Seismic isolation structure

Abstract

To suppress water infiltration into a base isolation device and a base isolation layer in a flood disaster while reducing labor and cost of construction.SOLUTION: The seismic isolation structure 10 includes a lower structure 20 having a foundation structure 22 and a retaining wall 24 provided on an outer peripheral portion of the foundation structure 22, a plurality of seismic isolation devices 30 installed on the foundation structure 22, an upper structure 40 supported by the foundation structure 22 via the plurality of seismic isolation devices 30, a water reservoir 50 formed at least on the outer peripheral portion of the foundation structure 22, surrounding the plurality of seismic isolation devices 30 in a plan view, and storing water so that the plurality of seismic isolation devices 30 are not submerged, and a water cut-off hanging wall 60 extending from the upper structure 40 into the water reservoir 50 and surrounding the plurality of seismic isolation devices 30 in a plan view.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a seismic isolation structure. [Background technology]

[0002] A seismic isolation structure is known that includes multiple seismic isolation mechanisms installed between a foundation structure and a superstructure, and multiple lower and upper water-stopping walls that are installed around the multiple seismic isolation mechanisms and surround the seismic isolation mechanisms (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2022-150598 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology disclosed in Patent Document 1, a seismic isolation device (seismic isolation mechanism) is surrounded by a plurality of lower water cut-off walls and upper water cut-off walls, thereby preventing water from entering the seismic isolation device during flood damage.

[0005] However, with the technology disclosed in Patent Document 1, multiple lower water cutoff walls and upper water cutoff walls must be provided around multiple seismic isolation devices, which may require construction work and cost.

[0006] Taking the above facts into consideration, the present invention aims to prevent water from entering the seismic isolation device and, ultimately, the seismic isolation layer during flooding, while reducing the effort and cost of construction. [Means for solving the problem]

[0007] The seismic isolation structure described in claim 1 comprises a lower structure having a foundation structure and a retaining wall provided on the outer periphery of the foundation structure, a plurality of seismic isolation devices installed on the foundation structure, an upper structure supported on the foundation structure via the plurality of seismic isolation devices, a water storage section formed on at least the outer periphery of the foundation structure, surrounding the plurality of seismic isolation devices in a planar view, and storing water to prevent the plurality of seismic isolation devices from being flooded, and a water-stop hanging wall extending from the upper structure into the water storage section and surrounding the plurality of seismic isolation devices in a planar view.

[0008] According to the seismic isolation structure of claim 1, the substructure has a foundation structure and a retaining wall provided on the outer periphery of the foundation structure. A plurality of seismic isolation devices are installed on the foundation structure. The upper structure is supported on the foundation structure via these seismic isolation devices.

[0009] In addition, a water storage section is formed at least on the outer periphery of the foundation structure. The water storage section surrounds the plurality of seismic isolation devices in a plan view and stores water to prevent the plurality of seismic isolation devices from being flooded. Furthermore, the water cut-off hanging wall extends from the upper structure into the water storage section and surrounds the plurality of seismic isolation devices in a plan view.

[0010] As a result, when rainwater seeps into the outer periphery of the foundation structure from between the retaining wall and the superstructure during flooding such as heavy rain or a tsunami, the rainwater is stored in the water storage section, thereby preventing flooding of the multiple seismic isolation devices and, ultimately, the seismic isolation layer.

[0011] Furthermore, when the water level in the water storage section reaches the lower end of the water cut-off hanging wall, the water level closes the inner space of the water cut-off hanging wall, and the internal pressure of the inner space of the water cut-off hanging wall prevents water from entering the inner space.

[0012] Furthermore, as the water level in the water storage section rises outside the waterstop hanging wall, the internal pressure in the space inside the waterstop hanging wall increases. Therefore, even if the water level in the water storage section rises outside the waterstop hanging wall, the internal pressure in the space inside the waterstop hanging wall suppresses the rise in the water level in the water storage section inside the waterstop hanging wall. Therefore, flooding of multiple seismic isolation devices is suppressed.

[0013] Furthermore, the water-stop hanging wall surrounds the plurality of seismic isolation devices in plan view, which reduces the construction effort and cost compared to a case in which a plurality of water-stop hanging walls surround a plurality of seismic isolation devices in plan view.

[0014] In this way, the present invention can reduce the effort and cost of construction while suppressing water infiltration into the seismic isolation device and, ultimately, the seismic isolation layer during flooding.

[0015] Furthermore, when multiple water-stopping hanging walls surround multiple seismic isolation devices in a plan view, the multiple water-stopping hanging walls may obstruct the space within the seismic isolation layer.

[0016] In contrast, the water cutoff hanging wall of the present invention, as described above, surrounds a plurality of seismic isolation devices in a plan view, thereby enabling the space within the seismic isolation layer to be used more effectively.

[0017] The seismic isolation structure described in claim 2 is the seismic isolation structure described in claim 1, wherein the water-stopping hanging wall is capable of being moved between a retracted state in which it is retracted toward the upper structure and an expanded state in which it extends from the upper structure into the water storage section.

[0018] According to the seismic isolation structure of claim 2, the water cut-off hanging wall is shifted between a retracted state in which it is retracted to the upper structure side and an expanded state in which it extends from the upper structure into the water storage section.

[0019] As a result, in the event of a flood, the water-stopping hanging wall can be deployed to prevent water from entering multiple seismic isolation devices.

[0020] On the other hand, by keeping the water stop hanging walls in a retracted state during normal times other than when floods occur, the maintainability of multiple seismic isolation devices is improved. Furthermore, interference between the water stop hanging walls and the seismic isolation devices during an earthquake is suppressed.

[0021] A seismic isolated structure according to a third aspect of the present invention is the seismic isolated structure according to the first aspect, wherein the depth of the water storage section is greater on the retaining wall side than on the seismic isolation device side.

[0022] According to the seismic isolation structure of claim 3, the depth of the water storage section is deeper on the retaining wall side than on the seismic isolation device side. This makes it easier for rainwater to be stored on the retaining wall side of the water storage section even if it seeps forcefully into the outer periphery of the foundation structure from between the retaining wall and the superstructure during a flood. This further prevents multiple seismic isolation devices from being flooded.

[0023] The seismic isolation structure described in claim 4 is a seismic isolation structure described in any one of claims 1 to 3, wherein the water storage section is provided in the foundation structure and, in a plan view, is formed by a water-stopping waist wall that surrounds multiple seismic isolation devices, or a water-stopping step section that makes the installation surface of the seismic isolation devices higher than the upper surface of the foundation structure.

[0024] According to the seismic isolation structure of claim 4, the water storage section is formed by a water-stopping waist wall that is provided on the foundation structure and surrounds the plurality of seismic isolation devices in plan view. Alternatively, the water storage section is formed by a water-stopping step section that raises the installation surface of the seismic isolation devices higher than the upper surface of the foundation structure. This allows the water storage section to be formed with a simple configuration. [Effects of the Invention]

[0025] As described above, according to the present invention, it is possible to reduce the effort and cost of construction while suppressing flooding of the seismic isolation device and, in turn, the seismic isolation layer during flood damage. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 2 is a cross-sectional elevation view showing the seismic isolation structure according to the first embodiment. [Figure 2]FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. [Figure 3] FIG. 2 is a cross-sectional elevation view showing the water-stopping hanging wall shown in FIG. 1 in an expanded state. [Figure 4] 4 is a partially enlarged cross-sectional elevation view corresponding to FIG. 3, showing a state in which the water surface of the water stored in the water storage section has reached the lower end of the water cut-off hanging wall. FIG. [Figure 5] 4 is a partially enlarged cross-sectional elevation view corresponding to FIG. 3, showing a state in which the water level of the water stored in the water storage section has risen above the lower end of the water cut-off hanging wall. FIG. [Figure 6] FIG. 10 is a cross-sectional elevation view showing a seismic isolation structure according to a second embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6. [Figure 8] 7 is a cross-sectional elevation view corresponding to FIG. 6, showing a state in which the water surface of the water stored in the water storage section has reached the lower end of the water cut-off hanging wall. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0027] (First embodiment) First, the first embodiment will be described.

[0028] (Seismic isolation structure) 1 shows a base isolation structure 10 according to a first embodiment. The base isolation structure 10 is, as an example, a base isolation structure. The base isolation structure 10 includes a substructure 20, a plurality of seismic isolation devices 30, and an upper structure 40.

[0029] (substructure) The substructure 20 is formed in an underground space excavated from the ground G. The substructure 20 has a foundation structure 22 and a retaining wall 24. The foundation structure 22 is a pressure-resistant slab laid along the bottom of the excavation of the ground G. The foundation structure 22 is made of reinforced concrete, and has multiple slab reinforcements (not shown) buried inside. The retaining wall 24 is provided on the outer periphery of the foundation structure 22.

[0030] The retaining wall 24 functions as an earth retaining wall that divides the underground space. The retaining wall 24 is made of reinforced concrete and has multiple wall reinforcements (not shown) inside. The retaining wall 24 rises from the outer periphery of the foundation structure 22 and is formed in a frame shape (annular shape) that follows the outer periphery of the foundation structure 22, and in plan view surrounds the upper structure 40, which will be described later.

[0031] (Seismic isolation device) The plurality of seismic isolation devices 30 are, for example, laminated rubber bearings. The plurality of seismic isolation devices 30 are installed at intervals in two horizontal directions on the upper surface 22A of the foundation structure 22. The lower flange of each seismic isolation device 30 is fixed to the foundation structure 22 via a lower mounting member 32. In other words, the upper surface 32U of the lower mounting member 32 is used as the installation surface for the seismic isolation device 30.

[0032] On the other hand, the upper flange of each seismic isolation device 30 is fixed to the upper structure 40 (described later) via an upper mounting member 34. The lower mounting member 32 and the upper mounting member 34 are made of, for example, reinforced concrete.

[0033] The fixing structure of the seismic isolation device 30 to the foundation structure 22 and the upper structure 40 can be changed as appropriate. The lower mounting member 32 and the upper mounting member 34 can be provided as needed and can be omitted as appropriate. Furthermore, the seismic isolation device 30 is not limited to a laminated rubber bearing, and may be, for example, a sliding bearing or a rolling bearing.

[0034] (superstructure) The upper structure 40 is composed of, for example, multiple layers. This upper structure 40 is supported on the foundation structure 22 via multiple seismic isolation devices 30. In other words, multiple seismic isolation devices 30 are installed in the seismic isolation layer 12 formed between the upper structure 40 and the foundation structure 22. The seismic isolation layer 12 is disposed in the underground space formed by the substructure 20.

[0035] The upper structure 40 is supported by a plurality of seismic isolation devices 30 so as to be movable in two horizontal directions relative to the foundation structure 22. Therefore, a seismic isolation clearance C is formed between the upper structure 40 and the retaining wall 24.

[0036] The seismic isolation clearance C is formed around the entire outer periphery of the upper structure 40. This seismic isolation clearance C prevents the upper structure 40 from interfering with the retaining wall 24 when the upper structure 40 moves horizontally relative to the foundation structure 22 during an earthquake. In addition, the seismic isolation clearance C is covered by an expansion joint 42.

[0037] The expansion joint 42 is bridged between the upper structure 40 and the retaining wall 24 so as not to hinder the relative horizontal movement between the upper structure 40 and the retaining wall 24. As an example, the expansion joint 42 of this embodiment has one end fixed to the upper structure 40 and the other end slidably placed on the retaining wall 24.

[0038] The expansion joint 42 of this embodiment does not have a general function of preventing flooding in the event of flood damage caused by heavy rain, tsunami, etc. Furthermore, the expansion joint 42 may be provided as needed and may be omitted as appropriate.

[0039] (Flood control structure) Next, the water ingress prevention structure of the seismic isolation device 30 will be described.

[0040] The flood suppression structure has a water storage section 50 and a water-stopping hanging wall 60. The water storage section 50 is a water storage space that stores water that has flooded from the seismic isolation clearance C to the outer periphery of the foundation structure 22 so that the multiple seismic isolation devices 30 installed in the seismic isolation layer 12 do not become flooded during flood damage such as heavy rain or a tsunami.

[0041] The water storage section 50 is formed by a water-stopping waist wall 52 provided on the foundation structure 22. The water-stopping waist wall 52 is a water-stopping wall that blocks water flowing from the outer periphery of the foundation structure 22 toward the seismic isolation layer 12 during flood damage. This water-stopping waist wall 52 is made of, for example, reinforced concrete, and has multiple wall reinforcement bars and the like buried inside (not shown).

[0042] 2, the water-stopping waist wall 52 is erected from the foundation structure 22 and is formed in a frame shape (annular shape) in plan view so as to surround the multiple seismic isolation devices 30 installed in the seismic isolation layer 12. The water-stopping waist wall 52 is also positioned so as not to hinder the deformation (shear deformation) of the seismic isolation devices 30.

[0043] As shown in Figure 1, the water-stopping waist wall 52 is disposed on the outer periphery of the seismic isolation layer 12, i.e., below the outer periphery of the upper structure 40. The water-stopping waist wall 52 faces the retaining wall 24 all around. A water storage section 50 is formed between the water-stopping waist wall 52 and the retaining wall 24.

[0044] The depth of the water storage section 50 is deeper on the retaining wall 24 side than on the seismic isolation device 30 side (upper structure 40 side). Specifically, the upper surface 22A of the outer periphery of the foundation structure 22, which forms the bottom of the water storage section 50, is an inclined surface that slopes downward from the water-stopping waist wall 52 toward the retaining wall 24. This inclined surface makes the depth of the water storage section 50 deeper from the seismic isolation device 30 side toward the retaining wall 24 side. As a result, water is stored in the water storage section 50 from the retaining wall 24 side, as shown in FIG. 3 .

[0045] The depth of the water storage section 50 can be changed as appropriate. For example, the depth of the water storage section 50 may be constant, or the seismic isolation device 30 side (superstructure 40 side) may be deeper than the retaining wall 24 side.

[0046] (Water-stopping hanging wall) The water cut-off hanging wall 60 extends from the upper structure 40 into the water storage section 50 during flooding, and serves as a water cut-off wall that blocks water flowing from the outer periphery of the foundation structure 22 toward the seismic isolation layer 12, and also forms an air pocket within the seismic isolation layer 12, thereby preventing water from entering the seismic isolation device 30. The water cut-off hanging wall 60 is formed, for example, from a concrete plate or a steel plate.

[0047] The water blocking hanging walls 60 are arranged along each side surface 40S (outer peripheral surface) of the lower part of the upper structure 40. The water blocking hanging walls 60 are capable of transitioning between a retracted state in which they are retracted to the upper structure 40 side and an expanded state in which they extend from the upper structure 40 into the water storage section 50.

[0048] Specifically, the water stop hanging wall 60 is supported by a lifting mechanism (not shown) so as to be movable up and down along the side surface 40S of the upper structure 40. As shown in Fig. 1, this water stop hanging wall 60 is positioned so that, in the retracted state, its lower end does not protrude downward from the underside of the upper structure 40. When the water stop hanging wall 60 is moved downward by the lifting mechanism from this retracted state, the water stop hanging wall 60 transitions to the deployed state.

[0049] 3, in the deployed state, the lower end of the water-stopping hanging wall 60 is disposed within the water storage section 50. More specifically, the lower end surface 60L of the water-stopping hanging wall 60 is positioned below the upper end surface 52U of the water-stopping waist wall 52. In other words, the upper end surface 52U of the water-stopping waist wall 52 is positioned above the lower end surface 60L of the water-stopping hanging wall 60.

[0050] 2, in the deployed state, the plurality of seismic isolation devices 30 are surrounded in a plan view by the water stop hanging wall 60. As a result, as shown in Fig. 4, in the event of a flood, when water is stored in the water storage section 50 and the water surface W reaches the lower end of the water stop hanging wall 60, the water surface W closes the inner space R of the water stop hanging wall 60, forming an air pocket in the inner space R. The internal pressure in the inner space R of the water stop hanging wall 60 prevents the plurality of seismic isolation devices 30 from becoming flooded.

[0051] The height of the water-stopping waist wall 52 is set to a height that prevents the water stored in the water storage section 50 from overcoming the water-stopping waist wall 52 due to the internal pressure of the inner space R of the water-stopping hanging wall 60.

[0052] In addition, in order to form an air pocket in the inner space R of the water-stopping hanging wall 60, it is preferable to provide highly airtight doors or sashes at openings such as pedestrian access openings and ventilation openings that lead from the upper structure 40 to the inner space R (seismic isolation layer) of the water-stopping hanging wall 60.

[0053] Furthermore, in this embodiment, in the retracted state, the lower end of the water stop hanging wall 60 is positioned so as not to protrude downward from the underside of the upper structure 40. However, in the retracted state, it is sufficient that the water stop hanging wall 60 is positioned closer to the upper structure 40 than in the deployed state, and for example, the lower end of the water stop hanging wall 60 may protrude downward from the underside of the upper structure 40.

[0054] (action) Next, the operation of the first embodiment will be described.

[0055] As shown in Fig. 1, in a seismic isolation structure 10 according to this embodiment, a substructure 20 has a foundation structure 22 and a retaining wall 24 provided on the outer periphery of the foundation structure 22. A plurality of seismic isolation devices 30 are installed on the foundation structure 22. A superstructure 40 is supported on the foundation structure 22 via these seismic isolation devices 30. In other words, in this embodiment, a plurality of seismic isolation devices 30 are installed on a seismic isolation layer 12 formed between the foundation structure 22 and the superstructure 40.

[0056] Here, if the multiple seismic isolation devices 30 installed in the seismic isolation layer 12 are flooded during a flood such as heavy rain or a tsunami, there is a possibility that these seismic isolation devices 30 may deteriorate or be damaged. In addition, the seismic isolation layer 12 may be accompanied by a parking lot or a machine room, and if the seismic isolation layer 12 is flooded, it may become difficult to continue using the seismic isolation structure 10.

[0057] One possible solution to this problem is to provide multiple water-stopping waist walls and water-stopping hanging walls around each of the multiple seismic isolation devices 30. However, in this case, it is necessary to provide water-stopping waist walls and water-stopping hanging walls around each of the seismic isolation devices 30, which may require additional work and cost for construction. Furthermore, multiple water-stopping waist walls and water-stopping hanging walls may obstruct the space within the seismic isolation layer 12. In addition, the water-stopping waist walls and water-stopping hanging walls may make it difficult for workers to approach the seismic isolation devices 30, which may reduce the ease of maintenance of the seismic isolation devices 30.

[0058] In contrast to this, in this embodiment, a water storage section 50 is formed on the outer periphery of the foundation structure 22. The water storage section 50 surrounds the plurality of seismic isolation devices 30 in a plan view and stores water to prevent the plurality of seismic isolation devices 30 from being flooded.

[0059] 3, when rainwater or the like seeps into the outer periphery of the foundation structure 22 from between the retaining wall 24 and the upper structure 40 during flood damage such as heavy rain or a tsunami, the rainwater or the like is stored in the water storage section 50. Therefore, the multiple seismic isolation devices 30 are prevented from being flooded.

[0060] Furthermore, the depth of the water storage section 50 is deeper on the retaining wall 24 side than on the seismic isolation device 30 side. As a result, even if rainwater or the like forcefully seeps into the outer periphery of the foundation structure 22 from between the retaining wall 24 and the upper structure 40 during a flood, the rainwater or the like is more likely to be stored on the retaining wall 24 side of the water storage section 50. This further prevents multiple seismic isolation devices 30 from being flooded.

[0061] Furthermore, in the event of a flood, the water stop hanging walls 60 are shifted from a retracted state in which they are retracted toward the upper structure 40 to a deployed state in which they extend from the upper structure 40 into the water storage section 50. In the deployed state, as shown by the two-dot chain line in Figure 2, the multiple seismic isolation devices 30 are surrounded by the water stop hanging walls 60 in a plan view.

[0062] 3, in the deployed state, the lower end surface 60L of the water-stopping hanging wall 60 is located below the upper end surface 52U of the water-stopping waist wall 52. In this state, as shown in FIG. 4, when the water surface W in the water storage section 50 reaches the lower end of the water-stopping hanging wall 60, the water surface W closes the inner space R of the water-stopping hanging wall 60. As a result, the internal pressure of the inner space R of the water-stopping hanging wall 60 prevents water from entering the inner space R.

[0063] 5, as the water level W in the water storage section 50 rises outside the water stop hanging wall 60, the internal pressure in the inner space R of the water stop hanging wall 60 rises. Therefore, even if the water level W in the water storage section 50 rises outside the water stop hanging wall 60, the internal pressure in the inner space of the water stop hanging wall 60 suppresses the rise in the water level W in the water storage section 50 inside the water stop hanging wall. Therefore, flooding of the multiple seismic isolation devices 30 is suppressed.

[0064] Furthermore, in the deployed state, as described above, the water-stopping hanging wall 60 surrounds, in plan view, the plurality of seismic isolation devices 30. Similarly, the water-stopping waist wall 52 surrounds, in plan view, the plurality of seismic isolation devices 30. As a result, in this embodiment, the construction effort and cost are reduced compared to when the water-stopping waist wall 52 and the water-stopping hanging wall 60 each surround, in plan view, the plurality of seismic isolation devices 30.

[0065] In this way, in this embodiment, it is possible to reduce the construction effort and cost while suppressing flooding of the seismic isolation device 30 in the event of a flood.

[0066] Furthermore, when viewed in a plan view, if multiple water-stopping waist walls 52 and water-stopping hanging walls 60 surround multiple seismic isolation devices 30, the multiple water-stopping waist walls 52 and water-stopping hanging walls 60 may obstruct the space within the seismic isolation layer 12.

[0067] In contrast, as described above, the water-stopping waist wall 52 and the water-stopping hanging wall 60 of this embodiment surround the multiple seismic isolation devices 30 in a plan view. This allows the space inside the seismic isolation layer 12 to be used more effectively in this embodiment. Furthermore, in this embodiment, the inner space R of the water-stopping hanging wall 60 is wider, making it easier to ensure maintenance space for the multiple seismic isolation devices 30. Therefore, deterioration in the maintainability of the multiple seismic isolation devices 30 is suppressed.

[0068] In addition, by keeping the water stop hanging walls 60 in a retracted state during normal times other than when flooding occurs, the maintainability of the multiple seismic isolation devices 30 is improved. Furthermore, even if the seismic isolation devices 30 are activated during an earthquake and the upper structure 40 moves horizontally relative to the foundation structure 22, the retracted state prevents the water stop hanging walls 60 from interfering with the seismic isolation devices 30, etc.

[0069] Second Embodiment Next, a second embodiment will be described. In the second embodiment, the same components as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0070] (Flood control structure) 6 and 7 show a seismic isolation structure 10 according to a second embodiment. The water inundation suppression structure of this seismic isolation structure 10 has a water storage section 70 and a water cut-off hanging wall 60.

[0071] (Water storage section) 6, the water storage section 70 is formed by a plurality of lower mounting members 72 provided on the foundation structure 22. The lower mounting members 72 are an example of a water blocking step that makes the installation surface of the seismic isolation device 30 higher than the upper surface 22A (bottom surface of the water storage section 70) of the foundation structure 22. In other words, the upper surface 72U of the lower mounting members 72 is used as the installation surface of the seismic isolation device 30, and is located at a higher position than the upper surface 22A of the foundation structure 22.

[0072] As an example, the upper surface 72U of the lower mounting member 72 is higher than the upper surface 72U of the lower mounting member 72 of the first embodiment (see FIG. 1).

[0073] The water storage section 70 is formed around the lower mounting member 72 and on the outer periphery of the foundation structure 22 by using the aforementioned lower mounting member 72 to raise the installation surface of the seismic isolation device 30 higher than the upper surface 22A of the foundation structure 22.

[0074] (Water-stopping hanging wall) As in the first embodiment, the water stop hanging wall 60 is capable of transitioning between a retracted state and an expanded state. As shown in Fig. 8 , in the expanded state, the lower end of the water stop hanging wall 60 is disposed within the water storage section 70. More specifically, the lower end surface 60L of the water stop hanging wall 60 is positioned below the upper surface 72U of the lower mounting member 72 (the installation surface of the seismic isolation device 30). In other words, the upper surface 72U of the lower mounting member 72 (the installation surface of the seismic isolation device 30) is positioned above the lower end surface 60L of the water stop hanging wall 60.

[0075] 7, in the deployed state, the plurality of seismic isolation devices 30 and the lower mounting members 72 are surrounded by the water-stopping hanging wall 60 in a plan view. As a result, in the event of a flood, when water is stored in the water storage section 70 and the water surface W reaches the lower end of the water-stopping hanging wall 60, the water surface W closes the inner space R of the water-stopping hanging wall 60, forming an air pocket in the inner space R. The internal pressure in the inner space R of the water-stopping hanging wall 60 prevents the plurality of seismic isolation devices 30 from becoming flooded.

[0076] The height of the upper surface 72U of the lower mounting member 72 is set to a height that prevents the water stored in the water storage section 70 from climbing over the lower mounting member 72 due to the internal pressure of the inner space R of the water-stopping hanging wall 60.

[0077] (action) Next, the operation of the second embodiment will be described.

[0078] As shown in Figure 8, according to the seismic isolation structure 10 of this embodiment, in the event of a flood, the water-stopping hanging wall 60 is transitioned from a retracted state in which it is retracted toward the upper structure 40 to an expanded state in which it extends from the upper structure 40 into the water storage section 70.

[0079] In the unfolded state, as shown by the two-dot chain line in Fig. 7, the plurality of seismic isolation devices 30 and the lower mounting member 72 are surrounded by the water-stopping hanging wall 60 in a plan view. Also, in the unfolded state, as shown in Fig. 8, the lower end surface 60L of the water-stopping hanging wall 60 is positioned below the upper surface 72U of the lower mounting member 72.

[0080] In this state, when the water surface W of the water storage section 70 reaches the lower end of the water stop hanging wall 60, the water surface W closes the inner space R of the water stop hanging wall 60. As a result, the internal pressure of the inner space R of the water stop hanging wall 60 prevents water from entering the inner space R.

[0081] Furthermore, although not shown, as the water level W of the water storage section 70 rises outside the water stop hanging wall 60, the internal pressure of the inner space R of the water stop hanging wall 60 rises. Therefore, even if the water level W of the water storage section 70 rises outside the water stop hanging wall 60, the internal pressure of the inner space of the water stop hanging wall 60 suppresses the rise of the water level W of the water storage section 70 inside the water stop hanging wall. Therefore, flooding of the multiple seismic isolation devices 30 is suppressed.

[0082] 7, in the deployed state, the water stop hanging wall 60 surrounds, in plan view, the multiple seismic isolation devices 30. As a result, in this embodiment, the construction effort and cost are reduced compared to when the water stop hanging wall 60 surrounds each of the multiple seismic isolation devices 30 in plan view.

[0083] In this way, in this embodiment, it is possible to reduce the construction effort and cost while suppressing flooding of the seismic isolation device 30 in the event of a flood.

[0084] Furthermore, in this embodiment, the water reservoir 70 is formed not only around the outer periphery of the foundation structure 22 but also around the plurality of lower mounting members 72. In other words, the water reservoir 70 of this embodiment has a larger water storage capacity than the water reservoir 70 of the first embodiment. Therefore, flooding of the plurality of seismic isolation devices 30 is further suppressed.

[0085] In this embodiment, a water-stopping step is formed by the lower mounting member 72. However, the water-stopping step may be any step as long as the installation surface of the seismic isolation devices 30 is higher than the upper surface 22A of the foundation structure 22, and may be, for example, a rectangular step (step) that surrounds the multiple seismic isolation devices 30 in a plan view.

[0086] (Variation) Next, modifications of the first and second embodiments will be described. Note that, in the following, various modifications will be described using the first embodiment as an example.

[0087] In the first embodiment, the water storage section 50 is formed on the outer periphery of the foundation structure 22. However, the water storage section 50 may be formed on the outer periphery and the center of the foundation structure 22, like the water storage section 70 in the second embodiment. In other words, the water storage section can be formed at least on the outer periphery of the foundation structure 22.

[0088] Furthermore, in the first embodiment described above, the water blocking hanging wall 60 is disposed along the side surface 40S of the upper structure 40. However, the position of the water blocking hanging wall 60 can be changed as appropriate, and for example, the water blocking hanging wall 60 may be disposed further inward of the upper structure 40 than the side surface 40S of the upper structure 40.

[0089] In the first embodiment, the water blocking hanging wall 60 is movable between a retracted state and an expanded state. However, the water blocking hanging wall 60 may not be movable between the retracted state and the expanded state, and may be immovably provided at the expanded state position, for example.

[0090] In the first embodiment, the foundation structure 22 is a pressure-resistant plate. However, the foundation structure 22 is not limited to a pressure-resistant plate, and may be, for example, a mat slab or a basement slab.

[0091] Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment and various modified examples may be used in appropriate combination, and it goes without saying that the present invention can be implemented in various forms as long as it does not deviate from the gist of the present invention. [Explanation of symbols]

[0092] 10 Seismic isolation structures 12 Seismic isolation layer 20 Undercarriage 22 Basic structure 22A Top 24 Retaining Wall 30 Seismic isolation device 32U top 40 Superstructure 50 Water storage section 52 Water-stopping waist wall 60 Water-stopping hanging wall 70 Water storage section 72 Lower mounting member (waterstop step) 72U top surface (earthquake-resistant device installation surface)

Claims

1. a substructure having a foundation structure and a retaining wall provided on the outer periphery of the foundation structure; a plurality of seismic isolation devices installed on the foundation structure; an upper structure supported on the foundation structure via a plurality of the seismic isolation devices; a water storage portion formed at least on the outer periphery of the foundation structure, surrounding the plurality of seismic isolation devices in a plan view, and storing water to prevent the plurality of seismic isolation devices from being flooded; a water-stopping hanging wall extending from the upper structure into the water storage section and surrounding the plurality of seismic isolation devices in a plan view; A seismic isolation structure equipped with:

2. The water-stopping hanging wall is capable of transitioning between a retracted state in which it is retracted to the upper structure side and a deployed state in which it extends from the upper structure into the water storage section. The seismic isolation structure according to claim 1.

3. The depth of the water storage section is deeper on the retaining wall side than on the seismic isolation device side. The seismic isolation structure according to claim 1.

4. The water storage section is provided in the foundation structure and is formed by a water-stopping waist wall that surrounds the plurality of seismic isolation devices in a plan view, or a water-stopping step section that raises the installation surface of the seismic isolation devices higher than the upper surface of the foundation structure. A seismic isolation structure according to any one of claims 1 to 3.

Images