundation member in which the pile head connecting rod is erected on the end plate provided on the head of the pile and embedded in the foundation member, The pile head joint structure characterized in that the ceiling surface is separated from the upper surface of the end plate so that a vertical load from the upper structure is transmitted to the pile only through the pile head joint rod . The pile head joining structure according to claim 1, wherein the pile head joining rod is composed of a rod member erected on the end plate and a fixing plate attached to a predetermined position of the rod member. The pile head joint structure according to claim 2, wherein a sheath pipe through which the rod member is inserted is provided in the pile head joint rod. Pile head joint temporary construction used for a pile head joint structure in which a pile head joint rod erected on an end plate provided at the head of the pile is buried in a foundation member of an upper structure in which the pile head is embedded A circular top plate with an insertion hole through which the rod for joining the pile heads is inserted, and a crowned member made of a cylindrical body suspended from the periphery of the circular top plate, The member is configured to be able to cover the head of the pile in a state where the pile head joining rod is inserted through the insertion hole formed in the circular top plate, When placing the fresh concrete during the formation of the foundation member, the fresh concrete is placed between the circular top plate and the head of the pile so that the separated state of the circular top plate and the end plate is maintained. It is configured not to flow in and is fresh After Nkurito curing, said base member by a vertical load from the superstructure is to be transmitted to the pile via only the pile head joint rod does not exert a rotational restraint to the head of the pile It is comprised as follows. The temporary tool for pile head joining characterized by the above-mentioned. The temporary tool for pile head joining of Claim 4 provided with the concrete inflow prevention material filled or arrange | positioned between the said circular top plate and the head of the said pile. Pile head joint temporary construction used for a pile head joint structure in which a pile head joint rod erected on an end plate provided at the head of the pile is buried in a foundation member of an upper structure in which the pile head is embedded A circular top plate with an insertion hole through which the rod for joining the pile heads is inserted, and a crowned member made of a cylindrical body suspended from the periphery of the circular top plate, The member is configured to be able to cover the head of the pile in a state where the pile head joining rod is inserted through the insertion hole formed in the circular top plate, When placing the fresh concrete during the formation of the foundation member, the fresh concrete is placed between the circular top plate and the head of the pile so that the separated state of the circular top plate and the end plate is maintained. It is configured not to flow in and is fresh After hardening, the foundation member is constructed so as not to restrain rotation of the head of the pile, and is interposed between the circular top plate and the head of the pile to maintain the separated state. A temporary tool for joining a pile head, characterized by comprising a spacer to be used.

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