JP5852462B2 - Base-isolated structure and construction method - Google Patents

Description

  The present invention relates to a foundation-isolated structure and a construction method thereof.

  Conventionally, a base isolation structure has been proposed in which a base foundation of a building is supported by a base made of steel, and a base isolation material is interposed between the base and the ground surface to isolate the building.

  However, in this seismic isolation structure, it is necessary to provide a frame for supporting the base of the building, so there is a problem that the cost increases as the frame is added.

  Therefore, as a method of realizing an inexpensive seismic isolation structure by omitting extra components, a sliding layer is provided between the base of the building and the ground surface, and the base of the building itself is moved horizontally with respect to the ground surface. A seismic isolation structure under the base has been proposed.

JP 2007-070859 A JP 2011-247032 A

  This base-isolated structure is realized by providing a base foundation of a building on a sliding layer after providing a sliding layer made of a pair of sliding materials on the ground surface. If the base foundation of the building is a PC foundation made of precast concrete, the construction is completed by sequentially installing the PC foundation on the sliding layer, but concrete is placed on the building base foundation at the construction site. If the foundation is to be completed on the spot, the base foundation of the building will be in close contact with the ground surface and the seismic isolation function will no longer be demonstrated.

  In view of the above problems, the present invention provides a foundation-isolated structure and a construction method thereof capable of realizing foundation-isolation even when the base of the building is a foundation on the ground. The task is to do.

  The above problem is that piece-shaped seismic isolation bearings are arranged apart from each other between the ground foundation installed on the ground or the concrete foundation supporting the building. A foundation foundation plate is provided to pass between the seismic isolation bearing materials, and the foundation foundation plate is used as a bottom formwork of the concrete foundation when the concrete foundation is placed. Solved by structure.

  In this seismic isolation structure under the foundation, piece-shaped seismic isolation bearings are arranged apart from each other, and a concrete foundation support plate is provided to pass between the seismic isolation bearings. Therefore, it is possible to prevent the concrete foundation and the ground surface from being in close contact with each other by using this concrete support plate as the bottom mold of the concrete foundation when the concrete foundation is placed. Moreover, since the seismic isolation bearing material is in the form of a piece, it is not necessary to smooth the ground or the ground foundation and the bottom of the concrete foundation over the entire surface, and it is only necessary to ensure partial smoothness. Furthermore, since this concrete support plate can be used as a part of the bottom of the concrete foundation, it is not necessary to remove it after placing the concrete, and the work of removing it can be omitted.

  In the seismic isolation structure under the foundation, the concrete foundation support plate may have a reinforcement support portion that supports reinforcement of the concrete foundation.

  Since the concrete foundation support plate has a reinforcing bar support part that supports the reinforcement of the concrete, it is not necessary to separately provide a support material for supporting the internal reinforcement of the concrete foundation. It is only necessary to install the reinforcing bar on the reinforcing bar support part provided on the foundation support plate.

  Moreover, in the above-described base-isolated structure, the concrete foundation support plate may have a formwork support portion that supports the formwork used when placing the concrete foundation.

  Since the concrete foundation support plate has a formwork support part that supports the formwork used when placing the concrete foundation, there is no need to separately provide a support material for supporting the formwork, and support after the concrete placement. The work of removing the material can be omitted.

  In addition, the above-described problems include a step of placing pieces of seismic isolation bearing materials adjacent to each other on the ground or a ground foundation installed on the ground, and the seismic isolation bearings. A step of providing a concrete foundation support plate to be passed between the materials, a step of installing reinforcement of the concrete foundation on the concrete foundation support plate and the seismic isolation bearing material, and the concrete foundation support plate and the seismic isolation support material. A foundation-isolated structure comprising a process for installing a formwork for concrete foundation placement, a process for placing concrete in the formwork, and a process for removing the formwork for concrete foundation placement after curing the concrete. It can also be solved by the construction method.

  Since the present invention is as described above, it is possible to provide a base-isolated structure and a construction method thereof that can realize base-isolation even when the base of the building is a foundation on the spot. it can.

FIG. 1 (a) is a front view showing an under-base seismic isolation structure according to an embodiment of the present invention, FIG. 2 (b) is a cross-sectional view along line AA in FIG. 1 (a), and FIG. ) Is a cross-sectional view taken along line B-B in FIG. Fig. (A) is a side view showing a concrete foundation support material, Fig. (B) is the same plan view, and Fig. (C) is the same perspective view. Drawing (a) thru / or (e) is a section side view which shows the construction method of a base-isolation system under a foundation one by one. Drawing (a) thru / or (d) is a perspective view showing other forms of concrete foundation support material.

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

  In the base-isolated structure 1 shown in FIG. 1, 2 is an inverted T-shaped concrete foundation comprising a rising portion 2a and a base 2b, 3 is a concrete foundation support plate, 4 is a base isolation material, and 5 is , Ground foundation, 6 is the ground.

  As shown in FIGS. 1 (a) and 1 (c), a ground foundation 5 is horizontally provided on the ground 6 that has been solidified, and a rectangular shape in plan view is provided on the ground foundation 5 on the ground. A pair of seismic isolation bearing materials 4 and 4 are arranged apart from each other. The width of the seismic isolation bearing material 4 is substantially the same as the width of the base portion 2 b of the concrete foundation 2, and the length of the seismic isolation bearing material along the extending direction of the concrete foundation 2 is longer than the width. Here, a polystyrene foamed resin material having a thickness of 20 mm, a width of 500 mm, and a length of 900 mm is used as the seismic isolation bearing material, and each is separated by 910 mm.

  As shown in FIGS. 1 (a) and 1 (d), a concrete foundation support plate 3 is installed so as to be passed between seismic isolation bearing materials arranged apart from each other. Here, it installs so that adjacent concrete foundation support plates 3 may pass between seismic isolation support materials at intervals, so that it may not continue.

  As shown in FIG. 2, the concrete foundation support plate 3 is folded upward in the vertical direction at the body portion 3a made of a rectangular steel plate having substantially the same width as the seismic isolation bearing material 4, and at both ends in the width direction of the body portion 3a. And folded back portions 3b and 3b, and a support portion 3c provided on the upper surface of the main body portion 3a with an interval in the length direction of the main body portion 3a.

  The folding | returning part 3b is provided in order to improve the rigidity of the main-body part 3a. The support part 3c is provided with a notch 3c1 for supporting the reinforcement of the concrete foundation in the upper central part opposite to the lower end part continuous with the main body part 3a, and the concrete foundation is raised on both sides of the notch 3c1 when the concrete foundation is placed The notch 3c2 for supporting the part 2a formwork is provided. The bar arrangement and the formwork can be supported by the cooperation of the adjacent support portions 3c. In addition, this support part serves also as the formwork support part which supports the reinforcement arrangement | positioning support part which supports reinforcement, and a formwork.

  Next, a construction method for realizing this base-isolated structure will be described.

  As shown in FIG. 3A, after the ground 6 is first solidified, the ground foundation 5 on the ground 6 is provided so that the surface thereof is horizontal. Then, on the ground foundation 5, a pair of seismic isolation bearing materials 4 and 4 are arranged so that adjacent seismic isolation bearing materials are separated from each other. A sliding sheet, a sliding plate, a sliding lubricant or the like may be provided between the seismic isolation bearing materials 4 and 4 in order to improve the sliding between the seismic isolation bearing materials 4 and 4. Further, the lower seismic isolation bearing material 4 may be fixed to the ground foundation 5 with a fastener or an adhesive after the ground foundation 5 is installed, or the lower seismic isolation bearing material when the ground foundation 5 is put into concrete. 4 may be arranged and integrated with the ground foundation 5.

  Next, as shown in FIG. 3 (b), the concrete foundation support plate 3 is disposed so as to pass between the seismic isolation bearing members 4 and 4.

  Next, as shown in FIG. 3 (c), a concrete foundation bar arrangement 7 is formed in the notch 3c1 of the support portion 3c of the concrete foundation support plate 3, and the concrete foundation rising portion 2a is placed in the notch 3c2. 8 is attached. In addition, 9 and 9 are the formwork for concrete foundation base part 2b placement, and are fixed to the surrounding ground with a supporting jig etc.

  Next, as shown in FIG. 3 (d), concrete is placed in the assembled frames 8 and 8 for the rising portion 2a and the molds 9 and 9 for the base portion 2b.

  Finally, as shown in FIG. 3 (e), after curing the concrete, the molds 8, 8 and the molds 9, 9 are removed to complete the base seismic isolation structure.

  In this seismic isolation structure under the foundation, piece-shaped seismic isolation bearings are arranged apart from each other, and a concrete foundation support plate is provided to pass between the seismic isolation bearings. Therefore, it is possible to prevent the concrete foundation and the ground surface from being in close contact with each other by using this concrete support plate as a concrete foundation bottom formwork at the time of placing the concrete foundation.

  Moreover, since the seismic isolation bearing material is in the form of a piece, it is not necessary to smooth the ground or the ground foundation and the bottom of the concrete foundation over the entire surface, and it is only necessary to ensure partial smoothness.

  Furthermore, since this concrete support plate can be used as a part of the bottom of the concrete foundation, it is not necessary to remove it after placing the concrete, and the work of removing it can be omitted.

  Since the concrete foundation support plate has a reinforcing bar support part that supports the reinforcement of the concrete, it is not necessary to separately provide a support material for supporting the internal reinforcement of the concrete foundation. It is only necessary to install the reinforcing bar on the reinforcing bar support part provided on the foundation support plate.

  Since the concrete foundation support plate has a formwork support part that supports the formwork used when placing the concrete foundation, there is no need to separately provide a support material for supporting the formwork, and support after the concrete placement. The work of removing the material can be omitted.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, the concrete foundation support plate is shown to be disposed so that adjacent concrete foundation support plates are separated from each other and passed between seismic isolation bearing materials. What is necessary is just to arrange | position so that it may pass between seismic support materials, and adjacent concrete foundation support plates may be arrange | positioned continuously.

  In the above embodiment, the concrete foundation support plate is shown as having a main body portion, a folded portion, and a support portion. However, the folded portion is provided to increase the surface rigidity of the concrete foundation support plate. As shown in FIGS. 4 (a) to 4 (d), ribs 11 may be provided on the main body, or as shown in FIGS. You may provide the ribs 12 and 13 in a direction or a transversal direction.

  Furthermore, a support portion is not necessarily required. As shown in FIGS. 4 (c) and 4 (d), the concrete foundation support plate is not provided with a support portion, and the receiving material for supporting the reinforcement and the formwork is separated. You may prepare as. In addition, at least two support parts are not required for a single concrete foundation support material, but only one support for a concrete foundation support plate in relation to the length of reinforcement and formwork and the length of the concrete foundation support plate. Needless to say, it may be three or more.

DESCRIPTION OF SYMBOLS 1 ... Base-isolated structure 2 ... Concrete foundation 3 ... Concrete foundation support plate 3a ... Main-body part 3b ... Fold-up part 3c ... Support part (bar arrangement support part, formwork support Part)
4 ... Seismic isolation bearing material 5 ... Ground foundation 6 ... Ground 7 ... Reinforcement (concrete foundation)
8 ... Formwork (for concrete foundation rising part placement)
9 ... Formwork (for concrete foundation base placement)

Claims (4)

  Between the ground foundation installed on the ground or the concrete foundation supporting the building, piece-shaped seismic isolation bearings are arranged separately from each other, and the seismic isolation bearings are arranged separately from each other. A seismic isolation structure under the foundation, wherein a concrete foundation support plate is provided so as to pass between the materials, and the concrete foundation support plate is used as a bottom formwork of the concrete foundation when the concrete foundation is placed.   The seismic isolation structure under a foundation according to claim 1, wherein the concrete foundation support plate has a reinforcement support portion that supports reinforcement of a concrete foundation.   The base foundation seismic isolation structure according to any one of claims 1 to 2, wherein the concrete foundation support plate has a formwork support portion that supports a formwork used when placing the concrete foundation. A step of placing pieces of seismic isolation bearing materials adjacent to each other on the ground or ground foundation installed on the ground separately from each other;
Providing a concrete foundation support plate to pass between the seismic isolation bearing materials;
Installing a concrete foundation bar arrangement on the concrete foundation support plate and the seismic isolation bearing material;
Installing a concrete foundation casting form on the concrete foundation support plate and seismic isolation bearing material;
Placing concrete in the formwork;
A method of constructing a base-isolated structure that includes a step of removing a formwork for placing a concrete foundation after curing the concrete.

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