JP2018159180A - Building foundation structure and construction method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a building foundation structure and a construction method thereof capable of suppressing horizontal deformation of a steel column at an outer boundary of a building based on a building foundation constructed: by respectively inserting each of column base part of steel columns to each of insides of steel pipes connected to each top of pile heads of a plurality of existing piles arranged along the outer boundary of the building; and by integrally connecting the steel columns to the existing piles without using footing beams and footing through pile head concrete poured in each of insides of the steel pipes.SOLUTION: Rib type beams 8 of reinforce concrete, which are arranged on the ground G along an outer boundary of a building 2, connecting in series each of a plurality of steel pipe columns 5 projecting upward from each of steel pipes 4, are integrated with reinforced concrete slab 9 installed on the ground within the building surrounded with beams.SELECTED DRAWING: Figure 2

Description

  The present invention inserts a column base portion of a steel column into each steel pipe joined on the pile heads of a plurality of prefabricated piles arranged along the outer periphery of the building, and via a pile head concrete placed in the steel pipe. Building foundation capable of suppressing horizontal deformation of steel columns on the outer periphery of the building on the premise of a building foundation in which steel columns are integrally joined to the existing pile without using foundation beams and footings It is related with a part structure and its construction method.

  The foundation beam is inserted into each steel pipe joined on the pile heads of a plurality of prefabricated piles arranged along the outer periphery of the building, and the column base part of the steel column is inserted into the steel pipe and placed inside the steel pipe. Patent Document 1 is known as a technique for integrally joining a steel column to an existing pile without using a footing.

  Patent Document 1 “Fundamental Concrete Pile with Steel Structure and Construction Method and Precast Concrete Pile with Steel Pipe” is designed to make the connection between the precast concrete pile and the steel column that make up the foundation structure solid and to transmit bending stress smoothly. However, by avoiding the work on the site and the root cutting work, it is an object to provide the foundation structure and construction method of steel-framed building and the precast concrete pile with steel pipe that can reduce the construction cost and shorten the construction period. Prefabricated concrete pile with a circular hollow cross section placed at a predetermined position, a steel pipe that is equal to or less than the outer diameter of the precast concrete pile and joined to the top end of the pile head of the precast concrete pile, and is installed at a predetermined position in the steel pipe and integrated with concrete It is made up of a steel column that is made into a steel pipe, and a mounting flange is provided at the lower end of the steel pipe and bolted to the upper end surface of the pile head, and the shear reinforcement is supported by the vertical bars protruding from the upper end surface of the pile head. And so as to fill the concrete is fixed by being bottomed steel pipe hanging in the hollow portion of the pile.

JP 2004-108034 A

  In this type of foundation structure shown by the background art, since there is no foundation beam that supports the floor slab of the first floor of the building, the floor of the first floor is often made of reinforced concrete.

  In this case, the soil concrete resists the horizontal lateral stress acting on the column base of the steel column at the inside of the building with respect to the outer periphery of the building, but there is no structure that resists this horizontal lateral stress at the outer periphery of the building. For this reason, there has been a problem that the horizontal deformation of the column base portion of the steel column becomes large.

  The present invention was devised in view of the above-described conventional problems, and a steel column base is attached to each steel pipe joined to the pile heads of a plurality of prefabricated piles arranged along the outer periphery of the building. The steel frame on the outer periphery of the building is premised on the foundation of the building in which the steel column is integrally joined to the existing pile without using the foundation beam and footing through the pile head concrete that is inserted and placed inside the steel pipe. It aims at providing the building foundation part structure which can suppress horizontal deformation | transformation of a pillar, and its construction method.

  In the building foundation structure according to the present invention, a steel column base is inserted into each steel pipe joined to the pile heads of a plurality of pre-built piles arranged along the outer periphery of the building, and the steel pipe is cast into the steel pipe. It is a building foundation structure in which the steel column is integrally joined to the existing pile without using the foundation beam and footing through the pile head concrete to be installed, along the outer periphery of the building on the ground A reinforced concrete slab provided on the ground inside the building surrounded by the reinforced concrete rib-like beam that is provided and connects a plurality of the steel columns protruding upward from the steel pipes in series. It is characterized by being integrated.

  The small beam is provided along the outer periphery of the building, and is integrated with a reinforced concrete waist wall on which a wall material is placed.

  A planar U-shaped reinforcing bar that engages with the beam reinforcing bar via the beam concrete is embedded along the outer periphery of the steel column at least in the beam concrete of the beam. In parallel with each other and at a position perpendicular to the transverse portion, and one end is connected to each end of the transverse portion. It is characterized by comprising a pair of fixing portions, the ends of which are formed with a length that reaches or exceeds the fixing length from the steel column and sandwiches the steel column from both sides.

  An edge cutting material is provided between the steel pipe and the small beam above the steel pipe so as to transmit a vertical longitudinal force and interrupt a horizontal lateral force.

  A construction method for a building foundation structure according to the present invention is a construction method for constructing the building foundation structure, wherein a plurality of the existing piles obtained by joining the steel pipes on the pile head are disposed on the outer periphery of the building. The steel column is placed in the ground, and the column base portion of the steel column is inserted into each of the steel pipes. A pile head construction process that integrally joins the pile, and a beam so as to connect a plurality of the steel columns arranged on the ground along the outer periphery of the building and projecting upward from the steel pipes in series. In order to integrate the reinforcing bar and the small beam and the slab, the slab reinforcing bar is arranged on the ground surrounded by the beam reinforcing bar so that at least a part of the beam is integrated with the beam reinforcing bar. Rebaring process including work, the beam rebar and A formwork process for installing a formwork surrounding the slab rebar, and a concrete placing process for constructing the beam and the slab integrally by placing beam concrete and slab concrete inside the formwork. It is characterized by that.

  Moreover, the construction method of the building foundation part structure concerning this invention is a construction method for constructing the said building foundation part structure, Comprising: The said several piles which joined the said steel pipe on the said pile head are said building Arranged along the outer periphery and placed on the ground, and after inserting the column base of the steel column into each of these steel pipes, the pile head concrete was placed inside these steel pipes, A pile head construction step that is integrally joined to the existing pile, and a plurality of the steel columns that are arranged along the outer periphery of the pile and projecting upward from the steel pipes on the ground. The ground surrounded by the beam reinforcing bar so that at least a part of the beam reinforcing bar is integrated with the beam reinforcing bar so as to integrate the beam, the slab, and the waist wall. Arrange slab reinforcement above and outside the building Laying steps including the work of laying wall rebars along the line, the formwork step of installing the formwork surrounding the beam reinforcement, the slab reinforcement and the wall reinforcement, and the beam concrete inside the formwork The slab concrete and the wall concrete are cast, or the beam concrete and the slab concrete are cast and then the wall concrete is cast, so that the small beam, the slab and the waist wall are integrally constructed. And a concrete placing process.

  In the bar arrangement process, a plane U-shaped reinforcing bar that is embedded in at least the beam concrete along the outer periphery of the steel column and engages the beam reinforcing bar via the beam concrete is arranged. It is characterized by.

  Before the bar arrangement step, an edge cutting material is provided between the steel pipe and the small beam.

  In the building foundation structure and its construction method according to the present invention, the column base of the steel column is inserted into each steel pipe joined on the pile heads of a plurality of pre-built piles arranged along the outer periphery of the building. Assuming the foundation of the building to be joined integrally with the existing pile without using the foundation beam and footing through the pile head concrete placed inside the steel pipe, the steel column on the outer periphery of the building Can be suppressed in the horizontal direction.

It is principal part sectional drawing which shows suitable one Embodiment of the building foundation part structure which concerns on this invention. It is an expanded side sectional view for showing the bar arrangement state of the building foundation part structure shown in FIG. It is front sectional drawing for showing the bar arrangement state of the building foundation part structure shown in FIG. It is a plane sectional view for showing the bar arrangement state of the building foundation part structure shown in FIG.

  EMBODIMENT OF THE INVENTION Below, suitable one Embodiment of the building foundation part structure concerning the present invention and its construction method is described in detail with reference to an accompanying drawing. FIG. 1 is a side sectional view of a main part of a building foundation part structure according to the present embodiment, FIG. 2 is an enlarged side sectional view for showing a bar arrangement state of the building foundation part structure shown in FIG. FIG. 4 is a front sectional view for illustrating a bar arrangement state of the building foundation structure shown in FIG. 1, and FIG. 4 is a plan sectional view for illustrating a bar arrangement state of the building foundation structure shown in FIG.

  The building foundation structure according to the present embodiment will be described below along the procedure of the construction method for the building foundation structure according to the present embodiment. First, the pile head construction process is carried out. A hollow cylindrical steel pipe 4 is installed on a steel ring 1b provided on the upper end surface of a pile head 1a of a prefabricated pile 1 such as a PC pile, and the steel pipe 4 is bolted or welded to the steel ring 1b. Thus, the steel pipe 4 is joined on the pile head 1a of the existing pile 1.

  Further, the ground surface is excavated along the outer periphery of the building 2 where the prefabricated pile 1 is placed to form the groove portion 3, and then arranged in the ground G along the groove portion 3 along the outer periphery of the building 2. Multiple.

  The groove portion 3 is formed to have an inclined surface 3a inclined upward toward the ground surface toward the inside of the building 2 on the side opposite to the outside of the building 2. The built-up pile 1 may be driven inward of the building 2 with respect to the outer periphery of the building 2 in accordance with the column installation position.

  Next, although not shown in the drawing, concrete is placed inside each steel pipe 4 to a height position where a steel column, in this embodiment, a hollow tubular steel pipe column 5 is installed. After the concrete is hardened, a level mortar is constructed on the concrete, and the column base 5a of the steel pipe column 5 is inserted into the steel pipe 4 and installed on the level mortar.

  Next, the pile head concrete Cp is placed inside the steel pipe 4 so as to be filled around the steel pipe column 5, and the steel pipe column 5 is integrally joined to the existing pile 1 through the pile head concrete Cp. . At this time, the steel pipe column 5 is also filled with concrete to a suitable height. Thereby, the steel pipe pillar 5 protruded upwards from the ground surface and the existing pile 1 in the ground G are integrated without using a foundation beam or a footing.

  Next, an operation of providing the edge cutting members 6 and 7 is performed. A crushed stone 6 is laid on the entire area inside the building 2 from the outside of the column surface 5b facing the outside of the building 2 of the steel pipe column 5 along the outer peripheral position of the building 2, and then abandoned concrete 7 is placed on the crushed stone 6 To do. That is, the edge members 6 and 7 are provided around the steel pipe column 5 in the groove 3, flat on the ground surface, and obliquely along the inclined surface 3 a on the inclined surface 3 a of the groove 3.

  The crushed stone 6 and the discarded concrete 7 are subjected to the vertical longitudinal force, that is, mainly the load of the building 2 between the steel pipe 4 and a rib-like beam 8 described later constructed in a range extending from the groove 3 to the inclined surface 3a. In addition to transmitting, it becomes an edge-cutting material that blocks horizontal lateral force, that is, transmission of seismic force, wind force, and the like.

  Next, a bar arrangement process is performed on the ground G. In the reinforcing bar arrangement process, at least the beam reinforcing bars 8a and 8b of the rib-like beam 8 and the slab reinforcing bar 9a of the slab 9 are arranged, and preferably, the wall reinforcing bar 10a of the waist wall 10 is also arranged. Work is performed.

  The reinforcing bars of the beam reinforcing bars 8a and 8b are equivalent to the well-known small beam reinforcing bars applied to so-called small beams, and the length direction is along the arrangement direction of the steel pipe columns 5, that is, along the outer periphery of the building 2. The plurality of main muscles 8a and the plurality of stirrup muscles 8b arranged to surround the plurality of main muscles 8a.

  The plurality of main muscles 8a are arranged in an annular shape at intervals. A plurality of stirrup muscles 8b are arranged at intervals from each other in the length direction of the main muscle 8a. The beam reinforcing bars 8a and 8b are arranged between the steel pipe columns 5 located on the outer periphery of the building 2 and the steel pipe columns 5 located on the inside of the building 2 or between the steel pipe columns 5 arranged on the inside of the building 2. You may make it streaks.

  The beam reinforcing bars 8 a and 8 b are arranged on the discarded concrete 7. The main reinforcing bars 8 a of the beam reinforcing bars 8 a and 8 b include those that abut against the steel pipe column 5 and those that pass through the side of the steel pipe column 5. The main reinforcement 8a arranged at the position where it abuts against the steel pipe column 5 is a position in front of the steel pipe column 5, and the upper end of the main reinforcement 8a is bent downward in an L shape downward, and the lower end of the main reinforcement 8a is the upper end. The bar is bent up into an L shape and placed (see part A in FIG. 3).

  The main reinforcement 8a passing through the side of the steel pipe column 5 is connected to a plurality of steel pipe columns 5 arranged on the discarded concrete 7 along the outer periphery of the building 2 and protruding upward from the steel pipes 4 in series. The bars are continuously joined by lap joints and the like. Beam rebars 8a and 8b provided between the steel pipe columns 5 located on the outer periphery of the building 2 and the steel pipe columns 5 located on the inner side of the building 2 or between the steel pipe columns 5 arranged on the inner side of the building 2, It is similarly arranged.

  The slab reinforcing bar 9a is arranged on the discarded concrete 7 on the ground G surrounded by the beam reinforcing bars 8a and 8b provided at least on the outer periphery of the building 2. The slab reinforcing bars 9a are configured to be assembled in a planar lattice shape. The slab reinforcing bars 9a are laid on the discarded concrete 7 so that they are arranged in multiple layers in the vertical direction and spaced apart from each other.

  In order to integrate the slab 9 and the small beam 8, the slab reinforcing bar 9a is inserted into the stirrup bar 8b inward so that the edge portion along the outer periphery of the building 2 is complicated with the beam reinforcing bars 8a and 8b. Is done. That is, a part of the slab reinforcing bar 9a is arranged to be swallowed by the small beam 8.

  The wall reinforcing bars 10a are arranged along at least the beam reinforcing bars 8a and 8b provided on the outer periphery of the building 2. The wall reinforcing bars 10a are configured to be assembled in an upright lattice shape. The wall reinforcing bars 10a are arranged in a multilayered manner in the left and right lateral directions so as to be spaced apart from each other so as to stand outward from the column surface 5b facing the outside of the building 2 of the steel pipe column 5 along the outer peripheral position of the building 2.

  In order to integrate the waist wall 10 and the small beam 8, the wall reinforcing bar 10a is inserted into the stirrup reinforcing bar 8b so that the lower part is complicated with the beam reinforcing bars 8a and 8b. That is, a part of the wall reinforcing bar 10a is arranged to be swallowed by the small beam 8.

  Further, in the bar arrangement process, a steel U-shaped steel reinforcing bar 11 is arranged along the outer periphery of the steel column 5. More specifically, the planar U-shaped form of the reinforcing reinforcing bar 11 is composed of a transverse portion 11a and a pair of fixing portions 11b that are connected to each other at both ends of the transverse portion 11a in the longitudinal direction at right angles. Accordingly, the traversing portion 11a and each fixing portion 11b are formed at a right angle. In other words, the pair of fixing portions 11b has a U-shape including a form in which one end in the length direction is connected to both ends in the length direction of the traversing portion 11a via a right-angled bent portion.

  The traversing portion 11 a is formed in a positional relationship parallel to the outer periphery of the building 2 and larger than the column width dimension of the steel pipe column 5. And the position of the traverse part 11a is set so that the both ends may protrude from the width direction both sides of the steel pipe pillar 5. As shown in FIG. A pair of fixing parts 11b, one end of which is connected to the transverse part 11a, are arranged so as to sandwich the steel pipe column 5 from both sides. Although the number of reinforcing bars 11 may be one, it is preferable to provide a plurality of reinforcing bars 11 in a plurality of stages in the height direction of the steel pipe column 5.

  In detail, the reinforcing bars 11 are arranged so that the traversing portion 11a is arranged in parallel with the outer periphery of the building 2, so that the fixing portion 11b is arranged so as to go inward of the building 2 from the position of the traversing portion 11a on the outer periphery of the building 2. And a pair of fixing | fixed part 11b is the length which reaches the fixing length L or more from the column surface 5c facing the building 2 inner side on the opposite side to the column surface 5b facing the building outer side of the steel pipe column 5 along the outer periphery position of the building 2 Formed with dimensions.

  Usually, the fixing portion 11b is extended inward of the slab 9 so as to be complicated with the slab reinforcing bar 9b. In other words, the traversing portion 11a is arranged in the vicinity of the wall rebar 10a or in a complicated position with the wall rebar 10a, and the fixing portion 11b is a slab that passes from the position of the wall rebar 10a and passes through the vicinity of the main bar 8a that is bent up and bent down. It reaches the rebar 9a and is arranged so as to be complicated. The reinforcing reinforcing bars 11 are arranged in an L-shaped arrangement along the corner shape at the corner column position because the traversing portion 11a is arranged in parallel with the outer periphery of the building 2.

  Next, a mold forming process is performed. In the mold process, a formwork (not shown) is installed by a known installation method so as to surround at least the reinforcing reinforcing bars 11, the beam reinforcing bars 8a and 8b, and the slab reinforcing bars 9a, and preferably surround the wall reinforcing bars 10a. Schematically, the formwork is installed so as to collectively surround the slab 9 and the rib-like beam 8 from the outside of the building 2, and the formwork for forming the waist wall is installed at the position of the waist wall 10. Is done.

  Next, beam concrete Cb is placed on the beam reinforcing bars 8a and 8b, slab concrete Cs is placed on the slab reinforcing bar 9a, and wall concrete Cw is placed on the wall reinforcing bar 10a. The slab concrete Cs and the beam concrete Cb are placed at the same height level so that they are flatly connected to form a flat plane, and the wall concrete Cw is raised at an appropriate height level rising from the flat plane. It is cast.

  Thereby, the reinforced concrete rib-like beam 8, the reinforced concrete slab 9, and the reinforced concrete waist wall 10 are integrally constructed. By placing these concretes Cb, Cs, Cw, in particular, by placing the beam concrete Cb, a plane U-shaped reinforcing bar 11 is embedded in the beam concrete Cb, and the beam reinforcing bar 8a passes through the beam concrete Cb. , 8b.

  The wall concrete Cw may be placed after the beam concrete Cb and the slab concrete Cs are placed. Even in this way, the waist wall 10 and the rib-like small beam 8 can be constructed integrally. The small beam 8 is formed to be thicker than the slab 9 due to the rib shape extending from the groove 3 at the position of the steel pipe 4 and the steel pipe column 5 to the inclined surface 3a. After the cast concrete Cb, Cs, Cw is hardened, the formwork is removed.

  That is, by the concrete placing process, on the ground G, the reinforced concrete rib-like beam 8 is constructed on the ground G to connect a plurality of steel pipe columns 5 protruding upward from each steel pipe 4 along the outer periphery of the building 2. The slab 9 made of reinforced concrete is constructed on the ground surface inside the building 2 surrounded by the small beam 8, and the small beam 8 and the slab 9 are integrated with each other. It is integrated with the reinforced concrete waist wall 10 constructed in this way.

  A wall material 12 such as an ALC wall is placed on the waist wall 10 along the outer periphery of the building 2, and the wall material 12 is supported by the waist wall 10.

  In the building foundation part structure and its construction method according to the present embodiment described above, each steel pipe 4 inside joined to the pile heads 1a of a plurality of pre-made piles 1 arranged along the outer periphery of the building 2 is provided. Inserting the column base 5a of the steel pipe column 5 and integrally joining the steel pipe column 5 to the existing pile 1 without using the foundation beam and footing through the pile head concrete Cp to be placed inside the steel pipe 4 Reinforced concrete ribbed beams 8 that are provided on the ground G along the outer periphery of the building 2 and that connect a plurality of steel pipe columns 5 projecting upward from the steel pipes 4 in series are provided on the ground G. Since it is integrated with the reinforced concrete slab 9 provided on the ground surface inside the building 2 surrounded by the beam 8, the steel tube column on the outer periphery of the building 2 is provided by the small beam 8 provided to connect the steel tube columns 5 to each other. Resistance to horizontal lateral force acting on It can be, it is possible to suppress the horizontal deformation.

  The slab rebar 9a and the wall rebar 10a are arranged in a complex manner on the beam rebars 8a and 8b, and the reinforced concrete slab 9 and the reinforced concrete waist wall 10 are integrated with the reinforced concrete rib-like beam 8 that connects the steel pipe columns 5 to each other. As a result, the cross-sectional performance of the beam 8 can be improved by the slab 9 and the waist wall 10 to increase the strength thereof, and sufficient strength and rigidity can be secured around the steel pipe column 5. While the weight of the wall material 12 placed on 10 is borne, the weight can be appropriately transmitted to and supported by the existing pile 1.

  Moreover, even if the situation where the slab 9 sinks occurs, a gap is not generated between the waist wall 10 and the wall material 12, and the wall material 12 on the waist wall 10 does not collapse. Structural integrity can be ensured. Moreover, even if the surface layer is a soft ground G, the settlement around the waist wall 10 on the outer periphery of the building 2 can be prevented by the existing pile 1, so that the ground improvement with respect to the bottom of the slab 9 and the wall material 12 can be made into the steel pipe column 5. Installation of the supporting structure to be supported can be omitted, and the construction period can be shortened and the cost can be reduced.

  A reinforcing member 11 in the shape of a plane U, which is embedded in at least the beam concrete Cb of the small beam 8 along the outer periphery of the steel pipe column 5 and engages with the beam reinforcing bars 8a and 8b via the beam concrete Cb, And one end of each of the transverse portions 11a are connected to each other at a position perpendicular to the transverse portion 11a and a transverse portion 11a formed in a positional relationship parallel to the width of the steel pipe column 5. Since the other end is formed with a length that reaches the fixing length L or more from the steel pipe column 5 and is composed of a pair of fixing portions 11b that sandwich the steel pipe column 5 from both sides, the outside of the building 2 that acts on the steel pipe column 5 Thus, the reinforcing bar 11 appropriately and reliably bears the horizontal lateral force to the structure, and the structural strength of the building 2 can be improved.

  Since the edge cutting members 6 and 7 for transmitting the vertical longitudinal force and blocking the transmission of the horizontal lateral force are provided between the steel pipe 4 and the small beam 8 thereabove, the horizontal transverse force acting on the small beam 8 is provided. Directional force can be reduced.

  If the upper surface of the slab 9 and the upper surface of the rib-like beam 8 are formed flat, the effective use area inside the building 2 can be ensured appropriately.

  The steel pipe 4 joined on the pile head 1a described above may be a normal steel pipe, but the steel pipe covering the outer periphery of the SC pile is extended from the pile head by a required length. May be. Moreover, as the ready-made pile 1, the structure which joined the SC pile to the upper part of the PHC pile by the dry-type construction method by the restraint hardware of ready-made goods may be sufficient.

  It is desirable not to provide a horizontal joint between the small beam 8 and the waist wall 10 and to provide a vertical joint in the small beam 8 and the waist wall 10. When joints are provided, it is preferable that the thickness of the small beams 8 and the like is increased by the depth of the joints so that cross-sectional defects are not generated in the small beams 8 and the like.

DESCRIPTION OF SYMBOLS 1 Prefabricated pile 1a Pile head 2 Building 4 Steel pipe 5 Steel pipe pillar 5a Column base 6 Crushed stone 7 Discarded concrete 8 Reinforced concrete ribbed beam 8a, 8b Beam reinforcement 9 Reinforced concrete slab 9a Slab reinforcement 10 Reinforced concrete waist wall 10a Wall reinforcement 11 Reinforcing bars in the shape of a plane U 11a Transverse part 11b Fixing part 12 Wall material Cb Beam concrete Cp Pile head concrete Cs Slab concrete Cw Wall concrete G Ground

Claims (8)

Insert the column base of the steel column into each steel pipe joined on the pile head of a plurality of prefabricated piles arranged along the outer periphery of the building, and place the foundation through the pile head concrete placed inside the steel pipe A building foundation structure in which the steel column is integrally joined to the existing pile without using beams and footings,
Reinforced concrete ribbed beams provided on the ground along the outer periphery of the building and connecting the plurality of steel columns projecting upward from the steel pipes in series are surrounded by the beam. A building foundation structure characterized by being integrated with a reinforced concrete slab provided on the ground.   2. The building foundation structure according to claim 1, wherein the beam is provided along the outer periphery of the building and integrated with a reinforced concrete waist wall on which a wall material is placed. A planar U-shaped reinforcing bar that engages with the beam reinforcement through the beam concrete is embedded in at least the beam concrete of the small beam along the outer periphery of the steel column,
The reinforcing reinforcing bars are in a positional relationship parallel to the outer periphery of the building and in a horizontal portion formed with dimensions larger than the width dimension of the steel column, and in a positional relationship perpendicular to the horizontal portion, both ends of the horizontal portion 2. One or more ends are connected to each other, and the other end is formed with a length dimension reaching the fixing length or more from the steel column, and comprises a pair of fixing portions sandwiching the steel column from both sides. 2. Building foundation structure described in 2.   4. An edge cutting material is provided between the steel pipe and the small beam above the steel pipe so as to transmit a vertical longitudinal force and interrupt a horizontal lateral force. Building foundation structure described in any of the sections. A construction method for constructing the building foundation structure according to any one of claims 1 to 4,
After a plurality of the existing piles joined with the steel pipes on the pile heads are arranged along the outer periphery of the building and placed on the ground, and the column bases of the steel columns are inserted into the steel pipes, respectively. A pile head construction step in which the pile head concrete is placed inside these steel pipes, and the steel column is integrally joined to the existing pile;
On the ground, along the outer circumference of the building and projecting upward from the steel pipes, a plurality of the steel columns arranged in series are arranged to reinforce the beam reinforcement, the beam and the slab To arrange the slab reinforcing bar on the ground surrounded by the beam reinforcing bar so that at least a part of the beam reinforcing bar is integrated,
A formwork process for installing a formwork surrounding the beam rebar and the slab reinforce,
A construction method of a building foundation part structure comprising a concrete placing step in which beam concrete and slab concrete are placed inside the formwork to construct the beam and the slab integrally. A construction method for constructing the building foundation structure according to any one of claims 2 to 4,
After a plurality of the existing piles joined with the steel pipes on the pile heads are arranged along the outer periphery of the building and placed on the ground, and the column bases of the steel columns are inserted into the steel pipes, respectively. A pile head construction step in which the pile head concrete is placed inside these steel pipes, and the steel column is integrally joined to the existing pile;
On the ground, along the outer circumference of the building and projecting upward from the steel pipes, a plurality of the steel columns arranged in series are arranged to reinforce the beam reinforcement, the beam and the slab In order to integrate the waist wall, a slab reinforcing bar is arranged on the ground surrounded by the beam reinforcing bar so that at least a part of them is complicated with the beam reinforcing bar, and a wall is formed along the outer periphery of the building. A bar arrangement process including an operation of arranging reinforcing bars;
A formwork step of installing a formwork surrounding the beam reinforcement, the slab reinforcement and the wall reinforcement;
Beam concrete, slab concrete and wall concrete are placed inside the formwork, or the wall concrete is placed after placing the beam concrete and the slab concrete, and the beam, the slab and the A construction method for a building foundation structure comprising a concrete placing process for integrally constructing a waist wall.   In the bar arrangement process, a plane U-shaped reinforcing bar that is embedded in at least the beam concrete along the outer periphery of the steel column and engages the beam reinforcing bar via the beam concrete is arranged. The construction method of the building foundation part structure of Claim 5 or 6 characterized by these.   The construction method of a building foundation part structure according to any one of claims 5 to 7, wherein an edge cutting material is provided between the steel pipe and the small beam before the bar arrangement step.

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