JP7706907B2 - Earthquake-proof building - Google Patents

Description

The present invention relates to a seismically isolated building equipped with a seismic isolation mechanism between the foundation structure and the superstructure.

A seismically isolated building includes a foundation structure, a seismic isolation mechanism placed on the foundation structure, and a superstructure supported by the seismic isolation mechanism, and the seismic isolation mechanism prevents horizontal shaking caused by earthquakes, etc. from being transmitted to the superstructure.

In general, seismically isolated buildings have clearance between the sides of the superstructure and the retaining wall to allow horizontal movement of the superstructure. Furthermore, the seismic isolation pit, where laminated rubber is installed as a seismic isolation device, is equipped with a drainage system, and is designed to prevent water from entering or accumulating.

However, in recent years, there has been a continuous stream of flooding and landslides caused by abnormal weather, and even if a seismic isolation pit is equipped with drainage facilities, there is a risk that water or soil may seep in due to submersion caused by heavy rain or river flooding during construction or after the pit begins operation, or due to burial of soil caused by landslides.

As a waterproof structure for the seismic isolation mechanism, a waterproof covering part consisting of a waterproof sheet that is detachably attached so as to cover the outer periphery of the laminated rubber body has been proposed (Patent Document 1).

JP 2018-71705 A

However, the invention in Patent Document 1 requires that the waterproof covering part made of a specially shaped waterproof sheet and the foamed plastic cushioning material be manufactured to match the shape of the seismic isolation mechanism, and has not yet been put to practical use.

Therefore, the present invention aims to provide a seismically isolated building that can prevent water from entering the seismic isolation mechanism even if the water depth exceeds the height of the seismic isolation mechanism, and that has a simple structure and is easy to construct.

The present invention has been made to solve at least some of the problems described above, and can be realized in the following aspects or application examples.

[1] One aspect of the seismic isolation building according to the present invention is as follows:
A seismic isolation building having a plurality of seismic isolation mechanisms in a seismic isolation pit between a foundation structure and a superstructure,
A plurality of lower water blocking walls extending upward from the foundation structure;
A plurality of upper water blocking walls extending downward from the upper structure;
Equipped with
each of the lower water blocking walls surrounds one of the seismic isolation mechanisms in a plan view and has an upper edge at a position spaced apart from the upper structure;
Each of the upper water blocking walls surrounds an outer side of one of the lower water blocking walls at a predetermined interval in a plan view and has a lower end edge at a position lower than the upper end edge,
The upper structure is configured to keep an area inside the upper water blocking wall and higher than the upper edge airtight,
The lower edge is set at a height such that when the seismic isolation pit is flooded to a height exceeding the height of the upper edge, the water will not exceed the upper edge due to the pressure of the air contained inside the upper water cutoff wall;
The lower water cutoff wall is made of reinforced concrete and is integral with the foundation structure.
The upper water cut-off wall is characterized in that it is made of reinforced concrete and formed integrally with the superstructure.

[ 2 ] In one aspect of the seismic isolation building,
The seismic isolation mechanism may include at least one of a laminated rubber, a sliding bearing, and a rolling bearing.

According to one aspect of the seismic isolation building of the present invention, even if water infiltrates between the foundation structure and the superstructure, it is possible to prevent water from infiltrating into the seismic isolation mechanism. In addition, according to one aspect of the seismic isolation building of the present invention, construction is easy due to the simple configuration installed around the seismic isolation mechanism.

FIG. 2 is a front view of the seismic isolation building according to the present embodiment. FIG. 2 is a partially enlarged cross-sectional view of the seismic isolation building according to the present embodiment. This is a cross-sectional view taken along line AA in FIG. This is an enlarged view of a portion of a seismically isolated building during an earthquake. This is an enlarged partial cross-sectional view of a seismically isolated building showing the seismic isolation pit flooded with water. FIG. 4 is a partially enlarged view of a seismically isolated building according to the first modified example. FIG. 11 is a partially enlarged view of a seismically isolated building according to the second modification.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are necessarily essential components of the present invention.

One aspect of the seismic isolation building according to this embodiment is a seismic isolation building with multiple seismic isolation mechanisms between a foundation structure and a superstructure, and includes multiple lower waterstop walls extending upward from the foundation structure and multiple upper waterstop walls extending downward from the superstructure, each of the lower waterstop walls surrounding one of the seismic isolation mechanisms in a plan view and having an upper edge spaced apart from the superstructure, each of the upper waterstop walls surrounding one of the lower waterstop walls in a plan view and having a lower edge lower than the upper edge, and the superstructure is configured to keep the area inside the upper waterstop walls and higher than the upper edge airtight.

1. Overview of a seismically isolated building A seismically isolated building 1 according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a front view of the seismically isolated building 1 according to this embodiment. Fig. 1 also shows a cross section of a foundation structure 20.

As shown in FIG. 1, the seismically isolated building 1 comprises a foundation structure 20, a superstructure 10 above the foundation structure 20, and a number of seismic isolation mechanisms 22 between the foundation structure 20 and the superstructure 10. The space between the foundation structure 20 and the superstructure 10 in the seismically isolated building 1 is a seismic isolation pit 30.

The superstructure 10 has a steel frame structural body, for example six stories above ground, whose lower end is supported by the seismic isolation mechanism 22. The superstructure 10 may be made of reinforced concrete, steel-reinforced concrete, or the like. The superstructure 10 may be two or more stories high, and is particularly applicable to high-rise buildings. The outer peripheral surface of the superstructure 10 is the side surface 12. The underside 14 of the first floor of the superstructure 10, which is the layer directly above the seismic isolation layer, is supported by the seismic isolation mechanism 22 via a footing.

The foundation structure 20 is a structure that is located below the superstructure 10 and constructed on the ground. The foundation structure 20 transmits the load of the superstructure 10 to the ground via the seismic isolation mechanism 22. For example, multiple piles (not shown) may be provided below the foundation structure 20, or the foundation structure 20 may be constructed directly on the ground if the ground is stable. The beams and slabs that make up the foundation structure 20 are made of reinforced concrete. The seismic isolation mechanism 22 is fixed onto the slab of the foundation structure 20 via a footing made of reinforced concrete. A retaining wall 23 rises upward on the outer periphery of the foundation structure 20, and the retaining wall 23 prevents soil and sand outside the retaining wall 23 from flowing into the seismic isolation pit 30.

The retaining wall 23 is part of the foundation structure 20 and is formed integrally with the slab of the foundation structure 20. The retaining wall 23 is made of reinforced concrete. The retaining wall 23 is formed at least a predetermined distance away from the side surface 12 of the superstructure 10. The second distance L2 between the retaining wall 23 and the side surface 12 is the distance at which the superstructure 10 is allowed to move in the horizontal direction X relative to the foundation structure 20, and is set according to earthquakes anticipated in the seismically isolated building 1.

A plurality of seismic isolation mechanisms 22 are provided for the seismic isolation building 1. The plurality of seismic isolation mechanisms 22 are installed at intervals at a plurality of locations in the seismic isolation pit 30. The seismic isolation mechanisms 22 are fixed on the foundation structure 20 via a lower footing. The seismic isolation mechanism 22 is a mechanism that supports the upper structure 10, reduces shaking in the horizontal direction X caused by an earthquake or the like transmitted to the upper structure 10, and provides a force that restores the change in the relative position of the upper structure 10, and is a so-called isolator. The seismic isolation mechanism 22 includes at least one of laminated rubber, sliding bearings, and rolling bearings. In this embodiment, an example in which the seismic isolation mechanism 22 uses laminated rubber whose upper and lower ends are fixed to the upper structure 10 and the foundation structure 20, respectively, is described. In particular, the seismic isolation mechanism 22 can be a sliding bearing that is considered to be greatly affected by water. The seismic isolation mechanism 22 may further include a damper that provides damping.

The seismic isolation pit 30 is a space surrounded by the superstructure 10, foundation structure 20, and retaining wall 23. In this embodiment, the seismic isolation pit 30 is described as being underground, but the seismic isolation pit 30 may be located above ground. If the seismic isolation building 1 is, for example, a warehouse, the height of the truck berth is the floor slab of the first floor, so the seismic isolation pit 30 is provided at approximately the same height as the ground surface. In that case, a protective wall can be provided to protect the inside of the seismic isolation pit 30 instead of the retaining wall 23.

The seismic isolation pit 30 is connected to the outside through the gap between the retaining wall 23 and the side surface 12. Therefore, in the event of flooding caused by river overflow due to heavy rain, which has become more frequent in recent years, this gap allows water to enter the seismic isolation pit 30. If the seismic isolation pit 30 is located near the ground surface, water intrusion may be prevented by providing a low wall around the seismic isolation pit 30, but if the flood exceeds this low wall, water will infiltrate into the seismic isolation pit 30. Water intrusion into the seismic isolation pit 30 may affect the function of the seismic isolation mechanism 22. For example, sliding bearings may not be able to perform their functions when flooded. There is also a possibility that the seismic isolation mechanism 22 may deteriorate or change in quality due to water. Considering the adverse effects on the seismic isolation mechanism 22, it is desirable to prevent water from entering the seismic isolation pit 30, but it is also desirable to at least prevent water from accessing the seismic isolation mechanism 22.

Therefore, the present invention prevents water from entering the seismic isolation mechanisms 22 by providing a water blocking wall for each seismic isolation mechanism 22. The water blocking walls are described in detail below.

2. Water Cutoff Wall The water cutoff wall will be described with reference to Figures 1 to 5. Figure 2 is a partially enlarged cross-sectional view of the seismic isolated building 1 according to this embodiment, Figure 3 is a cross-sectional view taken along line A-A in Figure 2, Figure 4 is a partially enlarged view of the seismic isolated building 1 during an earthquake, and Figure 5 is a partially enlarged cross-sectional view of the seismic isolated building 1 showing the state in which the seismic isolation pit 30 is flooded. In Figure 5, water 32 is indicated by shading.

As shown in FIG. 1, the seismically isolated building 1 is provided with a number of lower water stop walls 24 extending upward from the foundation structure 20 in the seismic isolation pit 30 in accordance with the number of seismic isolation mechanisms 22, and a number of upper water stop walls 16 extending downward from the superstructure 10. It is not necessary to provide lower water stop walls 24 and upper water stop walls 16 for all of the seismic isolation mechanisms 22 installed in the seismically isolated building 1. For example, it is not necessary to provide lower water stop walls 24 and upper water stop walls 16 around a type of seismic isolation mechanism whose function is not likely to be impaired by flooding.

2 and 3, each of the lower water stop walls 24 surrounds one seismic isolation mechanism 22 in a plan view (FIG. 3), and has an upper edge 240 at a position spaced apart from the upper structure 10. In this embodiment, the lower water stop wall 24 is rectangular in plan view, but is not limited thereto, and may be, for example, circular depending on the shape of the seismic isolation pit 30. The lower end of the lower water stop wall 24 is connected to the upper surface of the foundation structure 20. The lower water stop wall 24 is formed integrally with the foundation structure 20, and prevents water from seeping in from the outside to the inside of the lower water stop wall 24 at least until the water level exceeds the height of the lower water stop wall 24. In addition, since the upper edge 240 has a space from the upper structure 10, the function of the seismic isolation mechanism 22, i.e., the horizontal movement of the upper structure 10 relative to the foundation structure 20, is not hindered.

The lower water stop wall 24 has a constant first height H1 from the top surface of the foundation structure 20, and the upper edge 240 exists along the first height H1. The upper edge 240 does not have to be a constant height as long as it has a predetermined first height H1 in relation to the upper water stop wall 16 described below.

The lower water stop wall 24 has approximately the same thickness throughout. The material and thickness of the lower water stop wall 24 are set based on the waterproofing and the strength required to withstand the water pressure when the seismic isolation pit 30 is flooded. The lower water stop wall 24 may have an opening and a waterproof door to allow workers to access the inside of the lower water stop wall 24.

The lower water cutoff wall 24 is, for example, made of reinforced concrete and formed integrally with the foundation structure 20. The lower water cutoff wall 24 made of reinforced concrete can be constructed simultaneously with the slab of the foundation structure 20, making construction easy. Furthermore, the lower water cutoff wall 24 made of reinforced concrete can be constructed on-site without relying on special products as in the past, realizing low cost. The lower water cutoff wall 24 may also be formed, for example, from steel plates fixed to the foundation structure 20. In that case, it can be realized by welding the ends of four steel plates together and assembling them into a square frame as shown in Figure 3, and if the lower water cutoff wall 24 is annular, steel pipes may be used.

Each of the upper waterstop walls 16 surrounds one of the lower waterstop walls 24 in plan view (FIG. 3), and has a lower edge 160 at a position lower than the upper edge 240 of the lower waterstop wall 24. The outer shape of the upper waterstop wall 16 in plan view is preferably constructed to match the outer shape of the lower waterstop wall 24. In this embodiment, the upper waterstop wall 16 is rectangular in plan view, but may be circular, for example. The upper end of the upper waterstop wall 16 connects to the underside 14 of the superstructure 10. The upper waterstop wall 16 is formed integrally with the floor slab 140 at the lower end of the superstructure 10.

The upper structure 10 is configured to keep the area inside the upper water stop wall 16 and higher than the upper edge 240 (first height H1) airtight. The area kept airtight by the upper structure 10 is inside the upper water stop wall 16 and is at least higher than the upper edge 240, and considering volume changes due to air compression and waves on the water surface, it is preferable that the area is higher than the lower edge 160 (second height H2). By keeping this area airtight by the upper structure 10, even if the seismic isolation pit 30 is flooded, the pressure of the air contained inside the upper water stop wall 16 can prevent water from exceeding at least the upper edge 240. As a specific configuration, the upper water stop wall 16 prevents the movement of air from the inside to the outside of the upper water stop wall 16, except for ventilation below its lower edge 160, and also prevents water from entering from the outside to the inside. The floor slab 140 prevents air from moving from the inside of the upper water stop wall 16 to above the floor slab 140. The connection between the upper water stop wall 16 and the floor slab 140 also prevents air from moving from the inside to the outside of the upper water stop wall 16. The airtightness of this area may be such that the air pressure inside the upper water stop wall 16 can be maintained to such an extent that the water does not exceed the upper edge 240 when the water level rises to the lower edge 160. Note that, for example, an opening that is ventilated under normal conditions may be present inside the upper water stop wall 16 as long as it can be sealed when flooded. Since the lower edge 160 is located lower than the upper edge 240, the water does not exceed the upper edge 240 even if the seismic isolation pit 30 is flooded to a height exceeding the upper edge 240. The height relationship between the lower edge 160 and the upper edge 240 can be determined by the air pressure contained in the upper water stop wall 16, and the height of the lower edge 160 is set lower than the upper edge 240 so that the water does not exceed the upper edge 240 even if the seismic isolation pit 30 is flooded to a height exceeding the upper edge 240.

The lower end edge 160 of the upper water stop wall 16 does not contact the foundation structure 20. The lower end edge 160 has a gap between it and the upper surface of the foundation structure 20, so that the function of the seismic isolation mechanism 22 is not hindered. The upper water stop wall 16 is spaced from the upper surface of the foundation structure 20 by a constant second height H2. Here, the upper surface of the foundation structure 20 is, for example, the upper surface of a mat slab, which is located lower than the lower footing on which the seismic isolation mechanism 22 is installed. The lower end edge 160 does not need to be formed at a constant height as long as it is not higher than the second height H2. The second height H2 is lower than the height from the upper surface of the foundation structure 20 than the first height H1. Therefore, as shown in FIG. 2, the lower water stop wall 24 overlaps with the upper water stop wall 16 in the height direction Y by the difference between the first height H1 and the second height H2. The second height H2 is set to a level that the water does not exceed the lower water stop wall 24 due to the air pressure inside the upper water stop wall 16 even when the seismic isolation pit 30 is flooded.

The upper water cutoff wall 16 is, for example, made of reinforced concrete and formed integrally with the superstructure 10. The upper water cutoff wall 16 made of reinforced concrete can be constructed simultaneously with the floor slab 140, and therefore construction is easy. Furthermore, the upper water cutoff wall 16 made of reinforced concrete can be constructed on-site without relying on special products as in the past, and low cost can be achieved. Furthermore, the upper water cutoff wall 16 may be formed, for example, of steel plates fixed to the superstructure 10. In this case, it can be realized by welding the ends of four steel plates together and assembling them into a square frame as shown in FIG. 3, and if the upper water cutoff wall 16 is annular, a steel pipe may be used.

There is a predetermined first distance L1 between the outer surface of the lower waterstop wall 24 and the inner surface of the upper waterstop wall 16. The first distance L1 is the distance in the horizontal directions X and Z between the outer surface of the lower waterstop wall 24 and the inner surface of the upper waterstop wall 16 at a reference position before an earthquake occurs. It is preferable that the first distance L1 is at least the same distance as the second distance L2 (Figure 1) between the retaining wall 23 and the side surface 12. This is to ensure that the lower waterstop wall 24 and the upper waterstop wall 16 do not impede the horizontal movement of the seismic isolation mechanism 22.

As shown in FIG. 4, even if an earthquake causes the foundation structure 20 to move horizontally in the horizontal direction X (left side of the figure), if the movement distance is less than the first distance L1, the lower waterstop wall 24 will not collide with the upper waterstop wall 16. Also, if the first distance L1 is greater than the second distance L2, the side surface 12 of the upper structure 10 will collide with the retaining wall 23 before the lower waterstop wall 24 collides with the upper waterstop wall 16, preventing damage to the lower waterstop wall 24 and the upper waterstop wall 16.

As shown in Figure 5, with the seismically isolated building 1, even if water 32 enters the seismic isolation pit 30 from a river due to a flood, and the space between the foundation structure 20 and the upper structure 10 is flooded, the water can be prevented from crossing the lower water stop wall 24 and entering the seismic isolation mechanism 22. In Figure 5, the seismic isolation pit 30 is flooded, but the water has not entered the inside of the lower water stop wall 24. Water 32 has entered between the inside of the upper water stop wall 16 and the outside of the lower water stop wall 24, and the water level exceeds the second height H2, but the air pressure inside the upper water stop wall 16 prevents the water 32 from rising, and the water level does not reach the first height H1.

The seismically isolated building 1 is easy to construct because it only requires a simple structure of two walls, an upper water stop wall 16 and a lower water stop wall 24, which are provided around the seismic isolation mechanism 22.

3. Modification 1
A base-isolated building 1a according to Modification 1 will be described with reference to Fig. 6. Fig. 6 is a partial enlarged view of the base-isolated building 1a according to Modification 1. Note that a description of the same configuration as in Fig. 2 will be omitted.

The seismically isolated building 1a shown in FIG. 6 has multiple seismic isolation mechanisms 220 between the foundation structure 20 and the superstructure 10. The seismically isolated building 1a has multiple upper water-stopping walls 16a extending downward from the superstructure 10, and multiple lower footings 200 made of reinforced concrete that are part of the foundation structure 20 and extend upward.

The lower footing 200 is formed to protrude higher than the foundation structure 20, for example a concrete mat slab, and functions as a base for installing the seismic isolation mechanisms 220. Each of the seismic isolation mechanisms 220 is disposed on the lower footing 200. On the side of the superstructure 10 facing the lower footing 200, an upper footing 100 made of reinforced concrete is formed to protrude downward from the underside 14, and the seismic isolation mechanism 220 is disposed sandwiched between the upper footing 100 and the lower footing 200.

The seismic isolation mechanism 220 may be a laminated rubber like the seismic isolation mechanism 22 in the above embodiment, but in this example, an example using an elastic sliding bearing will be described. The elastic sliding bearing includes a sliding plate 222 fixed to the upper surface of the lower footing 200, and a laminated rubber part 224 installed on the sliding plate 222 via a relative moving part 223. The laminated rubber part 224 is fixed to the lower surface of the upper footing 100. The relative moving part 223 is composed of the upper surface of the sliding plate 222 and the lower surface of the laminated rubber part 224, and both surfaces are coated with, for example, fluororesin to realize a low friction coefficient or reduce the friction coefficient. The relative moving part 223 is configured so that the lower member and the upper member can move relatively in the horizontal directions X and Z. When the seismic isolation mechanism 220 is a rolling bearing, the relative moving part 223 is composed of a ball bearing and a rolling surface, and is, for example, a linear guide.

Each of the upper waterstop walls 16a surrounds one of the lower footings 200 in a plan view and has a lower edge 160 at a position lower than the upper end of the lower footing 200, and the upper structure 10 keeps the area inside the upper waterstop wall 16a and higher than the upper end of the lower footing 200 airtight. The area kept airtight by the upper structure 10 is inside the upper waterstop wall 16 and is at least higher than the upper end of the lower footing 200, and is preferably higher than the lower edge 160 considering volume changes due to air compression and waves on the water surface. By keeping this area airtight by the upper structure 10, the pressure of the air contained inside the upper waterstop wall 16 can prevent water from exceeding at least the upper end of the lower footing 200 even if the seismic isolation pit 30 is flooded. And because the lower edge 160 is located at a position lower than the upper end of the lower footing 200, even if the seismic isolation pit 30 is flooded, the water does not reach the seismic isolation mechanism 220 above the lower footing 200. The second height H2 of the lower edge 160 from the foundation structure 20 is set at a position lower than the third height H3 of the relative movement part 223 from the foundation structure 20, and is set at a position where water does not reach the top of the lower footing 200 even if the seismic isolation pit 30 is flooded to a height exceeding the lower edge 160 (second height H2) due to the pressure of the air contained in the upper water stop wall 16a. Since it is particularly desirable to prevent the relative movement part 223 from flooding in sliding bearings and rolling bearings, it is preferable that the lower edge 160 is set at a height where at least the relative movement part 223 does not come into contact with water.

The upper water stop wall 16a may be made of reinforced concrete as in the above embodiment, but in this example, it is made of steel plates fixed to the side of the upper footing 100. If the upper footing 100 is rectangular in plan view, the upper water stop wall 16a is formed into a frame by welding the adjacent ends of four steel plates. If the upper water stop wall 16a is annular, it may be made of steel pipes. The third distance L3 between the upper water stop wall 16a and the side of the lower footing 200 is preferably the same distance as the second distance L2 (Figure 1) between the retaining wall 23 and the side 12, or longer.

4. Modification 2
A base-isolated building 1b according to Modification 2 will be described with reference to Fig. 7. Fig. 7 is a partial enlarged view of a base-isolated building 1b according to Modification 2. Note that descriptions of the same configurations as those in Figs. 2 and 6 will be omitted.

The seismically isolated building 1b shown in FIG. 7 has multiple seismic isolation mechanisms 221 between the foundation structure 20 and the superstructure 10. The seismically isolated building 1b has multiple upper water-stopping walls 16b extending downward from the superstructure 10.

Each of the seismic isolation mechanisms 221 is disposed on the lower footing 200. The seismic isolation mechanism 221 is a sliding bearing or a rolling bearing having a relative moving part 223 that allows relative movement in the horizontal directions X and Z, and in this example, an example using an elastic sliding bearing will be described. The elastic sliding bearing includes a laminated rubber part 224 fixed to the upper surface of the lower footing 200, and a sliding plate 222 installed on the laminated rubber part 224 via a relative moving part 223. The sliding plate 222 is fixed to the lower surface of the upper footing 100. The relative moving part 223 is composed of the lower surface of the sliding plate 222 and the upper surface of the laminated rubber part 224. The relative moving part 223 is configured so that the lower member and the upper member can move relatively in the horizontal directions X and Z. When the seismic isolation mechanism 221 is a rolling bearing, the relative moving part 223 is composed of a ball bearing and a rolling surface, and is, for example, a linear guide.

Each of the upper water stop walls 16b surrounds one relative moving part 223 in a plan view and has a lower edge 160 at a position lower than the lower end of the relative moving part 223, and the upper structure 10 keeps the area inside the upper water stop wall 16b and higher than the lower end of the relative moving part 223 airtight. The area kept airtight by the upper structure 10 is inside the upper water stop wall 16 and is at least a region higher than the lower end of the relative moving part 223, and is preferably a region higher than the lower edge 160 considering volume change due to air compression and waves on the water surface. By keeping this area airtight, even if the seismic isolation pit 30 is flooded, the pressure of the air contained inside the upper water stop wall 16 can prevent water from exceeding at least the lower end of the relative moving part 223. In this example, if the seismic isolation pit 30 is flooded, even a part of the seismic isolation mechanism 221 will be flooded, but if at least the relative moving part 223 is not flooded, it can function as an isolator. Therefore, the upper water stop wall 16b is provided to a height that does not flood the relative moving part 223. The second height H2 of the lower edge 160 from the foundation structure 20 is set at a position lower than the third height H3 of the relative moving part 223 from the foundation structure 20, and is set at a position that does not allow water to reach the relative moving part 223 even if the seismic isolation pit 30 is flooded to a height exceeding the lower footing 200 due to the pressure of the air contained in the upper water stop wall 16b.

It is preferable that the fourth distance L4 between the upper water blocking wall 16b and the side of the laminated rubber section 224 is the same as or longer than the second distance L2 (Figure 1) between the retaining wall 23 and the side 12.

The seismic isolation building 1 according to the above embodiment and the seismic isolation buildings 1a and 1b according to the modified examples may be buildings having existing seismic isolation mechanisms 22, 220, and 221. In that case, the upper water stop walls 16, 16a, and 16b and the lower water stop wall 24 are constructed by post-construction around the existing seismic isolation mechanisms 22, 220, and 221.

The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the present invention includes configurations that are substantially the same as those described in the embodiments (for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effect). The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in the embodiments, or that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

1, 1a, 1b... seismically isolated building, 10... upper structure, 100... upper footing, 12... side, 14... bottom surface, 140... floor slab, 16, 16a, 16b... upper water stop wall, 160... lower edge, 20... foundation structure, 22, 220, 221... seismic isolation mechanism, 222... sliding plate, 223... relative movement part, 224... laminated rubber part, 23... retaining wall, 24... lower water stop wall, 240... upper edge, 30... seismic isolation pit, 32... water, L1... first interval, L2... second interval, L3... third interval, L4... fourth interval, H1... first height, H2... second height, H3... third height, X, Z... horizontal direction, Y... height direction

Claims (2)

A seismic isolation building having a plurality of seismic isolation mechanisms in a seismic isolation pit between a foundation structure and a superstructure,
A plurality of lower water blocking walls extending upward from the foundation structure;
A plurality of upper water blocking walls extending downward from the upper structure;
Equipped with
each of the lower water blocking walls surrounds one of the seismic isolation mechanisms in a plan view and has an upper edge at a position spaced apart from the upper structure;
Each of the upper water blocking walls surrounds an outer side of one of the lower water blocking walls at a predetermined interval in a plan view and has a lower end edge at a position lower than the upper end edge,
The upper structure is configured to keep an area inside the upper water blocking wall and higher than the upper edge airtight,
The lower edge is set at a height such that when the seismic isolation pit is flooded to a height exceeding the height of the upper edge, the water will not exceed the upper edge due to the pressure of the air contained inside the upper water cutoff wall;
The lower water cutoff wall is made of reinforced concrete and is integral with the foundation structure.
A seismically isolated building, characterized in that the upper water cut-off wall is made of reinforced concrete and is formed integrally with the superstructure. In claim 1,
A seismically isolated building, wherein the seismic isolation mechanism includes at least one of laminated rubber, a sliding bearing, and a rolling bearing.

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