JP2020066919A - Concrete filling method in cft column - Google Patents

Abstract

To provide a technique capable of improving workability for filling concrete in a CFT column having a branch structure.SOLUTION: A concrete filling method in branch column sections where a CFT column is branched into a plurality of branches from a joint part between the CFT column and a beam to a lower direction comprises: an insertion step of inserting a concrete filling pipe into a concrete press-in cavity through a filling pipe insertion hole after the concrete press-in cavity is installed below a lower diaphragm of the joint part between the CFT column and the beam and at a place between the branch column sections in such a way as to be communicatively connected through the filling pipe insertion hole opened in the lower diaphragm as well as to be communicatively connected through a side surface press-in hole opened on each of steel pipes forming each of the branch column sections; and a press-in step of simultaneously press-filling concrete pumped into the concrete press-in cavity to each of the branch column sections from the side surface press-in hole after pumping concrete into the concrete press-in cavity from a tip end part of the concrete filling pipe.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a concrete filling method for a CFT column.

The concrete-filled steel tube structure is abbreviated as CFT structure. The CFT structure is a structure in which concrete is filled inside rectangular steel pipes and circular steel pipes. In addition to its excellent seismic performance and fire resistance performance, it is a structural type that can be expected to improve design flexibility and workability, and can be used in various applications. It is applied to structures.

  Here, a drop-filling method and a press-fitting method are known as methods for filling concrete into a steel pipe for constructing a CFT column. The drop-filling method is to insert a filling pipe (for example, a tremie pipe) or a filling hose (for example, a flexible hose) for filling concrete into the steel pipe, and then launch the concrete sequentially from the bottom of the steel pipe upwards. This is a method of filling the inside of a steel pipe with concrete. In addition, the press-fitting method is a method in which a pressurizing port is formed in the lower portion of a steel pipe that constitutes a CFT column, and a concrete pump is used to drive up the concrete press-fitted from the pressurizing port upward.

  Further, at the joint between the CFT column and the steel beam, a horizontal reinforcing member called a diaphragm is installed at the beam flange position in the steel pipe column in order to transfer the stress of the beam to the steel pipe column. There are three types of diaphragms: an inner diaphragm that welds a plate to the inside of a steel pipe, a through diaphragm that cuts the steel pipe and re-welds by sandwiching the plate, and an outer diaphragm that welds a plate to the outside of the steel pipe. When applying an inner diaphragm or a through diaphragm to the joint, an opening (punching hole) for inserting a filling pipe or filling hose for filling concrete is formed in the diaphragm, and this placing hole is formed. Concrete is filled into the steel pipe with the filling pipe and the like inserted. In the construction of CFT columns, it is necessary to solidly fill the steel pipe with concrete without any gaps so that the steel pipe and concrete are integrated, and it is particularly important that the lower surface of the diaphragm is filled with concrete without gaps. It is said that.

JP, 2005-200849, A JP, 2006-16805, A

  By the way, when a CFT column is joined to a group of seismic isolation devices installed in a seismic isolation layer, a structure in which the CFT column is branched to a plurality of lower diaphragms at the CFT column / beam joint and is joined to the seismic isolation device Can be considered. For example, when two seismic isolation devices are connected to the seismic isolation layer, a bifurcated bifurcated column portion formed by bifurcating the CFT column at the position of the CFT column / beam joint is used for each seismic isolation device. A structure of joining is conceivable.

  When filling the CFT column having the above-described branched structure with concrete, the following points are raised as problems.

When adopting a general concrete drop-and-fill construction method, after filling the concrete with the filling hose for filling the concrete inserted in one branch pillar, distribute the insertion hose to the other branch pillar and insert it. However, since it is necessary to fill the other branch pillars with concrete, there is a concern that workability will deteriorate.

  Moreover, if a conventional general press-fitting method for concrete is to be adopted, it is necessary to prepare a plurality of sets of press-fitting devices for simultaneously press-fitting concrete into a plurality of branch column bases, which deteriorates workability. There is a risk.

  The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of improving workability when filling a CFT column having a branched structure with concrete.

  The present invention for solving the above problems employs the following means. That is, the present invention relates to a method for filling concrete into a branch column portion in which a CFT column is branched into a plurality of pieces downward from the CFT column / beam joint portion, the method being provided below the lower diaphragm of the CFT column / beam joint portion. At the position between the branch pillars, each branch is communicated with the CFT pillar-beam joint through a filling pipe insertion hole that opens in the lower diaphragm, and each side through a side face press-fit hole that opens in the steel pipe that forms each branch pillar. A concrete press-fitting chamber that communicates with a pillar is provided, and a concrete filling pipe for filling the CFT column with concrete is inserted into the concrete press-fitting chamber through the filling pipe insertion hole; Concrete is pumped from the tip into the concrete press-fitting chamber, and the concrete pumped into the concrete press-fitting chamber is pressed into the side face. And having a press-fitting step of press-fitting simultaneously into each branch pillar portion from.

  According to the present invention, it is possible to simultaneously press-fit concrete from a single concrete press-fitting chamber to each branch pillar without installing a press-fitting device for each of a plurality of branch pillars, so that the workability is very excellent. ing. Further, unlike the conventional general concrete drop-and-fill construction method, there is no need to sort and reinsert the filling hose for each branch column portion to be filled with concrete, which is excellent in workability.

  Here, the difference between the inner diameter of the filling pipe insertion hole and the outer diameter of the concrete filling pipe, the concrete pumped into the concrete press-fitting chamber through the gap between the filling pipe insertion hole and the concrete filling pipe It may be set to a predetermined size so as not to leak into the CFT column-beam joint from the concrete press-fitting chamber.

  Further, in the CFT pillar / beam joint, a partition wall is formed standing on the upper surface of the lower diaphragm and partitioning the internal space of the CFT pillar / beam joint to an intermediate height. The cement paste leaked from the concrete press-fitting chamber into the CFT column-beam joint through the gap between the filling pipe insertion hole and the concrete filling pipe may be blocked by the partition wall.

  In addition, the partition wall is formed in the CFT pillar-beam joint through the gap at least until the concrete press-fitted into the branch pillars from the side-face press-fitting holes in the press-fitting step is driven up to the height of the lower diaphragm. It may be provided so that the cement paste leaked into the can can be blocked.

  In addition, a plurality of notches are formed in the tip opening of the concrete-filled pipe to discharge the concrete to be pumped into the concrete-filled pipe toward each side press-fitting hole, and in the press-fitting step, the concrete-filled pipe is The concrete may be press-fitted into each of the branch pillars with the plurality of the cutouts in 1 being directed to the side-face press-fitting holes.

  Moreover, the lower end of each branch column may be connected to a seismic isolation device installed in the seismic isolation layer.

  ADVANTAGE OF THE INVENTION According to this invention, the workability at the time of filling a CFT pillar which has a branch structure with concrete can be improved.

FIG. 1 is a diagram showing a schematic configuration of a CFT structure according to the first embodiment. FIG. 2 is a diagram showing a schematic configuration of the CFT structure according to the first embodiment. FIG. 3 is a diagram showing a concrete-filled pipe according to the first embodiment. FIG. 4 is an enlarged view of the tip portion of the concrete-filled pipe according to the first embodiment. FIG. 5 is a side view of the tip portion viewed from the direction of arrow B in FIG. FIG. 6 is a diagram showing a state before the concrete-filled pipe is inserted into the steel pipe forming the CFT column according to the first embodiment. FIG. 7 is a sectional view taken along the line CC in FIG. FIG. 8 is a top view of the lower diaphragm according to the first embodiment. 9 is a sectional view taken along the line DD in FIG. 10: is a figure which shows the insertion process completion state which concerns on Embodiment 1. FIG. FIG. 11 is a diagram illustrating a press-fitting process according to the first embodiment. FIG. 12: is a figure which shows the state which the press injection process of the concrete to each branch pillar part which concerns on Embodiment 1 was completed. FIG. 13 is a diagram showing the state of the upper surface of the lower diaphragm at the time of completing the process of press-fitting concrete into each branch pillar. FIG. 14 is a diagram showing a state where the concrete filling pipe is pulled up by a predetermined height after the step of press-fitting the concrete into the lower pillar portion is completed. FIG. 15 is a diagram showing a state in which the lower region of the CFT column-beam joint is filled with concrete. FIG. 16 is a diagram showing a state where the upper region of the CFT column-beam joint is filled with concrete. FIG. 17 is a diagram showing a state where the CFT pillar-beam joint is completely filled with concrete. FIG. 18 is a diagram showing a state where concrete is blown out from the filling hole and each air hole opened in the upper diaphragm when the filling of the CFT column / beam joint with concrete is completed. FIG. 19: is a figure explaining the method of filling an upper pillar part with concrete. FIG. 20 is a diagram showing a state where the CFT pillar is completely filled with concrete. FIG. 21 is a diagram illustrating a modified example of the CFT structure according to the first embodiment.

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

<Embodiment 1>
1 and 2 are diagrams showing a schematic configuration of a CFT structure 1 according to the first embodiment. The CFT structure 1 has a CFT column 10 and steel beams 20A and 20B. The steel beams 20A and 20B are large beams that intersect at right angles. FIG. 2 shows a schematic configuration of the CFT structure 1 viewed from the X direction in FIG. 1, and FIG. 1 shows a schematic configuration of the CFT structure 1 viewed from the Y direction in FIG. The X direction is parallel to the longitudinal direction of the steel beam 20A, and the Y direction is parallel to the longitudinal direction of the steel beam 20B.

  1 and 2, not only the external structure but also the internal structure of the CFT pillar 10 in the CFT structure 1 is shown for convenience. The CFT column 10 is a concrete-filled steel pipe in which concrete 12 (illustrated by oblique hatching in FIGS. 1 and 2) is filled in a steel pipe 11 having a square or circular cross section. In the CFT column 10, a region above the CFT column / beam joint 30 where the CFT column 10 and the steel beams 20A and 20B are joined is referred to as an upper column 40, which is below the CFT column / beam joint 30. The area is called a lower pillar portion 50.

  The lower end of the lower pillar portion 50 of the CFT pillar 10 is connected to a seismic isolation device 61 installed in the seismic isolation layer 60. The lower pillar portion 50 in the present embodiment has a first branch pillar portion 50A and a second branch pillar portion 50B that bifurcate at the CFT pillar / beam joint portion 30 as a boundary. Moreover, the lower ends of the first branch column portion 50A and the second branch column portion 50B are respectively coupled to the respective seismic isolation devices 61A and 61B installed in the seismic isolation layer 60 in two rows.

  The seismic isolation device 61 is, for example, a laminated rubber bearing seismic isolation device having a laminated rubber 610 and an upper base plate 611 and a lower base plate 612 that sandwich the laminated rubber 610 from above and below. The seismic isolation layer 60 may be, for example, a seismic isolation layer provided on the middle floor of the building, or may be provided between the foundation structure and the superstructure. In the example of FIG. 1, the lower base plate 612 of each seismic isolation device 61A, 61B is integrally joined to the base plate 60A installed on the steel beam arranged in the seismic isolation layer 60 via anchor bolts or the like. The upper base plate 611 of each seismic isolation device 61A, 61B is integrally joined to the base plate 55 provided at the lower ends of the first branch column portion 50A and the second branch column portion 50B via anchor bolts or the like.

  The steel beam 20A, 20B is made of, for example, H-shaped steel, and has an upper flange 21, a lower flange 22, and a web 23. In the CFT pillar-beam joint 30, an upper diaphragm 31 and a lower diaphragm 32 are horizontally arranged at the level of the upper flange 21 and the lower flange 22, respectively. The upper diaphragm 31 and the lower diaphragm 32 are, for example, through-diaphragm type reinforcing members, and horizontally penetrate through the cross section of the CFT column 10. However, the upper diaphragm 31 and the lower diaphragm 32 may be inner diaphragm type reinforcing members. The plate thicknesses of the upper diaphragm 31 and the lower diaphragm 32 are designed to be larger than the plate thicknesses of the upper flange 21 and the lower flange 22, respectively (for example, increased by 2 sizes).

  In the CFT structure 1 according to the present embodiment, a concrete press-fitting chamber 70 is provided below the lower diaphragm 32 of the CFT pillar / beam joint 30 and between the branch pillars 50A and 50B. The concrete press-fitting chamber 70 is connected to the CFT pillar / beam joint 30 and the branch pillars 50A and 50B, and the interior thereof is filled with concrete 12. The concrete press-fitting chamber 70 is an auxiliary chamber used when filling the steel pipes forming the branch column parts 50A and 50B with concrete, and is a part that is not included (added) in terms of the structural yield strength of the CFT column 10. When the concrete is filled into each of the branch pillars 50A and 50B, the concrete is press-fitted from the concrete press-fitting chamber 70 through a side surface press-fitting hole described later. The details of the method for press-fitting concrete from the concrete press-fitting chamber 70 into the branch pillars 50A and 50B will be described later.

Here, each branch pillar part 50A and 50B in the lower pillar part 50 has a quadrangular prism shape. Reference numerals 501 and 502 in FIG. 1 denote an outer side wall and an inner side wall of the first branch pillar portion 50A. Reference numerals 503 and 504 in FIG. 1 denote an outer side wall and an inner side wall of the second branch column portion 50B. Reference numerals 505 and 506 in FIG. 2 denote a pair of common side walls common to the first branch column portion 50A and the second branch column portion 50B. Both ends of the outer side wall 501 and the inner side wall 502 of the first branch column part 50A are joined to the pair of common side walls 505 and 506, and the cross section of the first branch column part 50A has an outer wall 501 and an inner side wall 502. , And a pair of common sidewalls 505, 506. Further, both ends of the outer wall 503 and the inner side wall 504 of the second branch column portion 50B are joined to the pair of common side walls 505 and 506, and the cross section of the second branch column portion 50B is the outer wall 503 and the inner side wall 503. A wall 504 and a pair of common sidewalls 505, 506 are defined. Further, as shown in FIG. 1, the inner side wall 502 of the first branch column portion 50A and the inner side wall 504 of the second branch column portion 50B are arranged so as to face each other. Moreover, the cross-sectional shape of each of the branch pillars 50A and 50B is not particularly limited, and may have, for example, a circular cross section.

  Reference numeral 71 shown in FIG. 1 is a bottom wall forming the bottom of the concrete press-fitting chamber 70. The bottom wall 71 of the concrete press-fitting chamber 70 is a rectangular steel plate extending in parallel with the lower diaphragm 32, and each edge of the concrete press-fitting chamber 70 has an inner wall 502 of the first branch pillar 50A, It is joined to the inner side wall 504 of the bifurcated column portion 50B and the pair of common side walls 505 and 506, respectively. The shape of the concrete press-fitting chamber 70 configured as described above is as follows: the lower diaphragm 32, the bottom wall 71, the inner side wall 502 of the first branch pillar 50A, the inner side wall 504 of the second branch pillar 50B, and the pair of common side walls. It is defined by 505 and 506.

  Next, a concrete filling method for the CFT pillar 10 according to the present embodiment will be described. FIG. 3 is a view showing a concrete filling pipe 80 which is a steel pipe having a cylindrical shape for filling concrete into the steel pipe 11 of the CFT column 10. A pressure-feeding hose (or pressure-feeding pipe) 82 extending from a concrete pump car (not shown) is connected to the concrete-filled pipe 80 on the base end 81 side. FIG. 4 is an enlarged view of the tip portion 83 formed on the tip side of the concrete filling pipe 80, and is a side view of the tip portion 83 viewed from the direction of arrow A in FIG. FIG. 5 is a side view of the tip portion 83 as viewed from the direction of arrow B in FIG.

  As shown in FIGS. 4 and 5, a plurality of notches 85 are formed in the tip portion 83 of the concrete-filled pipe 80 for discharging the concrete pumped into the concrete-filled pipe 80 toward the sides. ing. In the present embodiment, in order to distribute the concrete from the concrete press-fitting chamber 70 to the pair of branch pillars 50A and 50B, the pair of notches 85 are arranged at positions facing each other. More specifically, the pair of notches 85 formed in the tip end portion 83 of the concrete-filled pipe 80 are arranged at positions shifted by 180 ° around the central axis of the concrete-filled pipe 80. Further, as shown in FIG. 4, the cutout portion 85 communicates with the tip end opening 84 of the concrete filling pipe 80, and is formed by notching the pipe wall forming the concrete filling pipe 80 in a U shape. There is. However, the shape of the cutout portion 85 is not particularly limited.

  FIG. 6 is a diagram showing a state before the concrete filling pipe 80 is inserted into the steel pipe 11 forming the CFT column 10 according to the first embodiment. Among the reference numerals shown in FIG. 6, the reference numerals common to those in FIG. 1 indicate the same members. As shown in FIG. 6, the CFT pillar 10 has a first branch pillar portion 50A and a second branch pillar portion 50B formed by bifurcating at the CFT pillar-beam joint portion 30 as a boundary.

  A concrete filling hole 310 is provided in the upper diaphragm 31 of the CFT column-beam joint portion 30 so as to penetrate the upper diaphragm 31. FIG. 7 is a sectional view taken along the line CC in FIG. Reference numeral CL1 shown in FIG. 7 is a central axis along the extending direction of the upper column 40. As shown in FIG. 7, the filling hole 310 formed in the upper diaphragm 31 has a circular cross section, and is arranged coaxially with the central axis CL1 of the upper column portion 40. Reference numeral 311 shown in FIG. 7 is an air hole provided so as to penetrate the upper diaphragm 31. In the present embodiment, air holes 311 having a circular cross section are arranged at the four corners of the upper diaphragm 31. The shapes, sizes, positions, numbers, etc. of the filling holes 310 and the air holes 311 opening in the upper diaphragm 31 can be appropriately changed.

Further, as shown in FIG. 6, a concrete press-fitting chamber 70 is provided below the lower diaphragm 32 in the CFT pillar-beam joint portion 30 and between the branch pillar portions 50A and 50B. The concrete press-fitting chamber 70 is arranged below the CFT pillar-beam joint 30 with the lower diaphragm 32 interposed therebetween. A filling pipe insertion hole 33 is opened in the lower diaphragm 32, and the CFT column-beam joint portion 30 and the concrete press-fitting chamber 70 communicate with each other through the filling pipe insertion hole 33. The inner diameter of the filling pipe insertion hole 33 is set to be slightly larger than the outer diameter of the concrete filling pipe 80. Further, a side surface press-fitting hole 52A is opened in the inner side wall 502 arranged between the concrete press-fitting chamber 70 and the first branch column portion 50A so as to penetrate the inner side wall 502, and the concrete side press-fitting hole 52A is used. The chamber 70 and the first branch post 50A communicate with each other. Further, a side surface press-fitting hole 52B is opened in the inner side wall 504 arranged between the concrete press-fitting chamber 70 and the second branch column part 50B so as to penetrate the inner side wall 504, and the concrete side press-fitting hole 52B is used. The chamber 70 and the second branch pillar 50B communicate with each other.

  Hereinafter, in the lower diaphragm 32, a region located above the first branch column 50A is referred to as a first region R1, and a region located above the second branch column 50B is referred to as a second region R2. In addition, a region of the CFT column-beam joint portion 30 located above the concrete press-fitting chamber 70 is referred to as a third region R3. FIG. 8 is a top view of the lower diaphragm 32 according to the first embodiment. The filling pipe insertion hole 33 is arranged at the center of the third region R3 in the lower diaphragm 32, and the center of the filling pipe insertion hole 33 is arranged coaxially with the central axis CL1 of the upper column portion 40.

  A partition wall 33A is provided at the boundary between the first region R1 and the third region R3 of the lower diaphragm 32 so as to stand upward from the upper surface 32a of the lower diaphragm 32. Further, a partition wall 33B is provided at a boundary portion between the second region R2 and the third region R3 in the lower diaphragm 32 so as to stand upward from the upper surface 32a of the lower diaphragm 32. The partition walls 33A and 33B are arranged in parallel so as to face each other, and both ends thereof are joined to the inner wall surface of the CFT column-beam joint portion 30. As shown in FIG. 6, the partition walls 33A and 33B are provided so as to partition the internal space of the CFT column-beam joint portion 30 to a height in the middle thereof. The height of each partition wall 33A, 33B can be changed appropriately.

  Here, in the internal space of the CFT pillar-beam joint portion 30, a region located above the first region R1 of the lower diaphragm 32 is referred to as a first internal region A1, and above the second region R2 of the lower diaphragm 32. The area located is called the second internal area A2, and the area located above the third area R3 of the lower diaphragm 32 is called the third internal area A3. The first inner region A1 and the third inner region A3 in the CFT pillar-beam joint portion 30 are separated by the partition wall 33A up to the middle in the height direction. Similarly, the second inner region A2 and the third inner region A3 in the CFT pillar-beam joint portion 30 are separated by the partition wall 33B to the middle in the height direction. The internal regions A1 to A3 of the CFT pillar-beam joint 30 communicate with each other at a height above the upper ends of the partition walls 33A and 33B.

  In the first region R1 of the lower diaphragm 32, a filling hole 34A for filling concrete and a plurality of air holes 36 are provided so as to penetrate the lower diaphragm 32. Similarly, in the second region R2 of the lower diaphragm 32, a filling hole 34B for filling concrete and a plurality of air holes 36 are provided so as to penetrate the lower diaphragm 32. As shown in FIG. 8, air holes 36 are provided at the four corners of the first region R1 of the lower diaphragm 32, respectively. Similarly, air holes 36 are provided at the four corners of the second region R2, respectively. The shape, size, position, number, etc. of the filling holes 34A, 34B and the air holes 36 that are opened in the lower diaphragm 32 can be changed as appropriate.

Further, as shown in FIG. 6, the side surface press-fitting holes 52A formed in the inner side wall 502 of the first branch post 50A and the side surface press-fitting holes 52B formed in the inner side wall 504 of the second branch post 50B are substantially the same. It is provided at the height. In the present embodiment, the side surface press-fitting holes 52A and 52B have circular cross sections with the same diameter, but the shape, size, position, number, etc. can be changed as appropriate. Note that FIG. 9 is a sectional view taken along the line DD in FIG.

  Next, a concrete filling method for the CFT pillar 10 will be described. In the concrete filling method according to the present embodiment, first, the lower pillar portion 50 (first branch pillar portion 50A) is obtained by press-fitting concrete into the lower pillar portion 50 (first branch pillar portion 50A and second branch pillar portion 50B). After filling the second branch column 50B) with concrete, the CFT column-beam joint 30 and the upper column 40 are sequentially filled with concrete. When press-fitting concrete into the lower pillar portion 50 (the first branch pillar portion 50A and the second branch pillar portion 50B), first, with the tip portion 83 of the concrete filling pipe 80 facing downward, the upper part of the CFT pillar 10 is placed. The pillar 40 is inserted from above. Next, the tip portion 83 of the concrete filling pipe 80 is inserted into the CFT column-beam joint 30 by inserting the filling hole 310 that opens into the upper diaphragm 31, and then the filling pipe insertion hole 33 that opens into the lower diaphragm 32. Through the concrete press-fitting chamber 70 (inserting step). In this inserting step, as shown in FIG. 10, the concrete filling pipe 80 is inserted into the concrete press-fitting chamber 70 to a depth where the height of the tip portion 83 of the concrete filling pipe 80 is substantially equal to the height of the side surface press-fitting holes 52A and 52B. Complete when you do. Therefore, FIG. 10 shows a state in which the insertion step according to the first embodiment is completed (hereinafter, referred to as “insertion step completion state”).

  In the insertion step completed state shown in FIG. 10, the pair of notches 85 formed in the tip end portion 83 of the concrete filling pipe 80 face the side surface press-fitting holes 52A, 52B opening in the inner side walls 502, 504, respectively. As described above, the direction and height of each notch portion 85 are adjusted. In the present embodiment, the concrete 12 is pressure-fed from the concrete pump truck (not shown) to the concrete filling pipe 80 through the pressure-feeding hose (or pressure-feeding pipe) 82 from the completion state of the inserting process. As a result, concrete is pressure-fed (discharged) into the concrete press-fitting chamber 70 from the tip 83 (tip opening 84 and notch 85) of the concrete filling pipe 80. As the concrete 12 to be pressure-fed from the concrete filling pipe 80 to the concrete press-fitting chamber 70, for example, high-fluidity concrete can be preferably used.

  FIG. 11 is a diagram illustrating a press-fitting step of simultaneously press-fitting the concrete 12 pumped into the concrete press-fitting chamber 70 from the side surface press-fitting holes 52A, 52B into the branch column parts 50A, 50B. In the press-fitting step shown in FIG. 11, the concrete 12 that has been pressure-fed to the concrete press-fitting chamber 70 from the tip end portion 83 (the tip end opening 84 and the notch portion 85) of the concrete-filled pipe 80 passes through the side-face press-fitting holes 52A and 52B and the branch pillar portions. By being press-fitted into 50A and 50B at the same time, the concrete 12 filled in each of the branch column parts 50A and 50B can be sequentially launched upward.

  FIG. 12 is a diagram showing a state in which the process of press-fitting concrete into each of the branch pillars 50A and 50B is completed. FIG. 13 is a diagram showing a state of the upper surface 32a of the lower diaphragm 32 at the time of completing the process of press-fitting concrete into the branch column parts 50A and 50B. In the present embodiment, the concrete 12 is simultaneously press-fitted into the branch pillar parts 50A, 50B from the concrete press-fitting chamber 70 located between the branch pillar parts 50A, 50B through the side face press-fitting holes 52A, 52B. The time at which the press-fitting of the concrete 12 is completed with respect to the branch column parts 50A and 50B can be generally adjusted.

  In FIG. 13, the concrete 12 is downward from the filling hole 34A and the air hole 36 opening in the first region R1 of the lower diaphragm 32, and the filling hole 34B and the air hole 36 opening in the second region R2 (concrete press-fitting chamber 70 side). ) Indicates that the situation is blowing out.

Next, the dimensional difference between the inner diameter of the filling pipe insertion hole 33 opening in the third region R3 of the lower diaphragm 32 and the outer diameter of the concrete filling pipe 80 (hereinafter, referred to as “clearance dimension”) will be described. In the present embodiment, the clearance dimension is such that the concrete 12 pumped into the concrete press-fitting chamber 70 during the press-fitting process passes through the gap between the filling pipe insertion hole 33 and the outer surface of the concrete filling pipe 80 from the concrete press-fitting chamber 70 to the CFT column. -It is set to a predetermined dimension that does not leak into the beam joint 30.

  For example, the clearance dimension between the filling pipe insertion hole 33 and the concrete filling pipe 80 may be about several mm to several tens of mm. By setting the clearance dimension between the filling pipe insertion hole 33 and the concrete filling pipe 80 as described above, the concrete press-fitting chamber 70 is connected to the CFT column-beam joint through the gap between the filling pipe insertion hole 33 and the concrete filling pipe 80. It is possible to prevent the concrete 12 from leaking into the inside 30. According to this, the concrete 12 leaking through the gap between the filling pipe insertion hole 33 and the concrete filling pipe 80 flows into the branch pillars 50A, 50B from the filling holes 34A, 34B and the air holes 36 in the lower diaphragm 32. It is possible to suppress (run down). As a result, when concrete is press-fitted into each of the branch column parts 50A and 50B, it is possible to suppress air from being accumulated on the lower surface of the lower diaphragm 32, and to concretely fill the lower surface of the lower diaphragm 32 with no gaps.

  Further, in the concrete filling pipe 80 in the present embodiment, the clearance dimension between the filling pipe insertion hole 33 and the concrete filling pipe 80 can be set to a small size, and as a result, at the time of concrete press-fitting into each branch pillar portion 50A, 50B. It is possible to preferably prevent the concrete 12 from flowing back to the CFT column-beam joint 30 from the gap between the filling pipe insertion hole 33 and the concrete filling pipe 80. Further, as described above, the clearance dimension between the filling pipe insertion hole 33 and the concrete filling pipe 80 is set to a small size, so that the filling pipe insertion hole 33 and the concrete filling pipe are inserted into each branch column portion 50A, 50B when concrete is press-fitted. It is possible to prevent the pressure from escaping from the gap between the pressure sensor 80 and 80. That is, it is possible to prevent the pressure in the concrete press-fitting chamber 70 from decreasing (escaping) when the concrete is press-fitted into each of the branch pillars 50A and 50B. This makes it possible to efficiently and smoothly press concrete into the respective branch pillars 50A and 50B by utilizing the pressure of the concrete pump without letting it escape.

  When concrete is press-fitted into each of the branch pillars 50A and 50B, it is expected that the cement paste will leak to the CFT pillar-beam joint 30 side from the gap between the filling pipe insertion hole 33 and the concrete filling pipe 80. To be done. Here, the symbol CP shown in FIG. 13 indicates the cement paste leaked from the concrete press-fitting chamber 70 through the gap between the filling pipe insertion hole 33 and the concrete filling pipe 80 during the press-fitting process. On the other hand, in the present embodiment, partition walls 33A and 33B are provided upright on the upper surface 32a of the lower diaphragm 32 so as to partition the internal space of the CFT pillar-beam joint portion 30 to an intermediate height.

  According to this, the cement paste CP leaked from the concrete press-fitting chamber 70 into the third internal region A3 of the CFT pillar-beam joint 30 through the gap between the filling pipe insertion hole 33 and the concrete filling pipe 80 during the press-fitting process. Can be blocked by the partition walls 33A and 33B. That is, the cement paste CP leaked from the concrete press-fitting chamber 70 can be retained on the third region R3 of the lower diaphragm 32. As a result, the cement paste CP can be suppressed from flowing from the filling holes 34A, 34B and the air holes 36 in the lower diaphragm 32 into the branch column parts 50A, 50B. As a result, when concrete is press-fitted into each of the branch column parts 50A and 50B, it is possible to suppress air from being accumulated on the lower surface of the lower diaphragm 32, and to concretely fill the lower surface of the lower diaphragm 32 with no gaps.

Further, in the present embodiment, at least until the concrete 12 press-fitted from the concrete press-fitting chamber 70 into the branch column parts 50A, 50B through the side-face press-fitting holes 52A, 52B is driven up to the height of the lower diaphragm 32. Pipe insertion hole 33 and concrete filling pipe 80
The height dimension of the partition walls 33A and 33B is designed so that the cement paste CP leaked into the CFT pillar-beam joint 30 can be blocked through the gap between the partition walls 33A and 33B. As a result, when the concrete 12 is press-fitted into each of the branch pillar portions 50A and 50B, it is possible to more reliably suppress the accumulation of air on the lower surface of the lower diaphragm 32, and to firmly insert the concrete 12 into each of the branch pillar portions 50A and 50B. Can be filled.

  The positions of the partition walls 33A and 33B that stand upright from the lower diaphragm 32 may be appropriately changed. For example, the partition wall 33A does not necessarily have to be provided at the boundary position between the first region R1 and the third region R3, and the position of the partition wall 33A is shifted from the boundary position to the first region R1 side or the third region R3 side. May be. Similarly, the partition wall 33B does not necessarily have to be provided at the boundary position between the second region R2 and the third region R3, and the position of the partition wall 33B is located from the boundary position to the second region R2 side or the third region R3 side. You may shift it. Further, the partition wall that is erected on the lower diaphragm 32 can be modified in various ways as long as it can block the cement paste CP leaked from the concrete press-fitting chamber 70 through the gap between the filling pipe insertion hole 33 and the concrete filling pipe 80. For example, an annular (for example, circular, elliptical, polygonal, etc.) partition wall may be provided upright on the upper surface 32a of the lower diaphragm 32 so as to surround the periphery of the filling pipe insertion hole 33.

  As described above, after the process of press-fitting the concrete 12 into the lower column part 50 (the first branch column part 50A and the second branch column part 50B) is completed, for example, the CFT column-beam joint part 30 is formed by the drop filling method. Then, the concrete 12 is sequentially filled into the upper pillar portion 40. Specifically, as shown in FIG. 14, the concrete filling pipe 80 is pulled up by a predetermined height to a height at which the tip portion 83 is pulled out from the filling pipe insertion hole 33 of the lower diaphragm 32. In the example shown in FIG. 14, the tip end portion 83 of the concrete filling pipe 80 is set at a position lower than the upper ends of the partition walls 33A and 33B in the CFT column-beam joint portion 30 (third inner region A3). In this state, the concrete 12 is filled into the CFT column-beam joint 30 by pumping the concrete 12 into the concrete filling pipe 80. FIG. 15 shows a state in which the lower region of the CFT column / beam joint 30 is filled with concrete 12.

  When the concrete 12 is filled into the CFT column-beam joint 30, the tip portion 83 of the concrete filling pipe 80 is gradually moved upward while the tip portion 83 of the concrete filling pipe 80 is inserted into the already filled concrete 12. It is advisable to fill the concrete 12 while pulling it up. FIG. 16 is a diagram showing a state in which the concrete 12 is filled in the upper region of the CFT column-beam joint 30.

  FIG. 17 is a diagram showing a state in which the concrete 12 has been completely filled into the CFT column / beam joint 30. FIG. 18 is a diagram showing a state in which the concrete 12 is blown out from the filling holes 310 and the air holes 311 opening in the upper diaphragm 31 when the filling of the concrete 12 into the CFT column-beam joint 30 is completed.

  When the filling of the concrete 12 into the CFT column-beam joint portion 30 is completed as described above, then, as shown in FIG. 19, the concrete filling pipe 80 is filled to a height at which the tip portion 83 is pulled out from the filling hole 310 of the upper diaphragm 31. After being pulled up by a predetermined height, the concrete 12 is pumped from the tip portion 83 of the concrete filling pipe 80 to fill the upper pillar portion 40 with the concrete 12. Then, with the tip portion 83 of the concrete filling pipe 80 inserted into the already filled concrete 12, the upper pillar portion 40 is filled with the concrete 12 while gradually pulling the tip portion 83 of the concrete filling pipe 80 upward. Then, as shown in FIG. 20, the filling of the CFT pillar 10 with the concrete 12 is completed.

As described above, the lower pillar portion 50 (first branch pillar portion 50A and second branch pillar portion 5 according to the present embodiment.
According to the method of filling concrete into 0B), the concrete press-fitting chamber 70 is provided below the lower diaphragm 32 of the CFT pillar-beam joint 30 and at a position between the branch pillar portions 50A and 50B. The concrete 12 is press-fitted from the press-fitting chamber 70 into the branch column parts 50A, 50B through the side surface press-fitting holes 52A, 52B. According to this, since it is possible to distribute the concrete 12 from the concrete press-fitting chamber 70 to the respective branch column parts 50A and 50B at the same time, it is possible to press-fit the concrete 12 into each of the plurality of branch column parts 50A and 50B. There is no need to install a device, and workability can be improved. Moreover, when it is going to fill each branch pillar part 50A, 50B with concrete using the conventional general concrete drop filling method, after filling one branch pillar part with concrete, the other branch pillar part Since it is necessary to re-distribute the filling hose to the concrete and then to fill the concrete, the workability may be deteriorated. However, according to the concrete filling method of the present embodiment, the concrete press-fitting chamber 70 and the branch pillar portions 50A, Since concrete can be pressed into 50B at the same time, the workability is superior to the conventional concrete drop-filling method.

  Further, in the present embodiment, since concrete is press-fitted into the branch pillar portions 50A and 50B from the concrete press-fitting chamber 70 provided below the CFT pillar-beam joint portion 30, each branch pillar portion 50A, It is possible to suppress the free fall height of the concrete flowing into the branch column parts 50A, 50B from the side surface press-fitting holes 52A, 52B at the start of press-fitting into the 50B. This makes it difficult for material separation to occur in the concrete, and suppresses deterioration of the quality of the concrete.

  Further, in the present embodiment, the concrete is filled with the pair of notches 85 formed in the tip portion 83 of the concrete filling pipe 80 so as to face the side surface press-fitting holes 52A and 52B opening in the inner walls 502 and 504, respectively. Since the concrete is press-fitted from the press-fitting chamber 70 into the branch column parts 50A and 50B, the concrete can be discharged (discharged) from the concrete filling pipe 80 toward the side surface press-fitting holes 52A and 52B. As a result, concrete can be more efficiently press-fitted into each of the branch pillars 50A and 50B.

  The lower pillar portion 50 in the present embodiment adopts a bifurcating structure that bifurcates at the CFT pillar-beam joint portion 30, but adopts a bifurcating structure that branches into three or more branch pillar portions. May be. Regardless of the number of branches of the lower pillar portion 50, a concrete press-fitting chamber 70 is formed below the lower diaphragm 32 of the CFT pillar-beam joint 30 and between the respective branch pillar portions, and each branch pillar portion is formed. By simultaneously press-fitting concrete from the concrete press-fitting chamber 70 through the side press-fitting holes that open to the steel pipe, it is possible to efficiently fill each branch column portion with concrete. In addition, it is preferable to determine the number and position of the notches 85 formed in the tip portion 83 of the concrete-filled pipe 80 so as to correspond to the number of side-face press-fit holes that are opened in the steel pipe forming each branch column. . For example, like the modification shown in FIG. 21, when the lower pillar part 50 has three branch pillar parts 50A to 50C that branch into three forks, each branch pillar part 50A to 50C and the concrete press-fitting chamber. It is preferable to provide three notches 85 in the tip end portion 83 of the concrete filling pipe 80 so that the side face press-fitting holes 52 </ b> A to 52 </ b> C communicating with 70 can be arranged to face each other. 21. FIG. 21 schematically shows a cross section of each of the branch column parts 50A to 50C and the concrete press-fitting chamber 70 according to the modification. FIG. 21 also shows the tip 83 of the concrete filling pipe 80 inserted into the concrete press-fitting chamber 70 through the filling pipe insertion hole 33. 21 is formed with three notches 85 at the tip portion 83 of the concrete-filled pipe 80 shown in FIG. 21, and the respective notches 85 are arranged at positions deviated by 120 ° around the central axis of the concrete-filled pipe 80. Has been done. By arranging each notch portion 85 in this way, when concrete is simultaneously press-fitted from the concrete press-fitting chamber 70 into each branch column portion 50A to 50C, each notch portion 85 in the concrete filling pipe 80 is inserted into the side surface press-fitting hole 52A to. Since it can be arranged to face each of the 52C, concrete can be efficiently press-fitted into each of the branch column parts 50A to 50C.

  Further, although the lower ends of the branch pillars 50A and 50B in the present embodiment are connected to the seismic isolation devices 61A and 61B installed in the seismic isolation layer 60, the present invention is not limited to this. That is, the concrete filling method of the present invention can be applied to various CFT columns having a branched structure.

1 ... CFT structure 10 ... CFT column 20A, 20B ... Steel beam 30 ... CFT column-beam joint 31 ... Upper diaphragm 32 ... Lower diaphragm 33 ... Filling tube insertion hole 40 ... Upper column part 50 ... Lower column part 50A, 50B ... Branch column part 52A, 52B ... Side face press fit hole 60 ... Seismic isolation layer 70 ... Concrete press fit room 80 ... Concrete filling pipe

Claims (6)

A method for filling concrete into a branch column part, in which a CFT column branches downward from a CFT column-beam joint part,
Below the lower diaphragm of the CFT pillar-beam joint and at a position between the respective branch pillars, each branch pillar communicates with the CFT pillar-beam joint through a filling pipe insertion hole opening in the lower diaphragm. A concrete press-fitting chamber that communicates with each branch column through a side press-fitting hole that opens in the steel pipe forming
An inserting step of inserting a concrete filling pipe for filling the CFT column with concrete into the concrete press-fitting chamber through the filling pipe insertion hole;
Pressing concrete into the concrete press-fitting chamber from the tip of the concrete-filled pipe, and press-fitting the concrete press-pressed into the concrete press-fitting chamber simultaneously into the branch pillars from the side face press-fitting holes,
A method for filling concrete in a CFT column, which has: The difference between the inner diameter of the filling pipe insertion hole and the outer diameter of the concrete filling pipe, the concrete pumped into the concrete press-fitting chamber through the gap between the filling pipe insertion hole and the concrete filling pipe Is determined to have a predetermined size so as not to leak into the CFT column-beam joint portion and the pressure in the concrete press-fitting chamber does not decrease.
The method for filling concrete in a CFT column according to claim 1. In the CFT pillar / beam joint, a partition wall is formed standing on the upper surface of the lower diaphragm and partitioning the internal space of the CFT pillar / beam joint to an intermediate height.
In the press-fitting step, the cement paste leaked from the concrete press-fitting chamber into the CFT column-beam joint through the gap between the filling pipe insertion hole and the concrete filling pipe is blocked by the partition wall,
A method for filling concrete in a CFT column according to claim 1 or 2. The partition wall leaks into the CFT column-beam joint through the gap at least until the concrete press-fitted into each branch column part from the side face press-fitting hole is driven up to the height of the lower diaphragm in the press-fitting process. It is provided so that the cement paste can be blocked.
A method for filling concrete in a CFT column according to claim 3. At the tip opening of the concrete-filled pipe, a plurality of notches are formed to discharge the concrete pumped to the concrete-filled pipe toward each side press-fitting hole,
In the press-fitting step, the concrete is press-fitted into each branch post in a state where the plurality of notches in the concrete-filled pipe are directed to the side-face press-fit holes,
A method for filling concrete in a CFT column according to any one of claims 1 to 4.   The filling method for concrete in a CFT column according to claim 1, wherein a lower end of each branch column part is connected to a seismic isolation device installed in a seismic isolation layer.

Images