JP6567355B2 - Joint structure of prestressed concrete structure - Google Patents

Description

  The present invention relates to a joint structure of a prestressed concrete structure, and more particularly to a joint structure that does not require a filler to be filled in a joint portion.

Conventionally, prestressed concrete in which a compressive force is preliminarily applied to columns and beams by the introduction of prestress may be employed for large span structures such as theaters and structures such as parking lots that have a large load.
For example, in Patent Document 1, a plurality of (precast) concrete columns preformed at a factory or the like are erected on a foundation, and precast concrete beams are bridged between the plurality of columns, and then mortar or the like. The joint between the column and the beam is filled with the filler, and pre-stress is introduced by tensioning the PC steel material inserted into the column and the beam, and the column and the beam are connected using the pre-stress. A method of joining is disclosed.

JP-A-11-172762

  However, in the joining method according to Patent Document 1, it takes a long time until the filler in the joint is cured and a predetermined strength is exhibited. There was a problem that time was lost until the filler was cured.

  In order to solve the above-described problems, an object of the present invention is to provide a prestressed concrete structure joint structure capable of shortening the work period by omitting the time until the filler is cured.

As a joining structure of a precast prestressed concrete structure for solving the above-described problems, a pair of precast concrete columns provided at a predetermined interval and a pair of pillars are installed and joined to each column. and beams of precast concrete, a first metal plate provided respectively on the side inner opposing pair of posts, and a second metal plate provided respectively on the end faces of both beams digit direction, one of the beam The contact surface of the second metal plate provided on the end surface of the first metal plate and the contact surface of the first metal plate provided on the inner surface of one of the pillars are in contact with each other, and the second surface provided on the other end surface of the beam In a state where the contact surface of the metal plate and the contact surface of the first metal plate provided on the inner side surface of the other column are in contact, the first metal plate, the second metal plate, and the beam from the outer surface of the one column. , Via the second metal plate, the first metal plate Comprising square and tendons insertion path formed so as to extend to the outer surface of the pillar, the tension member insertion path by compressive force generated by tension inserted through so the tendons of the first metal plate and a second metal plate a pair of columns and beams by contacting faces are in close contact with each other was engaged configuration tangent.
As another configuration, the first metal plate is fixed to a fixing recess formed on the inner side surface of the column so that the contact surface of the first metal plate and the inner side surface of the column are flush with each other, and a tension material is inserted. The path was formed so as to bend downward toward the center of the beam.
According to this configuration, the column and the beam are firmly joined by the tension material in a state where the frictional force is generated between the contact surface of the first metal plate and the contact surface of the second metal plate. Therefore, it is not necessary to fill the filler, and the construction period can be shortened.
Also, as another configuration, with the configuration of the processing Sabitsuke the contact surface of the first metal plate and the second metal plate is applied, the contact surface of the first metal plate and the second metal plate The frictional force generated on the contact surface can be further increased.
The above summary of the invention does not enumerate all necessary features of the present invention, and sub-combinations of these features can also be an invention.

It is a longitudinal cross-sectional view of a prestress concrete structure. It is a schematic perspective view which shows the junction structure of a column and a beam. It is a longitudinal cross-sectional view which shows the modification of the junction structure of a column and a beam. It is a longitudinal cross-sectional view of a prestress concrete structure. It is a schematic perspective view which shows the joining structure of a lower floor pillar and an upper floor pillar.

  Hereinafter, the present invention will be described in detail through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are included in the invention. It is not necessarily essential to the solution, but includes a configuration that is selectively adopted.

[Column and beam joint structure]
FIG. 1 is a longitudinal sectional view of a prestressed concrete (hereinafter, also referred to as PC) structure 10, and FIG. 2 is a schematic perspective view showing a joint portion between a column 20 and a beam 50. Hereinafter, the joint structure between the column 20 and the beam 50 will be described in detail.
As shown in FIG. 1, the PC structure 10 is installed between a pair of columns 20; 20 made of concrete (hereinafter also referred to as precast concrete) and a pair of columns 20; The main structure includes a precast concrete beam 50, a column 20; 20, a PC steel material 32 inserted through the inside of the beam 50, and a metal plate 40; 42 provided at a joint portion between the column 20 and the beam 50.

  As shown in FIG. 1, the pair of pillars 20; 20 are, for example, square pillar-shaped structures extending in the vertical direction with respect to the ground G. The columns 20; 20 are erected on the foundation concrete 22 embedded in the ground via the pedestal block 24. The columns 20; 20 are separated from each other with a predetermined interval in the extending direction of the beam 50.

  The beam 50 is, for example, a quadrangular columnar member that extends in a direction orthogonal to the columns 20; 20, and the size in the beam direction is set to be approximately equal to that between the pair of columns 20; 20. After the beam 50 is transported from the factory or the like to the site, the beam 50 is bridged between the columns 20; 20 using the compressive force generated by the introduction of prestress due to the tension of the PC steel material 32 at the site.

  A plurality of hollow sheath tubes 30A; 30B; 30C formed of metal or the like extend in the columns 20; As shown in FIG. 5, four sheath tubes 30 </ b> A embedded in the columns 20; 20 are provided evenly spaced so as to correspond to the corners of the columns 20; 20. It extends along the extension (height) direction of the column 20 until it reaches the upper end surface 20A. The sheath tube 30B embedded in the beam 50 extends along the beam direction of the beam 50, and is divided into, for example, two in the vertical direction. The sheath tube 30 </ b> C embedded in the upper end side of the column 20; 20 is arranged separately in the vertical direction so as to correspond to the positions of the above-described sheath tube 30 </ b> B facing both end surfaces of the beam 50. One end portion of the sheath tube 30C faces the fixture fixing hole 20T formed on the outer side surface 20B of the column 20; 20, and the other end portion faces the inner side surface 20C of the column 20; Therefore, in a state where the beam 50 is joined between the columns 20; 20, the beam 50 is formed between the columns 20; 20 by the sheath tube 30B embedded in the beam 50 and the sheath tube 30C embedded in the column 20; One tendon insertion path 35 extending along the spar direction is formed. As shown in the figure, the tension material insertion path 35 is curved downward as it goes toward the central portion of the beam 50, and when the tension force is introduced, the central portion side of the beam 50 is slightly upward. Joined in a warped state.

A PC steel material 32 as a tension material is inserted into a tension material insertion path 35 constituted by the sheath tube 30A embedded in the columns 20; 20 and the sheath tube 30B and the sheath tube 30C; 30C. As the PC steel material 32, a PC steel rod, a PC steel stranded wire, or the like is employed. The PC steel material 32 inserted into the sheath tube 30A of the column 20; 20 is fastened to the fixed fixing tool 36 disposed in the foundation concrete 22 at the lower end side, and the upper end side is arranged on the upper end surface 20A of the column 20; It is fixed with the tension fixing tool 38 provided.
Further, the PC steel material 32 inserted into the tension material insertion path 35 is fastened to a fixing fixing tool 36 disposed at one end side in a fixing tool fixing hole 20T formed on the outer surface 20B of the column 20 on one side. The other end side is fixed with the tension fixing device 38 provided in the fixing device fixing hole 20T formed on the outer side surface 20B of the other column 20.
Tension force (pre-stress) is introduced into the PC steel material 32 inserted through the sheath tube 30A and the tension material insertion passage 35 by being tensioned at one end by a hydraulic jack or the like (not shown), and the tension force is introduced. By being fixed in the state, a compressive force opposite to the tension direction acts on the pillars 20; 20 and the beam 50. That is, in the present embodiment, the prestress is introduced by a so-called post tension method. Further, after the introduction of the tension force, the sheath tube 30A and the tension material insertion path 35 are filled with a filler such as mortar, and the corrosion of the PC steel material 32 is prevented.

Next, with reference to FIG. 1, FIG. 2, the junction structure of the pillars 20; 20 and the beam 50 is demonstrated.
As shown in the figure, fixing concave portions 26 that are concave inward from the inner side surface 20C are formed on the inner side surfaces 20C of the columns 20; In the fixing recess 26, the metal plate 40 is firmly fixed and fixed via fixing means (not shown) such as an anchor bolt. The metal plate 40 is a rectangular plate made of, for example, iron or an iron alloy, and the shape and thickness thereof are formed to be equal to the shape of the fixing recess 26. Therefore, the outer surface 40A of the metal plate 40 serving as a contact surface fixed to the fixing recess 26 and the inner side surface 20C of the column 20 are flush with each other. It should be noted that the concrete is placed in the manufacture of the pillar 20 in a state where the metal plate 40 is disposed at a position corresponding to the fixing recess 26.

The metal plate 42 is firmly fixed to both end faces 52; 52 in the spar direction of the beam 50 laid between the columns 20; 20 through fixing means (not shown) such as anchor bolts. The metal plate 42 is a rectangular plate made of, for example, the same material as the metal plate 40 and having the same shape as the metal plate 40 and the end surface 52. That is, the metal plate 40 and the metal plate 42 have the same shape and the same area. And the joining of the pillar 20 and the beam 50 is a state in which the outer surface 40A of the metal plate 40 as a contact surface and the outer surface 42A of the metal plate 42 as a contact surface in contact with the outer surface 40A are in close contact with each other. It is made in. It should be noted that the concrete is placed in the production of the beam 50 in a state where the metal plate 42 is disposed at positions corresponding to both end faces 52; 52 of the beam 50 in the spar direction.
More specifically, the outer surface 40A and the outer surface 42A are subjected to rusting by polishing with equipment such as shot blasting, application of a chemical containing an oxidizing agent, or leaving in the air. Then, the outer surfaces 40A; 42A of the rusted metal plates 40; 42 are in close contact with each other with extremely high frictional force due to the compressive force generated by the introduction of the tension force to the PC steel material 32 ( As a result, the beam 50 is bonded to the column 20 extremely firmly. Further, the surface of the outer surface 40A; 42A is originally formed as a smooth surface in comparison with the surface of concrete, and the outer surfaces 40A; 42A are pressure-bonded by a high compressive force. There is no gap due to the intervening rust, and the joint filling process with mortar or the like, which is necessary when directly joining concrete, can be omitted. In the present embodiment, the outer surface 40A and the outer surface 42A have been rusted. However, the present invention is not limited to this. The kind is not ask | required.

  Next, the construction process of the PC structure 10 will be briefly described with reference to FIGS. 1 and 2. First, the pillars 20; 20 and the beam 50 as precast concrete are produced in advance and are carried to the construction site. In the column 20 created in advance, the sheath tube 30A and the sheath tube 30C are embedded, and a metal plate 40 is fixed in the fixing recess 26. Similarly, a sheath tube 30B is embedded in the beam 50, and metal plates 42; 42 are fixed to both end faces 52; 52 in the spar direction. At the construction site, the foundation concrete 22 is constructed in advance by cast-in-place concrete, and the sheath in the foundation is located in the foundation concrete 22 at a position corresponding to the position of the plurality of sheath tubes 30A embedded in the column 20. A tube 22A is embedded. Further, in the sheath tube 22A, a PC steel material 32 having one end fastened by a fixed fixing tool 36 is disposed in advance and protrudes upward from the ground G. Next, the pedestal block 24 is placed on the foundation concrete 22. In the pedestal block 24, similarly to the basic concrete 22, a plurality of sheath tubes 24 </ b> A are embedded at positions corresponding to the positions of the plurality of sheath tubes 30 </ b> A in the column 20. Inserts the PC steel material 32 protruding upward from the ground G into each sheath tube 24A.

  Next, the pillar 20 is erected on the base block 24 using a heavy machine such as a crane. Specifically, each of the plurality of PC steel materials 32 protruding on the pedestal block 24 is inserted into a plurality of sheath tubes 30A embedded in the column 20, and the upper end portion of the PC steel material 32 is connected to the upper end surface 20 </ b> A of the column 20. It is assumed that it protrudes from. Thereafter, the upper end portion of the PC steel material 32 protruding from the upper end surface 20A is tensioned upward by a hydraulic jack or the like, and fixed and fixed by the tension fixing tool 38. Accordingly, the columns 20; 20 are erected on the foundation concrete 22 and the pedestal block 24 in a state where a compressive force in the vertical direction is applied.

  Next, the beam 50 is joined between the columns 20; Specifically, the beam 50 is lifted by a heavy machine such as a crane, and the beam 50 is positioned at an appropriate position between the columns 20; That is, the metal plate 40 provided on the inner side surface 20 </ b> C of the one pillar 20 and the metal plate 42 provided on the one end surface 52 of the beam 50 are brought into close contact with each other. Similarly, the metal plate 40 provided on the inner side surface 20C of the other column 20 and the metal plate 42 provided on the other end surface 52 of the beam 50 are in a state of facing each other and closely contacting each other, and the beam 50 is connected to the column 20; It is installed between 20.

  Thereafter, a plurality of PC steel materials 32 are inserted into the tension member insertion path 35 through the fixing member fixing hole 20T formed in one column 20, and the fixing member fixing hole formed in the other column 20 is inserted into the end portion. The state protrudes from 20T. One end portion of the PC steel material 32 is fixed by a fixing and fixing tool 36, and the other end portion is tensioned in a girder direction by a hydraulic jack, and is fixed and fixed by a tension fixing tool 38 on the outer side surface 20B side of the other column 20. . As a result, the outer surface 40A and the outer surface 42A of the metal plate 40; 42 are firmly pressed together, and the beam 50 is stably joined between the columns 20;

FIG. 3 is a longitudinal sectional view showing a modified example of the joint structure of the column 20 and the beam 50. In the following description, the same reference numerals are used for the same components as those in the above embodiment, and the description thereof is omitted. Further, in FIG. 3, the tension material insertion path 35, the PC steel material 32, and the fixing fixing tool 36 are not illustrated in order to make the joining structure easy to see.
As shown to Fig.3 (a), it differs from the above-mentioned form by the point by which the receiving part 70 which receives the load of the beam 50 was provided in the inner surface 20C of the pillar 20 which concerns on this embodiment. The receiving portion 70 is a portion having a rectangular cross-section located immediately below the fixing recess 26 of the column 20, and slightly protrudes from the inner side surface 20 </ b> C of the column 20 toward the beam 50.
Thus, according to the pillar 20 according to the present modification, the joint filling step can be omitted as in the case described above, and the joining work between the pillar 20; 20 and the beam 50 is facilitated, and the PC structure. 10 workability can be improved. In addition, by temporarily placing the beam 50 on the receiving portion 70, a heavy machine such as a crane can move to the next lifting operation, so that the lifting time of the beam 50 by the heavy machine is shortened. Therefore, the construction time of the PC structure 10 can be shortened.

The column 20 and the beam 50 shown in FIG. 3B are different from the above-described embodiment in that the joint portion is inclined. As shown in the drawing, an inclined portion 80 having a triangular cross-sectional shape is formed on the inner side surface 20C of the column 20. The inclined portion 80 is formed with an inclined surface 80A that is inclined to the beam 50 side from the upper side to the lower side of the inner side surface 20C. A metal plate 40 having a shape corresponding to the inclined surface 80A is fixed to the inclined surface 80A. Further, the end surface 52 of the beam 50 in the spar direction is formed as an inclined surface 50A that inclines toward the column 20 side from the lower side to the upper side so as to complement the inclined surface 80A. A metal plate 42 having a shape corresponding to the inclined surface 50A and facing the metal plate 40 is fixed to the inclined surface 50A. That is, the outer surface 40A of the metal plate 40 and the outer surface 42A of the metal plate 42 are opposed to each other while being inclined with each other. In FIG. 3 (b), only the joint portion on one side is inclined. However, the present invention is not limited to this, and the joint portion on one side and the other side (that is, both ends 52 in the beam direction of the beam 50). 52) may be inclined.
Thus, according to the pillar 20 according to the present modification, the joint filling step can be omitted as in the case described above, and the inclined surface 80A supports the load of the beam 50. The beam 50 can be more firmly joined, and the joining work between the columns 20; 20 and the beam 50 is facilitated. In addition, since the load of the beam 50 acts on the inclined surface 80A, the degree of pressure bonding between the metal plate 40 and the metal plate 42 can be improved. Furthermore, since the heavy machine such as a crane can move to the next lifting work by temporarily placing the beam 50 on the inclined portion 80, the lifting time of the beam 50 by the heavy machine is shortened. Therefore, the construction time of the PC structure 10 can be shortened.

[Joint structure between columns]
FIG. 4 is a vertical cross-sectional view of a PC structure 10 ′ according to another embodiment, and FIG. 5 is a schematic perspective view showing a joint portion between the lower floor pillar 20P and the upper floor pillar 20Q. In the above-described embodiment, the joint structure between the pillar 20 and the beam 50 has been described. However, the present invention is not limited to this, and the joint structure between the lower floor pillar 20P and the upper floor pillar 20Q can be similarly applied.

  As shown in FIGS. 4 and 5, the PC structure 10 ′ is erected on the lower floor pillar 20 </ b> P as the first pillar erected on the upper surface of the pedestal block 24 and on the upper end surface 60 of the lower floor pillar 20 </ b> P. The upper pillar 20Q as the second pillar, and the metal plates 46 and 48 provided on the upper end surface 60 of the lower floor pillar 20P and the lower end face 62 of the upper floor pillar 20Q, respectively, are provided. The column 20Q is joined by the PC steel material 32 via the metal plates 46; The lower floor pillar 20P and the upper floor pillar 20Q are both precast concrete, and have substantially the same shape as the pillar 20 of the above embodiment. The lower floor pillar 20P may be on-site (place-in-place) concrete.

  A metal plate 46 and a metal plate 48 similar to those of the above-described embodiment are firmly fixed and fixed to the upper end surface 60 of the lower floor column 20P and the lower end surface 62 of the upper floor column 20Q through fixing means such as anchor bolts. The That is, the joining of the lower floor pillar 20P and the upper floor pillar 20Q according to the present embodiment is performed by using the outer surface 46A of the metal plate 46 as a contact surface and the metal plate 48 as a contact surface that faces and contacts the outer surface 46A. The outer surface 48A is in close contact with the outer surface 48A. The outer surface 40A and the outer surface 42A are rusted in the same manner as described above.

  In constructing such a PC structure 10 ', the lower floor pillar 20P and the upper floor pillar 20Q as precast concrete are produced in advance and are carried into the construction site. At the construction site, the lower floor pillar 20P is erected with respect to the foundation concrete 22 and the pedestal block 24 that are constructed in advance. Specifically, a plurality of PC steel materials 32 protruding upward from the pedestal block 24 are inserted into a plurality of sheath tubes 30A embedded in the lower floor pillar 20P in advance, and the PC steel materials 32 are inserted from the upper end surface 60 and the metal plate 46. The state protrudes upward. Further, the upper floor pillar 20Q is suspended by a heavy machine, and the upper floor pillar 20Q is erected on the lower floor pillar 20P. Specifically, a plurality of PC steel materials 32 protruding from the upper end surface 60 and the metal plate 46 are inserted into a plurality of sheath tubes 30A embedded in the upper floor column 20Q in advance, and upward from the upper end surface 64 of the upper floor column 20Q. Let it be in the protruding state. Thereafter, the upper end portion of the PC steel material 32 protruding from the upper end surface 64 is tensioned upward by a hydraulic jack or the like, and fixed and fixed by the tension fixing tool 38. Thereby, the lower floor pillar 20P and the upper floor pillar 20Q are erected on the foundation concrete 22 and the pedestal block 24 in a state where a compressive force in the vertical direction is applied. The outer surface 46A of the metal plate 46 and the outer surface 48A of the metal plate 48 are firmly pressed by the compression force, and the foundation concrete 22, the pedestal block 24, the lower floor pillar 20P, and the upper floor pillar 20Q are made of PC steel. They are joined together by prestress due to the tension of 32.

  Thus, also in the joining structure of the lower floor pillar 20P and the upper floor pillar 20Q according to the present embodiment, the metal plates 46; 48 are provided at the joint between the lower floor pillar 20P and the upper floor pillar 20Q, and the PC steel material. Since the outer surfaces 46A and 48A are in close contact with each other due to the tension of 32, it is not necessary to fill with a filler such as mortar, the time until the filler is cured can be omitted, and the construction period can be shortened. It becomes possible. Further, since the outer surfaces 46A and 48A subjected to rust processing are joined, the frictional force between the outer surfaces 46A and 48A can be increased.

Although the present invention has been described through a plurality of embodiments, the technical scope of the present invention is not limited to the above embodiments, and those skilled in the art can make various changes and improvements by combining the embodiments. Is obvious. Further, it is apparent from the scope of the claims that the embodiments added with such various changes and improvements can be included in the technical scope of the present invention.
For example, in the present embodiment, the beam 50 is installed between the pair of columns 20; 20, but is not limited thereto, and can be applied to a cantilever beam that joins only one end side of the beam 50. is there.

10 Prestressed concrete (PC) structure,
20 pillars, 20C inner side, 20P lower floor pillar, 20Q upper floor pillar,
26 fixing recess, 30A; 30B; 30C sheath tube, 32 PC steel,
40; 42; 46; 48 Metal plate, 50 beams, 70 receiving part, 80 inclined part.

Claims (3)

A pair of precast concrete columns provided at a predetermined interval ;
A precast concrete beam installed between the pair of columns and joined to each column ;
A first metal plate provided respectively on the side surfaces among the mutually opposing front Symbol pair of pillars,
A second metal plate provided respectively on the end faces of both the digit direction of the beam,
The contact surface of the second metal plate provided on one end surface of the beam and the contact surface of the first metal plate provided on the inner surface of the one column are in contact with each other, and the other end surface of the beam In a state where the contact surface of the second metal plate provided on the first metal plate and the contact surface of the first metal plate provided on the inner surface of the other column are in contact with each other, the first metal plate is exposed from the outer surface of the one column. A tension material insertion path formed to extend to the outer surface of the other pillar via the second metal plate, the beam, the second metal plate, the first metal plate;
With
And the pair of columns and beams is engaged against by the contact surfaces of the first metal plate by the compression force generated by tension was inserted through the tendon insertion path tendons and second metal plates are adhered to each other The joint structure of the prestressed concrete structure characterized by that. The first metal plate is fixed to a fixing recess formed on the inner side surface of the column such that the contact surface of the first metal plate and the inner side surface of the column are flush with each other;
The joint structure for a prestressed concrete structure according to claim 1 , wherein the tendon insertion path is formed so as to bend downward toward the center of the beam .   The joint structure of the prestressed concrete structure according to claim 1 or 2, wherein a rusting process is applied to the contact surfaces of the first metal plate and the second metal plate.

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