Damper mounting structure in seismic isolation device and seismic isolation device

Abstract

To prevent a damper or a damper fixing part from deteriorating at a relatively early stage, in the surrounding of a damper mounting structure part at which a portion of the damper made of nonferrous metal is inserted into an insertion hole of the damper fixing part.SOLUTION: A damper mounting structure 10 in a seismic isolation device 100 comprises: a damper 1 made of non-ferrous metal; and a damper fixing part 21 made of steel and having a damper insertion hole 211, with a portion of the damper 1 inserted into the damper insertion hole 211. A sacrificial anode material with a natural potential (VC) lower than a natural potential (VA) of the damper 1 and lower than a natural potential (VB) of the damper fixing part 21 is arranged between the damper 1 and the damper fixing part 21.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a damper mounting structure in a seismic isolation device, and to a seismic isolation device. More specifically, the present invention relates to a mounting structure for an elastic-plastic hysteretic damper that utilizes the plastic deformation of metal in a seismic isolation device, and to a seismic isolation device equipped with an elastic-plastic hysteretic damper that utilizes the plastic deformation of metal. [Background technology]

[0002] As an example of a seismic isolation device that is placed between the upper structure and lower structure of a building to absorb vibration energy from earthquakes, etc., a known seismic isolation device is an elastic-plastic type hysteretic system seismic isolation damper that utilizes the plastic deformation of metal and has a damper with a U-shaped curved portion having a pair of straight sections and a curved section connecting them as a vibration energy absorption section (see Patent Document 1).

[0003] Traditionally, the above-mentioned elastic-plastic hysteretic isolation dampers have been widely made of steel, but in recent years, dampers made of various non-ferrous metals, such as copper, aluminum, or alloys of these metals, have also been proposed (see paragraph

[0033] of Patent Document 1 and page 2 of Non-Patent Document 1, etc.).

[0004] Here, as an installation structure for mounting an elastic-plastic type hysteretic isolation damper to a building structure, an installation structure (see Figures 1 and 2) has been proposed in which the damper is fixed to the mounting base with the straight part of the damper inserted into the insertion hole of the damper fixing part of the block-shaped mounting base, which can be joined to the structure directly or via another substrate, etc.

[0005] However, in a seismic isolation device that uses a damper made of a non-ferrous metal, around the damper mounting structure where the straight part of the damper is inserted and fixed into the insertion hole of the damper fixing part as described above, there is a concern that deterioration of either the damper or the damper fixing part, which is the mounting part of the damper, will progress more quickly than with conventional steel dampers due to dissimilar metal contact corrosion in the damper mounting structure (when dissimilar metals with different natural potentials are in contact and in a corrosive environment where an electrolyte is present nearby, a corrosion current will flow due to the difference in natural potential between these dissimilar metals, and corrosion of the metal with the lower natural potential will be accelerated).

[0006] As a technical means for preventing galvanic corrosion, a pipe joint with an additional structural part for physically preventing contact between dissimilar metals with different natural potentials (see Patent Document 2) has been proposed. However, this is a means for preventing galvanic corrosion by maintaining a non-contact state, and maintaining a non-contact state in the damper fixing part that transmits the extremely large seismic force generated in a building by an earthquake is extremely difficult in relation to the strength required for that part, so the conversion of such a technology to other uses is not realistic.

[0007] Alternatively, as a general technical means for preventing metal corrosion, it is possible to apply an anticorrosive coating using epoxy resin or the like to parts at high risk of corrosion (see Patent Document 2). However, it is known that, in the case of bimetallic contact corrosion, the occurrence of minute defects (pinholes) in the coating causes a phenomenon in which corrosion is rapidly accelerated. Therefore, the above-mentioned anticorrosive coating is insufficient as a means for preventing corrosion in seismic isolation devices that require high reliability and long-term durability. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2022-107225 [Patent Document 2] JP 2012-077803 A [Patent Document 3] International Publication No. 2019 / 065939 [Non-patent literature]

[0009] [Non-Patent Document 1] Journal of Structural Engineering, Architectural Institute of Japan, Vol. 69B "Seismic isolation dampers using brass and the effects of damper shape and material properties on their deformation performance" (Daiki Nagai and 2 others) Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to suppress the phenomenon in which deterioration of either the damper or the damper fixing part progresses more quickly around a damper mounting structure in which a part of a damper made of a non-ferrous metal is inserted and fixed in an insertion hole of the damper fixing part than in a conventional steel damper. A ) and the natural potential (V B ) when comparing V A V than B If V is large, deterioration of the damper due to galvanic corrosion will be accelerated, and conversely, V A V than B If the value is small, deterioration of the mounting base will be accelerated. [Means for solving the problem]

[0011] The inventors have demonstrated that in a seismic isolation device using a damper made of a non-ferrous metal, the natural potential (V C The inventors have come to the conclusion that the above-mentioned problems can be solved by interposing a sacrificial anode material having a porosity of 100% or more between the two, and have thus completed the present invention. More specifically, the present invention provides the following.

[0012] (1) A damper mounting structure for a seismic isolation device, comprising a damper made of non-ferrous metal, and a damper fixing part made of steel, having a damper insertion hole, into which a part of the damper is inserted, and a natural potential (V A ) and the natural potential (V B ) lower than the natural potential (V C A damper mounting structure, in which a sacrificial anode material having a

[0013] According to the damper mounting structure of (1), it is possible to suppress the phenomenon in which deterioration of either the damper or the damper fixing part progresses more quickly around the damper mounting structure part in which a part of a damper made of a non-ferrous metal is inserted and fixed into the insertion hole of the damper fixing part than in the case of conventional steel dampers.

[0014] (2) A damper mounting structure as described in (1), in which a corrosion prevention film made of the sacrificial anode material is provided on the side of a part of the damper that is inserted into the damper insertion hole.

[0015] According to the damper mounting structure of (2), when a clearance exists between the inner surface of the damper insertion hole and the damper, the above-mentioned effects provided by the damper mounting structure described in (1) can be realized with high precision.

[0016] (3) A damper mounting structure as described in (1), in which a corrosion prevention film made of the sacrificial anode material is provided on the inner surface of the damper insertion hole.

[0017] According to the damper mounting structure of (3), when a clearance exists between the inner surface of the damper insertion hole and the damper, the above-mentioned effects provided by the damper mounting structure described in (1) can be realized with high precision.

[0018] (4) A damper mounting structure as described in (1), in which an end of the joint surface between the damper fixing portion and the damper at the opening of the damper insertion hole is covered with a corrosion-preventive block made of the sacrificial anode material.

[0019] According to the damper mounting structure of (4), when there is no clearance between the inner surface of the damper insertion hole and the damper, the above-mentioned effects provided by the damper mounting structure described in (1) can be realized with high precision.

[0020] (5) A damper mounting structure according to any one of (1) to (4), wherein the damper is made of copper, aluminum, or lead, or an alloy primarily composed of these non-ferrous metals, and the sacrificial anode material is made of zinc or an alloy primarily composed of zinc.

[0021] (5) The damper mounting structure makes it possible to suppress the phenomenon in which deterioration of either the damper or the damper fixing part around the damper mounting structure progresses more quickly than in conventional steel dampers in a seismic isolation device equipped with a damper made of non-ferrous metals, such as copper or aluminum, for which demand is expected to increase in the future.

[0022] (6) A seismic isolation device equipped with an elastic-plastic type hysteretic isolation damper that utilizes the plastic deformation of metal, the seismic isolation device comprising a structure in which the damper is fixed to the damper fixing portion by a damper mounting structure described in any one of (1) to (4).

[0023] According to the seismic isolation device of (6), by enjoying the above-mentioned effects of the damper mounting structure described in any one of (1) to (4), in a seismic isolation device equipped with a damper made of non-ferrous metal, the demand for which is expected to increase in the future, it is possible to suppress the phenomenon in which deterioration of either the damper or the damper fixing part around the damper mounting structure progresses more quickly than in conventional steel dampers. Effect of the Invention

[0024] According to the present invention, it is possible to suppress the phenomenon in which deterioration of either the damper or the damper fixing part progresses more quickly in the vicinity of the damper mounting structure in which a part of a damper made of a non-ferrous metal is inserted and fixed into the insertion hole of the damper fixing part than in the case of conventional steel dampers. [Brief description of the drawings]

[0025] [Figure 1] 1 is a perspective view showing an example of a seismic isolation device including a damper mounting structure in the seismic isolation device of the present invention. [Diagram 2] 2 is a perspective view of a damper mounting structure in the seismic isolation device of the present invention. FIG. [Diagram 3] 3 is a cross-sectional view showing in more detail the configuration of a joint portion between a damper and a damper fixing portion in the damper mounting structure of FIG. 2. [Figure 4] FIG. 4 is an exploded perspective view of the damper mounting structure of FIG. 3. [Diagram 5] A cross-sectional view showing the configuration of the joint portion between the damper and the damper fixing portion in another embodiment of the damper mounting structure in the seismic isolation device of the present invention. [Figure 6] 6 is a partial enlarged view showing in more detail the configuration of a joint portion between a damper and a damper fixing portion in the damper mounting structure of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The present invention is directed to a seismic isolation device having an elastic-plastic hysteretic seismic isolation damper that utilizes the plastic deformation of metal, and is particularly directed to a seismic isolation device in which the damper is made of a non-ferrous metal and the damper fixing portion, which is the mounting portion of the damper, is made of steel.

[0027] <Seismic isolation device> First, an example of an embodiment of the present invention will be described below with reference to the drawings regarding the overall configuration of a "seismic isolation device" that can be configured using the damper mounting structure of the present invention.

[0028] As shown in Fig. 1, a seismic isolation device 100 configured including the "damper mounting structure in a seismic isolation device" (hereinafter also simply referred to as "damper mounting structure") of the present invention has dampers 1 (1A-1D) made of elastic-plastic material joined via mounting base parts 2 (2A-2D) to an upper substrate 3 connected to the upper structure of a building and a lower substrate 4 connected to the lower structure. In this seismic isolation device 100, when an earthquake occurs, vibration energy is absorbed by the plastic deformation of these dampers 1 (1A-1D).

[0029] 1 and 2, the damper 1 (1A to 1D) is a U-shaped damper having a pair of parallel straight portions 12 (12A to 12D) and a curved portion 11 (11A to 11D) connecting one end of each of the straight portions 12 (12A to 12D). As described above, the metal material constituting the damper 1 (1A to 1D) having the above shape can be a non-ferrous metal, specifically, a non-ferrous metal such as copper, lead, or aluminum, or an alloy with these various metals.

[0030] As shown in Fig. 2, the mounting base 2 may be composed of a damper fixing portion 21 to which the damper 1 is directly attached and a joint plate portion 22 to which the upper substrate 3 and the lower substrate 4 are joined, or may be a block-shaped member in which the portions capable of performing each of these functions are integrally formed. Regardless of the structure, the damper 1 is fixed to the mounting base 2 (2A to 2D) with a part of the straight portion 12 near the end inserted into the damper insertion hole 211 of the damper fixing portion 21 (see Figs. 2 to 4). As the metal material constituting the damper fixing portion 21 having the above-mentioned shape, various steels mainly composed of iron can be used as described above.

[0031] <Damper mounting structure for seismic isolation device> The "damper mounting structure in a seismic isolation device" of the present invention is a partial structure of the seismic isolation device 100, and refers to a connecting structure (damper mounting structure 10) between the damper 1 made of non-ferrous metal and the damper fixing part 21 made of steel. However, the "damper mounting structure in a seismic isolation device (damper mounting structure 10)" of the present invention is a structure in which a specific natural potential V C The main feature that differs from the damper mounting structure in conventional seismic isolation devices is the arrangement of a sacrificial anode material 13 (13A, 13B) having the above structure.

[0032] The sacrificial anode material 13 (13A, 13B) in the present invention is a material that reduces the natural potential of the non-ferrous metal constituting the damper 1 to V A Similarly, the natural potential of the steel constituting the damper fixing part 21 is V B Then, V A >V C And V B >V C (V A >V C ∧V B >V C ) the natural potential V C In this way, the natural potential V C By disposing the sacrificial anode material 13 having the above structure between the damper 1 and the damper fixing part 21, it is possible to suppress the phenomenon in which the deterioration of the damper or the damper fixing part progresses earlier around the damper mounting structure in a seismic isolation device equipped with a non-ferrous metal damper than in a conventional steel damper. Note that the natural potential [V] in this specification is the value of the potential difference between each metal and the reference electrode measured in a state where no current or voltage is applied from the outside, and each natural potential [V A ], [V B ], [V CThe magnitude relationship between the values ​​is determined by comparing the measured values. The natural potential of each metal can be measured in accordance with the "Japan Society of Civil Engineers Standard: Method for Measuring Natural Potential in Concrete Structures (JSCE-E601-2000)."

[0033] Here, the arrangement of the sacrificial anode material 13 (13A, 13B) between the damper 1 and the damper fixing part 21 is such that the occurrence of bimetallic corrosion can be suppressed between the damper 1 made of a non-ferrous metal and the damper fixing part 21 made of steel, and a specific natural potential V C Any configuration may be used as long as the sacrificial anode material 13 (13A, 13B) having the above structure is arranged, and for example, the arrangements according to the first embodiment and the second embodiment described in detail below can be cited as specific examples of preferred arrangements of the sacrificial anode material 13 (13A, 13B). Furthermore, in a structural portion where the damper 1 and the damper fixing part 21, which have different natural potentials, are in direct contact with each other, and when there is a risk that an electrolyte may be present near the contact surface between the two metals, the sacrificial anode material 13 (13A, 13B) is arranged in such a manner that it contacts both the damper 1 and the damper fixing part 21, even if the arrangement is different from each embodiment (the first embodiment and the second embodiment) described in detail below, it is within the technical scope of the "damper mounting structure in a seismic isolation device" of the present invention.

[0034] Specific examples of preferred material combinations for the damper 1, the damper fixing portion 21, and the sacrificial anode material 13 (13A, 13B) in the damper mounting structure 10 (V A >V C ∧V B >V C Specific examples of combinations that satisfy ) include the combinations shown in Table 1 below.

[0035] [Table 1]

[0036] [First embodiment] As a first embodiment of the "damper mounting structure in a seismic isolation device" of the present invention, there can be mentioned a damper mounting structure 10A, which is an application example to a mounting structure (hereinafter also referred to as a "mechanical mounting structure") configured to mechanically fix the damper 1 by a fixing bolt 23 in a state in which a part of the straight portion 12 of the damper 1 near the end is inserted into the damper insertion hole 211 (see FIG. 4) of the damper fixing portion 21 as shown in FIG. 3. The fixing bolt 23 in the damper mounting structure 10A can be replaced by other fasteners (e.g., rivets or pins) that can fasten and fix the two together with the shaft-shaped portion passing through the damper 1.

[0037] In the above-mentioned "mechanical mounting structure", it is unavoidable to provide a certain clearance between the contact surfaces of the damper 1 and the damper fixing portion 21 in terms of design, and therefore it is difficult to completely prevent electrolyte such as condensation from entering this clearance. Since the above-mentioned bimetallic corrosion occurs in a structural portion where dissimilar metals with different natural potentials are in direct contact with each other and an electrolyte is present near the contact surface between the two metals, in the "mechanical mounting structure", bimetallic corrosion can occur over the entire insertion range of the damper 1 in the damper insertion hole 211 (the range of length l from the end of the damper 1 in FIG. 4).

[0038] In contrast, in the damper mounting structure 10A which is the first embodiment of the "damper mounting structure in a seismic isolation device" of the present invention, as shown in Figs. 3 and 4, a part of the damper 1 that is inserted into the damper insertion hole 211 of the damper fixing part 21 (within the range of length l from the end of the damper 1 in Fig. 4) is provided with a specific natural potential V C A corrosion prevention film 13A made of a sacrificial anode material having the above structure is provided.

[0039] 3 and 4, the combination of metals constituting the damper 1, the damper fixing portion 21, and the corrosion prevention film 13A may be any combination that satisfies the requirements for the natural potential described above, including the specific examples shown in Table 1 above. As an example, the damper mounting structure 10A may be an example in which the damper 1 is made of brass, the damper fixing portion 21 is made of carbon steel, zinc is selected as the sacrificial anode material, and the corrosion prevention film 13A made of zinc is provided on the side surface of the damper 1 within a length 1 from the end of the damper 1. The corrosion prevention film 13A may be provided by any of various known coating film forming means, such as spray coating, paste coating, wrapping with tape, plating, bushing, or sheet attachment.

[0040] In addition, the damper mounting structure 10A is configured such that, instead of forming the corrosion prevention film 13A around the damper 1 as described above, a specific natural potential V C Alternatively, the corrosion prevention film 13A made of a sacrificial anode material having the above structure can be provided on the inner surface of the damper insertion hole 211 by a coating film forming means such as hot dip galvanizing.

[0041] 3 and 4, the combination of metals constituting the damper 1, the damper fixing portion 21, and the corrosion prevention film 13A may be any combination that satisfies the requirements for the natural potential described above, including the specific examples shown in Table 1 above. As an example, the damper mounting structure 10A may be an example in which the damper 1 is made of brass, the damper fixing portion 21 is made of carbon steel, zinc is selected as the sacrificial anode material, and the corrosion prevention film 13A made of zinc is provided on the side surface of the damper 1 within a length 1 from the end of the damper 1. The corrosion prevention film 13A may be provided by any of various known coating film forming means, such as spray coating, paste coating, wrapping with tape, plating, bushing, or sheet attachment.

[0042] According to the damper mounting structure 10A, which is the first embodiment of the "damper mounting structure in a seismic isolation device" described above, when a clearance exists between the inner surface of the damper insertion hole 211 and the damper 1, for example when the damper is mounted by a "mechanical mounting structure", it is possible to suppress the phenomenon in which deterioration of the damper 1 or the damper fixing portion 21 made of a non-ferrous metal progresses more quickly than in conventional dampers made of steel.

[0043] [Second embodiment] As a second embodiment of the "damper mounting structure in a seismic isolation device" of the present invention, there can be mentioned a damper mounting structure 10B, which is an application example to a mounting structure (hereinafter also referred to as a "material mounting structure") configured in such a manner that, when a portion of the straight portion 12 of the damper 1 near the end is inserted into the damper insertion hole 211 (see FIG. 4) of the damper fixing portion 21 as shown in FIG. 5, the damper 1 is fixed to the inner surface of the damper insertion hole 211 by brazing material 24.

[0044] In the above-mentioned "material mounting structure," the damper 1 and the damper fixing part 21 are in close contact (or integrated) by design. Therefore, it is safe to assume that electrolyte such as condensation will not penetrate into the joint surface itself. However, in the area where the damper 1 and the damper fixing part 21 are close to each other (for example, the area around e in FIG. 6), a corrosion cell circuit may be formed due to the adhesion of electrolyte such as condensation, resulting in bimetallic corrosion.

[0045] In contrast, in the damper mounting structure 10B, which is the second embodiment of the "damper mounting structure in a seismic isolation device" of the present invention, as shown in Figure 6, at the opening of the damper insertion hole 211, the end e of the joint surface between the damper fixing portion 21 and the damper 1 is covered with a corrosion-prevention block 13B made of a sacrificial anode material.

[0046] 6, the combination of the metals constituting the damper 1, the damper fixing portion 21, and the corrosion prevention mass 13B can be various combinations that satisfy the requirements related to the natural potential, as in the first embodiment. The corrosion prevention mass 13B can be provided by various known application methods, such as spray application, paste application, plating, etc.

[0047] According to the damper mounting structure 10B, which is the second embodiment of the "damper mounting structure in a seismic isolation device" described above, when there is no clearance between the inner surface of the damper insertion hole 211 and the damper 1, such as when the damper is mounted by a "material mounting structure," it is possible to suppress the phenomenon in which deterioration of the damper 1 or the damper fixing portion 21 made of a non-ferrous metal progresses more quickly than in conventional dampers made of steel. [Explanation of symbols]

[0048] 1(1A~1D) Damper 10 (10A, 10B) Damper mounting structure 11 (11A~11D) Curved section 12(12A~12D) Straight section 13A Sacrificial anode material (corrosion prevention film) 13B Sacrificial anode material (corrosion prevention block) 2(2A~2D) Mounting base 21, 21A Damper fixing part 211 Damper insertion hole 22 Joint plate part 23(23a, 23b, 23c) Fixing bolt 24 Brazing material 3 Top Board 4 Bottom Board 100 Seismic isolation device

Claims

1. A damper mounting structure in a seismic isolation device, A damper made of a non-ferrous metal; a damper fixing part made of steel, having a damper insertion hole, and a part of the damper being inserted into the damper insertion hole; Between the damper and the damper fixing portion, a natural potential (V Ａ ) and the natural potential (V Ｂ ) lower than the natural potential (V Ｃ ) is disposed on a sacrificial anode material having a Damper mounting structure.

2. a corrosion prevention film made of the sacrificial anode material is provided on a side surface of a part of the damper that is inserted into the damper insertion hole; The damper mounting structure according to claim 1.

3. A corrosion prevention film made of the sacrificial anode material is provided on the inner surface of the damper insertion hole. The damper mounting structure according to claim 1.

4. At the opening of the damper insertion hole, an end of a joint surface between the damper fixing portion and the damper is covered with a corrosion prevention block made of the sacrificial anode material. The damper mounting structure according to claim 1.

5. The damper is made of copper, aluminum, or lead, or an alloy containing these non-ferrous metals as a main component, The sacrificial anode material is made of zinc or an alloy mainly composed of zinc.

5. The damper mounting structure according to claim 1.

6. A seismic isolation device equipped with an elastic-plastic hysteretic seismic isolation damper that utilizes the plastic deformation of metal, The damper mounting structure according to any one of claims 1 to 4 includes a structure in which the damper is fixed to the damper fixing portion. Earthquake isolation device.

Images