JP4195406B2 - Seismic isolation method for existing building and seismic isolation building - Google Patents

Description

  The present invention relates to a seismic isolation method for an existing building and a seismic isolation building using the method, and is particularly suitable for seismic isolation of a detached house. The present invention relates to a method of installing a device to make it seismically isolated, and to a seismically isolated building that has been seismically isolated by this method.

Conventionally, as a method of seismic isolation of this type of existing building, an upper frame is wound around the upper outer peripheral surface of the existing column seismic isolation device installation location, while a lower frame body is installed on the lower outer peripheral surface of the base isolation device installation location A first step of winding the frame, a second step of inserting a vertical support material between the upper frame body and the lower frame body, and attaching both ends of the vertical support material to both frame bodies, and an existing space between the two frame bodies The third step of excising the column, and attaching the upper lid to the lower surface of the upper frame to cover the lower end surface of the upper existing column, which is the upper existing column after excision, and attaching the lower lid to the upper surface of the lower frame The fourth step of covering the upper end surface of the lower existing column, which is the lower existing column after excision, and the seismic isolation device is inserted into the space where the existing column is excised, and this seismic isolation device is attached to both lids The fifth step and the sixth step of removing the vertical support material and supporting the upper existing column by the lower existing column via the seismic isolation device. (For example, refer to Patent Document 1).
JP-A-10-131517 (paragraph [0009])

  By the way, the above-mentioned seismic isolation method describes an example of an RC column as an existing column, and is suitable for seismic isolation of an existing building having an RC column or a steel column. It is not suitable for seismic isolation of detached houses. For example, if the seismic isolation method described in Patent Document 1 is used for a wooden house, it is necessary to perform the above six steps for all of the many pillars constituting the upper structure, and the construction work becomes extremely complicated. There was a problem that the work time was enormous. In addition, a large number of seismic isolation devices themselves are necessary, which is disadvantageous in terms of cost, and there is a problem that construction cannot be performed unless there are no residents.

  The present invention has been made in view of such problems, and the purpose of the present invention is to facilitate construction work, shorten the construction period, achieve cost reduction associated with seismic isolation, and In some cases, it is possible to provide a seismic isolation method for an existing building that can be constructed in a resident state and that can be constructed without moving its contents in a warehouse or the like. Another object of the present invention is to provide a seismic isolation method for existing buildings, which can reduce the amount of waste associated with the seismic isolation of existing buildings, and which is excellent in environmental friendliness.

  In order to achieve the above object, the seismic isolation method for an existing building according to the invention described in claim 1 is a method for isolating an existing building having an upper structure and a foundation for supporting the upper structure. A step of forming a notch in the foundation of an existing building, a step of inserting support means into the notch, and supporting the upper surface of the notch with the support means, and an upper foundation by cutting the foundation horizontally. And a step of separating the lower foundation, a step of installing a seismic isolation device between the divided lower foundation and the upper foundation, and a step of removing the support means and supporting the upper foundation with the seismic isolation device. It is characterized by. In other words, the existing foundation is divided up and down, the upper foundation is used to secure the rigid floor of the upper structure after the seismic isolation, the lower foundation is used as the base after the seismic isolation, and the upper and lower foundations are used. Install a seismic isolation device between and support the upper foundation.

The seismic isolation method for existing buildings constructed as described above forms a notch for inserting support means such as a jack into the foundation, and then supports the upper surface of the notch with a jack or the like and then cuts the foundation up and down. The base is divided into an upper foundation and a lower foundation, and a seismic isolation device is installed in the gap between the upper and lower foundations. The existing building can be seismically isolated with a short construction period and low cost, and waste can be reduced. In addition, if the existing building is a residence, it can be seismically isolated while it is resident, and even in the case of a warehouse, etc., it can be seismically isolated while accommodating articles and the like.

  Moreover, as a seismic isolation method of the existing building by the invention of Claim 2, it is further provided with the process of reinforcing the divided | segmented lower foundation and / or upper foundation as a post process of the process of dividing the said foundation. It is a feature. For example, fix the steel frame material using the anchor member on the lower surface of the upper foundation, fix the steel frame, etc., and reinforce the lower foundation by increasing the concrete thickness or using a solid foundation be able to. According to this configuration, in order to reinforce at least one of the upper and lower foundations divided as needed, the strength of the upper and lower foundations divided by the upper and lower parts and reduced in strength can be increased, thereby providing stable relief. Seismic performance can be obtained.

  In the seismic isolation method for an existing building according to the invention described in claim 3, as an after step of the step of dividing the foundation, an upward pulling prevention process of the anchor member connecting the upper structure and the foundation is performed. It is characterized by that. For example, when the foundation is divided into upper and lower portions, the lower end of the anchor bolt protrudes from the upper foundation, and the upper end can be prevented from being pulled out by screwing into the protruding end and connecting a nut. When configured in this manner, the anchor member can be used to strengthen the connection between the upper foundation and the upper structure, and by sandwiching a reinforcing material such as a steel frame material or a frame from the divided upper foundation, It is also possible to efficiently reinforce the upper foundation and prevent pulling out at the same time.

  According to the seismic isolation method for an existing building according to claim 1, it is possible to perform seismic isolation of an existing building such as a detached house with easy construction. In addition, since it is not necessary to dismantle and move an existing building, in the case of a residence, construction can be carried out while occupying, eliminating the need for moving and reducing the cost of seismic isolation. Furthermore, since the existing foundation is used, waste can be reduced and environmentally friendly construction is possible, and the dismantling and re-laying of the foundation can be omitted, and the construction period can be shortened.

According to the seismic isolation method for an existing building according to claim 2, the strength of the upper and lower foundations, which have been reduced in strength, is increased by reinforcing the foundations divided in the vertical direction as necessary. Seismic performance can be obtained. Moreover, according to the seismic isolation method of the existing building of Claim 3, the coupling | bonding of an upper foundation and an upper structure can be strengthened using an anchor member, and seismic isolation performance can be improved.

  Hereinafter, an embodiment of a seismic isolation method for an existing building according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an elevation view of an existing building that implements the seismic isolation method according to the present embodiment, and FIG. 2 is a perspective view showing the foundation of the existing building of FIG. 1 and 2, the existing building 1 is a wooden two-story detached house. For example, a wooden upper structure 3 composed of pillars and beams is installed on the upper part of a reinforced concrete foundation 2, and the foundation 2 is located at the upper part. The direct foundation which directly supports the structure 3 is comprised. On the upper part of the upper structure 3, a roof part 4 sown with tiles or the like is formed.

  Since the wooden upper structure 3 has a frame structure, a large number of pillars and beams are used. The foundation and the foundation 2 of the upper structure 3 are composed of a large number of anchor bolts 5 embedded in the foundation 2. It is connected with. If such a detached building is seismically isolated by the above-described conventional seismic isolation method, the number of pillars is large and the construction becomes complicated. The upper structure is not limited to a wooden frame structure, and may be an appropriate structure such as a structure using a steel frame structure or a steel frame structure structure unit. The foundation may be of an appropriate form such as a cloth foundation, a solid foundation, an unreinforced concrete foundation, or the like.

  Here, an example of the seismic isolation device used in the seismic isolation method of this embodiment will be described with reference to FIG. FIG. 3 is a vertical sectional view and a horizontal sectional view of the seismic isolation device. The seismic isolation device 10 is generally installed between the foundation and the upper structure, and includes a lower tray 12 having a flat bowl-shaped concave surface 11 and an upper surface having a concave surface 13 having a shape obtained by vertically inverting it. It is comprised from the saucer 14 and the rolling body 15 which consists of a steel ball located between an upper and lower saucer, and fixes the base 16 by fixing the lower saucer 12 to the foundation 16, and fixing the upper saucer 14 to the upper structure 17. The upper structure 17 is insulated and the displacement of the foundation 16 due to vibration such as an earthquake is prevented from being directly transmitted to the upper structure 17. In this type of seismic isolation device 10, the lower tray 12 is fixed to the upper surface of the base 16 with bolts, the upper tray 14 is fixed downward to the upper structure 17, and the rolling body 15 is interposed between the upper and lower trays. Let In addition, instead of the mortar-shaped surfaces of the upper and lower trays, an arc surface or an ellipse having a large curvature radius may be formed so that the center part is recessed.

  Next, a method for making the existing building 1 having the above-described structure seismic isolation will be described in detail with reference to FIGS. When constructing this construction method, the resident who lives in the existing building 1 does not need to move basically, and household goods tools and the like can be used as they are. In addition, when an existing building is not a residential building such as a warehouse, it can be constructed without the need to move articles or the like housed therein.

First, as a first step, as shown in FIG. 4B, a rectangular notch 20 for inserting a support means such as a jack or a seismic isolation device to be described later is formed on the foundation 2 in FIG. 4A. As the cutout portion, a shape penetrating the base 2 having a predetermined thickness is preferable, but a shape of a recess or a recess that does not penetrate may be used. The notch 20 can be formed by cutting a concrete portion with a water jet, for example. Moreover, the concrete of the foundation 2 can also be cut out and formed by a chain saw or the like. Furthermore, you may form a through-hole continuously using drilling machines, such as a hole saw. In this embodiment, notches 20... Having a width of several tens of centimeters are formed on the outer peripheral foundation at intervals of 2 to 3 m, and a plurality of notches are horizontally arranged at the same intervals on an inner base portion (not shown). Form. The positions where the notches 20 are formed are preferably positions where the anchor bolts 5 for fixing the foundations of the foundation 2 and the upper structure 3 are avoided. In addition, when forming a notch part in an intermediate | middle foundation, it is necessary to remove a one part floor board.

  As a second step, as shown in FIG. 4c, jacks 21 are inserted as support means in the notches 20 formed in the above-described step, the jack base is brought into contact with the bottom surface of the notches, The movable shaft is brought into contact with the upper surface of the notch 20 to support the upper portion of the foundation 2. That is, the movable shaft of the jack 21 is raised, and the upper surface of the notch is pressed with a predetermined pressure by the movable shaft. In this embodiment, as shown in FIG. 4c, five notches 20 are formed on one surface of the outer peripheral side, and three jacks 21 are inserted. For example, a jack is inserted from a part of the removed floor board into the notch formed in the foundation not exposed to the outer periphery. In this way, the notches 20 are formed at predetermined intervals on the lateral foundation and the longitudinal foundation, and the jack 21 is inserted into the notch to support the upper portion of the foundation 2. Use a hydraulic or mechanical jack. In addition, as shown in FIG. 4b, seven notches may be formed including notches indicated by broken lines, and jacks may be inserted into every other three notches.

  Next, as a third step, as shown in FIG. 4c, the foundation 2 is cut in the horizontal direction and divided into an upper foundation 2A and a lower foundation 2B. That is, using a tool such as a water jet, a chain saw, or a concrete cutter used in the first step, a cutting line 22 is horizontally placed along the upper side of the notch 20, and the lower side of the notch 20 A cutting line 23 is horizontally inserted in accordance with the above, and the concrete block cut into blocks by the upper and lower cutting lines 22 and 23 is removed to form a work space. If the anchor bolt 5 is cut along the cutting line 23 along the lower side, and the cutting line 22 along the upper side is cut so as not to cut the anchor bolt 5 and the lower end of the anchor bolt protrudes, the pull-out preventing process described later is easy. Can be done.

  FIG. 5 shows the state in which the upper foundation 2A and the lower foundation 2B are separated from each other by the cutting lines 22 and 23, and in the installation process of the seismic isolation device 10 to be described later, In this embodiment, 12 seismic isolation devices 10 (6 in the drawing) are installed.

  In this way, as shown in FIG. 6a, after the foundation 2 is divided horizontally into upper and lower foundations 2A and 2B, the lower end of the protruding anchor bolt 5 is threaded as a fourth step. Then, the nut is screwed and clamped by sandwiching a plate 24 such as an iron plate from below, and a pull-out prevention process is performed. This pull-out prevention process prevents the anchor bolt 5 from coming out of the upper foundation 2A, and the coupling between the upper structure 3 and the upper foundation 2A by the anchor bolt 5 can be strengthened as shown in a cross section in FIG. 6b. . If the foundation 2 is cut horizontally so that the anchor bolt 5 does not protrude from the lower surface of the upper foundation, the concrete around the lower end of the anchor bolt is dug with a chisel to expose it, and after threading, the nut is screwed and pulled out. It may be prevented.

  In this pull-out prevention process, when the vertical bending rigidity or in-floor rigidity of the upper foundation 2A is insufficient, a steel frame material such as H steel is sandwiched and used as a reinforcing member instead of the plate 24. Reinforce the upper foundation 2A. It is preferable to configure the steel frame material as a long one so as to be in contact with the upper part of the seismic isolation device described later. The reinforcing process of the upper foundation 2A is performed as a subsequent process of dividing the foundation 2, that is, a fifth process, and this reinforcing fixation will be described later.

In the present embodiment, the reinforcement of the lower foundation 2B is performed as the sixth step together with the reinforcement of the upper foundation 2A. When the existing foundation is a cloth foundation, the lower foundation 2B can be reinforced by applying a slab arrangement to form a solid foundation. It is also possible to reinforce the reinforcing bar except for the jack 21 and to reinforce the concrete so as to embed the reinforcing bar. Furthermore, the concrete may be simply beaten. The step of reinforcing the sixth lower foundation will also be described later. In this way, by reinforcing the upper foundation 2A and the lower foundation 2B divided in the horizontal direction, the upper and lower mounting portions of the seismic isolation device 10 are strengthened, and the seismic isolation performance after construction can be improved. it can.

  Then, as shown in FIG. 6b, the plurality of jacks 21 are raised evenly to expand the work space. That is, the plurality of jacks 21 are evenly raised, the upper foundation 2A is jacked up, and the work space in which the seismic isolation device is inserted and installed is widened. The jack-up process is performed as necessary, and can be omitted when the installed seismic isolation device has a small vertical height and a large work space is not necessary. By using hydraulic jacks and piping from all the jacks from a pressurizing device (not shown), the upper foundation 2A can be raised evenly.

  Thereafter, as a seventh step, the seismic isolation device 10 is installed in a work space jacked up as shown in FIG. 6c. The seismic isolation device 10 is connected by a connection bar (not shown) with the upper and lower trays 12 and 14 sandwiching the rolling body 15 at the time of installation. A hole-in anchor, a chemical anchor (not shown), etc. are processed with respect to the installation place of the seismic isolation apparatus of the lower foundation 2B, and the lower receiving tray 12 is fixed to the lower foundation 2B using these anchors. Similarly, processing of a hole-in anchor, a chemical anchor, or the like is performed on the upper foundation 2A, and when the jack 21 is lowered, the upper foundation 2A and the upper receiving tray 14 of the seismic isolation device come into contact with each other. The upper tray 14 is fixed to the upper base 2A.

  Then, as the eighth step, when the jack 21 is completely lowered and removed, the upper base 2A and the upper structure 3 can be supported by the seismic isolation devices 10 in place of the jack 21. Moreover, if the connection bar which fixes the upper and lower saucers of the seismic isolation apparatus 10 is removed, the upper saucer 14 will become free with respect to the lower saucer 12, and will connect the upper foundation 2A to the lower foundation 2B so that movement is possible. Can do. Thereby, the seismic isolation of the existing building 1 is completed as shown in FIG.

  In the seismic isolation device 10, the rolling body 15 such as a steel ball is normally located at the center of the lower tray 12 and the upper tray 14, but the rolling body 15 moves even if the lower foundation 2 </ b> B vibrates due to an earthquake or the like. Therefore, the vibration is not transmitted directly to the upper foundation 2A. When the earthquake subsides, the rolling body 15 returns to the center of the lower tray 12 and the center of the upper tray 14 returns to the rolling body 15 to restore the seismic isolation device 10 to its original position. In addition, when a seismic isolation device having a damper function is used in combination, the seismic energy can be attenuated to speed up the restoration of the seismic isolation device.

  In the present embodiment, the seismic isolation device 10 uses a rolling support type, but a sliding support type seismic isolation device may be used, or a seismic isolation device in which rubber and a steel plate are laminated may be used. Moreover, you may use the cross linear guide type seismic isolation apparatus which crossed and connected the linear guide which has a guide rail and a slider. In addition, as a seismic isolation device, a seismic isolation device that has a damper function that attenuates the relative displacement between the upper foundation and the lower foundation, and a wind-fixed type seismic isolation device that prevents movement of the upper structure due to wind pressure in strong winds are used. May be used.

Next, a step of reinforcing the divided lower foundation 2B and / or upper foundation 2A as a fifth step after the step of dividing the foundation 2 will be described with reference to FIG. The reinforcement of the upper foundation 2A can be achieved, for example, by tightening with a nut with a reinforcing material (not shown) such as an angle material instead of the iron plate 24 when the anchor bolt 5 is pulled out. Further, as shown in FIG. 8, this can be achieved by tightening a reinforcing member 25 such as C steel or H steel with a plurality of anchor bolts 5 and nuts. By receiving the upper receiving tray 14 of the seismic isolation device 10 with the reinforcing member 25 fixed in this manner, stress concentration at the connecting portion between the upper receiving tray 14 of the seismic isolation device 10 and the upper foundation 2A can be prevented, and the seismic isolation building can be prevented. The durability of can be improved.

  Moreover, you may reinforce the divided | segmented lower foundation 2B as a post process of the process of dividing the foundation 2, ie, a 6th process. FIG. 9 shows a cross-sectional view of the reinforcing portion of the foundation in the step of reinforcing the lower foundation. In FIG. 9a, the foundation 2 is divided into an upper foundation 2A and a lower foundation 2B, and a reinforcing angle member 30 is bolted to the lower foundation 2B in accordance with a rising portion and a footing portion. Further, in FIG. 9b, a reinforcing bar 31 is inserted into the lower foundation 2B in a mesh shape, and a solid foundation 32 is driven so as to embed the reinforcing bar. Furthermore, it can also reinforce by using both of the above. Thus, the rigidity of the foundation parted up and down can be improved by reinforcing the lower foundation 2B.

  FIG. 10 shows a perspective view of the main part of the reinforcing portion of the foundation in the step of reinforcing the lower foundation 2B. In FIG. 10 a, the lower foundation 2 </ b> B forms a reinforcing base portion 35 that is wide with respect to the corner portion. Moreover, in FIG. 10b, the reinforcement base part 36 is formed in the cross | intersection part of the lower foundation 2B. It is preferable that the reinforcing base portions 35 and 36 are formed with a concrete frame to the same height as the upper surface of the lower foundation 2B, and support the lower tray of the seismic isolation device 10 at this portion. If it is simultaneously formed, the concrete placing process is simplified and the strength of the reinforcing portion can be greatly improved.

  Thus, according to the seismic isolation method of the present embodiment, the notch 20 is formed in the foundation 2 of the existing building 1 (first step), the jack 21 is inserted, and the jack 21 is inserted into the upper surface of the notch. Is supported (second step) and then horizontally cut and divided into upper base 2A and lower base 2B (third step), and seismic isolation device 10 is installed between upper base 2A and lower base 2B ( Since the jack 21 is removed after the seventh step) and the upper foundation is supported by the seismic isolation device 10 (the eighth step), the construction is easy, the construction period can be shortened, and the existing building can be seismically isolated at low cost. it can. In addition, the anchor bolt 5 can be prevented from being pulled out (fourth step) as needed, and the base divided in the upper and lower directions can be reinforced (steps 5 and 6) to improve seismic isolation performance. it can.

  Another embodiment of the present invention will be described in detail with reference to FIG. FIG. 11 is an elevational view showing a divided state of a foundation according to another embodiment of the seismic isolation method according to the present invention. In addition, in this embodiment, in the process of cutting the foundation of the existing building into the upper foundation and the lower foundation in the above-described embodiment, the foundation is divided up and down with two cutting lines, whereas the foundation with one cutting line is used. It is characterized by dividing the top and bottom. Other substantially equivalent configurations are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 11 a shows an elevational view of a foundation cut by a single cutting line 22 a along the upper side of the notch 20 to form an upper foundation 2 </ b> C and a lower foundation 2 </ b> D. Further, FIG. 11b shows an elevational view of a foundation that is cut at one cutting line 23a along the lower side of the notch 20 to form an upper foundation 2E and a lower foundation 2F. In this embodiment, as in the above-described embodiment, for example, an existing building can be seismically isolated while being resident, construction is easy, construction period can be shortened, and waste can be reduced at low cost. Have. Moreover, in this embodiment, the cutting process of the foundation can be simplified by setting the cutting line of the foundation to one, the construction time can be shortened, and the disposal of concrete can be reduced. Strength after splitting is also improved.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention described in the claims. Design changes can be made. For example, as a support means for supporting the upper foundation and the upper structure, it is needless to say that the necessary number of jacks is set depending on the weight to be supported. Of course, it is also possible to use a jack having a necessary jack-up amount in accordance with the seismic isolation device to be used.

  Although an example of an anchor bolt is shown as an anchor member for connecting the upper structure and the foundation, an anchor plate may be fixed to the foundation and the bolt may be screwed to the plate. Moreover, although the example which fixes the base of an upper structure with an anchor member was shown, when an upper structure is a building unit, what is necessary is just to fix the lower beam which comprises a building unit. Further, when the notch is formed on the foundation, the anchor bolt may be formed in the anchor bolt portion to prevent the anchor bolt from being pulled out in advance.

The elevation view of the existing building which enforces the seismic isolation construction method concerning this invention. The perspective view of the foundation of the existing building shown in FIG. An example of the seismic isolation apparatus used with the seismic isolation method concerning this invention is shown, (a) is sectional drawing which shows a fixed state, (b) is the sectional view on the AA line of (a). The principal part elevation which shows the process of one Embodiment of the seismic isolation construction method which concerns on this invention. The perspective view of the state which divided the foundation into the upper foundation and the lower foundation. The principal part elevation which shows the process of the seismic isolation construction method following FIG. The principal part elevation of the completion state which shows the process of the seismic isolation construction method following FIG. The principal part elevation of the completion state using another reinforcing material. (A), (b) is principal part sectional drawing of embodiment which each reinforced the lower foundation. (A), (b) is a principal part perspective view of other embodiment which reinforced the lower foundation, respectively. (A), (b) is an elevational view of a foundation showing a divided state of another embodiment in which the foundation is divided by one cutting line.

Explanation of symbols

  1: existing building, 2: foundation, 2A: upper foundation, 2B: lower foundation, 3: upper structure, 5: anchor bolt (anchor member), 10: seismic isolation device, 20: notch, 21: jack ( Support means), 22, 23, 22a, 23a: cutting line, 25: reinforcing material (upper basic reinforcing part), 30: reinforcing angle material (lower basic reinforcing part), 31: reinforcing bar (lower basic reinforcing part), 32: Solid foundation (lower foundation reinforcement), 35, 36: Reinforcement base (lower foundation reinforcement)

Claims (3)

A method of seismically isolating an existing building comprising an upper structure and a foundation that supports the upper structure,
Forming a notch in the foundation of an existing building, inserting support means into the notch, supporting the upper surface of the notch with the support means, and cutting the foundation horizontally. A step of dividing the upper foundation and the lower foundation, a step of installing a seismic isolation device between the divided lower foundation and the upper foundation, and a step of removing the support means and supporting the upper foundation with the seismic isolation device And seismic isolation method for existing buildings.   The seismic isolation method for an existing building according to claim 1, further comprising a step of reinforcing the divided lower foundation and / or upper foundation as a subsequent step of the step of dividing the foundation.   3. The existing building according to claim 1, wherein, as a subsequent step of the step of dividing the foundation, an upward pull-out prevention process of an anchor member connecting the upper structure and the foundation is performed. Seismic isolation method.

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