JP6853056B2 - Concrete pillar - Google Patents

Description

The present disclosure relates to concrete columns in a multi-story building, in particular, a joint structure of concrete columns.

Conventionally, when constructing a multi-story building using precast concrete members (hereinafter referred to as "PCa members"), the columns on the lower floors and the columns on the upper floors are rigidly joined at the column-beam joint, and the rigid frame is made of columns and beams. It was common to use a structural framework (for example, Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 2000-12166 Japanese Unexamined Patent Publication No. 2006-225897 Japanese Unexamined Patent Publication No. 2013-221361

FIG. 10 shows a bending moment diagram in a lower floor of a multi-layer rigid frame structure 3 including concrete columns 1 and beams 2 according to the prior art. The inflection point 4 of the bending moment generated in the column 1 at the time of an earthquake (the point where the positive and negative bending moments are exchanged) was often biased toward the stigma side on the lowest floor. In addition, the inflection point 4 on the top floor was often biased toward the column base side (not shown). Therefore, the absolute value of the bending moment becomes large at the column base or the stigma on the side far from the inflection point 4, and the main reinforcement is provided on the entire concrete column of the hierarchy according to the amount of the main reinforcement required for the column base or the stigma. The placement was a factor in increasing construction costs.

In view of these problems, it is an object of the present invention to provide an uncleat column in a multi-story building in which the designer can set the inflection point of the bending moment generated at the time of an earthquake to a desired position.

The concrete column according to at least some embodiments of the present invention is a concrete column (11) in a multi-story building, and is a lower column (14) having a plurality of lower main bars (17) and a lower concrete portion (18). ), And at least a part (19a) of the plurality of upper main bars (19a) is joined to at least a part (17a) of the plurality of lower main bars. The upper pillar (15) is arranged inside the lower main bar and the upper main bar in a cross-sectional view, and is provided at the lower recess (23) provided at the upper end of the lower concrete portion and the lower end of the upper concrete portion. It is characterized by including a joint member (16) that is received by the upper recess (24) and transmits a shearing force and an axial compressive force between the lower column and the upper column.

According to this configuration, an inflection point (4) is generated at the joint joint portion (13) that joins the lower column and the upper column. Therefore, the building designer desires by determining the position of the joint joint portion. An inflection point can be set at the position.

In the above configuration, the concrete column according to at least some embodiments of the present invention has the other part (17b) of the plurality of lower main bars and the other part (19b) of the plurality of upper main bars. It is characterized in that it is not joined to each other.

At the inflection point and its vicinity, the bending moment during an earthquake is close to zero, so most of the main bar joints are unnecessary. Therefore, it is possible to reduce the material cost and the construction cost for the joint by not performing the joint of some of the main bars.

The concrete column according to at least some embodiments of the present invention is characterized in that, in any of the above configurations, the joint member is located at a height of 1/3 to 2/3 of a predetermined layer. To do.

According to this configuration, the absolute values of the bending moments generated at the column base and the capital of a predetermined layer at the time of an earthquake are approximated, and the bending moment is compared with the case where the anti-bending point is closer to the column base or the capital. The maximum absolute value of is reduced. Therefore, an increase in the amount of the main muscle can be suppressed.

In any of the above configurations, the concrete column according to at least some embodiments of the present invention has at least a part of the plurality of lower main bars or at least a part of the plurality of upper main bars corresponding to the above. It is characterized in that it does not adhere to a predetermined section on the upper end side of the lower concrete portion or the lower end side of the upper concrete portion.

According to this configuration, it is possible to reduce the resistance of the joint joint portion to rotation during an earthquake and reduce the damage to the lower and upper concrete portions caused by the rotation.

The concrete column according to at least some embodiments of the present invention further includes hoop muscles (25, 26) in any of the above configurations, and has a unit length in the vertical direction in the section where the joint member exists. The amount of the hoop muscle (25) per hit is larger than the amount of the hoop muscle (26) per unit length in the vertical direction in the portion close to the section where the joint member exists. To do.

According to this configuration, the joint joint portion of the lower concrete portion and the upper concrete portion is reinforced against the axial compressive force between the joint member and the lower concrete portion and the upper concrete portion and the horizontal shear force at the time of an earthquake. be able to.

In any of the above configurations, the concrete column according to at least some embodiments of the present invention has the strength of the portion of each of the plurality of lower main bars and / or the plurality of upper main bars intersecting the beam. It is characterized by being composed of partial high-strength reinforcing bars that are higher than the strength of the part.

At the intersection of the beam and the column separated from the joint (inflection point), the absolute value of the bending moment at the time of an earthquake becomes large, but according to this configuration, the reinforcing bar strength of the intersection is high, so the intersection There is no need to increase the main muscle mass.

The concrete column according to at least some embodiments of the present invention is said to allow the lower column and / or the upper column to tilt in at least one direction with respect to the joint member in any of the above configurations. The lower and / or upper part of the joint member is characterized by having a curved surface or a corner portion (27) that can be slidably contacted with the lower recess and / or the upper recess that is received.

According to this configuration, the frictional force between the joint member and the lower recess and / or the upper recess at the time of tilting can be reduced.

The concrete column according to at least some embodiments of the present invention is characterized in that, in any of the above configurations, the joint member is made of concrete having a higher strength than the lower concrete portion and the upper concrete portion. To do.

According to this configuration, the joint member can be manufactured from a relatively inexpensive material, and the axial compressive force and the shearing force at the time of an earthquake can be reliably transmitted.

The concrete columns according to at least some embodiments of the present invention are applied to the central columns of the building (columns arranged inside the outer peripheral portion of the frame of the building) in any of the above configurations. It is characterized by.

According to this configuration, since the axial tensile force does not act on the center column, the joints of the main bars can be reduced at the joint joint portion, and thereby the resistance to the bending moment at the joint joint portion can be reduced. ..

The concrete column according to at least some embodiments of the present invention is characterized in that, in any of the above configurations, the lower column and the upper column are made of a precast concrete member.

According to this configuration, the construction period can be shortened.

According to the present invention, it is possible to provide a concrete column in a multi-story building in which a designer can set an inflection point of a bending moment generated during an earthquake at a desired position.

Bending moment diagram of concrete columns according to the embodiment Longitudinal section of the joint of concrete columns according to the embodiment Section III-III sectional view in FIG. Cross-sectional view showing a modified example of the joint portion of the concrete column according to the embodiment. Perspective view (omnidirectional rotation) showing an example of a joint member applied to a concrete column according to an embodiment. Perspective view (bidirectional rotation) showing an example of a joint member applied to a concrete column according to an embodiment. Perspective view (unidirectional rotation) showing an example of a joint member applied to a concrete column according to an embodiment. Perspective view (non-rotating) showing an example of a joint member applied to a concrete column according to an embodiment. Schematic cross-sectional view showing a modified example of a concrete column according to an embodiment (when a joint member is created at a construction site). Bending moment diagram of the lower concrete column according to the conventional example

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the frame 10 of a multi-story building includes a reinforced concrete column 11 extending in the vertical direction and a reinforced concrete beam 12 extending in the horizontal direction and rigidly joined to the column 11. .. The columns 11 and beams 12 are preferably constructed using PCa members, but may be constructed using cast-in-place concrete. At least one layer of at least one column 11 in the frame 10 is provided with a joint joint portion 13 which can be regarded as a pin type joint.

The structure of the joint joint portion 13 will be described in detail with reference to FIGS. 2 and 3. In the cross-sectional view, the concrete of the main body of the pillar 11 is shown as if it were seen through. The pillar 11 provided with the joint portion 13 is between the lower pillar 14 made of the PCa member arranged below, the upper pillar 15 made of the PCa member arranged above, and the lower pillar 14 and the upper pillar 15. It is provided with a joint member 16 arranged in. Of the PCa members constituting the pillar 11, those in which both the upper end and the lower end are joined by the joint joint portion 13 are the lower pillar 14 when viewed from the joint joint portion 13 on the upper end side, and the joint joint portion on the lower end side. Seen from 13, it is the upper pillar 15.

The lower column 14 has a plurality of lower main bars 17 extending along the vertical direction, and a lower concrete portion 18 in which the lower main bars 17 are embedded. The upper column 15 has a plurality of upper main bars 19 extending along the vertical direction, and an upper concrete portion 20 in which the upper main bars 19 are embedded.

The plurality of lower main bars 17 and the plurality of upper main bars 19 are such that the joint lower main bar 17a and the joint upper main bar 19a, which are a part thereof, are joined to each other by a mechanical joint, and the remaining non-joined lower main bar 17b and the non-joined upper main bar It is not joined to each other with 19b. The lower joint main bar 17a and the upper joint main bar 19a are preferably arranged at equal intervals with each other. For example, among the plurality of lower main bars 17 and the plurality of upper main bars 19, those arranged at four corners in a cross-sectional view. Can be the joint lower main bar 17a and the joint upper main bar 19a, and the others can be the non-join lower main bar 17b and the non-join upper main bar 19b. The mechanical joint is embedded in the lower end of the upper concrete portion 20 along the vertical direction, and the upper end of the joint lower main bar 17a protruding from the upper end of the lower concrete portion 18 is attached to the connecting pipe 21 that receives the lower end of the joint upper main bar 19a. It is done by injecting grout after insertion. The upper end of the non-joined lower main bar 17b and the lower end of the non-joined upper main bar 19b may be shortened by using a 180 degree hook or by providing a mechanical fixing tool.

Further, when the joint joint portion 13 of the pin type joint is rotated (tilting of the lower pillar 14 and / or the upper pillar 15 with respect to the joint member 16) due to an earthquake, the lower concrete portion 18 is prevented from being damaged and the joint joint portion is prevented from being damaged. In order to reduce the bending resistance of 13, it is preferable that the joint lower main bar 17a does not adhere the concrete of the lower concrete portion 18 in a predetermined section on the upper end side of the lower concrete portion 18. Specifically, the joint lower main bar 17a is embedded in the upper end side of the lower concrete portion 18 along the vertical direction and penetrates into a hollow pipe 22 such as a sheath pipe not filled with grout. The concrete of the lower concrete portion 18 is not adhered in the extending section of the empty pipe 22. Instead of installing the hollow pipe 22, the adhesion of concrete may be prevented by wrapping a tape around the joint lower main bar 17a in that section.

Further, as the lower main bar 17 and / or the upper main bar 19, a partial high-strength reinforcing bar in which the strength of the portion intersecting the beam 12 is higher than the strength of the end portion by high-frequency heat treatment or the like may be used. A relatively large bending moment is generated at the intersection with the beam 12, but by using the high-strength reinforcing bar, it is not necessary to increase the amount of the lower main bar 17 and the upper main bar 19 at the intersection with the beam 12. Further, for example, since there is no mechanical joint for joining a reinforcing bar having a strength equivalent to SD980 class at the time of filing the application of the present application, it is practically impossible to apply a reinforcing bar having a high strength as a whole to the main reinforcing bar of the present embodiment, but the end portion. If is a partial high-strength reinforcing bar of normal strength (for example, SD390), a mechanical joint for a reinforcing bar of normal strength can be used, so that it can be applied to the main reinforcing bar of the present embodiment. .. When the joint joint portion 13 is provided in the middle portion of the layer where the bending moment is smaller than the intersection with the beam 12, such a partial high-strength reinforcing bar can be applied.

The joint member 16 is formed by the lower pillar 14 and the upper pillar 15 so as to be received by the lower recess 23 provided at the upper end of the lower concrete portion 18 and the upper recess 24 provided at the lower end of the upper concrete portion 20. Placed in between.

An axial compressive force is applied between the joint member 16, the lower recess 23, and the upper recess 24, and a horizontal shear force acts in the event of an earthquake. Therefore, when it is necessary to reinforce the joint portion 13 of the lower column 14 and the upper column 15, the lower column 14 and the upper column 15 each arrange the restraint hoop muscle 25 in the section where the joint member 16 exists. The amount of restraint hoop muscles 25 arranged per unit length in the vertical direction is larger than that of the normal hoop muscles 26, that is, the hoop muscles 26 arranged in the portion close to the section where the joint member 16 exists. .. As shown in FIG. 3, the restraint hoop muscle 25 is arranged so as to surround all the lower main muscles 17 or the upper main muscles 19. As shown in FIG. 4, the restraint hoop muscle 25 may be arranged so as to surround a part of the lower main muscle 17 or the upper main muscle 19 and the joint member 16. In this case, the lower main bar 17 or the upper main bar 19 surrounded by the restraint hoop muscle 25 is preferably the lower main bar 17 or the upper main bar 19 arranged at equal intervals with each other or at positions symmetrical with each other in the cross-sectional view. ..

The shape of the joint member 16 can be changed according to the performance and structural form required for the joint joint portion 13. FIG. 5 shows an example of the shape of the joint member 16 suitable when the joint joint portion 13 is a pin joint that can rotate in all directions. The joint member 16 in FIG. 5a is a sphere, and the shapes of the lower recess 23 and the upper recess 24 at this time have a radius equal to or slightly larger than the radius of the sphere so as to be in sliding contact with the lower portion and the upper portion of the joint member 16, respectively. It is a part of the lower end side and the upper end side of the spherical surface having. Both the lower column 14 and the upper column 15 are rotatable in all directions with respect to the joint member 16.

The lower part of the joint member 16 in FIG. 5b is a cylinder whose axis extends in the vertical direction, and the upper part is a hemisphere. At this time, the lower recess 23 fits the lower portion of the cylindrical joint member 16, and the upper recess 24 has the same shape as the upper recess 24 corresponding to the joint member 16 in FIG. 5a and is the upper portion of the joint member 16. To slide in contact with. The lower column 14 does not rotate with respect to the joint member 16, but the upper column 15 can rotate with respect to the joint member 16 in all directions.

The joint member 16 of FIG. 5c has a shape in which a truncated cone having a thin end side is superposed on the upper and lower bottom surfaces of a cylindrical body. A plurality of corner portions 27 (sides sliding on the surface of the lower recess 23 or the upper recess 24) in which one spherical surface circumscribes, such that the inclination of the side surface gradually approaches the horizontal direction toward the end. It may be a polygonal shape in which truncated cones are overlapped. The shapes of the lower recess 23 and the upper recess 24 at this time are a part of the lower end side and the upper end side of the spherical surface having the same or slightly larger radius as the radius of the circumscribed sphere, respectively. Both the lower column 14 and the upper column 15 are rotatable in all directions with respect to the joint member 16.

The lower part of the joint member 16 in FIG. 5d is a cylindrical body, and the upper part has the same shape as the upper part in FIG. 5c. At this time, the lower recess 23 has the shape of a cylindrical surface that fits the lower portion of the joint member 16 of the cylindrical body, and the upper recess 24 has the same shape as the upper recess 24 corresponding to the joint member 16 of FIG. 5c. .. The lower column 14 does not rotate with respect to the joint member 16, but the upper column 15 can rotate with respect to the joint member 16 in all directions.

FIG. 6 shows an example of the shape of the joint member 16 suitable when the joint joint portion 13 is a pin joint that can rotate in two directions. In the joint member 16 of FIG. 6a, a cylinder having an axis extending in the horizontal direction and having the same diameter and height is divided into two in a horizontal plane passing through the axis, and the two semi-cylinders are divided into two with respect to each other in the vertical direction. It exhibits a combined shape by rotating it 90 °. At this time, the shapes of the lower recess 23 and the upper recess 24 are the lower end side of the cylindrical surface having a radius equal to or slightly larger than the radius of the cylindrical body, which is configured in the direction corresponding to the lower portion and the upper portion of the joint member 16, respectively. And a part of the shape on the upper end side. The upper pillar 15 is rotatable in one direction (X direction) with respect to the joint member 16, and the lower pillar 14 is rotatable in one direction (Y direction) orthogonal to the joint member 16 in the X direction. As a result, the joint joint portion 13 can rotate in two directions.

In the joint member 16 of FIG. 6b, a regular octagonal prism having an axis extending in the horizontal direction and two side surfaces arranged horizontally is divided into two by a horizontal plane passing through the axis, and the two prisms are axially oriented in the vertical direction. It has a shape in which it is rotated by 90 ° and joined to each other. At this time, the shapes of the lower recess 23 and the upper recess 24 are formed in directions corresponding to the lower part and the upper part of the joint member 16, respectively, and have the same or slightly larger radius as the radius of the cylinder circumscribing the prism. It is a part of the lower end side and the upper end side of the surface. The upper pillar 15 is rotatable in one direction (X direction) with respect to the joint member 16, and the lower pillar 14 is rotatable in one direction (Y direction) orthogonal to the joint member 16 in the X direction. As a result, the joint joint portion 13 can rotate in two directions.

FIG. 7 shows an example of the shape of the joint member 16 suitable when the joint joint portion 13 is a pin joint that can rotate in one direction. The joint member 16 of FIG. 7a is a cylindrical body whose axis extends in the horizontal direction, and the shapes of the lower concave portion 23 and the upper concave portion 24 at this time are arranged in the directions corresponding to the joint member 16, and are cylindrical bodies, respectively. It is a part of the lower end side and the upper end side of the cylindrical surface having a radius equal to or slightly larger than the radius of. Both the lower column 14 and the upper column 15 can rotate in the same direction with respect to the joint member 16.

The lower part of the joint member 16 of FIG. 7b is a rectangular parallelepiped, and the upper part is a pillar body having a semicircular bottom surface similar to the upper part of the joint member 16 of FIG. 7a. At this time, the lower recess 23 has a shape for fitting the lower portion of the joint member 16, and the upper recess 24 has the same shape as the upper recess 24 corresponding to the joint member 16 in FIG. 7a. The lower column 14 does not rotate with respect to the joint member 16, but the upper column 15 can rotate in one direction with respect to the joint member 16.

The joint member 16 of FIG. 7c is a regular octagonal prism whose axis extends in the horizontal direction and whose two planes are arranged horizontally. Instead of a regular octagonal prism, it may be another polygonal prism with a cylinder circumscribing. The lower recess 23 and the upper recess 24 are each in the shape of a part of a lower part and an upper part of a cylinder circumscribing a regular octagonal prism arranged in a direction corresponding to the joint member 16 or a cylinder surface slightly larger than the cylinder. A corner portion 27 having a side parallel to the axis of the joint member 16 slides on the surfaces of the lower recess 23 and the upper recess 24, so that both the lower column 14 and the upper column 15 are the same 1 with respect to the joint member 16. It is rotatable in the direction.

The lower portion of the joint member 16 of FIG. 7d has the same shape as the lower portion of the joint member 16 of FIG. 7b, and the upper portion has the same shape as the upper portion of the joint member 16 of FIG. 7c. At this time, the lower recess 23 fits the lower portion of the joint member 16, and the upper recess 24 has the same shape as the upper recess 24 corresponding to the joint member 16 in FIG. 7c. The lower column 14 does not rotate with respect to the joint member 16, but the upper column 15 can rotate in one direction with respect to the joint member 16.

Since the joint members 16 having the shapes of FIGS. 5a, 5b, 6a, and 7a and 7b are curved and are in sliding contact with the lower recess 23 and the upper recess 24, it is required to suppress the frictional force during rotation. Suitable for the case, the joint member 16 having the corners 27 in the shapes of FIGS. 5c and 5d, 6b, and 7c and 7d is a case where the joint member 16 is made of concrete, and the formwork thereof is made. It is suitable when workability such as installation is important. In addition, in the joint joint portion 13 having the joint members 16 having the shapes of FIGS. 5b and 5d and 7b and 7d, the joint members 16 are turned upside down and the shapes of the lower recess 23 and the upper recess 24 are exchanged. The upper column 15 does not rotate with respect to the joint member 16, but the lower column 14 may be rotatable with respect to the joint member 16.

FIG. 8 shows an example of the shape of the joint member 16 suitable for the case where the joint joint portion 13 is non-rotating. The joint member 16 of FIG. 8 forms a rectangular parallelepiped having planes orthogonal to the vertical direction. The lower recess 23 and the upper recess 24 have a shape that fits the lower part and the upper part of the rectangular parallelepiped shape of the joint member 16, respectively. The joint member 16 shown in FIG. 8 is suitable when the joint joint portion 13 is provided at a position at the inflection point 4 (see FIG. 11) even if the joint joint portion 13 is not provided.

It should be noted that FIGS. 1 to 3 show a case where the center of the joint member 16 is located at the joint between the lower concrete portion 18 and the upper concrete portion 20. However, in the range where the lower end side of the joint member 16 is received by the lower recess 23 and the upper end side is received by the upper recess 24, the center of the joint member 16 is vertically oriented from the joint between the lower concrete portion 18 and the upper concrete portion 20. It may be misaligned. In this case, the shapes of the lower recess 23 and the upper recess 24 are deformed in response to the deviation. For example, when the joint member 16 is a sphere as shown in FIG. 5a and the center of the sphere is shifted toward the lower concrete portion 18, the lower recess 23 has the shape of the lower half of the spherical surface. The upper portion is opened with a contour equal to or larger than the maximum cross section of the sphere so that the joint member 16 can be inserted, and the upper recess 24 is a part of the shape of the upper end side of the spherical surface.

The joint member 16 preferably has a higher strength than the lower concrete portion 18 and the upper concrete portion 20, and for example, high-strength concrete, steel material, resin, or the like can be used as a material. The joint member 16 may be a PCa member, or may be created at a construction site of a building using an injection grout (see FIG. 9).

A joint 28 is arranged between the upper end of the lower concrete portion 18 and the lower end of the upper concrete portion 20. If the joint 28 is an organic seal joint that does not bear the compressive force in the vertical direction, it is not necessary to cover the joint 28 with fire resistance, and the rotation followability to the rotation of the joint joint portion 13 at the time of an earthquake is improved. Further, if the joint 28 is a low-strength mortar joint, the material cost can be reduced, and in the event of an earthquake, the joint portion 13 can rotate due to the destruction of the mortar, and even if it is destroyed, it can be easily repaired.

In the joint portion 13 of the column 11, the lower column 14 is arranged at a predetermined position, the joint member 16 is placed in the lower recess 23, and the upper column 15 is received by the upper recess 24 in the upper portion of the joint member 16. In addition, the joint lower main bar 17a is moved from above to the lower side and placed at a predetermined position so that the joint lower main bar 17a is inserted into the connection pipe 21, and grout is injected into the connection pipe 21 to form the joint lower main bar 17a and the joint upper main bar. It is constructed by joining 19a to each other and constructing a joint 28.

When the joint member 16 is created at the construction site of a building, the lower column 14 is arranged at a predetermined position, and the upper column 15 is inserted from the upper side to the lower side so that the joint lower main bar 17a is inserted into the connecting pipe 21. After moving and arranging them in predetermined positions, as shown in FIG. 9, a backup material 29 is arranged between the upper end of the lower concrete portion 18 and the lower end of the upper concrete portion 20 around the lower recess 23 and the upper recess 24. Then, the grout is injected into the lower recess 23 and the upper recess 24 to create the joint member 16. The grout may be injected into the connecting pipe 21 either before or after the joint member 16 is created. After that, the joint 28 is constructed.

The column 11 having the joint portion 13 can be applied to a central column of a building to which a tensile force in the axial direction does not act. Further, the column 11 having the joint joint portion 13 is made to bear an axial tensile force on another member such as a shear wall (not shown), or the amount of the joint lower main bar 17a and the joint upper main bar 19a is increased. It can also be applied to the outer columns of buildings by increasing it to resist tensile forces.

The joint portion 13 resists axial compressive force and shearing force, but does not resist bending force. Therefore, as shown in FIG. 1, by providing the joint joint portion 13, the distribution of the bending moment at the time of an earthquake changes, and the inflection point 4 is generated at the position where the joint joint portion 13 is provided. Therefore, by providing the joint joint portion 13, the inflection point 4 can be set at a position intended by the designer. If the joint joint portion 13 is provided so that the joint member 16 is located in the middle portion of the hierarchy, for example, at a height of 1/3 to 2/3, preferably 1/2 height, the column base portion and the stigma portion can be provided. The absolute value of the bending moment of the part becomes close or equal, and the maximum value of the absolute value of the bending moment decreases. Therefore, the amount of the lower main bar 17 and the upper main bar 19 can be reduced to reduce the material cost. Further, by providing the joint joint portion 13 at the position of the column intended by the designer, the distribution of the bending moment generated in the entire frame 10 of the building can be changed to design an economical building.

Further, since the bending moment generated at the time of an earthquake is close to zero in the joint joint portion 13, it is not necessary to join all the lower main bars 17 and the upper main bars 19 to each other, and a mechanical joint for low-strength reinforcing bars. Can be used, and the material cost and construction cost of mechanical joints can be reduced.

Although the description of the specific embodiment is completed above, the present invention can be widely modified without being limited to the above embodiment. For example, the ratio and arrangement of the lower joint main bar and the non-joint lower main bar, and the ratio and arrangement of the upper joint upper main bar and the non-joint upper main bar may be changed, or all the lower main bars and the upper main bar may be joined. Good. Further, the joint lower main bar and the joint upper main bar may be joined to each other on the upper end side of the lower concrete portion. In this case, instead of the configuration in which the joint lower main bar is not attached to the upper end side of the lower concrete portion, the joint upper main bar May not be attached to the lower end side of the upper concrete portion.

4: Anti-curving point 10: Multi-layer building frame 11: Column 12: Beam 13: Joint joint 14: Lower column 15: Upper column 16: Joint member 17: Lower main bar 17a: Joint lower main bar 17b: Non-joined lower main bar 18: Lower concrete part 19: Upper main bar 19a: Joint upper main bar 19b: Non-joined upper main bar 20: Upper concrete part 23: Lower recess 24: Upper recess 25: Restraint hoop bar 26: Hoop bar 27: Corner

Claims (9)

A concrete pillar in a multi-story building
A lower column with multiple lower main bars and lower concrete parts,
And the top post to have a plurality of upper main reinforcement and the upper concrete part,
The lower column is arranged inside the lower main bar and the upper main bar in a cross-sectional view, and is received by a lower recess provided at the upper end of the lower concrete portion and an upper recess provided at the lower end of the upper concrete portion. And a joint member that transmits shear force and axial compressive force between the upper columns .
A part of the plurality of upper main bars is joined to a part of the plurality of lower main bars, and the rest of the plurality of upper main bars is not joined to any of the plurality of lower main bars, and the plurality of lower main bars A concrete column characterized in that the remaining portion is not joined to any of the plurality of upper main bars. The concrete column according to claim 1 , wherein the joint member is located at a height of 1/3 to 2/3 of a predetermined layer. Wherein the portion of the part or the plurality of upper main reinforcement of the plurality of lower main reinforcement, characterized in that it does not adhere to the lower end of the predetermined section of the upper side or the upper concrete portion of the lower concrete corresponding parts The concrete pillar according to claim 1 or 2. With more hoop muscles
The amount of the hoop muscle per unit length in the vertical direction in the section where the joint member is present is the amount of the hoop muscle per unit length in the vertical direction in the portion close to the section where the joint member is present. The concrete pillar according to any one of claims 1 to 3 , wherein the amount is larger than the amount of. Claims 1 to 4 , wherein each of the plurality of lower main bars and / or each of the plurality of upper main bars is composed of partial high-strength reinforcing bars in which the strength of the portion intersecting the beam is higher than the strength of the end portion. The concrete pillar according to any one item. In order to allow the lower column and / or the upper column to tilt in at least one direction with respect to the joint member, the lower and / or upper portion of the joint member slides into the receiving lower recess and / or upper recess. The concrete column according to any one of claims 1 to 5 , wherein the concrete column has a curved surface or a corner portion that can be contacted. The concrete column according to any one of claims 1 to 6 , wherein the joint member is made of the lower concrete portion and concrete having a higher strength than the upper concrete portion. The concrete pillar according to any one of claims 1 to 7 , wherein the concrete pillar is applied to the central pillar of the building. The concrete pillar according to any one of claims 1 to 8 , wherein the lower pillar and the upper pillar are made of a precast concrete member.

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