JP5713710B2 - Seismic isolation structure and its construction method - Google Patents

Description

  The present invention relates to construction technology for seismic isolation devices used in buildings. More specifically, the present invention relates to a construction technique for improving workability, shortening the work period, and improving construction accuracy for a seismic isolation device composed of an upper pedestal and a lower pedestal installed with the seismic isolation device interposed therebetween. .

  In a conventional base-isolated building, the building is supported by the ground via a base-isolated layer, and the base-isolated layer is the upper building base, which is the lowest part of the main body of the building, and the upper pedestal, base isolation device, lower pedestal, and lower base. It is constituted by.

  The seismic isolation building absorbs energy input at the time of the earthquake by the seismic isolation device, so it is possible to reduce the earthquake response acceleration of the building compared to the seismic building, but the building structure has a lower foundation, lower pedestal, The seismic device and upper pedestal were added, and the construction period was long because they were constructed in order.

  In addition, regarding the functions and durability of the seismic isolation device, the seismic isolation device installation state, in particular its horizontal state, and the connection between the seismic isolation device and the lower pedestal on the lower foundation concrete side or the upper pedestal installation surface on the upper building foundation side. The state is greatly affected.

  Therefore, in order to ensure a good installation state, the lower pedestal is constructed in the following procedure. The anchor frame is welded and fixed on the embedding plate embedded in the concrete of the lower foundation, and the structure consisting of the anchor bolt, coupler, hexagon bolt and lower base plate that is the installation surface of the seismic isolation device is welded to the anchor frame at the anchor bolt part. Fix it.

  After that, rebars other than the reinforcing bars embedded when placing the lower foundation concrete were placed, and the formwork for placing the lower pedestal concrete was installed on the outer periphery of the reinforcing bar to a height that left a space below the lower base plate. Place concrete to the bottom.

  After the concrete is cast, the concrete is cured until it reaches the required strength, and the lower base plate is adjusted to be horizontal, and the space surrounded by the cast lower pedestal and the lower base plate is surrounded by a mold, and a non-shrink grout material is press-fitted. After the non-shrink grout material is hardened, the construction of the lower pedestal is completed by removing the formwork. After that, install the seismic isolation device and install the upper pedestal.

  In addition, in the construction of the upper pedestal, concrete is placed at the same time as the upper building foundation, but the upper pedestal protrudes downward from the lower surface of the upper building foundation, and the formwork and bar arrangement become complicated. In particular, when seismic isolation is required for facilities with heavy buildings such as nuclear facilities, several hundred large seismic isolation devices with a load capacity of around 1000 tons are required, and the installation interval of the seismic isolation devices is reduced. However, there is a concern that the construction period will be prolonged.

  The conventional seismic isolation structure is a base isolation building shown in FIG. 9 in which a lower foundation concrete 2 is provided on the ground 1 and a base isolation device 4 is installed on the lower foundation concrete 2 via a lower pedestal 3. The device 4 supports the building foundation 6 and the building 7 via the upper pedestal 5.

  FIG. 10 shows a conventional seismic isolation structure. The lower foundation concrete 2, the lower pedestal 3, the upper pedestal 5, and the building foundation 6 have a reinforced concrete structure. The lower flange 10 at the lower end of the seismic isolation device 4 and the lower base plate 8 at the upper end of the lower pedestal 3 are fastened by bolts 12, and the upper flange 11 at the upper end of the seismic isolation device 4 and the upper base plate 9 at the lower end of the upper pedestal 5 are fastened by bolts 12. doing.

  11 and 12 show the construction of the lower pedestal 3. The embedded plate 13 and the reinforcing bar 14 are arranged before the lower foundation concrete 2 is placed. After the lower foundation concrete 2 is placed, the lower pedestal 3 is arranged. 3 is installed.

  As shown in FIG. 11, first, the anchor frame 15 is welded and fixed onto the embedded plate 13 embedded in the lower foundation concrete 2. Next, a combination of the anchor bolt 16, the coupler 17, the bolt 12, and the lower base plate 8 is welded and fixed to the anchor frame 15 at the anchor bolt 16 portion so that the lower base plate 8 is kept horizontal.

  Next, in addition to the reinforcing bar 14 fixed to the lower foundation concrete 2, the reinforcing bar is arranged so that the lower pedestal 3 has sufficient strength. Next, a space 18 is provided below the lower base plate 8 on the outer periphery of the reinforcing bar 14, and a formwork 18 for placing concrete is assembled. Thereafter, the concrete is cast to the lower part of the lower base plate 8 and cured until the required strength is reached.

  Next, in FIG. 12, after adjusting the lower base plate 8 to be horizontal, the lower base plate 8 is surrounded by a grout form 20, and a press-fitting pump 21 is used to place the non-shrink grout material 19. Place and cure until the required strength is reached. Finally, when the non-shrink grout material 19 reaches the required strength, the grout material mold 20 and the bolts 12 used for fixing the lower base plate 8 are removed.

  After that, the seismic isolation device 4 is installed on the lower pedestal 3, the upper base plate 9 is installed, the upper pedestal 5 and the building foundation 6 are reinforced, and the formwork for placing concrete is installed. Then, the concrete is cast and cured until the concrete reaches the required strength. After the concrete reaches the required strength, the construction of the seismic isolation structure is completed by removing the formwork.

  As a measure for improving workability in the installation work of the seismic isolation device, for example, in Reference 1, the seismic isolation device mounting surface is provided from the outside of the concrete placement site of the pedestal for the purpose of eliminating welds as much as possible and reducing members. There has been proposed a method of using a fixture having a function of securing the plate and securing the level of the mounting surface.

Japanese Patent Laid-Open No. 10-246028

  Thus, in the conventional seismic isolation structure, it is necessary to carry out in the order of construction of the lower pedestal, installation of the seismic isolation device, and construction of the upper pedestal. In addition, in the construction of pedestals, reinforcing bar reinforcement, assembling and removing the formwork for placing concrete, adjusting the level of the reinforcement, formwork, and base plate at the installation stage, and materials for them It is necessary to carry in and out as a field work, which requires a great number of man-hours and construction periods. Furthermore, translation work of the seismic isolation structure and the upper building is impossible, and the construction of the seismic isolation structure is a critical path in the construction process, so it is required to construct the seismic isolation structure in a shorter period of time. ing.

  This invention solves the above subject, and it aims at providing the base isolation structure which aims at reduction of the field work regarding construction of a base isolation structure, shortening of a process period, and improvement of construction accuracy.

  The present invention relates to a seismic isolation device provided between the base isolation building and the foundation on the ground, an upper pedestal provided between the base isolation building and the base isolation device, and between the base isolation device and the foundation on the ground. In the seismic isolation structure having the lower pedestal provided, the seismic isolation device, the upper pedestal and the lower pedestal are integrally formed as a seismic isolation module.

  Also, in seismic isolation structures, a connecting jig that supports the tensile load acting between the upper pedestal and lower pedestal is detachably provided between the upper pedestal and lower pedestal, which occurs before the installation of the seismic isolation structure It is characterized by preventing shear deformation of the seismic isolation device due to tensile load.

In the seismic isolation structure, the upper pedestal and the lower pedestal are made of a steel plate concrete structure manufactured in advance before the installation of the seismic isolation structure.
Further, in the seismic isolation structure, the upper pedestal and the lower pedestal include a pedestal steel plate provided on the outer periphery, a rib for supporting a vertical load, a stud for joining the pedestal steel plate and concrete, an anchor frame for increasing pedestal rigidity, It has a concrete inflow hole.

  In the base isolation structure, a plurality of base isolation devices are provided between the upper pedestal and the lower pedestal.

  In addition, the seismic isolation device provided between the base isolation building and the ground, the upper pedestal provided between the base isolation building and the base isolation device, and the lower pedestal provided between the base isolation device and the ground are seismically isolated. In the construction method of the seismic isolation structure integrally formed as a module, the seismic isolation structure is manufactured in advance as a hollow steel plate concrete structure before installation of the seismic isolation structure, and is detachably connected between the upper pedestal and the lower pedestal After fixing the jig to prevent the tensile load acting before the seismic isolation structure is installed and the shear deformation of the seismic isolation device, and installing the seismic isolation structure on the foundation on the ground, the upper pedestal and lower pedestal Concrete is poured into the pedestal to complete the upper pedestal and the lower pedestal, and then the connecting jig is removed from the seismic isolation structure.

  In the seismic isolation structure of the present invention, the lower pedestal and the upper pedestal are connected by a connecting jig and configured as a seismic isolation structure. It is possible to prevent the tensile load generated by the shear deformation of the seismic device and the weight of the seismic isolation device or the lower pedestal from acting on the seismic isolation device.

Further, the upper pedestal and lower pedestal lighter weight during transport than the pedestal of conventional reinforced concrete structure by steel Ita構 Concrete joined with concrete, also a seismic isolation module that combines pedestal and isolator lightweight And can be installed in a batch, improving workability.

Furthermore, in the case of steel Ita構 forming the lower pedestal and the upper pedestal is bonded to the concrete has the practical effect that the fixing bolts of the connecting jig can be fixed directly to the steel pedestal.

The longitudinal cross-sectional view which shows the seismic isolation module of the seismic isolation apparatus which concerns on Example 1 of this invention. AA line sectional view in FIG. BB sectional drawing in FIG. Explanatory drawing which shows the conveyance state of the seismic isolation module of the seismic isolation apparatus which concerns on Example 1 of this invention. The longitudinal cross-sectional view which shows the seismic isolation module installation state of the seismic isolation apparatus which concerns on Example 1 of this invention. CC sectional view taken on the line in FIG. The longitudinal cross-sectional view which shows the seismic isolation module of the seismic isolation apparatus which concerns on Example 2 of this invention. DD sectional view taken on the line in FIG. The front view which shows the conventional seismic isolation building. The front view which shows the conventional seismic isolation structure. The longitudinal cross-sectional view which shows the construction procedure first half of the lower pedestal in the conventional seismic isolation structure. The longitudinal cross-sectional view which shows the construction procedure latter half of the lower pedestal in the conventional seismic isolation structure.

  Embodiments of the present invention will be described below with reference to the drawings.

  The construction form of the seismic isolation structure concerning Example 1 of this invention is demonstrated using FIGS. 1-4.

  In FIG. 1, the seismic isolation module 22 includes a lower pedestal 3, a seismic isolation device 4, an upper pedestal 5, and a connecting steel plate 25 as a connecting jig, which are fastened by bolts 12. In Example 1, the portions corresponding to the lower pedestal 3 and the upper pedestal 5 in FIG. 1 are manufactured by a steel plate concrete structure. The lower pedestal 3 has an outer surface by a lower pedestal steel plate 23 and the upper pedestal 5 has an upper pedestal steel plate 24. It is composed.

  The inner surface of the lower pedestal 3 is welded with a lower pedestal steel plate 23 around the entire circumference, and the lower pedestal steel plate 23 is prevented from buckling together with the lower pedestal steel plate 23 to support the upper load until the concrete is placed and the lower pedestal steel plate 23. Studs 26 used to integrate the steel plate 23 and the concrete are arranged at regular intervals. On the upper surface of the lower pedestal 3, a coupler 17 for fixing the lower flange 10 of the seismic isolation device 4 with bolts 12 and the lower pedestal An anchor frame 15 for increasing the rigidity of the welding is fixed by welding.

  The upper pedestal 5 is connected to the upper flange 11 of the seismic isolation device 4 and is composed of the same member as the lower pedestal 3, but the anchor frame 15 of which is to secure anchorage to the building foundation 6 part concrete. The upper pedestal steel plate 24 has a height equal to or higher than the height of the upper pedestal steel plate 24, and has an I-bolt 28 for hanging the seismic isolation module 22 as a unit at the top.

  In FIG. 2, a concrete inflow hole 31 is provided in the upper part of the lower pedestal 3. In FIG. 3, the arrangement of the anchor frame 15, the coupler 17, the stud 26 and the rib 27 is shown.

  FIG. 4 shows an example of conveyance of the seismic isolation module 22 according to the first embodiment of the present invention by the crane 29, and the lower pedestal 3 and the upper pedestal 5 are connected by a connecting steel plate 25 in the seismic isolation module 22. Thus, the shear deformation of the seismic isolation device 4 due to the load acting when the crane 29 is suspended is prevented, and the tensile load generated by the weight of the seismic isolation device 4 and the lower pedestal 3 acts directly on the seismic isolation device 4. It is preventing.

  FIG. 5 is a longitudinal sectional view showing a state where the seismic isolation module 22 according to the first embodiment of the present invention is installed on the lower foundation concrete 2.

  In FIG. 6, the seismic isolation module 22 has an embedding depth required to transmit loads from both the lower foundation concrete 2 and the lower pedestal 3 and is embedded to fix the lower pedestal 3 to the lower foundation concrete 2. Arranged on the anchor frame 30, the installation position of the module can be set accurately.

  After the seismic isolation module 22 is arranged, the concrete of the lower pedestal 3 is placed by injecting concrete from the concrete inlet 31 shown in FIG. Thereafter, a formwork necessary for placing concrete on the building foundation 6 is installed, and the upper pedestal 5 and the building foundation 6 are placed simultaneously.

  The connecting steel plate 25 can be removed when the formwork necessary for the concrete placement of the building foundation 6 is installed and the position of the upper pedestal 5 is determined. Since it can be performed in parallel, it is not critical to the process.

  FIG. 7 shows a longitudinal sectional view of the seismic isolation module 22 according to the second embodiment of the present invention, and FIG. 8 shows a sectional view at the height of the seismic isolation device 4.

  In the second embodiment, as shown in FIG. 8, the four seismic isolation devices 4 are configured as an integrated seismic isolation module 22 between the lower pedestal 3 and the upper pedestal 5. According to the second embodiment, it is possible to construct a plurality of seismic isolation devices 4 at the same time. Therefore, the number of man-hours can be greatly reduced, and the period required for construction of the seismic isolation structure can be further shortened.

  As described above, the seismic isolation structure of the present invention is configured as a modular base isolation structure in which the lower pedestal and the upper pedestal are connected by a connecting steel plate. Further, it is possible to prevent the seismic isolation device from being subjected to shear deformation due to a load acting at the time of installation or a tensile load generated by the weight of the seismic isolation device or the lower pedestal from acting on the seismic isolation device.

  In addition, when the upper pedestal and lower pedestal have a steel plate concrete structure, the module composed of the pedestal and the seismic isolation device has enough strength to stand up before the concrete is placed, and the steel plate concrete structure Since concrete can be cast after installation, the module that combines the pedestal and the seismic isolation device can be made lighter, the weight during transportation can be reduced, and the workability can be improved because they can be installed together.

  Also, by making the upper pedestal and lower pedestal into steel plate concrete structure, welding work, reinforcing bar placement, assembling and removing the formwork for concrete placement, which were necessary in the reinforced concrete structure, It is not necessary to adjust the level of construction and carry in / out materials. This reduces work on site and shortens the process.

  In addition, since the upper and lower pedestals are made of steel-plate concrete structure, the flatness and levelness of the surface of the pedestal is ensured, so the seismic isolation device can be installed directly on the surface of the pedestal, and the conventional reinforced concrete structure pedestal This eliminates the need to place the base plate and non-compressible grout used in the production process, thus reducing the amount of material, reducing work on site, and shortening the work period.

  Furthermore, when the lower pedestal and the upper pedestal have a steel plate concrete structure, the fixing bolt of the connecting steel plate can be directly fixed to the steel plate of the pedestal.

  Modules that combine seismic isolation devices and pedestals can be manufactured at the factory, so it is easy to improve manufacturing accuracy compared to on-site work, and it is easy to secure work space at the factory. Improves.

DESCRIPTION OF SYMBOLS 1 ... Ground, 2 ... Lower foundation concrete, 3 ... Lower pedestal, 4 ... Seismic isolation device, 5 ... Upper pedestal, 6 ... Building foundation, 7 ... Building, 8 ... Lower base plate, 9 ... Upper base plate, 10 ... Lower flange, DESCRIPTION OF SYMBOLS 11 ... Upper flange, 12 ... Bolt, 13 ... Embedded plate, 14 ... Rebar, 15 ... Anchor frame, 16 ... Anchor bolt, 17 ... Coupler, 18 ... Formwork, 22 ... Seismic isolation module, 23 ... Lower pedestal steel plate, 24 ... Upper pedestal steel plate, 25 ... Connection steel plate, 26 ... Stud, 27 ... Rib, 28 ... I bolt, 30 ... Embedded anchor frame, 31 ... Concrete injection port

Claims (5)

A seismic isolation device provided between the base isolation building and the foundation on the ground, an upper pedestal provided between the base isolation building and the base isolation device, and provided between the base isolation device and the foundation on the ground In a base-isolated structure with a lower pedestal,
The upper pedestal and the lower pedestal are formed as a steel plate structure for joining with concrete, and a pre-manufactured concrete injectable space is provided in the steel plate structure of the upper pedestal and the lower pedestal, and the seismic isolation device, the upper pedestal, and A base-isolated structure in which the lower pedestal is integrally formed as a base isolation module.   In the seismic isolation structure according to claim 1, a connection jig for supporting a tensile load acting between the upper pedestal and the lower pedestal is detachably provided between the upper pedestal and the lower pedestal, A seismic isolation structure characterized by supporting a tensile load generated during transportation and installation of the seismic isolation structure and preventing occurrence of shear deformation of the seismic isolation device. 2. The base-isolated structure according to claim 1 , wherein the upper pedestal and the lower pedestal include a pedestal steel plate provided on an outer periphery, a rib for supporting a vertical load, a stud for joining the pedestal steel plate and concrete, and a pedestal. A base-isolated structure having an anchor frame for increasing rigidity and a concrete inflow hole. In seismic isolation structure according to any of claims 1 to 3, wherein between the upper pedestal and the lower pedestal, base isolation structure is characterized by providing a plurality of said seismic isolation device. A base isolation device provided between the base isolation building and the foundation on the ground, an upper pedestal provided between the base isolation building and the base isolation device, and a lower pedestal provided between the base isolation device and the ground In the construction method of the seismic isolation structure integrally formed as a seismic isolation module,
Producing the seismic isolation structure as a steel plate structure having a space where concrete can be poured before the seismic isolation structure is installed in the seismic isolation building,
The transfer of the upper pedestal and Kymene Shin structures before securing the universal coupling jig detachably between the lower pedestal to prevent shear deformation of the isolator to support the tension load generated during installation work,
After installing the seismic isolation structure on the ground, concrete is poured into the upper and lower pedestals to complete the upper and lower pedestals,
The construction method of the base isolation structure characterized by removing the connecting jig from the base isolation structure thereafter.

Images