JP7836708B2 - Seismic isolation support member reinforcement structure - Google Patents

Description

This invention relates to a reinforcement structure for seismic isolation support members.

A seismic isolation retrofitting method is known in which existing columns are reinforced by wrapping them with steel plates, then partially removed, and seismic isolation devices are installed (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 9-100634

Incidentally, seismic isolation devices are fixed to concrete members, for example, by embedding studs provided on the flange portion into the outer circumference of concrete members such as footings.

However, if the distance from the stud to the outer surface of the concrete member (edge clearance) is short, there is a possibility that the outer surface of the concrete member may undergo cone-shaped fracture starting from the stud during an earthquake.

Considering the above facts, this invention aims to suppress cone-shaped fracture of the outer surface of concrete members during earthquakes.

The seismic isolation support member reinforcement structure according to the first embodiment comprises: a seismic isolation device; a concrete member disposed above or below the seismic isolation device; a joining member having an anchoring portion embedded in the outer periphery of the end of the concrete member and joining the flange portion of the seismic isolation device and the concrete member; and a steel frame surrounding the outer periphery of the end of the concrete member and restraining the end.

According to the seismic isolation support member reinforcement structure of the first embodiment , a concrete member is placed above or below the seismic isolation device. This concrete member and the flange portion of the seismic isolation device are joined by a connecting member. The connecting member has an anchoring portion embedded in the outer circumference of the end portion of the concrete member.

Here, the steel frame surrounds the outer surface of the end of the concrete member. By restraining the end of the concrete member with this steel frame, cone-shaped fracture of the outer surface of the concrete member's end, originating from the anchoring point of the joint, is suppressed during an earthquake.

The seismic isolation support member reinforcement structure according to the second embodiment is provided with a gap-filling material in the gap between the outer surface of the concrete member and the steel frame, in addition to the seismic isolation support member reinforcement structure according to the first embodiment.

According to the seismic isolation support member reinforcement structure of the second embodiment , by providing a gap between the outer surface at the end of the concrete member and the steel frame, construction errors of the concrete member and construction errors of the steel frame can be absorbed.

Furthermore, by providing gap-filling material in the gap between the outer surface of the concrete member's end and the steel frame, the end of the concrete member can be efficiently restrained by the steel frame.

Thus, this invention improves the constructability of steel frames while suppressing cone-shaped fracture of the outer surface of the end of concrete members during earthquakes, starting from the anchoring portion of the joint member.

The seismic isolation support member reinforcement structure according to the third embodiment is the seismic isolation support member reinforcement structure according to the second embodiment , wherein the gap-filling material is a filler material that is filled into the gap.

According to the seismic isolation support member reinforcement structure of the third embodiment , the gap between the outer surface at the end of the concrete member and the steel frame can be easily filled by filling the gap with a filler material. Therefore, the constructability of the steel frame is improved.

The seismic isolation support member reinforcement structure according to the fourth embodiment is an elastic body that is placed in the gap in a compressed state, in the seismic isolation support member reinforcement structure according to the second embodiment .

According to the seismic isolation support member reinforcement structure of the fourth embodiment , a compressed elastic body is placed in the gap between the outer surface of the end of the concrete member and the steel frame. This improves the efficiency of stress transmission between the end of the concrete member and the steel frame.

Therefore, during an earthquake, it is possible to further suppress cone-shaped fracture of the outer surface of the end of the concrete member, starting from the anchoring portion of the joint member.

As described above, the present invention makes it possible to suppress cone-shaped fracture of the outer surface of a concrete member during an earthquake.

This is a vertical cross-sectional view showing a seismic isolation device, an upper footing, and a lower footing to which the seismic isolation support member reinforcement structure according to the first embodiment is applied. This is a cross-sectional view taken along line 2-2 in Figure 1. This is a cross-sectional view taken along line 3-3 in Figure 2. This is a partially enlarged plan view of Figure 2, showing a corner of the steel frame. This is a cross-sectional view taken along line 5-5 in Figure 4. This is a partially enlarged plan view of Figure 2, showing the reinforcing ribs and studs. This is a cross-sectional view corresponding to Figure 2, showing the upper footing to which the seismic isolation support member reinforcement structure according to the second embodiment is applied. This is a cross-sectional view taken along line 8-8 in Figure 7.

(First Embodiment)
First, I will describe the first embodiment.

(Seismic isolation structure)
Figure 1 shows the seismic isolation layer of a seismic isolation structure 10 to which the seismic isolation support member reinforcement structure according to the first embodiment is applied. The seismic isolation layer of the seismic isolation structure 10 is provided with a seismic isolation device 20, an upper footing 40U, and a lower footing 40L. The upper footing 40U and the lower footing 40L are examples of concrete members.

(Upper footing)
The upper footing 40U is made of reinforced concrete and protrudes downward from the underside of a beam (not shown). The cross-sectional shape of the upper footing 40U is rectangular. The underside of this upper footing 40U rests on the upper surface of the upper flange portion 24 of the seismic isolation device 20, which will be described later.

(Lower footing)
The lower footing 40L is positioned below the upper footing 40U. This lower footing 40L is made of reinforced concrete and protrudes upward from the upper surface of a beam (not shown). The cross-sectional shape of the lower footing 40L is rectangular. The lower surface of the lower flange portion 26 of the seismic isolation device 20, which will be described later, rests on the upper surface of this lower footing 40L.

In this embodiment, the cross-sectional shape and size of the upper footing 40U and the upper flange portion 24 are the same; however, the cross-sectional shape and size of the upper footing 40U and the upper flange portion 24 may be different.

(Seismic isolation device)
The seismic isolation device 20 is positioned between the upper footing 40U and the lower footing 40L, and is joined to the upper footing 40U and the lower footing 40L, respectively. The seismic isolation device 20 is, for example, a laminated rubber bearing, and supports the upper footing 40U so that it can move horizontally relative to the lower footing 40L. The seismic isolation device 20 has a seismic isolation device body 22, an upper flange portion 24, and a lower flange portion 26.

The seismic isolation device body 22 is formed in a cylindrical shape. Furthermore, the seismic isolation device body 22 has multiple metal layers and rubber layers that are alternately stacked. An upper flange portion 24 is provided at the upper end of the seismic isolation device body 22. On the other hand, a lower flange portion 26 is provided at the lower end of the seismic isolation device body 22.

Furthermore, the seismic isolation device body 22 is not limited to a cylindrical shape; for example, it may be formed in a rectangular prism shape.

The upper flange portion 24 and the lower flange portion 26 are, for example, formed from a rectangular steel plate or the like in a plan view. Furthermore, the upper flange portion 24 and the lower flange portion 26 protrude outward from the seismic isolation device body 22.

Furthermore, the upper flange portion 24 and the lower flange portion 26 are not limited to a rectangular shape in plan view; for example, they may be formed in a circular shape. Also, the upper flange portion 24 and the lower flange portion 26 are examples of flange portions.

The upper flange portion 24 is joined to the upper footing 40U. Specifically, multiple studs (headed studs) 28 are provided on the upper surface of the upper flange portion 24. These multiple studs 28 protrude upward from the upper surface of the upper flange portion 24.

As shown in Figure 2, the multiple studs 28 are arranged at intervals along the circumference of a circle larger than the seismic isolation device body 22, centered on the central axis O of the seismic isolation device body 22, as indicated by the dashed line.

Furthermore, multiple studs 28 are embedded in the outer periphery of the lower end (end) of the upper footing 40U. These studs 28 connect the seismic isolation device 20 and the upper footing 40U in a way that allows for the transmission of shear force.

As shown in Figure 1, the lower flange portion 26 is joined to the lower footing 40L. Specifically, multiple studs 28 are provided on the lower surface of the lower flange portion 26. The arrangement of these studs 28 is the same as that of the studs 28 provided on the upper flange portion 24.

Multiple studs 28 protrude downward from the lower surface of the lower flange portion 26 and are embedded in the outer circumference of the upper end (end) of the lower footing 40L. These studs 28 connect the seismic isolation device 20 and the lower footing 40L in a manner that allows for the transmission of shear force.

The number and arrangement of the studs 28 can be changed as appropriate. Furthermore, the studs 28 are an example of a joining member. The entire stud 28 is embedded in the upper footing 40U or the lower footing 40L as an anchoring portion.

(Seismic isolation support member reinforcement structure)
Here, as shown in Figure 3, if the distance from the outer surface of the stud 28 to the side surface (outer surface) 40S of the upper footing 40U (hereinafter referred to as "edge clearance dimension R") is short, as shown by the dotted line, the side surface 40S of the upper footing 40U may undergo cone-shaped failure starting from the stud 28 during an earthquake.

As a countermeasure, in this embodiment, as shown in Figure 1, a seismic isolation support member reinforcement structure is applied to the lower end of the upper footing 40U where the studs 28 are embedded, and to the upper end of the lower footing 40L where the studs 28 are embedded.

The seismic isolation support member reinforcement structure applied to the upper footing 40U and the lower footing 40L is the same. Therefore, the seismic isolation support member reinforcement structure applied to the upper footing 40U will be described below, and the description of the seismic isolation support member reinforcement structure applied to the lower footing 40L will be omitted.

As shown in Figure 2, the seismic isolation support member reinforcement structure according to this embodiment includes a steel frame 50. The steel frame 50 is arranged around the lower end of the upper footing 40U. Furthermore, in plan view, the steel frame 50 has four steel members 52 joined together in a rectangular frame shape. Each steel member 52 is formed from an H-shaped steel and is arranged along each side surface 40S of the upper footing 40U.

As shown in Figure 3, each steel frame member 52 has an inner flange portion 54 and an outer flange portion 56 that face each other in the horizontal direction, and a web portion 58 that connects the inner flange portion 54 and the outer flange portion 56.

Furthermore, each steel frame member 52 is positioned with the thickness direction of the web portion 58 oriented vertically, and the surface of the inner flange portion 54 facing the upper footing 40U (hereinafter referred to as the "restraining surface 54S") facing the side surface 40S of the upper footing 40U. In other words, the steel frame member 52 is positioned with its strong axis direction facing the upper footing 40U.

As shown in Figures 4 and 5, the steel frame member 52 is supported by post-installed anchors 70 protruding from the side surface 40S of the upper footing 40U, with a gap between the restraining surface 54S of the inner flange portion 54 and the side surface 40S of the upper footing 40U. The post-installed anchors 70 are provided in pairs (two layers, upper and lower) on both sides of the width direction of the side surface 40S of the upper footing 40U.

Note that the post-installed anchor 70 is an example of a support member.

The upper and lower post-installed anchors 70 are inserted into through holes (not shown) formed in the inner flange portion 54 at the top and bottom of the web portion 58 of the steel frame member 52. The inner flange portion 54 is then fixed to the upper and lower post-installed anchors 70 by clamping it from both sides with a pair of nuts 72 attached to each post-installed anchor 70.

The number and arrangement of the post-installed anchors 70 can be changed as appropriate. Furthermore, the support members are not limited to post-installed anchors 70; for example, brackets fixed to the side surface 40S of the upper footing 40U may also be used.

As shown in Figure 4, at each corner of the steel frame 50, the web portions 58 at the ends of adjacent steel members 52 are joined together by bolts 60 and nuts (not shown), with the web portions 58 overlapping. Note that the inner flange portions 54 at the ends of adjacent steel members 52 are partially cut away to prevent interference.

A mortar-blocking member 62 is provided at the corner of the end of adjacent steel frame members 52. The mortar-blocking member 62 is formed from an L-shaped steel (angle). This mortar-blocking member 62 is positioned across the inner flange portions 54 of adjacent steel frame members 52, sealing the gaps between these inner flange portions 54.

As shown in Figure 3, a bottom formwork 64 is provided on the steel frame member 52. The bottom formwork 64 is formed from a plate material such as a steel plate. Furthermore, the bottom formwork 64 extends from one end to the other in the longitudinal direction (in the direction of the material axis) of the steel frame member 52 and is fixed to the lower end of the inner flange portion 54 of the steel frame member 52 by welding or other means.

The bottom formwork 64 extends from the lower end of the inner flange portion 54 toward the upper footing 40U, sealing the gap between the restraining surface 54S of the inner flange portion 54 and the side surface 40S of the upper footing 40U from below. The bottom formwork 64 may be attached to the steel frame member 52 in a factory or similar facility, or it may be attached to the steel frame member 52 on-site.

The gap between the restraining surface 54S of the inner flange portion 54 and the side surface 40S of the upper footing 40U is filled with a filler material 66 such as grout or mortar. Through this filler material 66, the restraining surface 54S of the inner flange portion 54 is in close contact with the side surface 40S of the upper footing 40U. Note that the filler material 66 is just one example of a gap-filling material.

The height H2 of the restraining surface 54S on the inner flange portion 54 of the steel frame member 52 is higher than the height H1 of the stud 28. The lower end 54S1 of this restraining surface 54S is located below the lower surface 40U1 (lower end of the side surface 40S) of the upper footing 40U, and the upper end 54S2 of the restraining surface 54S is positioned at approximately the same height as the tip 28T of the stud 28. As a result, on the side surface 40S of the upper footing 40U, the portion closer to the seismic isolation device 20 than the tip 28T of the stud 28 is restrained by the restraining surface 54S of the steel frame member 52.

As shown in Figure 2, the steel frame member 52 is provided with multiple reinforcing ribs 68. Each reinforcing rib 68 is provided in a rib-like manner on the upper and lower surfaces of the web portion 58. Furthermore, each reinforcing rib 68 is arranged along the opposing direction between the restraining surface 54S of the inner flange portion 54 (see Figure 3) and the side surface 40S of the upper footing 40U, connecting the inner flange portion 54 and the outer flange portion 56.

As shown in Figure 6, the reinforcing ribs 68 are positioned opposite the stud 28 where the edge clearance R is shortest. Specifically, in a plan view, they are positioned along the extension of a virtual line V that connects the center C of the stud 28 where the edge clearance R is shortest to the side surface 40S of the upper footing 40U with the shortest distance. These reinforcing ribs 68 support the inner flange portion 54 from the side opposite the upper footing 40U.

The number and arrangement of the reinforcing ribs 68 can be changed as appropriate. Furthermore, the reinforcing ribs 68 can be provided only as needed.

(effect)
Next, the operation of the first embodiment will be described.

As shown in Figure 1, according to the seismic isolation support member reinforcement structure of this embodiment, an upper footing 40U is positioned on top of the seismic isolation device 20. This upper footing 40U and the upper flange portion 24 of the seismic isolation device 20 are joined via a plurality of studs 28. The plurality of studs 28 are embedded in the outer circumference of the lower end of the upper footing 40U.

As described above using Figure 3, if the edge clearance R of the stud 28 is short, as shown by the dotted line, the side surface 40S at the lower end of the upper footing 40U may undergo cone-shaped failure starting from the stud 28 during an earthquake.

As a countermeasure, in this embodiment, as shown in Figure 2, a steel frame 50 is provided around the lower end of the upper footing 40U. The steel frame 50 surrounds the side surface (outer periphery) 40S at the lower end of the upper footing 40U. By restraining the side surface 40S at the lower end of the upper footing 40U with this steel frame 50, cone-shaped fracture of the side surface 40S at the lower end of the upper footing 40U, originating from the stud 28, is suppressed during an earthquake.

Furthermore, by surrounding the lower end side surface 40S of the upper footing 40U with the steel frame 50, for example, in Figure 2, the steel member 52 positioned to the left of the upper footing 40U can take a reaction force from the right side surface 40S of the upper footing 40U, thereby restraining the left side surface 40S of the upper footing 40U. Therefore, for example, the number of post-installed anchors 70 supporting the steel member 52 can be reduced.

As a result, drilling work on the side 40S of the existing upper footing 40U is reduced, improving constructability and suppressing damage to the internal reinforcement of the upper footing 40U. Furthermore, the need for prior inspection of the internal reinforcement of the upper footing 40U is reduced, further improving constructability.

Furthermore, as shown in Figure 3, the lower end 54S1 of the restraining surface 54S of the steel frame member 52 is located below the lower surface 40U1 of the upper footing 40U, and the upper end 54S2 of the restraining surface 54S is located at approximately the same height as the tip 28T of the stud 28. In other words, in this embodiment, on the side surface 40S of the upper footing 40U, the portion closer to the seismic isolation device 20 than the tip 28T of the stud 28 is restrained by the restraining surface 54S of the steel frame member 52.

This makes it possible to more reliably suppress cone-shaped fracture of the lower end side surface 40S of the upper footing 40U, starting from the stud 28, during an earthquake.

Furthermore, the steel members 52 constituting the steel frame 50 are positioned with their strong axis direction facing the upper footing 40U. This increases the restraining force on the side surface 40S of the upper footing 40U compared to when the steel members 52 are positioned with their weak axis direction facing the upper footing 40U.

Furthermore, as shown in Figure 6, the steel frame member 52 is provided with reinforcing ribs 68. The reinforcing ribs 68 are positioned opposite the stud 28 where the edge clearance R is shortest. By supporting the inner flange portion 54 with these reinforcing ribs 68, the restraining force on the side surface 40S of the upper footing 40U is further enhanced.

Therefore, during an earthquake, the cone-shaped fracture of the lower end surface 40S of the upper footing 40U, originating from the stud 28, is further suppressed.

Furthermore, by providing a gap between the restraining surface 54S of the inner flange portion 54 of the steel frame member 52 and the side surface 40S of the upper footing 40U, construction errors of the upper footing 40U and the steel frame 50 can be absorbed.

Furthermore, by filling the gap between the restraining surface 54S of the steel frame member 52 and the side surface 40S of the upper footing 40U with filler material 66, the restraining surface 54S of the steel frame member 52 is in close contact with the side surface 40S of the upper footing 40U via the filler material 66. This allows the restraining surface 54S of the steel frame member 52 to efficiently restrain the side surface 40S of the upper footing 40U. Additionally, since the filler material 66 can easily fill the gap between the restraining surface 54S of the steel frame member 52 and the side surface 40S of the upper footing 40U, workability is improved.

Furthermore, by constructing the steel frame 50 from multiple steel members 52 and assembling the steel frame 50 on-site, the transportability and lifting capabilities of the steel members 52 are improved.

Thus, in this embodiment, while improving the constructability of the steel frame 50, it is possible to suppress cone-shaped fracture of the lower end surface 40S of the upper footing 40U, starting from the anchoring portion of the stud 28, during an earthquake.

(Second Embodiment)
Next, a second embodiment will be described. In the second embodiment, components and the like that have the same configuration as in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

Figures 7 and 8 show the upper footing 40U to which the seismic isolation support member reinforcement structure according to the second embodiment is applied. As shown in Figure 7, the seismic isolation support member reinforcement structure according to this embodiment comprises a steel frame 80, a plurality of base members 100, and a plurality of elastic bodies 102X, 102Y.

(Steel frame)
The steel frame 80 is positioned around the lower end of the upper footing 40U. In plan view, the steel frame 80 has four steel members 82X, 82Y joined together in a rectangular frame shape. Each steel member 82X, 82Y is formed from an H-shaped steel and is positioned along each side 40S of the upper footing 40U.

Each steel member 82X and 82Y has an inner flange portion 84 and an outer flange portion 86 that face each other horizontally, and a web portion 88 connecting the inner flange portion 84 and the outer flange portion 86. Furthermore, each steel member 82X and 82Y is positioned so that its strong axis direction faces the side surface 40S of the upper footing 40U. Each steel member 82X and 82Y is appropriately reinforced by reinforcing ribs 90.

The pair of steel members 82X are positioned on both sides of the upper footing 40U in a predetermined direction (arrow X direction). On the other hand, the pair of steel members 82Y are positioned on both sides of the upper footing 40U in a direction intersecting the predetermined direction (arrow Y direction). Furthermore, the pair of steel members 82X are positioned between the ends of the pair of steel members 82Y.

The pair of steel members 82X and 82Y are positioned with a gap between the restraining surface 84S of their respective inner flange portions 84 and the side surface 40S of the upper footing 40U. A pair of base members 100 and multiple elastic bodies 102X and 102Y are positioned in each gap.

(Base component)
The pair of base members 100 are formed from steel plates or the like. Of the pair of base members 100, one base member 100 is positioned along the restraining surface 84S of the steel frame members 82X, 82Y, and the other base member 100 is positioned along the side surface 40S of the upper footing 40U. Multiple elastic bodies 102X, 102Y are positioned between this pair of base members 100.

Furthermore, the pair of base members 100 may be provided as needed and can be omitted as appropriate.

(Elastic body)
The multiple elastic bodies 102X and 102Y are, for example, disc springs. These elastic bodies 102X and 102Y are arranged so that their expansion and contraction directions are opposite to the side surface 40S of the upper footing 40U and the restraining surface 84S of the steel frame members 82X and 82Y. Note that the elastic bodies 102X and 102Y are examples of gap-filling material and spring members.

Multiple elastic bodies 102X are held in a compressed state between a pair of base members 100 by narrowing the distance between a pair of steel frame members 82X using multiple tension members 110. Similarly, multiple elastic bodies 102Y are held in a compressed state between a pair of base members 100 by narrowing the distance between a pair of steel frame members 82Y using multiple tension members 120.

Specifically, the multiple tension members 110 are formed from tension wires such as PC steel bars. Each tension member 110 is positioned to cross the end of the steel frame member 82X. One end of each tension member 110 is fixed to a bracket 112 provided at the end of the steel frame member 82X by a nut 114.

Furthermore, the other end of the tension member 110 is fixed to a bracket 112 provided on the steel frame member 82X by a nut 114. By tightening these nuts 114 onto the tension member 110 and narrowing the distance between the pair of steel frame members 82X, the multiple elastic bodies 102X and 102Y are held in a compressed state. Note that the tension members 110 are provided above and below the steel frame members 82X, respectively.

The multiple tension members 120 are formed from tension wires, such as PC steel bars. Each tension member 120 is arranged along the steel frame member 82Y, and both ends are fixed by nuts 124 to brackets 122 provided at the ends of a pair of opposing steel frame members 82Y. By tightening these nuts 124 onto the tension members 120 and narrowing the distance between the pair of steel frame members 82Y, the multiple elastic bodies 102Y are held in a compressed state.

The tension members 120 are positioned above and below the steel frame members 82X and 82Y, respectively. However, for example, the tension members 120 may be inserted into through holes formed in the inner flange portion 84 and outer flange portion 86 of the steel frame member 82Y, and through holes formed in each reinforcing rib 90 of the steel frame member 82X, and both ends of the tension members 120 may be fixed to the outer flange portion 86 of the steel frame member 82Y with nuts 124.

(effect)
Next, the operation of the second embodiment will be described.

As shown in Figure 7, in the seismic isolation support member reinforcement structure, multiple compressed elastic bodies 102X and 102Y are positioned in the gap between the side surface 40S of the lower end of the upper footing 40U and the restraining surface 84S of the steel members 82X and 82Y constituting the steel frame 80. This enhances the stress transmission efficiency between the side surface 40S of the lower end of the upper footing 40U and the restraining surface 84S of each steel member 82X and 82Y.

Furthermore, by placing the elastic bodies 102X and 102Y in the gap while compressed, prestress is applied to the lower end of the upper footing 40U. This makes it possible to more reliably suppress cone-shaped fracture of the side surface 40S of the lower end of the upper footing 40U, originating from the stud 28, during an earthquake.

Furthermore, in this embodiment, post-installed anchors and the like are not required, and there is no need to drill holes in the upper footing 40U. Therefore, damage to the internal reinforcement of the upper footing 40U is suppressed, and workability is improved.

Furthermore, in this embodiment, the elastic bodies 102X and 102Y are formed by disc springs. This allows for a larger elastic force to be obtained in a smaller installation space compared to, for example, the case where the elastic bodies are formed by coil springs. Therefore, the steel frame 80 can be miniaturized.

Note that the elastic material is not limited to disc springs; other spring components such as coil springs may also be used.

(Variant)
Next, modifications of the first and second embodiments described above will be explained. In the following, various modifications will be explained using the first embodiment as an example, but these modifications can also be appropriately applied to the second embodiment.

In the first embodiment described above, the height H2 of the restraining surface 54S of the steel frame member 52 is higher than the height H1 of the stud 28. However, the restraining surface 54S of the steel frame member 52 only needs to be able to restrain at least a portion of the side surface 40S of the upper footing 40U (lower end portion) where the stud 28 is embedded, as shown in the vertical cross-sectional view in Figure 3. Therefore, for example, the height H2 of the restraining surface 54S of the steel frame member 52 may be the same as the height H1 of the stud 28, or it may be lower than the height H1 of the stud 28.

Furthermore, during an earthquake, if the side surface 40S of the upper footing 40U undergoes cone-shaped fracture originating from the stud 28, stress tends to concentrate at the lower end of the side surface 40S. Therefore, it is preferable that the restraining surface 54S of the steel member 52 restrains at least the lower end of the side surface 40S of the upper footing 40U.

Furthermore, in the first embodiment described above, a filler material 66 is filled into the gap between the restraining surface 54S of the steel frame member 52 and the side surface 40S of the upper footing 40U. However, for example, the filler material 66 may be omitted, and the restraining surface 54S of the steel frame member 52 may be brought into contact with the side surface 40S of the upper footing 40U.

Furthermore, in the first embodiment described above, the steel frame member 52 is formed from H-shaped steel. However, the steel frame member is not limited to H-shaped steel; for example, it may be formed from I-shaped steel, C-shaped steel, L-shaped steel, or other structural steel, or it may be formed from steel pipe.

Furthermore, in the first embodiment described above, the joining member is a stud 28. However, the joining member is not limited to a stud 28. The joining member may, for example, consist of an embedded nut embedded in the lower end of the upper footing 40U and a bolt that penetrates the upper flange portion 24 of the seismic isolation device 20 and is tightened into the embedded nut. In this case, the embedded nut embedded in the lower end of the upper footing 40U serves as the anchoring portion of the joining member.

Furthermore, the connecting member may consist of an anchor member, one end of which is embedded in the end of the upper footing 40U, and a nut that secures the other end of the anchor member to the upper flange portion 24 of the seismic isolation device 20. In this case, the portion of the anchor member embedded in the lower end of the upper footing 40U becomes the anchoring portion.

Furthermore, in the first embodiment described above, the seismic isolation support member reinforcement structure is applied to both the upper footing 40U and the lower footing 40L. However, the seismic isolation support member reinforcement structure according to the first embodiment can be applied to at least one of the upper footing 40U and the lower footing 40L.

Furthermore, in the first embodiment described above, the concrete members are an upper footing 40U and a lower footing 40L. However, the concrete members are not limited to the upper footing 40U and the lower footing 40L; for example, in an intermediate seismic isolation structure, they may be concrete columns positioned above or below the seismic isolation device.

Furthermore, in the first embodiment described above, the seismic isolation device 20 is a laminated rubber bearing. However, the seismic isolation device is not limited to a laminated rubber bearing; for example, it may also be a sliding bearing or a rolling bearing.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment. Various modifications may be appropriately combined and used, and it goes without saying that the invention can be implemented in various forms without departing from the spirit of the invention.

20 Seismic isolation device 28 Stud (jointing member, anchoring part)
40U Upper footing (concrete member)
40L Lower footing (concrete member)
50 Steel frame 66 Filling material (gap filler)
80 Steel frame 102 Elastic material (gap filling material)
102X Elastic material (gap filler)
102Y Elastic material (gap filler)

Claims (5)

Seismic isolation device,
A concrete member positioned above or below the seismic isolation device,
A connecting member having an anchoring portion embedded in the outer circumference of the end of the concrete member, and joining the flange portion of the seismic isolation device and the concrete member,
A steel frame that surrounds the outer circumferential surface of the end of the concrete member without covering the surface on the seismic isolation device side at the end of the concrete member, and restrains the end of the concrete member,
A seismic isolation support member reinforcement structure equipped with this feature. The concrete member is provided with a gap-filling material that is placed in the gap between the outer surface of the concrete member and the steel frame.
The seismic isolation support member reinforcement structure according to claim 1. The gap-filling material is a filler material that is filled into the gap.
The seismic isolation support member reinforcement structure according to claim 2. The concrete member comprises a support member that protrudes from the outer circumferential surface of the end portion and supports the steel frame,
The seismic isolation support member reinforcement structure according to any one of claims 1 to 3. Seismic isolation device,
A concrete member positioned above or below the seismic isolation device,
A connecting member having an anchoring portion embedded in the outer circumference of the end of the concrete member, and joining the flange portion of the seismic isolation device and the concrete member,
A steel frame surrounds the outer circumferential surface of the end of the concrete member and restrains the end,
An elastic body is placed in a compressed state in the gap between the outer surface of the concrete member and the steel frame ,
A seismic isolation support member reinforcement structure equipped with this feature.