JP2005113622A - Concrete foundation for building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact concrete foundation capable of standing a column on it while maintaining pressure tightness for the column. <P>SOLUTION: This concrete foundation 1 connected with an underground beam 8 and standing the column 2 on its upper face is constituted by bonding reinforcing steel plates 40, 41 on an outer peripheral side face other than a connection part with the underground beam 8. On the reinforcing steel plates 40, 41, many projections 50 protruding into the concrete foundation 1 are formed, and it is preferable that these projections 50 have different shape reinforcing bars. The reinforcing steel plates 40, 41 are used as forms when molding concrete of the concrete foundation 1 and are buried into the ground by back filling together with the concrete foundation 1 after molding concrete. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a concrete foundation for building which is connected to an underground beam and has a column erected on the upper surface.

  As shown in FIG. 1, the underground foundation portion of the building is formed with a plurality of concrete foundations 1 spaced apart from each other, and the concrete foundations 1 are connected by underground beams 8. A column such as a steel column 2 or a reinforced concrete column is erected on 1.

FIG. 7 shows an example of a conventional concrete foundation 1. The lower end base plate 103 of the steel column 2 is placed on the concrete foundation 1, and the anchor rebar 100 embedded in the concrete foundation 1 is projected upward. The upper end portion of the anchor reinforcing bar 100 is inserted into the insertion hole of the base plate 103 and fixed by a nut 104 (see Patent Document 1).
JP 2003-193560 A

  When the column 2 is installed on the concrete foundation 1 as shown in FIG. 7, the vicinity of the upper end corner P <b> 1 of the concrete foundation 1 has low pressure resistance and is easily chipped. By setting the dimension to be a certain length longer than the dimension of the base plate 103, consideration is given so that the pressure of the base plate 103 does not affect the vicinity of the upper end corner P1 of the concrete foundation 1.

  However, increasing the size of the upper surface of the concrete foundation 1 naturally leads to an increase in the size of the concrete foundation 1, which increases the construction time and increases the amount of concrete used, leading to high costs.

  An object of the present invention is to make the concrete foundation compact and save the amount of concrete used while maintaining the pressure resistance against the columns. It also aims to reduce the construction time for concrete foundations.

  In order to solve the above-mentioned problem, a concrete foundation for a building according to the present invention is a concrete foundation for a building which is connected to an underground beam and has a column standing on the upper surface, and a reinforcing iron plate is attached to the outer peripheral side surface. is there.

  Preferably, the reinforcing iron plate is formed with a number of protrusions protruding into the concrete foundation, and for example, deformed reinforcing bars are used as the protrusions.

(1) By reinforcing the outer peripheral surface of the concrete foundation on which the column is erected with a reinforcing steel plate, the upper surface of the concrete foundation is kept as narrow as the base plate of the steel column while keeping the top surface of the concrete foundation as narrow as possible. It is possible to prevent the portion from being chipped due to the pressure of the column. That is, the concrete foundation can be made compact while maintaining the pressure resistance against the columns, the amount of concrete used can be reduced, and the cost can be reduced.

(2) Since the reinforcing steel plate surrounds the outer peripheral side surface of the concrete foundation, it can be used as a formwork for foundation when placing concrete. As a result, the cost of the formwork can be saved, and the work for removing the formwork after placing the concrete is not necessary, and the construction time can be shortened.

(3) By forming a large number of protrusions that protrude into the concrete foundation on the reinforcing iron plate, it is possible to increase the bonding strength between the concrete foundation and the reinforcing iron plate, thereby increasing the strength of the concrete foundation.

(4) When a deformed reinforcing bar is used as the protrusion, the bond strength between the concrete foundation and the reinforcing iron plate is further improved.

[Underground foundation part of building]
FIG. 1 is a plan view of an underground foundation portion of a building as described above, and a plurality of concrete foundations 1 are formed in the building construction range at intervals in the vertical and horizontal directions. The foundations 1 are connected by underground beams 8, and a column such as a steel column 2 or a reinforced concrete column is erected on the concrete foundation 1.

  As can be understood from FIG. 1, two underground beams 8 are joined in an L shape to the concrete foundation 1 at the corner position A1 of the building construction range, and the outer peripheral position (except for the corner position A1) of the building construction range. ) Three underground beams 8 are joined to each concrete foundation 1 in A2 in a T shape, and four underground beams 8 are joined to each concrete foundation 1 in the internal position A3 in a cross shape. .

  In the present embodiment, the concrete foundation 1 at the corner position A1 where the underground beam 8 is joined in an L shape and the concrete foundation 1 at the outer peripheral position A2 joined in a T shape as shown in FIGS. Reinforcing iron plates 40, 41, 43, and 44 are attached.

  FIG. 2 shows a concrete foundation 1 at a T-shaped joint (position A2), in which three reinforcing iron plates 40, 41 are attached to the outer peripheral side surface of the concrete foundation 1, and each reinforcing iron plate 40, 41 has an inside of the concrete foundation 1. Many protrusions 50 made of reinforcing steel bars are formed, and these protrusions 50 enhance the bonding strength between the reinforcing iron plates 40 and 41 and the concrete foundation 1.

  The reinforcing iron plate 40 attached to the surface to which the underground beam 8 is not connected is formed with bent portions at both ends, and the bent outer surface covers the exposed outer peripheral side surface of the surface where the underground beam 8 is joined. Further, a flange portion 40a formed integrally with the bent portion is fixed to the underground beam 8 with a bolt 46 or the like. The reinforcing iron plate 41 attached to the surface to which the underground beam 8 is connected is formed in an L shape, and flange portions 41a are integrally formed at both ends. The flange portion 41a is attached to the underground beam 8 by bolts 47 or the like. It is fixed. In this way, by reinforcing the outer peripheral side surface of the concrete foundation 1 with the reinforcing iron plates 40 and 41, the overall pressure resistance of the concrete foundation 1 is increased, and in particular, the upper corner P1 in FIG. 6 is reinforced. Even if the width of the upper surface of the concrete foundation 1 is reduced, the pressure resistance (strength) against the column can be maintained.

  FIG. 3 shows a concrete foundation 1 at an L-shaped joint (position A1), in which three reinforcing iron plates 43, 44, 41 are attached to the outer peripheral side surface of the concrete foundation 1, and each reinforcing iron plate 43, 44, 41 includes As in the case of FIG. 2, a large number of reinforcing bar protrusions 50 are formed in the concrete foundation 1, and the bonding strength between the reinforcing steel plates 43, 44, 41 and the concrete foundation 1 is maintained by these protrusions 50. .

  Each of the two reinforcing iron plates 43 and 44 attached to the surface (two surfaces) to which the underground beam 8 is not connected has a bent portion at one end, and the underground beam 8 is joined by each bent portion. Further, the flange portions 43a and 44a formed integrally with the bent portion are fixed to the underground beam 8 with bolts 48. The flange portions 43b and 44b formed at the other ends of the reinforcing iron plates 43 and 44 are connected to each other by bolts 49. The remaining one reinforcing iron plate 41 is formed in an L shape, and flange portions 41a are integrally formed at both ends, and the flange portions are fixed to the underground beam 8 by bolts 47 or the like. In this way, by reinforcing the outer peripheral side surface of the concrete foundation 1 with the reinforcing iron plates 43, 44, 41, the entire compressive strength of the concrete foundation 1 becomes higher as in the case of FIG. In particular, the strength of the upper end corner P1 in FIG. 6 is increased, and the strength against the pillar can be maintained even if the width of the upper surface of the concrete foundation 1 is reduced.

  As the protrusion 50 made of reinforcing bars, for example, deformed reinforcing bars as shown in FIGS. 4 and 5 can be adopted. 4 is formed with longitudinal ribs 53 and spiral ribs 54 extending in the reinforcing bar length direction, and the deformed reinforcing bar protrusions 50 in FIG. 5 are longitudinal bars extending in the reinforcing bar length direction. The rib 53 is composed of a large number of substantially annular ribs 55. Thus, if the deformed reinforcing bar is used as the protrusion 50, the bonding strength between the reinforcing iron plate 40 and the concrete foundation 1 can be further increased.

[Example of column base structure]
FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 2, for example, and shows a state where the steel column 2 is installed on the upper surface of the concrete foundation 1. The steel column 2 is formed in a rectangular tube shape, and a rectangular base plate 4 is welded to the lower end via a backing metal 3 or the like. A mortar layer (post-packed mortar layer) 7 is formed on the upper surface of the concrete foundation 1, and the base plate 4 is placed on the upper side of the mortar layer 7 through a pair of upper and lower thick steel plate sliding support members 10, 11. Has been.

  The vertical and horizontal dimensions of the upper surface of the concrete foundation 1 and the vertical and horizontal dimensions of the base plate 4 are set to be substantially the same. That is, the dimension of the upper surface of the concrete foundation 1 is set to be substantially the same as that of the base plate 4.

  The upper and lower sliding support members 10 and 11 are stacked so as to be relatively slidable in the horizontal direction, and the lower sliding plate 11 is fixed to the upper side of the concrete foundation 1 with a bolt 13 or the like via the mortar layer 7 and is moved upward. The support member 10 is fixed to the base plate 4 of the column steel frame 2 by welding.

  An anchor frame 20 fixed on the discarded concrete 5 is embedded in the concrete foundation 1, and the anchor frame 20 has four or more leg members 21 and a cross-girder shape at the upper end of the leg member 21. A plurality of horizontal members 22 welded to each other, and a plurality of bundles of anchor members (wire bundles) 27 are fixed to the horizontal members 22 via fixing brackets 25. The anchor member protective tube 26 to be housed is fixed.

  The anchor member 27 and the protective tube 26 extend substantially vertically upward in the concrete foundation 1, the protective tube 26 reaches the upper end of the mortar layer 7, the anchor member 27 extends further upward from the upper end opening of the protective tube 26, and slides downward. It passes through the insertion space 16 of the support member 11, the insertion space 15 of the upper sliding support member 10, the insertion hole 30 of the base plate 4, and the insertion hole of the cradle 32, and protrudes above the base plate 4 and is connected to the fastening bracket 31. Yes. The fastening bracket 31 is taper-fitted to the conical receiving surface of the cradle 32 welded to the base plate 4 and presses the base plate 4 downward.

  The anchor member 27 is formed by bundling, for example, several to several tens of spring steel wires with a plurality of constraining metal pieces 39 or band steel, and in a natural state, the restoring force of the spring steel in FIG. In this way, it is maintained in a vertical straight line, and is bent within the elastic deformation range for a lateral load (horizontal load) exceeding a predetermined value, and is restored to its original linear state by removing the lateral load. . As the spring steel wire 38 of the anchor member 27, for example, a piano wire, a hard steel wire, a stainless steel wire, an oil tempered wire, etc. are included, and those having improved spring performance by cold working and heat treatment are preferably used. .

[Concrete foundation construction]
2 and 3, the reinforcing iron plates 40, 41, 43, and 44 are assembled together with the underground beam formwork (not shown) as a formwork at a predetermined position, and fluid concrete is poured into the formwork so that the concrete The foundation 1 and the underground beam 8 are concrete-molded.

  After the concrete molding, the formwork for the underground beam is removed, but the reinforcing iron plates 40, 41, 43, 44 are strongly coupled to the concrete foundation 1 via the protruding reinforcing bars 50, and both end flange portions 40a, 41a, 43a, 44a, 43b, 44b are fixed with bolts 46, 47, 48, etc., and then buried in the ground together with the concrete foundation 1.

[Example of column base method]
(1) An example of the column base method will be briefly described. When the concrete foundation 1 is formed, the anchor frame 20, the anchor member protection pipe 26 and the anchor member 27 of FIG. 6 are embedded in the concrete foundation 1.

(2) After the concrete foundation 1 is molded, a mirror-shaped central mortar layer 7a is formed at the approximate center of the upper end face (top end face) of the concrete foundation 1. Then, the sliding support members 10 and 11 are placed on the upper side of the central mortar layer 7a, and the upper end portions of the anchor members 27 are inserted into the spaces 16 and 15 and protrude upward.

(3) The steel column 2 is suspended by, for example, a crane, the anchor member 27 is inserted into each insertion hole 30 of the base plate 4, and the upper end portion of the anchor member 27 is temporarily fixedly coupled to the fastening fitting 31.

(4) A ground beam is assembled to each steel column 2, the verticality of the steel column 2 and the horizontal level of the beam steel frame are adjusted, the fastening bracket 31 is finally tightened, and the gap between the concrete foundation 1 and the lower sliding support member 11 Is filled with non-shrink mortar to complete the mortar layer 7.

[Other embodiments]
(1) Although the said embodiment demonstrated the concrete foundation which installs a steel frame column, it is also possible to apply to the concrete foundation which installs a reinforced concrete column or a steel frame reinforced concrete column.

(2) As shown in FIG. 7, it is also possible to adopt a structure in which a reinforcing iron plate is attached to the outer peripheral surface of the concrete foundation 1 to which the base plate 103 of the steel column 2 is rigidly coupled by the anchor reinforcing bars 100 according to the present invention.

(3) The sticking protrusion 50 formed on the reinforcing steel plate is not limited to the deformed reinforcing bar, but is bent into a metal protrusion having a bulging portion for retaining, such as a mushroom shape or arrow shape, or a hook shape or a hook shape. It is also possible to use a rebar.

(4) In the above embodiment, the present invention is applied to the concrete foundation 1 having a T-shaped or L-shaped joint as shown in FIG. 1, but the present invention is applied to the concrete foundation 1 having a cross-shaped joint (internal position A3). It is also possible to apply. Although not shown, the present invention can also be applied to a concrete foundation joined to one underground beam, or to a concrete foundation not joined to another concrete foundation but joined to an underground beam.

It is a top view of the underground foundation part of the building to which the present invention is applied. It is a horizontal cross-sectional enlarged view of the concrete foundation of FIG. It is a horizontal cross-sectional enlarged view of another concrete foundation of FIG. It is an enlarged side view which shows an example of protrusion. It is an enlarged side view which shows another example of protrusion. It is the concrete foundation which applied this invention, Comprising: It is a longitudinal cross-sectional enlarged view which shows the state which installed the pillar. It is a longitudinal cross-sectional view of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Concrete foundation 2 Steel column 4 Base plate 8 Underground beam 40, 41, 43, 44 Reinforcement iron plate 50 Protrusion

Claims (3)

  A concrete foundation for building, which is connected to an underground beam and has a column on the upper surface, and a reinforcing iron plate is attached to the outer peripheral side surface.   2. The concrete foundation for buildings according to claim 1, wherein the reinforcing iron plate is formed with a plurality of protrusions protruding into the concrete foundation. The concrete foundation for building according to claim 2, wherein the protrusion is a deformed reinforcing bar.

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