Seismic retrofit method using base isolation packing under foundation in wooden building

Abstract

To provide a seismic retrofit method using a base isolation packing under a foundation in a wooden building capable of imparting a base isolation function with respect to an existing building which has poor earthquake resistance.SOLUTION: A retrofit method for imparting a base isolation function with respect to a building of a retrofit object includes: a nut removing step of removing an existing nut; an insertion clearance securing step of securing a predetermined insertion clearance between a base and a foundation; a base isolation clearance securing step of securing a predetermined base isolation clearance between an inner peripheral surface of a through-hole and an anchor bolt by expanding the through-hole of the foundation; a base isolation packing insertion step of inserting a base isolation packing constituted so as to slip with respect to the foundation at the time of an earthquake; and a nut mounting step of screwing an existing or a new nut with the anchor bolt.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for seismic isolation renovation using seismic isolation packing under the foundation of a wooden building. [Background technology]

[0002] A known seismic isolation mechanism using anchor bolts and friction seismic isolation devices includes an anchor bolt embedded in the foundation of a building to secure the foundation, a through-hole through which the anchor bolt is inserted and which passes vertically through the foundation, a nut that screws into the upper end of the anchor bolt, and a friction seismic isolation device that is interposed between the foundation and the base (see Patent Document 1). The friction seismic isolation device has a first sliding plate located at the upper level and in close contact with the base, and a second sliding plate located at the lower level and in close contact with the base, with the surfaces where the first and second sliding plates are overlapped being smooth. In this seismic isolation mechanism, the smooth portion of the friction seismic isolation device functions as a sliding surface, acting as an isolator that slides during an earthquake, and a large number of small seismic isolation devices that use the bending stress of the anchor bolt as a spring are activated, providing a significant seismic isolation effect. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7018550 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 is targeted at newly constructed buildings. The inventors of the present application have been diligently studying whether it is possible to provide a seismic isolation function to existing buildings that lack earthquake resistance.

[0005] The present invention aims to provide a seismic isolation renovation method using seismic isolation gaskets under the foundations of wooden buildings, which can provide seismic isolation functions to existing buildings that have poor earthquake resistance. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides: A concrete foundation; A wooden base and An anchor bolt extending upward from the foundation; a through hole formed in the base and through which the anchor bolt is inserted; A building renovation method for imparting a seismic isolation function to a building to be renovated, the building having a nut threadedly engaged with the anchor bolt, a nut removal step of removing the existing nut; an insertion clearance ensuring step of ensuring a predetermined insertion clearance between the foundation and the base; a seismic isolation clearance ensuring process of widening the through hole of the base to ensure a predetermined seismic isolation clearance between the inner circumferential surface of the through hole and the anchor bolt; a seismic isolation packing insertion process for inserting a seismic isolation packing configured to slide relative to the base during an earthquake between the foundation and the base with the insertion clearance secured; A seismic isolation renovation method using a seismic isolation packing under the foundation of a wooden building is provided, which includes a nut installation process in which the existing nut or a newly installed nut is screwed onto the anchor bolt while the seismic isolation packing is inserted between the foundation and the base.

[0007] In the seismic isolation renovation method using seismic isolation packing under the foundation of the wooden building, The building to be renovated has an existing packing between the foundation and the base, In the insertion clearance securing step, a part of the existing packing is removed, and a predetermined insertion clearance is secured by using the remaining existing packing. After the seismic isolation packing insertion step, an existing packing complete removal step may be included in which any remaining existing packing is removed.

[0008] In the seismic isolation renovation method using seismic isolation packing under the foundation of the wooden building, In the insertion clearance securing step, a wedge packing having an insertion portion with a thickness corresponding to the insertion clearance is inserted between the foundation and the base, It is preferable that the method includes a wedge packing removal step of removing the wedge packing from between the foundation and the base after the seismic isolation packing insertion step.

[0009] In the seismic isolation renovation method using seismic isolation packing under the foundation of the wooden building, It is preferable that the method further includes, after the nut attaching step, a reinforcement attaching step of attaching a shear reinforcement that restricts movement of the base in the shear direction relative to the foundation.

[0010] In the seismic isolation renovation method using seismic isolation packing under the foundation of the wooden building, The shear stiffener may be a shear stiffener plate.

[0011] In the seismic isolation renovation method using seismic isolation packing under the foundation of the wooden building, The shear reinforcement may be a shear reinforcement bolt.

[0012] In the seismic isolation renovation method using seismic isolation packing under the foundation of the wooden building, The seismic isolation packing is formed in a flat plate shape and has a position adjustment groove into which a tool can be inserted when the packing is inserted into the foundation and the base, It is preferable that after the seismic isolation packing insertion step, a seismic isolation packing position adjustment step be included in which a tool is inserted into the position adjustment groove to adjust the position of the seismic isolation packing.

[0013] In the seismic isolation renovation method using seismic isolation packing under the foundation of the wooden building, In the nut attaching step, it is preferable that a washer through which the anchor bolt is inserted be engaged with the base, thereby restraining the upper end side of the anchor bolt toward the base. [Effects of the Invention]

[0014] According to the seismic isolation renovation method of the present invention, which uses seismic isolation gaskets under the foundations of wooden buildings, it is possible to impart seismic isolation functions to existing buildings that have poor earthquake resistance. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a partial cross-sectional explanatory diagram of a building before renovation, showing a first embodiment of the present invention. FIG. [Figure 2] 1 is a flowchart of a method for renovating a building. [Figure 3] This is an explanatory partial cross-sectional view of a building showing the state after the existing nuts have been removed and insertion clearance has been secured by wedge packing. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 10 is a partial cross-sectional explanatory diagram of a building showing the state in which a through hole is being enlarged using a drill with a taper. [Figure 7] This is a partial cross-sectional explanatory diagram of a building showing the state in which a seismic isolation gasket has been installed and a new nut has been attached. [Figure 8] FIG. 10 is a top view of the seismic isolation packing. [Figure 9] FIG. 2 is a side view of the seismic isolation packing. [Figure 10] FIG. 10 is a perspective view of a washer having a slippage prevention function. [Figure 11] FIG. 1 is a partial cross-sectional explanatory diagram of a building showing the state in which a shear reinforcement plate has been installed. [Figure 12] FIG. 1 is a front view of a shear reinforcement plate. [Figure 13] This is an explanatory diagram of a partial cross section of the building after renovation. [Figure 14] This is an explanatory plan view showing the arrangement of seismic isolation gaskets and reinforcing plates in a building after renovation. [Figure 15]This is a partial cross-sectional explanatory diagram of a building showing a modified example in which shear reinforcement bolts have been installed. [Figure 16] FIG. 10 is a side view of a modified bolt fastener. [Figure 17] FIG. 10 is a bottom view of a modified bolt fastener. [Figure 18] FIG. 10 is a cross-sectional explanatory view of a nut and a washer showing a modified example. [Figure 19] FIG. 10 is a partial cross-sectional explanatory diagram of a building before renovation, showing a second embodiment of the present invention. [Figure 20] This is an explanatory plan view showing the arrangement of anchor bolts, etc. in a building before renovation. [Figure 21] 1 is a flowchart of a method for renovating a building. [Figure 22] This is an explanatory partial cross-sectional view of a building showing the state in which the existing nuts have been removed and the remaining existing gasket ensures insertion clearance. [Figure 23] FIG. 10 is a partial cross-sectional explanatory diagram of a building showing the state in which a through hole is being enlarged using a drill with a taper. [Figure 24] This is a partial cross-sectional explanatory diagram of a building showing the state in which a seismic isolation gasket has been installed and a new nut has been attached. [Figure 25] 1A and 1B are bottom views of the seismic isolation packing, where (a) shows the entire structure and (b) shows only the cylindrical portion. [Figure 26] 1A and 1B are cross-sectional side views of the seismic isolation packing, where (a) shows the entire structure and (b) shows only the cylindrical portion. [Figure 27] FIG. 10 is a cross-sectional view illustrating a newly installed nut. [Figure 28] This is an explanatory diagram of a partial cross section of the building after renovation. [Figure 29] This is an explanatory plan view showing the arrangement of seismic isolation gaskets and other parts in a building after renovation. DETAILED DESCRIPTION OF THE INVENTION

[0016] 1 to 14 show a first embodiment of the present invention, in which FIG. 1 is a partial cross-sectional explanatory diagram of a building before renovation, FIG. 2 is a flowchart of a method for renovating a building, FIG. 3 is a partial cross-sectional explanatory diagram of a building after the existing nuts have been removed and wedge packings have been used to ensure insertion clearance, FIG. 4 is a side view of the wedge packing, FIG. 5 is a top view of the wedge packing, FIG. 6 is a partial cross-sectional explanatory diagram of a building after the through hole has been enlarged using an expanding drill, FIG. 7 is a partial cross-sectional explanatory diagram of a building after the seismic isolation packing has been installed and a new nut has been attached, FIG. 8 is a top view of the seismic isolation packing, FIG. 9 is a side view of the seismic isolation packing, FIG. 10 is an oblique view of a washer with a slippage prevention function, FIG. 11 is a partial cross-sectional explanatory diagram of a building after the shear reinforcement plate has been installed, FIG. 12 is a front view of the shear reinforcement plate, FIG. 13 is a partial cross-sectional explanatory diagram of a building after renovation, and FIG. 14 is a plan view showing the arrangement of the seismic isolation packing and reinforcement plate in the building after renovation.

[0017] As shown in Figure 1, the building 1 before renovation has a foundation 2 made of concrete, a base 3 made of wood, an anchor bolt 4 extending upward from the foundation 2, a through hole 5 formed in the base 3 and through which the anchor bolt 4 is inserted, and a nut 6 that screws onto the anchor bolt 4. The renovation method of this embodiment is applicable regardless of the diameters of the anchor bolt 4 and the through hole 5, but here the description will be given assuming that the diameter of the anchor bolt 4 is 12 mm and the diameter of the through hole 5 is 18 mm.

[0018] As shown in FIG. 2, the renovation method for the building 1 of this embodiment includes a rotten part repair process S1 in which the floor and the column base are exposed and rotten parts, damaged parts, etc. are repaired; a nut removal process S2 in which the existing nuts 6 are removed; an insertion clearance securing process S3 in which a wedge packing 10 is inserted between the foundation 2 and the base 3 to secure a predetermined insertion clearance; a seismic isolation clearance securing process S4 in which a through hole 5 in the base 3 is widened to secure a predetermined seismic isolation clearance between the inner peripheral surface of the through hole 5 and the anchor bolt 4; and a seismic isolation clearance securing process S5 in which a wedge packing 10 is inserted between the foundation 2 and the base 3 with the insertion clearance secured to prevent the base 2 from sliding against the base 3 during an earthquake. a seismic isolation packing position adjustment process S6 for adjusting the position of the seismic isolation packing 20 by inserting a tool into the position adjustment groove 26 of the seismic isolation packing 20; a wedge packing removal process S7 for removing the wedge packing 10 from between the foundation 2 and the base 3; a nut installation process S8 for screwing a newly installed nut 36 onto the anchor bolt 4 while the seismic isolation packing 20 is inserted between the foundation 2 and the base 3; and a reinforcing plate installation process S9 for installing a shear reinforcing plate 40 that restricts the shear movement of the base 3 relative to the foundation 2.

[0019] In this embodiment, the repair process S1 for rotten areas, etc., is performed before the nut removal process S2, but the timing of repairing the building can be changed as desired, and it is not necessary to simultaneously provide the seismic isolation function and repair the building. In this embodiment, as shown in Figure 3, the existing nuts 6 are removed in the nut removal process S2 to allow the base 3 to move upward, and wedge packing 10 is inserted between the foundation 2 and the base 3 in the insertion clearance securing process S3.

[0020] As shown in FIG. 4, the wedge packing 10 is formed as a flat plate overall. In this embodiment, the wedge packing 10 is made of engineering plastic. The wedge packing 10 may be made of any material, such as metal. As shown in FIG. 5, the wedge packing 10 is rectangular in plan view and includes a main body 11 having a thickness corresponding to the insertion clearance, a first inclined portion 12 formed on the outer edge of the upper surface of one short side, a second inclined portion 13 formed on the first inclined portion 12 side of the upper outer edge of one long side, and a protrusion 14 formed on the opposite side of the upper outer edge of one long side from the first inclined portion 12. The insertion clearance is set to be larger than the thickness of the seismic isolation packing 20 and is 7 mm in this embodiment. The lower surface of the wedge packing 10 is formed flat. The first inclined portion 12 is formed across the width of the wedge packing 10 and slopes downward toward the outside in the normal direction. The second inclined portion 13 is formed on one longitudinal end of the wedge packing 10 and is inclined downward toward the outside in the normal direction. The protruding portion 14 is formed on the other longitudinal end of the wedge packing 10 and protrudes a predetermined height above the main body portion 11. In this embodiment, the protruding height of the protruding portion 14 is 5 mm.

[0021] With one longitudinal end of the wedge packing 10 configured as described above in contact with the space between the foundation 2 and the base 3, the wedge packing 10 can be moved in one longitudinal direction to ensure an insertion clearance between the foundation 2 and the base 3, as shown in FIG. 3. Since the wedge packing 10 has the first inclined portion 12, moving the wedge packing 10 in one longitudinal direction causes the base 3 to move upward. The wedge packing 10 is pushed into a position where the protruding portion 14 contacts the base 3. In this embodiment, the movement of the wedge packing 10 in one longitudinal direction is achieved by hitting the other longitudinal end of the wedge packing 10 with a hammer.

[0022] As shown in FIG. 6 , in this embodiment, in the seismic isolation clearance ensuring step S4, the through hole 5 in the base 3 is enlarged with the wedge packing 10 inserted between the foundation 2 and the base 3. The through hole 5 is enlarged using an enlargement drill 50 while the anchor bolt 4 remains inserted in the through hole 5. A conventional enlargement drill 50 can be used. Considering the seismic isolation function of the building during an earthquake, the diameter of the enlarged through hole 51 is preferably 10 mm or more larger than the diameter of the anchor bolt 4. Furthermore, considering damage to various parts and facilities of the building during an earthquake, the difference between the diameter of the enlarged through hole 51 and the diameter of the anchor bolt 4 is preferably 30 mm or less. In this embodiment, the diameter of the enlarged through hole 51 is 24 mm for an anchor bolt 4 with a diameter of 12 mm. As shown in FIG. 7 , after the enlargement of the through hole 51 is completed, a seismic isolation packing 20 is inserted between the foundation 2 and the base 3.

[0023] As shown in Figures 8 and 9, the seismic isolation packing 20 is formed in a rectangular shape when viewed from above. The upper surface 21 that contacts the base 3 is smooth, and the lower surface 22 that contacts the foundation 2 has multiple protrusions 23. In this embodiment, the seismic isolation packing 20 is made of engineering plastic and has a thickness of 5 mm. The seismic isolation packing 20 may be made of any material, for example, metal. The longitudinal dimension of the seismic isolation packing 20 is set to be equal to the distance from the center of the column 7 to the anchor bolt 4. Specifically, the planar dimensions of the seismic isolation packing 20 in this embodiment are 100 mm for the short side and 200 mm for the long side. In this embodiment, each protrusion 23 is frustum-shaped. The shape of each protrusion 23 is arbitrary, and may be, for example, cylindrical, prismatic, or truncated pyramidal. The dimensions of each protrusion 23 are arbitrary, but for example, the height from the lower surface 22 can be 0.2 mm to 0.3 mm, and the diameter of the base end can be about 1 mm. Each protrusion 23 functions as an anti-slip device for the foundation 2 during an earthquake. Instead of the protrusions 23, the lower surface can also be roughened.

[0024] As shown in FIG. 8 , the upper outer edge of one long side and one short side of the seismic isolation packing 20 is formed with a first inclined surface 24 that slopes downward toward the outside in the normal direction, and the upper outer edge of the other long side and one short side is formed with a second inclined surface 25 that is steeper than the first inclined surface 24. The seismic isolation packing 20 also has a position adjustment groove 26 that can accommodate tools, etc. The position adjustment groove 26 penetrates the flat portion of the seismic isolation packing 20 in the thickness direction and extends inward from the other long side. The position adjustment groove 26 can be omitted. In this embodiment, the position adjustment groove 26 is formed so that the width dimension at the terminal end is larger than that at the base end. In this embodiment, the position adjustment groove 26 also has an inclined surface 27 that is formed continuously with the second inclined surface 25.

[0025] In the seismic isolation packing insertion step S5, the seismic isolation packing 20 configured as described above is inserted between the foundation 2 and the base 3 with the wedge packings 10 ensuring an insertion clearance, as shown in FIG. 9 . In this embodiment, the insertion clearance is set to be larger than the thickness of the seismic isolation packing 20, allowing the seismic isolation packing 20 to be inserted smoothly. Then, in the seismic isolation packing position adjustment step S6, a tool is inserted into the position adjustment groove 26 of each seismic isolation packing 20 to adjust the installation position of the seismic isolation packing 20 to the desired position. Note that the seismic isolation packing position adjustment step S6 can be omitted. After adjusting the position of each seismic isolation packing 20, the wedge packings 10 are removed from between the foundation 2 and the base 3.

[0026] In this embodiment, the wedge packing 10 is removed in the wedge packing removal step S7 by applying force to the portion of the wedge packing 10 that protrudes from the gap between the foundation 2 and the base 3, thereby rotating the wedge packing 10. The wedge packing 10 is rotated by hitting the side of the wedge packing 10 near the protruding portion 14 with a hammer.

[0027] In the nut installation process S8, with the wedge packing 10 removed, a new nut 36 is threaded onto the anchor bolt 4. It is desirable for the new nut 36 to have a loosening prevention function. For example, if the existing nut is a countersunk nut, the existing nut 6 may be reused instead of the new nut 36. In this embodiment, a washer 30 with a slippage prevention function is used to thread the anchor bolt 4 onto the base 2. As shown in FIG. 10 , the washer 30 has a flat portion 32 with an insertion hole 31 for the anchor bolt 4 formed therein, and a protruding portion 33 formed on the outer edge of the flat portion 32 and protruding downward from the flat portion 32. The washer 30 has a circular shape in a plan view, and the protruding portion 33 is formed by bending the outer edge of the washer 30 so that it slopes downward toward the outside in the radial direction. The diameter of the radially inner end of the protruding portion 33 of the washer 30 is larger than the diameter of the through hole 51. The outer diameter of the washer 30 is arbitrary, but can be, for example, 45 mm.

[0028] The method for fastening the anchor bolt 4 and nut 36 to the base 3 using the washer 30 to prevent slippage in the nut attachment step S8 will be described. First, the base 3 is set on the foundation 2 so that the anchor bolt 4 passes through the through-hole 51. The washer 30 is then inserted into the anchor bolt 4 and brought into contact with the top surface of the base 3. In this state, the nut 36 that threads onto the anchor bolt 4 is tightened, moving the washer 30 downward and driving the protruding portion 33 into the base 3. The metal washer 30 has a high strength compared to the wooden base 3, allowing the protruding portion 33 to be smoothly driven into the base 3. The driving depth of the protruding portion 33 is arbitrary as long as at least a portion of the protruding portion 33 is driven into the base 3, but can be, for example, 2 mm to 3 mm. The protruding portion 33 may be driven into the base 3 until the flat portion 32 contacts the top surface of the base 3. The downward movement of the washer 30 stops at a position according to the torque of the tool used, and the anchor bolt 4 and the nut 36 are tightened. In this way, by using the anti-slip washer 30, the top of the anchor bolt 4 is restrained against the base 2.

[0029] After the nuts 36 are attached to the anchor bolts 4, a shear reinforcement plate 40 is attached to the foundation 3 as shown in FIG. 11 . In this embodiment, the shear reinforcement plate 40 is used to compensate for a lack of shear force due to a small number of existing anchor bolts 4. If the shear force is sufficient, the shear reinforcement plate 40 does not need to be installed. As shown in FIG. 12 , the shear reinforcement plate 40 is formed in a plate shape and includes a base-side fixing portion 41 attached to the side of the foundation 3, a diagonal extension portion 42 extending diagonally downward from the lower end of the base-side fixing portion 41 and away from the foundation 3, and a base-side abutment portion 43 extending downward from the lower end of the diagonal extension portion 42 and abutting against the upper end of the foundation 2. The base-side fixing portion 41 has multiple fixing holes 44, and the shear reinforcement plate 40 is fixed to the foundation 3 with large wood screws (not shown).

[0030] The shear reinforcement plate 40 configured as described above restricts movement in one shear direction of the foundation 3. In this embodiment, as shown in Fig. 14, a pair of shear reinforcement plates 40 are used, and the pair of shear reinforcement plates 40 are arranged facing each other. As a result, one shear reinforcement plate 40 restricts movement in one shear direction, and the other shear reinforcement plate 40 restricts movement in the other shear direction, thereby enabling balanced reinforcement of the shear strength of the building.

[0031] After the above steps, as shown in Figure 13, the renovated building 1 has the seismic isolation plate 20 inserted between the foundation 2 and the base 3, a seismic isolation clearance is secured between the inner surface of the through-hole 51 and the anchor bolt 4, and the anchor bolt 4 is restrained near the top of the base 3. This makes it possible to provide seismic isolation functionality to the existing building 1, which has poor earthquake resistance.

[0032] The seismic isolation effect of the remodeled building 1 during an earthquake will be described. When a relative horizontal load is applied to the foundation 2 and the base 3 during an earthquake, horizontal slippage occurs between the upper surface 21 of each seismic isolation packing 20 and the lower surface of the base 3, generating frictional resistance and dissipating seismic energy. The upper surface 21 of each seismic isolation packing 20 slides against the lower surface of the base 3, thereby functioning as an isolator. In this embodiment, inclined surfaces 24 and 25 are formed at the corners of each seismic isolation packing 20, preventing the corners from digging into the base 3 and facilitating slippage between each seismic isolation packing 20 and the base 3. Meanwhile, each convex portion 23 of each seismic isolation packing 20 functions as an anti-slip surface, preventing slippage between the lower surface of each seismic isolation packing 20 and the upper surface of the foundation 2. The foundation 2 and each seismic isolation packing 20 are bonded together with an adhesive as needed. Furthermore, when a relative horizontal load is applied to the foundation 2 and base 3 during an earthquake, the anchor bolts 4 are bent, generating bending stress inside the anchor bolts 4, which causes the wood to act as a buffer and generates bending stress inside the shear reinforcement plates 40. In addition to being consumed by the buffering effect of the wood, earthquake energy is also consumed by bending stress in the anchor bolts 4 and shear reinforcement plates 40. In this way, the anchor bolts 4, shear reinforcement plates 40, and each seismic isolation packing 20 work together to consume earthquake energy.

[0033] In this embodiment, the diameter of the through hole 51 after expansion is 10 mm or more larger than the diameter of the anchor bolt 4, so a relatively large bending stress can be generated in the anchor bolt 4 throughout the entire length of the through hole 51. Furthermore, in this embodiment, the difference between the diameter of the through hole 51 and the diameter of the anchor bolt 4 is 30 mm or less, so the amount of relative movement between the foundation 2 and the base 3 is kept to 30 mm or less, and a seismic isolation effect can be obtained while reducing the possibility of causing major damage to various parts and equipment of the building during an earthquake.

[0034] In the above embodiment, the wedge packing 10 is used to ensure the insertion clearance, but other means may be used to ensure the insertion clearance. Also, although the shear reinforcement plate 40 is installed in the building 1, the building 1 may be configured without the shear reinforcement plate 40.

[0035] Furthermore, other reinforcing devices can be installed instead of the shear reinforcement plate 40. In this case, the reinforcing plate installation step S9 becomes the installation step of the other reinforcing device. For example, as shown in FIG. 15, a shear reinforcement bolt 60 can be used as the other reinforcing device. The shear reinforcement bolt 60 may have any configuration, but FIG. 15 shows an example in which the shear reinforcement bolt 60 is additionally installed on the foundation 2 and the base 3 together with a bolt fixing device 61. The shear reinforcement bolt 60 is made of metal, has a head at the upper end that is equilaterally hexagonal when viewed in the axial direction, and is formed with a male thread along its entire length. The shear reinforcement bolt 60 may be made of any material, such as engineering plastic. A bolt without a head can also be used as the shear reinforcement bolt, in which case a nut is used to thread onto the shear reinforcement bolt.

[0036] As shown in Figure 16, the additional bolt fastener 61 is made of, for example, engineering plastic and includes a cylindrical main body 61a having an internal thread formed on its inner surface that can be threaded with the bolt 60, a protrusion 61b formed on the lower side of the outer surface of the main body 61a and extending at least in the vertical direction, and a flange 61c extending radially outward from the upper end of the main body 61a. The bolt fastener 61 may be made of any material, including metal, for example. The main body 61a has a general portion 61d with a substantially constant outer diameter and a small-diameter portion 61e formed at the lower end that has a smaller outer diameter than the general portion 61d. The small-diameter portion 61e is tapered downward.

[0037] 16, the upper ends of the main body 61a and the flange portion 61c are formed to be approximately flat. The flange portion 61c comes into contact with the upper surface of the base 3 when the main body 61a is press-fitted into the through-hole 62. The flange portion 61c has a protrusion 61f on its lower surface to prevent loosening of rotation. A plurality of protrusions 61f are formed at intervals around the circumferential direction of the main body 61a.

[0038] As shown in Fig. 17, a plurality of protrusions 61b are formed at intervals around the circumferential direction of the main body 61a. As shown in Fig. 16, each protrusion 61b is formed at an angle with respect to the axial direction of the main body 61a, so that the main body 61a is press-fit into the through-hole 62 while rotating in a predetermined rotation direction about the central axis. The predetermined rotation direction is the same direction as the direction in which the main body 61a loosens relative to the shear reinforcement bolt 60, which in this example is clockwise when viewed from above.

[0039] To install the shear reinforcement bolt 60, a through hole 62 is formed in the base 3, and then an insertion hole 63 is formed in the foundation 2. The bolt fixing device 61 is hammer-press-fitted into the through hole 62 of the base 3. The bolt fixing device 61 is press-fitted into the through hole 62 while it is threadedly engaged with the shear reinforcement bolt 60. It is also possible to press-fit the bolt fixing device 61 into the through hole 62 without threading it with the shear reinforcement bolt 60; in this case, the shear reinforcement bolt 60 can be threaded into the bolt fixing device 61 after the press-fitting. The lower end side of the main body 61a of the bolt fixing device 61 has a small diameter 61e that is smaller in outer diameter than the general portion 61d, so that the main body 61a can be smoothly press-fitted into the through hole 62. Furthermore, when the bolt fixing device 61 is pressed into place, the protrusions 61b formed on the lower side of the main body 61a bite into the inner circumferential surface of the through-hole 62, while the upper portion of the main body 61a where the protrusions 61b and flanges 61c are not formed is tightened to the base 3 due to wood shrinkage. In this example, the protrusions 61b are inclined relative to the axial direction, so the main body 61a is pressed into the through-hole 62 while rotating in a predetermined direction around the central axis. The bolt fixing device 61 is then fixed to the base 3 with the flanges 61c of the main body 61a in contact with the upper surface of the base 3 and the protrusions 61f biting into the upper surface of the base 3. The shear reinforcement bolts 60 are then tightened and locked. The shear reinforcement bolts 60 can also be used to reinforce the shear strength of a building.

[0040] In the above embodiment, the nut 36 is threaded onto the anchor bolt 4 using the washer 30 without performing countersinking on the base 3. However, as shown in FIG. 18 , a countersink 3a may be formed in the base 3 so that the nut 36 does not rise higher than the top surface of the base 3. In addition, while the protrusion 33 of the washer 30 is shown to be inclined downward toward the outside in the radial direction, the shape of the protrusion 33 is not limited to this. In addition, while the washer 30 is shown to be circular in plan view, the shape of the washer 30 in plan view is not limited to this. The shape, etc. of the washer 30 can be changed as desired as long as it is configured to restrain the anchor bolt 4 toward the base 3.

[0041] Figures 19 to 29 show a second embodiment of the present invention, in which Figure 19 is a partial cross-sectional explanatory diagram of a building before renovation, Figure 20 is a plan view explanatory diagram showing the arrangement of anchor bolts and other items in the building before renovation, Figure 21 is a flowchart of a method for renovating a building, Figure 22 is a partial cross-sectional explanatory diagram of a building after the existing nuts have been removed and the existing gaskets that remain in place to ensure insertion clearance, Figure 23 is a partial cross-sectional explanatory diagram of a building showing the through hole being enlarged with a drill bit, Figure 24 is a partial cross-sectional explanatory diagram of a building after the seismic isolation gaskets have been installed and a new nut has been attached, Figure 25 is a bottom view of the seismic isolation gasket, Figure 26 is a side cross-sectional view of the seismic isolation gasket, Figure 27 is a cross-sectional explanatory diagram of the newly installed nut, Figure 28 is a partial cross-sectional explanatory diagram of the building after renovation, and Figure 29 is a plan view explanatory diagram showing the arrangement of seismic isolation gaskets and other items in the building after renovation.

[0042] As shown in Figure 19, building 101 to be renovated has foundation 102 made of concrete, sill 103 made of wood, existing gaskets 104, 114 made of, for example, resin and installed between foundation 102 and sill 103, anchor bolt 105 extending upward from foundation 102, through hole 106 formed in sill 103 and through which anchor bolt 105 is inserted, and nut 107 threadedly engaged with anchor bolt 105. When hold-down hardware 109 is installed on column 108 of building 101 as shown in Figure 16, anchor bolt 115, through hole 116, and existing nut 117 for fastening to the column are installed in addition to anchor bolt 105, through hole 106, and existing nut 107 for fastening to the foundation. This building 101 also has joists 113 that are hung across foundation 103 and positioned below stud 118.

[0043] As shown in Figure 20, in this embodiment, an existing packing 104 that is square in plan view and an existing packing 114 that is rectangular in plan view are installed. Holes 141, 142 through which anchor bolts 105, 115 can be inserted are formed in both of the existing packings 104, 114. The renovation method of this embodiment can be applied regardless of the diameters of the anchor bolts 105, 115 and the through holes 106, 116, but here, the description will be given assuming that the diameter of the anchor bolt 105 for fastening to the base is 12 mm, the diameter of the through hole 106 is 18 mm, the diameter of the anchor bolt 115 for fastening to the column is 16 mm, and the diameter of the through hole 116 is 22 mm.

[0044] As shown in FIG. 21, the renovation method for the building 101 of this embodiment includes a rotten part repair process S101 in which the foundation and the column base are exposed and rotten parts, damaged parts, etc. are repaired; a nut removal process S102 in which the existing nuts 7 and 17 are removed; an insertion clearance securing process S103 in which some of the existing packings 104 and 114 are removed and the remaining existing packings 104 and 114 are used to secure a predetermined insertion clearance; and a seismic isolation clearance securing process S104 in which the through holes 106 and 116 of the foundation 103 are widened to secure a predetermined seismic isolation clearance between the inner circumferential surfaces of the through holes 106 and 116 and the anchor bolts 105 and 115. a seismic isolation packing insertion process S105 for inserting a seismic isolation packing 120 configured to slide against the base 103 during an earthquake between the foundation 102 and the base 103 with an insertion clearance secured; a seismic isolation packing position adjustment process S106 for adjusting the position of the seismic isolation packing 120; a complete existing packing removal process S107 for removing the remaining existing packings 104, 114; and a nut installation process S108 for screwing newly installed nuts 171, 172 onto the anchor bolts 105, 115 with the seismic isolation packing 120 inserted between the foundation 102 and the base 103.

[0045] In this embodiment, the repair process S101 for rotten areas, etc., is performed before the nut removal process S102. However, the timing of repairing the building can be changed as desired, and the addition of seismic isolation functions and repairing the building do not necessarily have to be performed simultaneously. As shown in FIG. 22 , in the nut removal process S102, the existing nuts 107, 117 are removed to release the tightened connection between the foundation 102 and the base 103. After this, in the insertion clearance ensuring process S103, some of the existing packings 104, 114 are removed, and the remaining existing packings 104, 114 ensure insertion clearance between the foundation 102 and the base 103 for inserting the seismic isolation packing 120. The existing packings 104, 114 can be removed by any method, for example, by dismantling them with a plastic drill. Furthermore, the existing packings 104, 114 to be removed and the existing packings 104, 114 to be left behind can be selected arbitrarily, but for example, it is possible to remove the existing packings 104, 114 at the location where the seismic isolation packing 120 will be installed, and then leave the existing packings 104, 114 with the anchor bolts 105, 115 inserted through them. The insertion clearance only needs to be larger than the thickness of the seismic isolation packing 120, and in this embodiment it is 20 mm, which is the thickness dimension of the existing packings 104, 114.

[0046] As shown in FIG. 23 , in this embodiment, in the seismic isolation clearance ensuring step S104, the through holes 106, 116 of the base 103 are enlarged while the existing packings 104, 114 for ensuring insertion clearance between the foundation 102 and the base 103 remain. The through holes 106, 116 are enlarged using an enlargement drill 50 while the anchor bolts 105, 115 remain inserted in the through holes 106, 116. In consideration of the seismic isolation effect of the building during an earthquake, the diameters of the enlarged through holes 161, 162 are preferably 10 mm or more larger than the diameters of the anchor bolts 105, 115. Furthermore, in consideration of damage to various parts and facilities of the building during an earthquake, the difference between the diameters of the enlarged through holes 161, 162 and the diameters of the anchor bolts 105, 115 is preferably 30 mm or less. In this embodiment, the diameter of the through hole 161 after expansion is 24 mm for the anchor bolt 105 for fastening to the base, which has a diameter of 12 mm. Also, the diameter of the through hole 162 after expansion is 28 mm for the anchor bolt 115 for fastening to the column, which has a diameter of 16 mm. As shown in FIG. 24 , after the expansion work of the through holes 161, 162 is completed, the seismic isolation packing 120 is inserted between the foundation 102 and the base 103.

[0047] As shown in FIG. 25(a), the seismic isolation packing 120 has an upper surface 121 that is smooth so that the frictional resistance with the base 103 is relatively small, and as shown in FIG. 26(a), a plurality of protrusions 122 are formed on the lower surface so that the frictional resistance with the foundation 102 is relatively large. Specifically, the upper surface 121 of the seismic isolation packing 120 has a friction coefficient with the lower surface of the base 103 of 0.2 or more and 0.3 or less, and is set so that it slides against the base 103 during an earthquake. Each protrusion 122 functions as an anti-slip surface against the foundation 102 during an earthquake. It is also possible to roughen the lower surface instead of the protrusions 122.

[0048] In this embodiment, the seismic isolation packing 120 is formed in a rectangular shape in a plan view and has a flat plate portion 123 and multiple cylindrical portions 124 protruding downward from the flat plate portion 123, with the upper surface 121 of the flat plate portion 123 coming into contact with the base 103. The cylindrical portions 124 serving as pillars are aligned vertically and horizontally in a plan view. As shown in Figures 25(b) and 26(b), multiple protrusions 122 that come into contact with the foundation 102 are formed on the lower end surface of each cylindrical portion 124.

[0049] In this embodiment, a plurality of protrusions 122 are formed at equal intervals in the circumferential direction on the lower surface of the cylindrical portion 124. Each of the protrusions 122 has a truncated cone shape. The shape of each of the protrusions 122 can be changed as desired, and can be, for example, a cylindrical shape, a prismatic shape, a truncated pyramid shape, or the like.

[0050] As shown in Figure 26(a), corners 125 formed by the top and side surfaces of flat plate portion 123 are chamfered. In this embodiment, corners 125 are curved with a predetermined curvature. Note that corners 125 may be angular rather than rounded. In this embodiment, seismic isolation packing 120 is made of engineering plastic and has a vertical dimension of 13 mm. Note that the material of seismic isolation packing 120 is arbitrary, and it may be made of metal, for example.

[0051] The seismic isolation packing 120 is placed directly below the columns 108 and studs 118, and is therefore designed to have a compressive strength corresponding to the column axial force of the columns 108 and studs 118. The column axial force accounts for approximately 80% of the total building load, and in a normal building it is between 10 kN and 30 kN, so it is desirable for the seismic isolation packing 120 to have a compressive strength that exceeds this, between 30 kN and 50 kN. In this embodiment, the long side of the seismic isolation packing 120 is set to a dimension equal to the distance from the center of the column 108 to the anchor bolt 105 used to fasten the foundation. Specifically, the planar dimensions of the seismic isolation packing 120 in this embodiment are a short side of 100 mm and a long side of 200 mm.

[0052] In the seismic isolation packing insertion step S105, the seismic isolation packing 120 configured as described above is inserted between the foundation 102 and the base 103, with the remaining existing packings 104, 114 ensuring insertion clearance, as shown in FIG. 24 . In this embodiment, the seismic isolation packing 120 is inserted directly below the columns 108 and studs 118. It is also inserted below the columns 108 and studs 118, as well as above the main supports and base supports (not shown) where a relatively large load is applied to the base 103. Because the seismic isolation packing 120 is not installed where the anchor bolts 105, 115 are installed, installation of the seismic isolation packing 120 substantially eliminates reaction forces on the anchor bolts 105, 115, thereby preventing shear failure of the wood. Furthermore, the load acting on the anchor bolts 105, 115 is reduced, eliminating the need for the anchor bolts 105, 115 to absorb a relatively large reaction force. Then, in the seismic isolation packing position adjustment step S106, the installation position of the seismic isolation packing 120 is adjusted to the desired position. Note that the seismic isolation packing position adjustment step S106 can be omitted. After adjusting the position of each seismic isolation packing 120, the remaining existing packings 104, 114 are removed in the existing packing complete removal step S107. The remaining existing packings 104, 114 can be removed by any method, but for example, they can be removed by dismantling them with a plastic drill.

[0053] In the nut attachment process S108, with the existing packings 104, 114 removed, new nuts 171, 172 are threaded onto the anchor bolts 105, 115. Note that the existing nuts 107, 117 may be reused instead of the new nuts 171, 172. In this embodiment, a new nut 171 is used to thread onto the anchor bolt 105 for fastening the foundation, and after tightening, the upper end of the nut 171 is flush with the upper surface of the foundation 103. In this embodiment, structural plywood is laid on the upper surfaces of the foundation 103 and the nuts 171.

[0054] As shown in Figure 27, the nut 171 has a long nut portion 171a that screws onto the anchor bolt 105 and a round seat 171b formed on the upper end of the long nut portion 171a. The nut 171 is a so-called countersunk nut, and the underside of the round seat 171b has multiple triangular ridges 171c that radiate outward in the radial direction. Each triangular ridge 171c has a triangular cross section with an acute apex angle, and is formed so that the height of the apex increases as it moves radially outward. The top of the anchor bolt 105 is restrained against the base 103 by the nut 171, which has the long nut portion 171a and the round seat 171b.

[0055] 28 and 29, after the renovation, the building 101 has seismic isolation packing 120 inserted between the foundation 102 and the base 103, seismic isolation clearances secured between the inner surfaces of the through holes 161, 162 and the anchor bolts 105, 115, and the anchor bolts 105 for fastening the base are restrained near the top of the base 103. This makes it possible to impart seismic isolation functionality to the existing building 101, which has poor earthquake resistance.

[0056] The seismic isolation effect of the renovated building 101 during an earthquake will be described. When a relative horizontal load is applied to the foundation 102 and the base 103 during an earthquake, horizontal slippage occurs between the upper surface 121 of each seismic isolation packing 120 and the lower surface of the base 103, generating frictional resistance and dissipating seismic energy. The upper surface 121 of each seismic isolation packing 120 slides against the lower surface of the base 103, thereby functioning as an isolator. In this embodiment, the corners 125 of each seismic isolation packing 120 are chamfered, so the corners 125 do not dig into the base 103, making it easier for each seismic isolation packing 120 to slip against the base 103. Meanwhile, the convex portions 122 of each seismic isolation packing 120 function as anti-slip devices, preventing slippage between the lower surface of each seismic isolation packing 120 and the upper surface of the foundation 102. The foundation 102 and each seismic isolation packing 120 are bonded together with an adhesive as needed. Furthermore, when a relative horizontal load is applied to the foundation 102 and base 103 during an earthquake, the anchor bolts 105, 115 are bent, generating bending stress inside the anchor bolts 105, 115 and a buffering effect of the wood. In addition to being consumed by the buffering effect of the wood, earthquake energy is also consumed by bending stress in the anchor bolts 105, 115. In this way, the anchor bolts 105, 115 and each seismic isolation packing 120 work together to consume earthquake energy.

[0057] In this embodiment as well, the diameter of the through holes 161, 162 after expansion is 10 mm or more larger than the diameter of the anchor bolts 105, 115, so a relatively large bending stress can be generated in the anchor bolts 105, 115 throughout the entire length of the through holes 161, 162. Furthermore, in this embodiment, the difference between the diameter of the through holes 161, 162 and the diameter of the anchor bolts 105, 115 is 30 mm or less, so the amount of relative movement between the foundation 102 and the base 103 is kept to 30 mm or less, and a seismic isolation effect can be obtained while reducing the possibility of causing major damage to various parts and equipment of the building during an earthquake.

[0058] In the second embodiment, the top of the anchor bolt 105 for fastening the base is restrained by the seat nut 170, but it may also be restrained by using a washer 30 having a slip prevention function relative to the base 103, as in the first embodiment.

[0059] In the second embodiment, the remaining existing packings 104, 114 are used to ensure the insertion clearance, but the existing packings 104, 114 may be used in combination with the wedge packings as in the first embodiment to ensure the insertion clearance. In this case, the wedge packings used have a thickness corresponding to the insertion clearance. The shape, dimensions, and material of the seismic isolation packing 120 can also be changed as desired, as long as it is configured to slide against the base 103 during an earthquake.

[0060] Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the above-described embodiments. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention. [Explanation of symbols]

[0061] 1 Building 2 Basics 3. Foundation 3a Seat hole 4 anchor bolts 5 through holes 6 nuts 7 Pillars 10 Wedge packing 11 Main body 12 1st slope 13 2nd slope part 14 Protrusion 20 Seismic isolation packing 21 Top side 22 Bottom side 23 Convex part 24 1st slope 25 Second slope 26 Position adjustment groove 27 Slope 30 washer 31 Insertion hole 32 Flat area 33 Protrusion 36 Nut 40 Shear reinforcement plate 41 Base side fixing part 42 Diagonal extension part 43 Foundation side contact part 44 holes 50 Diameter expansion drill 51 Through hole 60 Shear reinforcement bolt 61 Bolt fixing device 61a Main unit 61b Projection part 61c Flange 61d General section 61e Small diameter section 61f Convex part 101 Buildings 102 Basics 103 Foundation 104 Existing packing 105 anchor bolt 106 Through hole 107 Existing nut 108 pillars 109 Hold-down hardware 113 Pull-out 114 Existing packing 115 anchor bolt 116 through hole 117 Existing nut 118 Studs 120 Seismic isolation packing 121 Top surface 122 convex part 123 Flat plate part 124 Cylindrical part 125 Corner 141 holes 142 holes 161 Through hole 162 Through hole 171 Nut 171a Long nut part 171b Maruza 171c triangular ridge 172 Nut S1 Repair process for decayed areas, etc. S2 Nut removal process S3 Insertion clearance securing process S4 Seismic isolation clearance securing process S5 Seismic isolation packing insertion process S6 Seismic isolation packing position adjustment process S7 Wedge packing removal process S8 Nut installation process S9 Reinforcement plate installation process S101 Repair process for decayed areas S102 Nut removal process S103 Insertion clearance securing process S104 Seismic isolation clearance securing process S105 Seismic isolation packing insertion process S106 Seismic isolation packing position adjustment process S107 Complete removal of existing packing S108 Nut installation process

Claims

1. A concrete foundation; A wooden base and An anchor bolt extending upward from the foundation; a through hole formed in the base and through which the anchor bolt is inserted; A building renovation method for imparting a seismic isolation function to a building to be renovated, the building having a nut threadedly engaged with the anchor bolt, a nut removal step of removing the existing nut; an insertion clearance ensuring step of ensuring a predetermined insertion clearance between the foundation and the base; a seismic isolation clearance ensuring process of widening the through hole of the base to ensure a predetermined seismic isolation clearance between the inner circumferential surface of the through hole and the anchor bolt; a seismic isolation packing insertion process for inserting a seismic isolation packing configured to slide relative to the base during an earthquake between the foundation and the base with the insertion clearance secured; A seismic isolation renovation method using a seismic isolation packing under the foundation of a wooden building, which includes a nut installation process in which the existing nut or a newly installed nut is screwed onto the anchor bolt while the seismic isolation packing is inserted between the foundation and the base.

2. The building to be renovated has an existing packing between the foundation and the base, In the insertion clearance securing step, a part of the existing packing is removed, and a predetermined insertion clearance is secured by using the remaining existing packing. A seismic isolation renovation method using seismic isolation gaskets under the foundation of a wooden building as described in claim 1, which includes a complete existing gasket removal process of removing any remaining existing gaskets after the seismic isolation gasket insertion process.

3. In the insertion clearance securing step, a wedge packing having an insertion portion with a thickness corresponding to the insertion clearance is inserted between the foundation and the base, A seismic isolation renovation method using seismic isolation gaskets under the foundation in a wooden building as described in claim 1, which includes a wedge gasket removal process of removing the wedge gaskets from between the foundation and the base after the seismic isolation gasket insertion process.

4. A seismic isolation renovation method using seismic isolation gaskets under the foundation of a wooden building as described in claim 1, which includes a reinforcement installation process for installing shear reinforcement that restricts shear movement of the base relative to the foundation after the nut installation process.

5. The seismic isolation renovation method for a wooden building using seismic isolation gasket under the foundation as described in claim 4, wherein the shear reinforcement device is a shear reinforcement plate.

6. The seismic isolation renovation method for a wooden building using seismic isolation gaskets under the foundation as described in claim 4, wherein the shear reinforcement device is a shear reinforcement bolt.

7. The seismic isolation packing is formed in a flat plate shape and has a position adjustment groove into which a tool can be inserted when the packing is inserted into the foundation and the base, A seismic isolation renovation method using seismic isolation gaskets under the foundation of a wooden building as described in claim 1, which includes a seismic isolation gasket position adjustment process in which, after the seismic isolation gasket insertion process, a tool is inserted into the position adjustment groove to adjust the position of the seismic isolation gasket.

8. A seismic isolation renovation method using seismic isolation gaskets under the foundation for wooden buildings as described in claim 1, wherein in the nut installation process, a washer through which the anchor bolt is inserted is driven into the foundation to restrain the upper end side of the anchor bolt to the foundation side.

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