JP4472726B2 - Base-isolated building structure - Google Patents

Description

  The present invention relates to a base-isolated building structure.

As a conventional base-isolated building structure, an invention disclosed in Japanese Patent Laid-Open No. 64-14445 is known. In this base-isolated building structure, seismic isolation devices are installed at appropriate intervals between the upper and lower housings, so that these seismic isolation devices absorb the vibrations during the earthquake and prevent the seismic energy from being transmitted to the upper housing. It is to make. However, since this base-isolated building structure has an upper frame and seismic isolation device joined by a cast-in-place reinforced concrete beam, there are many on-site work such as formwork construction, reinforcement work and concrete placement. The construction period is long, and the span of the beam cannot be lengthened. In order to solve these problems, the invention of Japanese Patent Laid-Open No. 2000-220210 has been made. In this method, a seismic isolation device and a precast prestressed concrete beam are joined to a connecting block made of precast concrete, and the seismic isolation device and the upper frame are integrally joined.
JP-A-64-14445 JP 2000-220210 A

  However, in the above-mentioned base-isolated building structure, the conventional problems have been solved. However, since the precast members cannot be connected to each other by reinforcing bars, the wiring amount of PC steel wires has to be increased. When the wiring amount of the PC steel wire increases, as shown in FIG. 12, the amount of axial deformation due to the prestress introduction force increases and the seismic isolation device 51 is deformed before exhibiting the seismic isolation function (building structure). The seismic isolation device on the outside of the object is greatly deformed), and there is a fear that the seismic isolation performance of the seismic isolation device 51 cannot be fully exhibited during an earthquake.

  The present invention has been made in view of these problems, and its purpose is to reduce the field work and to efficiently join the upper frame and the seismic isolation device in a short period of time, and to improve the seismic isolation performance of the seismic isolation device. It is to provide a seismic isolation building structure that can be fully utilized.

The seismic isolation building structure for solving the above problems is a seismic isolation building structure in which a seismic isolation device is installed between the upper and lower housings, and on the upper surface of the seismic isolation device installed in the lower housing , a connecting portion of the end portion of the beam of the lowest floor of precast concrete and cast in place reinforced concrete of the upper building frame are integrally joined, the lower end muscle protruding from the end portion of the beam of the precast concrete by Rukoto be fixed by the connecting portion The connecting portion and the beam are integrally joined . Further, the precast concrete beam and the integrally joined connecting portion are tensioned by a prestressed tension material . The pillars in the upper frame and the beams other than the lowest floor are precast concrete. These pillars and beams are joined together by the cast-in-place reinforced concrete column beam joints, and the beams are tensioned by the prestressed tension material. Including what has been done. Also, the pillars in the upper frame and the beams other than the bottom floor are precast concrete, and tension materials for prestressed introduction are wired to these pillars and beams. Including being crimp-bonded. Moreover, the beam of an upper frame contains the prestressed concrete to which the primary prestress was provided with the tension material embed | buried beforehand. The seismic isolation device is composed of a seismic isolation device main body, an upper surface side mounting plate, and a lower surface side fixing plate, and the fixing plate is provided with an anchor material that is fixed to the lower housing. This includes that a placement portion for placing the end portion of the beam and a formation portion for the on- site hitting connection portion are provided.

  The top bar of the precast concrete beam is placed on the top concrete. Because it can be connected, for example, at the end of the beam, if the bending strength is borne by the beam main bar and the tension material (PC steel wire) in half, the amount of tension material (PC steel dose) is reduced by half. The amount of tension material can be greatly reduced because the entire cross section of the concrete bears the shearing force, so the amount of axial deformation caused by the prestressing force is reduced by half, and the prestressing force is not hindered. It can be suppressed to the extent. The seismic isolation performance of the seismic isolation device can be shortened in a short period of time by securing high strength and rigidity of the upper frame, and significantly reducing the cost by greatly omitting on-site reinforcement work, formwork and concrete placement work. It is possible to provide an inexpensive base-isolated building structure that can efficiently exhibit the above. In addition, the column and the beam are joined together via the column-beam joint of the cast-in-place reinforced concrete, and the beam is fastened with a tension material for introducing prestress. The rigidity can be increased and the amount of tendon (PC steel dose) can be reduced. In addition, since the columns and beams are precast concrete, it is possible to attach the beams to the columns without any concrete placement work on site, and the construction work of the upper frame can be performed efficiently, and the quality of factory production It can be set as a high member. Moreover, in order to fully exhibit the seismic force absorption performance by the seismic isolation device, the overall rigidity and strength can be increased without enlarging the beam member cross section of the upper frame. In addition, the beam of the upper frame is prestressed concrete to which primary prestress is applied by a pre-embedded tendon material. Generation of cracks due to construction load can be suppressed. Also, at the design stage, the cross section stress due to the design load is borne by the primary PC steel at the central cross section of the beam span, and the secondary PC steel mainly bears the stress of the end cross section, reducing the amount of secondary PC steel. it can. In addition, because prestress is applied to the beam, it is possible to extend the span by 20 to 30 m or more, and it is possible to respond freely to the plan to use the plane in the building. It can be reduced and the economy can be improved significantly. In addition, the seismic isolation device is composed of the seismic isolation device main body, the fixed plate on the lower surface side, and the mounting plate on the upper surface side. By performing the level adjustment, it is possible to easily absorb the construction error of the lower frame and improve the construction accuracy. Further, the mounting plate is provided with a mounting portion, and the beam can be easily installed at a predetermined position by attaching a cap nut at a predetermined position of the beam. Also, in the temporary installation until the beam is integrated with the connecting part by inserting bolts from the mounting plate into the cap nut and temporarily fixing the beam, it is possible to prevent shaking and falling during small and medium earthquakes and strong winds. can do. Also, by performing position confirmation and horizontal level alignment, construction errors of the lower frame can be easily absorbed and construction accuracy can be greatly improved, and the seismic isolation performance of the seismic isolation device can be demonstrated more efficiently. . In addition, after the seismic isolation building structure is completed, the seismic isolation device body can be removed simply by removing the fixing bolts when performing maintenance or replacement of the seismic isolation device body.

  Hereinafter, embodiments of the seismic isolation building structure of the present invention will be described. In each embodiment, the same components are described with the same reference numerals, and only different components are described with different reference numerals.

  FIGS. 1-7 is the seismic isolation building structure 1 of 1st Embodiment. In this seismic isolation building structure 1, a seismic isolation device 4 is installed between an upper housing 2 and a lower housing 3, and a beam (large beam) 5 of the upper housing installed on the upper surface of the seismic isolation device 4 is in-situ reinforced concrete. The connecting portion 6 is integrally joined. That is, as shown in FIG. 2, the seismic isolation device 4 is installed at the joint between the beam 5 and the column 16 on the lowest floor of the upper housing 2. As shown in FIG. 3, the upper frame 2 may have a configuration in which a small beam 5 a is installed between the beams. The small beam 5 a is prestressed by the PC steel wire 35 and joined to the beam 5. Has been.

  Here, the upper housing 2 refers to a housing constructed above the seismic isolation device 4, and the lower housing 3 refers to a housing constructed below the seismic isolation device 4. Therefore, for example, in a building where the seismic isolation device 4 is installed on the middle floor, each layer below the seismic isolation device 4 becomes the lower housing 3, and is constructed below the seismic isolation device 4 in FIG. 1. The pile foundation 7 and the foundation slab 25 become the lower housing 3.

  As shown in FIG. 4, the seismic isolation device 4 is formed by alternately laminating circular thin steel plates 9 and rubber plates 10, and a lead damper 4 a is installed through these central portions. A base isolation device body 8 including an upper plate 11 and a lower plate 13 above and below, a mounting plate 12 installed on the upper plate 11 of the base isolation device body 8 with fixing bolts 27, and a base isolation device. The fixing plate 14 is provided on the lower plate 13 of the apparatus main body 8 with fixing bolts 27. The fixing plate 14 is fixed to the upper surface of the pile foundation 7 by an anchor material 29, and the mounting plate 12 is fixed to the connection portion 6 of the cast-in-place reinforced concrete by a stat bolt 30.

  The fixing bolts 27 of the upper and lower plates 11 and 13 are attached to a plurality of large-diameter holes 15 for inserting bolts, and the installation position of the seismic isolation device main body 8 is confirmed and adjusted by the holes 15 and the horizontal level is adjusted. I do. Therefore, when the lower plate 13 of the seismic isolation device main body 8 is fixed to the fixing plate 14, the installation position of the seismic isolation device main body 8 is confirmed and adjusted, and the horizontal level is adjusted. When fixing, the same adjustment as described above is performed to absorb the construction error of the lower casing 3.

  Further, when carrying out maintenance or replacement of the seismic isolation device main body 8, the upper casing 2 is supported by a temporary receiving means such as a jack and the fixing bolt 27 is removed, so that the seismic isolation device main body 8 can be simply lifted up. Can be removed, so that the upper housing 2 and the lower housing 3 can be efficiently replaced without tearing apart.

  On the other hand, the connecting portion 6 of the cast-in-place reinforced concrete is formed on the upper surface of the mounting plate 12 and fixes the lower reinforcing bar 31 protruding from the end of the precast concrete beam (the beam on the lowermost floor of the upper frame) 5 installed thereon. And this is connected with the lower reinforcement 31 of the other beam by the reinforcing bar joint 32, and the beams 5 are integrally joined by arranging the upper reinforcement 34 of the beam on the top concrete 33. The connecting portion 6 is also provided with a stud bolt 30 from the mounting plate 12 to integrally join the mounting plate 12, and a PC steel rod 36 for joining the column 16 is also provided.

  Therefore, the beams 5 are integrally joined together by the joint portion 6 of the cast-in-place reinforced concrete, and the seismic isolation device 4 is also integrally joined. The PC steel rod 36 is joined to the PC steel material 39 in the column by the coupler 28, and the column 16 is integrally joined to the connecting portion 6 by tensioning the PC steel material 39. The column 16 is erected on the connecting portion 6 via a column base block 37, and the accuracy of the construction is ensured by changing the height of the column base block 37.

  A PC steel wire (tensile material) 35 for introducing prestressed material is wired along the length direction from the end 17 of the beam to the beam 5 through the connecting portion 6 and is tensioned with a predetermined tension force. Thus, the beams 5 are joined together via the connecting portion 6.

  Since the beams 5 are joined by the beam main bars 31 and 34 fixed to the connecting portion 6 as described above, the beam main bars 31 and 34 can partially bear the bending strength at the end 17 of the beam. Since the PC steel dose (tensile material amount) can be greatly reduced by bearing the shear force on the entire cross section of the concrete, for example, the bending strength is halved between the beam main bars 31 and 34 and the PC steel wire 35. If it is assumed that it is burdened one by one, the PC steel dose can be reduced by half, the amount of axial deformation due to the prestress introduction force can also be reduced by half, and the prestress introduction force can be suppressed to an extent that does not hinder.

  Although not shown in the drawings, a steel frame built in advance from the end 17 of the beam of the above-mentioned precast concrete to a predetermined length (fixing length) inside the beam protrudes from the end of the beam and is fixed in the connecting portion. A similar effect can be achieved by connecting the steel frame projecting from the end 17 of the beam with a steel joint.

  Furthermore, since these beams 5 are integrally joined by the top concrete 33 of the cast-in-place concrete slab or the synthetic slab in addition to the connecting portion 6 and the horizontal rigidity becomes infinite, as shown in FIG. Even if the amount of axial deformation due to the introduction of prestress to the beam 5 increases, the seismic isolation device 4 is not affected and is not deformed.

  As shown in FIGS. 4 and 6, the end 17 of the beam is installed on the mounting portion 24 of the flat rectangular mounting plate 12 and is fixed by a bolt 19 screwed into an insert hardware (cap nut) 18. The gap 20 between the ends of each beam is closed by a closing plate 21. In the temporary construction until it is integrated with the connecting portion 6 by inserting the bolt 19 from the mounting plate 12 into the insert hardware 18 and fixing the beam 5, it is prevented from shaking and falling during a small or medium earthquake or strong wind. You can This is not limited to the bolt 19 as long as the end 17 of the beam can be stopped.

  As shown in FIG. 7, the closing plate 21 includes a closing plate 22 that closes the gap portion 20 and a side plate 23 attached to the side surface of the beam, and the side plate 23 is placed at the four corners of the mounting plate 12 along the side surface of the beam. The placement portion 24 is formed by the side plates 23 of the adjacent closing plates 21 that are installed. As described above, the side plate 23 serves as a guide for installing the end portion 17 of the beam, and the width of the side plate 23 serves as a reference for the installation depth of the end portion 17 of the beam. When the end portion 17 is installed, the bolt hole of the mounting plate 12 and the insert hardware 18 are matched, and the bolt 19 can be screwed in without aligning them. In addition, this obstruction board 21 can also be installed not only in four places as mentioned above but in three places or two places. These alignments are not limited to the width of the side plate 23 but can also be performed by previously drawing a reference line (not shown) on the mounting plate 12.

  When the beam 5 installed on the mounting plate 12 is large and it is necessary to reinforce the mounting part 24, the beam 5 may be supported by a support material 26 installed on the foundation slab 25 as shown in FIG. it can.

  FIG. 8 shows a base-isolated building structure 38 according to the second embodiment. This seismic isolation building structure 38 is the first implementation except that the columns 16 and 5 are precast concrete, and these columns 16 and 5 are integrally joined via the column-beam joint 40 of the cast-in-place reinforced concrete. It is the same structure as the seismic isolation building structure 1 of the form.

  This column 16 is built in the connecting portion 6 via a column base block 37, and a PC steel rod 36 from the connecting portion 6 is joined to a PC steel material 39 of the column 16 by a coupler 28. Prestressed by being tense by force.

  An end 17 of the beam is installed on the mounting projection 41 at the head of the column 16, and the upper end bar 34 of the beam is arranged on the top concrete 33, and the lower end bar 31 protruding from the end 17 of the beam is provided. It is fixed to the beam-to-column joint 40 of the cast-in-place reinforced concrete, and is joined by the reinforcing bar 32 and the lower bar 31 protruding from the end 17 of the other beam.

  A PC steel wire (straining material) 35 for introducing prestressed material is wired to the beam 5 from the beam end 17 through the column beam joint 40 along the length direction, and is tensioned with a predetermined tension force. As a result, the column 16 and the beam 5 are integrally joined via the column beam joint 40.

  Moreover, since these beams 5 are also joined by the beam main bars 31 and 34 fixed to the column beam joint portion 40 as described above, the PC steel dose can be reduced at the end portion 17 of the beam.

  FIG. 9 shows a seismic isolation building structure 42 according to the third embodiment. The columns 16 and the beams 5 of the seismic isolation building structure 42 are precast concrete, and the first and the other are the first except that these columns 16 and the beams 5 are pressure-bonded and joined by a PC steel wire (tensile material) 35 for introducing prestressed. It is the same structure as the seismic isolation building structure 1 of embodiment.

  Similarly to the above, this column 16 is built in the connecting portion 6 via the column base block 37, and the PC steel rod 36 from the connecting portion 6 is joined to the PC steel material 39 of the column 16 by the coupler 28. The steel material 39 is tensed with a predetermined tension and prestressed.

  Ends 17 of the beams are installed on the mounting jaws 43 of these columns 16, and prestressed PC steel wires (tension members) 35 are placed on the beams 5 from the ends 17 of the beams. The pillar 16 and the beam 5 are pressure-bonded and joined by being wired along the length direction through 43 and being tensioned with a predetermined tension force.

  FIG. 10 shows a seismic isolation building structure 44 according to the fourth embodiment. This seismic isolation building structure 44 is obtained by joining the beams 5 with a joining cable 45, and the other configuration is the same as that of the seismic isolation building structure 1 of the first embodiment. In this case, instead of the lower end bar 31 of the beam fixed to the connecting part 6, the joining cable 45 is wired from the connecting part 6 to the end part 17 of the beam to join the beams 5. Works the same as This joining cable 45 is configured by inserting a PC steel wire 35 into a sheath tube 47 filled with a grout 48, and penetrates the connecting portion 6 from the upper surface of one beam and is disposed on the upper surface of the other beam. In 47, the PC steel wire 35 is wired in a state in which no tension is applied, that is, in a state in which it is not tensioned, and serves as a reinforcing bar. Note that the upper end bars 34 of the beams are arranged on the top concrete 33 in the same manner as described above.

  FIG. 11 shows a base-isolated building structure 49 according to the fifth embodiment. In this seismic isolation building structure 49, the beam 5 is made of full precast concrete, and the connecting cables 45 and 46 are arranged in the connecting portion 6 in place of the lower end bar 31 and the upper end bar 34 of the beam, and the upper surface of the beam is used for uneven adjustment. A mortar 50 is placed. In this structure, a lower joint cable 45 in place of the lower end bar 31 of the beam and an upper joint cable 46 in place of the upper end bar 34 of the beam are wired from the connecting portion 6 to the end portion 17 of the beam so that the beams 5 are integrated. It is joined. Except this, it is the same structure as the seismic isolation building structure 1 of said 1st Embodiment. The joining cables 45 and 46 have the same configuration as described above, and are composed of a sheath tube 47 filled with a grout 48 and a PC steel wire 35 that is not tensioned.

  In the first to fifth embodiments, the beam 5 of the upper casing 2 may be a beam prestressed by a primary tension material in a pretension or post tension manner.

  Further, in the first to fifth embodiments, the column 16 of the upper frame is not limited to the above, and may be a cast-in-place concrete column, a steel pipe concrete column, or the like. The seismic isolation device main body 8 is not limited to the above-described one, and may be of a type in which an oil damper or a metal damper and a support are combined. These are collectively referred to as a seismic isolation device main body 8. Further, the seismic isolation device 4 may be configured by a single body of the seismic isolation device main body (the mounting plate 12 and the fixed plate 14 are removed) 8. Furthermore, the lower housing 3 is not limited to the above, but may be other foundation structures, for example, a structure in which a footing is provided on a pile head, or an independent foundation or a cloth foundation. good.

  In addition, about each structure in said embodiment, if it is a range which does not deviate from the main point of this invention, the structure is not limited.

It is sectional drawing of the seismic isolation building structure of 1st Embodiment. It is a top view of an upper housing. (1) is a top view of an upper housing, (2) is sectional drawing of (1). It is sectional drawing of the junction part of a beam and a seismic isolation apparatus. It is sectional drawing of the base-isolated building structure where the upper housing was axially deformed. (1) is a sectional view of the mounting plate, (2) is the same plan view, (3) is a sectional view of the seismic isolation device main body, and (4) is a front view of the closing plate. (1) is a perspective view which mounts the edge part of a beam on a mounting plate, (2) is a perspective view of a mounting plate. It is sectional drawing of the seismic isolation building structure of 2nd Embodiment. It is sectional drawing of the seismic isolation building structure of 3rd Embodiment. It is sectional drawing of the seismic isolation building structure of 4th Embodiment. It is sectional drawing of the seismic isolation building structure of 5th Embodiment. It is a conceptual diagram of the conventional seismic isolation building structure.

Explanation of symbols

1, 38, 42, 44, 49 Base-isolated building structure 2 Upper housing 3 Lower housing 4, 51 Seismic isolation device 4a Lead damper 5 Beam 5a Small beam 6 Connecting portion 7 Pile foundation 8 Seismic isolation device body 9 Thin steel plate 10 Rubber Plate 11 Upper plate 12 Mounting plate 13 Lower plate 14 Fixed plate 15 Hole 16 Column 17 End of beam 18 Insert hardware 19 Bolt 20 Gap portion 21 Blocking plate 22 Closing plate 23 Side plate 24 Mounting portion 25 Base slab 26 Support material 27 Fixing bolt 28 Coupler 29 Anchor material 30 Stud bolt 31 Lower end bar 32 Reinforcing bar joint 33 Top concrete 34 Upper end bar 35 PC steel wire 36 PC steel rod 37 Column base block 39 PC steel member 40 Column beam joint 41 Mounting projection 43 Mount Jaw 45, 46 Joint cable 47 Sheath tube 48 Grout 50 Uneven adjustment Mortar

Claims (6)

A seismic isolation building structure seismic isolation device is installed between the upper skeleton and lower skeleton, on the upper surface of the seismic isolation device installed in the lower skeleton, the ends of the beam of the lowest floor of the precast concrete of the upper skeleton and is joined with connecting portions of the cast-in-place reinforced concrete integral, the fixing to connection portion and the beams by Rukoto lower muscle protruding from the end portion of the beam of precast concrete in the connecting portion is characterized in that it is integrally joined Seismic isolation building structure. 2. The base-isolated building structure according to claim 1, wherein the precast concrete beam and the integrally joined connecting portion are tensioned by a prestressed introduction tension material. 3. The columns of the upper frame and the beams other than the lowest floor are precast concrete, and these columns and beams are joined together by the column-beam joints of cast-in-place reinforced concrete, and the beams are tensioned by the prestressed tension material. The base-isolated building structure according to claim 1.   The columns of the upper frame and the beams other than the lowermost floor are precast concrete, and tension materials for prestressed introduction are wired to these columns and beams. The base-isolated building structure according to claim 1, wherein the base-isolated building structure is crimp-bonded. The base-isolated building structure according to any one of claims 1 to 4 , wherein the beam of the upper frame is prestressed concrete to which primary prestress is applied by a previously embedded tendon. The seismic isolation device is composed of a seismic isolation device main body, an upper surface side mounting plate, and a lower surface side fixing plate. The fixing plate is provided with an anchor material that is fixed to the lower housing, and the mounting plate has a beam. The base-isolated building structure according to any one of claims 1 to 5 , further comprising a placement portion for placing the end portion of the base plate and a forming portion for the on- site connection portion .

Images