Flood damage reduction building

Abstract

To provide a building that suppresses flood to the interior of a floor structure 16 and a wall structure 15 after taking in flood into the building when a water depth around the building due to flooding, etc. becomes deeper.SOLUTION: The building comprises a flood suppressing function (flood suppressing layer) 1 by applying a moisture-permeable waterproof sheet 1b and a waterproof moisture-permeable coating 1e to the floor structure 16 and the wall structure 15. Therefore, flood is taken in through a flood intake port 2 and once pulled under the floor by an introduction path body 4. If the flood reaches above the floor, as surrounding water recedes, interior water is discharged from the flood intake port 2 and an interior discharge port 3, and underfloor water is discharged from an underfloor discharge port 6a. If the interior of the floor structure 16, etc. is not flooded, the building can be restored after a disaster by washing, disinfecting, drying, etc. of a surface of the floor, etc. and the underfloor.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a building, a floor structure, and a method for reducing flood damage, which are provided with a water infiltration suppression layer in a floor structure or the like to suppress water infiltration into the floor structure or wall structure when the building is inundated by flood or the like. [Background technology]

[0002] In areas expected to be inundated by floods, there are many existing buildings made of wood or light steel that have spaces under the floor. In such buildings, it is difficult to prevent serious damage to the floor structure, etc., caused by flooding under or above the floor. In particular, if a building is surrounded by water roughly one meter deep or more, the water pressure will damage windows and other fixtures, causing muddy water to suddenly seep in from those locations; or, if there are no areas that are flooded and no water is present, the building will inevitably become detached from its foundation due to buoyancy. Furthermore, in most cases, when flooding occurs, wastewater penetrates into the floor and wall structures, corroding wood and other materials, making it necessary to completely remove the floor structures and carry out repairs. However, this work takes a considerable amount of time and is very expensive. Such severe flood damage has occurred frequently in various places in recent years, and it is predicted that it will continue to occur frequently in the future.

[0003] In June 2020, the Architectural Institute of Japan pointed out a problem in its recommendations (Non-Patent Document 1), stating that "no specific design methods or details have been presented for the two approaches of preventing water from entering a building, and actively allowing water to enter a building so that it does not wash away due to buoyancy, while limiting damage inside the building and improving recoverability."

[0004] At present, there are no proposals that can be applied to existing buildings regarding a method for actively flooding a building with water while limiting damage inside the building and improving recovery. In other words, no flood damage mitigation functions or methods have been proposed that can be applied to existing buildings when a building is flooded.

[0005] In April 2021, the applicant proposed a device for preventing flooding of buildings due to floods and other factors when the water depth around the building is approximately less than one meter, which can also be applied to existing buildings (Patent Document 1). In addition, there have been many proposals (Patent Document 2, etc.) regarding application to new construction or preventing flooding of buildings by replacing foundation drains. However, both of these devices are proposed to prevent water from entering buildings. In particular, when the flood depth reaches a certain level, even if the building flood prevention device proposed by the applicants is applied alone, there is a limit to the damage reduction effect on buildings. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2022-167731 A [Patent Document 2] Patent No. 6534605 [Non-patent literature]

[0007] [Non-Patent Document 1] Proposal: "Issues that the construction industry must address in response to increasingly severe flood damage, with a focus on detached houses," June 2020, Architectural Institute of Japan Summary of the Invention [Problem to be solved by the invention]

[0008] Non-Patent Document 1 indicates that the challenge is to achieve "a method for actively flooding a building with water while limiting damage inside the building and improving restoration." In addition, it proposes that if a building is flooded above and below the floor, by installing a device in the building with a flood suppression function that suppresses water from flooding into the floor and wall structures that are important for the structure, after the water subsides, if the floor structures are not flooded, the building can be restored by cleaning, disinfecting, drying, etc. the surfaces of the floors, etc., and the underfloor areas, etc., without the need to completely remove the floor structures, etc.

[0009] The present invention has been made in consideration of the above-mentioned problems and proposals, and its main purpose is to provide a building, a floor structure, and a method for reducing flood damage that enable damage reduction in the event of a flood disaster. [Means for solving the problem]

[0010] In order to solve the above problems, a building according to one aspect of the present invention has a floor space, a floor structure is provided above the floor space, and a water ingress prevention layer is provided between the floor structure and the floor space. This prevents water from ingressing from the floor space into the floor structure, thereby reducing the damage caused by flooding.

[0011] In the above aspect, the floor structure may include a joist, a floor joist arranged on the joist, and a floor underlayment arranged on the floor joist, and the water infiltration suppression layer may be a waterproof sheet attached to the underside of the floor joist. In this way, the waterproof sheet can suppress water infiltration into the floor structure.

[0012] In the above-mentioned aspect, the waterproof sheet may be attached to the side surface of the joist as well, which makes it possible to further suppress water from entering the floor structure.

[0013] In the above aspect, the waterproof sheet may also be attached to a side surface of a base placed on the foundation of the building, which makes it possible to further suppress water from entering the floor structure.

[0014] In the above aspect, the floor structure includes a joist, a floor joist arranged on the joist, and a floor base material arranged on the floor joist, and the water infiltration suppression layer may be a waterproof coating film or a waterproof sheet formed on the lower surface of the floor base material. This makes it possible to suppress water infiltration into the floor structure.

[0015] In the above aspect, a water infiltration suppression layer may be further provided on the indoor side of the underfloor material included in the floor structure. This makes it possible to suppress water infiltration into the floor structure from the indoor side.

[0016] In the above aspect, the water infiltration suppression layer may be provided at a joint portion of members included in the floor structure. This makes it possible to suppress water infiltration from the joint portion.

[0017] In the above aspect, a water infiltration suppression layer may be further provided on the indoor side of the wall base material of the wall portion provided above the foundation. This makes it possible to suppress water infiltration into the wall portion from the indoor side.

[0018] In another aspect of the present invention, a building has a wall portion above a foundation, and the wall portion is provided with a water inlet for taking in floodwater from the outdoors into the building. This allows the water pressure and buoyancy to be reduced by taking in the floodwater, thereby making it possible to reduce damage caused by flooding.

[0019] In the above aspect, the water supply system may further include an indoor outlet provided below the water inlet of the wall portion, and a backflow prevention valve provided at the indoor outlet. This makes it possible to discharge water inside the building to the outdoors when the water outside recedes.

[0020] In the above aspect, an introduction path body may be further provided, which is connected to the flood water intake port and introduces the introduced flood water into the underfloor space below the floor structure. This makes it possible to introduce the introduced flood water into the underfloor space.

[0021] In addition, the floor structure of a building according to another aspect of the present invention is a floor structure provided above an underfloor space of a building, and is provided with a water ingress prevention layer on the underfloor space side of the floor structure. This prevents water from ingressing from the underfloor space into the floor structure, thereby making it possible to reduce damage caused by flooding.

[0022] In another aspect of the present invention, a method for reducing flood damage to a building includes forming a flood-suppression layer between a floor structure and an under-floor space of a building having a floor space above the floor structure, thereby suppressing flooding from the under-floor space into the floor structure, thereby making it possible to reduce flood damage.

[0023] In the above aspect, a water infiltration suppression layer may be further formed on the indoor side of the underfloor material included in the floor structure. This makes it possible to suppress water infiltration into the indoor side as well.

[0024] In the above aspect, a water infiltration suppression layer may be further formed on the indoor side of the wall base material of the wall portion provided above the foundation. This makes it possible to suppress water infiltration into the wall portion from the indoor side. Effect of the Invention

[0025] According to the present invention, it is possible to reduce damage caused by flooding. [Brief description of the drawings]

[0026] [Figure 1] 1 is a schematic diagram showing the floor structure 16 of the building flood damage reduction device as seen from the side. [Diagram 2] This is a schematic diagram of the installation locations of floodwater intakes 2, etc. on the exterior perimeter of the building. [Diagram 3] This is a schematic diagram showing the indoor water inlet 2 and the fixed introduction path body 4 from above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] In order to solve the above problems and achieve the above objects, the invention described in aspect 1 is characterized in that the building is provided with a water ingress prevention function (water ingress prevention layer) by attaching a waterproof sheet to the foundation, joists, floor underlayment material, etc., without gaps, under the floor structure (underside of the floor) such as floor underlayment material and joists, so that water does not enter the floor structure such as joists, floor joists, and gaps where the floor underlayment material and flooring material are joined, and / or by applying a waterproof paint to the underside surface of the floor underlayment material and floor joists, which are the lower part of the floor structure, or by using building materials with water ingress prevention function such as artificial wood. Also, it is characterized in that even an existing building can be provided with a water ingress prevention function without undergoing major renovation work such as removing the floor structure. Similarly, in the case of embodiments 2 to 9, no major renovation work is required, and existing buildings can be converted into buildings that reduce flood damage by incorporating flood suppression functions in the floor structure, etc.

[0028] The invention described in aspect 2 is characterized in that, among the buildings described in aspect 1, the building is provided with a device having a water infiltration suppression function below the floor structure, and the water infiltration suppression function is achieved by attaching a breathable waterproof sheet without any gaps to the entire surface of the floor underlayment to suppress water infiltration into the floor structure.

[0029] The invention described in aspect 3 is a building among the buildings described in aspect 1, characterized in that the lower part of the floor structure is provided with a water ingress prevention function, and the water ingress prevention function is achieved by applying a water-repellent, breathable paint and / or a waterproof, breathable paint to all surfaces that come into contact with water, such as floor underlayment, thereby preventing water from ingressing into the floor structure.

[0030] The invention described in embodiment 4 is a building described in any one of embodiments 1 to 3, characterized in that the building is provided with a water ingress prevention function by attaching a waterproof sheet to the indoor side of the floor underlayment under the tatami mats and / or applying a waterproof paint to the indoor side surface of the floor underlayment, thereby preventing water from infiltrating into the floor underlayment under the tatami mats and into the floor structure.

[0031] The invention described in aspect 5 is a building described in any one of aspects 1 to 4, characterized in that the building is provided with a water-infiltration suppression function that suppresses erosion of the foundation by applying waterproof paint to at least one surface of the foundation.

[0032] The invention described in embodiment 6 is a building described in any one of embodiments 1 to 5, characterized in that the building is provided with a water infiltration prevention function that prevents water from infiltrating into the wall structure by attaching a waterproof sheet to the interior side of the wall base material of the wall structure and / or applying a waterproof paint to the surface of the wall base material.

[0033] The invention described in aspect 7 is characterized in that the building is equipped with a water inlet such as a window to let water into the building, and an indoor outlet to drain the water from inside the building when the water around the building recedes.

[0034] The invention described in embodiment 8 is the building described in embodiment 7, characterized in that the building is equipped with a tubular introduction path body that introduces floodwater entering through the floodwater intake into under the floor, and an accumulation section at the end of the introduction path body that accumulates soil, sand, etc.

[0035] The invention described in embodiment 9 is a building described in any one of embodiments 1 to 8, characterized in that it is provided with water-ingress prevention functional parts at floor joints, floor sub-material joints, floor material and threshold joints, floor material and wall joints, wall sub-material joints, wall outlet installation parts, wall switch installation parts, areas around under-floor inspection hatches, and joints between toilet bowls and floors, etc., making it difficult for water to penetrate into the floor structure and wall structure.

[0036] The invention described in aspect 10 is characterized in that it is a building having a function of preventing water from entering the interior of the floor structure and wall structure described in any one of aspects 1 to 9.

[0037] According to the inventions of aspects 1 to 3, it is expected that water will be prevented from entering the floor structure when a flood or the like occurs inside a building. According to the invention of aspect 4, even if water does flood above the floor, it is expected that water will be prevented from flooding into the underfloor material and floor structure that support the tatami mats. According to the invention of aspect 5, even if water inundates under the floor and the foundation remains submerged for a long period of time, sewage is unlikely to reach the inside of the foundation. According to the invention of aspect 6, it is expected that in the event of flooding, water can be prevented from entering the wall structure from the inside of the room. According to the seventh aspect of the invention, when the flood depth around the building exceeds a certain depth, the flood water is taken in through the flood water intake installed at a high position of the building, so the infiltration of soil and sand is reduced, and as the surrounding water recedes, the water inside the room can be discharged outside through the indoor outlet. This is expected to suppress the buoyancy of the building and the water pressure from inside and outside the building. According to the invention of aspect 8, by first guiding water that has flooded into the building under the floor, flooding above the floor can be avoided depending on how the surrounding water recedes. Also, by providing a soil and sand accumulation section in the introduction path, soil and sand can be prevented from entering under the floor, which is expected to reduce the work of removing soil and sand from under the floor during recovery work. According to the invention of aspect 9, by applying a water ingress prevention function to each joint etc. where water comes into contact, it is expected that water ingress into the floor structure and wall structure can be prevented, which is expected to lead to the protection of the floor structure etc. According to the invention of aspect 10, a method for mitigating flood damage using a building structure that prevents water from entering the floor and wall structures can reduce the number of days and costs required for restoration and repair work, and if construction waste can be reduced, a decarbonization effect can be expected. In any case, the above effects cannot be expected in water of sufficient depth or rapid current that could cause a building to be completely or partially destroyed.

[0038] Hereinafter, the embodiments for carrying out the present invention will be described. However, the embodiments described below and the technical scope of the present invention are not limited to the embodiments and drawings below, and existing technologies and the like are used to carry out the present invention. In the schematic diagram, some parts are shown with gaps between them to make the placement of each part easier to understand, but in reality, the parts are in close contact with each other in areas where watertightness needs to be ensured.

[0039] An embodiment of the first aspect will be described. This is a building that has the function of preventing water from entering the floor structure 16, which is important for the building structure, in the event of a flood or the like causing water to enter under the floor of the building. In the past (conventional) buildings, waterproofing measures were taken on the exterior walls of the building by attaching a moisture-permeable waterproof sheet 1b to the wall base material in the ventilation layer on the inside of the exterior wall with a tacker or the like, and by applying a waterproof coating 1c to wooden exterior walls, so as to prevent the infiltration of heavy rain that falls sideways. In this way, there is no proposal to use a waterproof sheet 1a such as a breathable waterproof sheet 1b in the space under the floor as a measure to prevent water from entering the building, nor to apply a waterproof coating 1c such as a water-repellent, breathable coating 1d to the floor base material 11 to waterproof the floor structure 16. However, when a previous building is flooded or the like, the water that seeps in is sewage containing bacteria, etc., and if this water seeps into the floor structure 16, it can cause decay, etc., and therefore renovation work will be required to completely remove the floor structure 16 and install a new floor structure 16. Therefore, in previous buildings, even if the amount of water seeping under the floor increases and the water comes into contact with the floor structure 16, it is not possible to suppress or reduce the damage caused by water seepage within the floor structure 16 (joists 9, floor joists 10, subfloor material 11, insulation, gaps between the insulation material and the subfloor material 11, etc.), particularly the erosion damage to the subfloor material 11 and the insulation. In addition, complete removal and renovation of floor structure 16 (including flooring material 12) will require a considerable amount of time and will be very expensive.

[0040] Therefore, in order to prevent water from entering the floor structure 16, one embodiment provides a building having a water-ingress prevention function 1 of a waterproof sheet 1a below the floor substructure 11, which is the floor structure 16, and the joists 10 below it, i.e., between the floor structure 16 and the space under the floor. It should be noted that the waterproof sheet 1a includes a moisture-permeable waterproof sheet 1b and other waterproof and airtight sheets. In this embodiment, the water infiltration suppression function (water infiltration suppression layer) 1 may be a sheet-like member such as a moisture-permeable waterproof sheet 1b, or may be a sheet-like or flat waterproof member partially made of resin or metal. As shown in Fig. 1, this water ingress prevention function 1 is fixed to the foundation 8, joists 9, floor joists 10, and floor underlayment 11 with, for example, a water-resistant adhesive to ensure watertightness. In order to ensure the strength of the adhesive joints, it is appropriate to use a flat plate-shaped member to press the joints and use screws, etc. In this way, by installing the water infiltration suppression function 1 below the floor structure 16, even if the amount of water infiltration increases and reaches the floor structure 16, it is possible to suppress water infiltration into the floor structure 16. In order to prevent the waterproof sheet 1a from being pushed up and damaged by the water pressure when the fiber-based insulation is crushed by the water pressure, it is advisable to provide some slack when applying the waterproof sheet 1a, to use formwork members that will enable the insulation to remain flat even when subjected to water pressure, or to use a foam-based insulation material (solid) that will not deform under water pressure. In the case of an existing building, the building of embodiment 1 can be created by attaching the waterproof sheet 1a to the entire surface of the floor structure 16, particularly the floor base material 11, during work under the floor.

[0041] Another embodiment provides a water ingress prevention function 1 on the lower part of a floor structure 16. For example, as shown in Fig. 1, a waterproof coating 1c is applied to the lower part of a floor underlayment 11. This may also be applied to the surfaces of the joists 9 and 10, particularly the surfaces that come into contact with water, and the joints where the materials come into contact. Furthermore, the material itself, such as the floor joists 10, may be a building material, such as artificial wood, that has a water infiltration suppression function 1. The waterproof coating 1c includes the water-repellent, moisture-permeable coating 1d and the waterproof, moisture-permeable coating 1e. In the case of an existing building, the building can be converted into the building of embodiment 1 by carrying out work under the floor, such as applying waterproof coating 1c and caulking the joints. In the case of a new building, artificial wood or the like may be used for the joists 10, or the floor underlay 11 may be made of structural plywood with a waterproof coating 1c / overlay, such as surface-treated concrete formwork plywood. However, the waterproof coating 1c / overlay is preferably a waterproof / breathable coating 1e or the like that has a moisture-permeable function.

[0042] Although the above two embodiments may be used alone, a combination of the two will provide a better waterproofing effect for the floor structure 16. If a building has a floor structure 16 equipped with a flood suppression function 1 that suppresses such flooding, once the water around the building recedes and the flooding is resolved, and the floor structure 16 is no longer flooded, it will be possible to restore the building without having to completely remove the floor structure 16 by cleaning and disinfecting the surface of the flood suppression function 1.

[0043] An embodiment of aspect 2 will now be described. This is a building among the buildings described in embodiment 1, which is provided with a water ingress suppression function 1 below the floor structure 16, and is characterized in that the water ingress suppression function 1 is a moisture-permeable waterproof sheet 1b. In the case of buildings made of wood or the like, underfloor ventilation is important for protecting the building because it affects the interior of the floor structure 16 and even indoor ventilation. Therefore, the building is characterized in that the waterproof sheet 1a is replaced with a moisture-permeable waterproof sheet 1b having a moisture-permeable effect.

[0044] An embodiment of aspect 3 will now be described. This is a building among the buildings described in aspect 1, which is provided with a water ingress prevention function 1 by applying a waterproof coating 1c to the lower part of the floor structure 16, and is characterized in that the water ingress prevention function 1 is a water-repellent, breathable coating 1d or / and a waterproof, breathable coating 1e. When the joists 10, etc. are made of wood, they themselves need to be able to expel moisture and stay dry, and in order to allow underfloor ventilation to extend from within the floor structure 16 to the interior of the room, as in embodiment 2, the building is provided with waterproof coating 1c applied to the underfloor material 11, which is water-repellent and waterproof coatings 1d and 1e with moisture permeability, providing a water ingress prevention function 1. In the case of existing buildings, the product is provided with flood prevention function 1 to the extent that it can be applied, such as to surfaces that come into contact with water. In newly constructed buildings, it may be acceptable to use a product with water ingress prevention function 1 by applying it to surfaces other than those that come into contact with water.

[0045] An embodiment of aspect 4 will now be described. This is a building according to any one of aspects 1 to 3, characterized in that the indoor side of the underfloor material 11 that supports the tatami mats underneath the tatami mats and / or the indoor side surface of the underfloor material 11 is provided with a water ingress prevention function 1. Although not shown, refer to Figure 1. Corridors, Western-style rooms, and the like generally use wood flooring 12 or vinyl flooring 12, which are at least not surface materials that absorb water. However, what differs from these materials in flooring materials is the tatami mat areas of Japanese-style rooms, etc. In the event of flooding above the floor level, the tatami mats can be prevented from actual damage if they are lifted up. However, the floor underlayment 11 that supports the tatami mats was previously often made of solid planks of cedar or other materials, but recently unwaterproofed structural plywood has become the norm. Therefore, if wastewater seeps into the underfloor material 11 under the tatami mats, it will be difficult to clean, disinfect, and dry the material when it is restored, and it is thought that the underfloor material 11 will not be able to be sufficiently sterilized. Although the up-down direction of this water ingress prevention function 1 is reversed from that of the embodiments 1 to 3, i.e., Fig. 1, the mechanism is the same as Fig. 1 of the embodiment 1, etc., and a moisture-permeable waterproof sheet 1b, etc. is provided on the indoor side of the underfloor material 11. Also, a water-repellent and moisture-permeable coating 1d, etc. is applied to the indoor surface of the underfloor material 11. In any case, it is preferable to have moisture permeability to prevent moisture from entering the tatami mat. If such a water ingress prevention function 1 is provided on the indoor side of the floor underlayment 11, even if it is structural plywood, the waterproofing effect to the inside will be the same as for the wood flooring material 12, making it relatively easy to clean, disinfect, and dry when it is time to restore it. In addition, it is even better to use the waterproof sheet 1a and the waterproof coating 1c together in terms of waterproofing effect. Regarding construction, there is no big difference between existing buildings and newly constructed buildings, and since the interior space is larger than the space under the floor, construction is considered to be relatively easy. Note that when constructing a new building or renovating the floor area, building materials with water ingress prevention function 1 such as artificial wood may be used, and the construction of water ingress prevention layer 1 such as waterproof sheet 1a may not be limited to the floor underlayment 11 under the tatami mats, but may be provided on a wide area of ​​floor underlayment 11 such as under the tatami mats.

[0046] An embodiment of aspect 5 will be described. This is a building according to any one of aspects 1 to 4, characterized in that at least one surface of the foundation 8 is provided with a water ingress prevention function 1. The foundation 8 of a wooden building is extremely important in terms of the building structure, so if water comes into contact with its surface, it is possible that bacteria and the like will enter the interior and erode the foundation 8. Therefore, it is desirable to apply a waterproof coating 1c to the entire surface of the foundation 8 to provide a water ingress prevention function 1 in order to protect the foundation 8 and the building. It is also desirable that wood such as pillars, studs, furring strips, joists 9, floor joists 10, and underfloor materials 11 have water infiltration prevention function 1 on all surfaces, just like the foundation 8. The requirement to equip all surfaces with flood prevention features1 applies to newly constructed buildings. Existing buildings shall be equipped with flood prevention features1 to the extent possible.

[0047] An embodiment of aspect 6 will now be described. This is a building equipped with a water ingress prevention function 1 of a floor structure 16 described in any one of aspects 1 to 5, and further characterized in that the water ingress prevention function 1 is provided on the indoor side of the wall base material 15a of the entire wall and / or on the surface of the wall base material 15a. If the building is flooded, and the flooding is limited to under the floor, there will be almost no damage to the inside of the wall structure 15. Also, as in modes 1 and 2, if the waterproof sheet 1a is attached to almost the entire surface of the lower part of the floor structure 16, it is possible to prevent water from directly flooding into the wall structure 15 from under the floor. However, if the water does not contain under the floor and rises above the floor, even a small amount of water will seep into the wall base material 15a and wall structure 15 if the wall surface is covered with paper cloth or the like and no waterproof airtight sheet or the like is attached underneath. Furthermore, if the wall base material 15a is a gypsum board, a large amount of water will seep into the wall structure 15 from that location.

[0048] Therefore, in order to reduce damage caused by flooding in the wall structure 15, a flood suppression function 1 is provided on the entire indoor side of the wall base material 15a. Although not shown, refer to FIG. Similar to the floor structure 16, this water infiltration prevention function 1 involves attaching a waterproof sheet 1a to the indoor side of the wall base material 15a and / or applying a waterproof coating 1c to the indoor side surface of the wall base material 15a. Specifically, if it is an existing building, the surface wallpaper is replaced with vinyl wallpaper. When replacing the wallpaper, waterproof coating 1c is applied to the wall base material 15a. If the base material is plasterboard, waterproof sheet 1a can be attached with a waterproof adhesive. In the case of a new building, the same procedure as for an existing building is followed, and the waterproof sheet 1a is attached to the indoor side of the wall base material 15a, and the waterproof coating 1c is applied. It is preferable that the building has a wall structure 15 having a water ingress suppression function 1 that uses the waterproof sheet 1a and the waterproof coating 1c in combination.

[0049] An embodiment of aspect 7 will now be described. The water pressure and buoyancy on a building increases as the water depth around the building deepens. In a typical wooden building, if the water depth exceeds approximately one meter, it is said that it will be difficult to maintain a water-resistant state due to water pressure and buoyancy. It has been pointed out that airtight buildings are particularly susceptible to the effects of buoyancy. In addition, in any building, if the water gets deeper and the water pressure increases, the glass in the bay windows will break, causing a torrent of muddy water to flow onto the floor. Proposals for flood prevention measures to date have aimed to prevent flooding of approximately one meter or less by using waterstops and other water prevention devices. However, there are many existing buildings in areas expected to be flooded with water depths exceeding one meter, and new buildings will likely continue to be constructed using conventional construction techniques. Furthermore, if a building were to be surrounded by water that is more than one meter deep, even if it is still water, it would be unable to avoid flooding, and a flooded building would suffer severe damage due to the large amount of water seeping into the floor structure 16 and wall structure 15.

[0050] Therefore, as shown in Figure 2, in the event of a flood exceeding approximately 1 meter, flood water intakes 2 are provided in several locations on the building wall to allow flood water to enter the building actively from these locations. By incorporating submersion, it is possible to suppress the effects of water pressure and buoyancy at a certain level of water depth and water current. These floodwater intakes 2 are, for example, windows installed at a height of one meter from the ground. From a functional standpoint, there are no particular limitations on the shape or size of the floodwater intakes 2 such as windows. However, in the case of windows, these windows are left open when a flood or other event is predicted, so crime prevention issues can be reduced by making them sliding windows (vertical or horizontal) wide enough to prevent others from entering even if the windows are left open to allow family members to evacuate. Figure 3 shows the open state of the window glass 2a of a horizontal sliding window. Also, instead of a window, a ventilation opening with a diameter of, for example, about 20 centimeters may be used. The number of installations should be at least several throughout the building, and the locations of installations should be determined taking into consideration the layout of the building as well as the surrounding environment, etc. For example, installation should be avoided in directions where there is a lot of soil and sand, such as in fields, or in directions where water currents will hit directly. If a flood occurs and the water level exceeds the bottom of these several flood inlets 2, water will enter the room through open windows and other flood inlets 2. In this case, it is believed that the more flood inlets 2 there are and the larger the open door area, the less rapid the flooding into the building will be. Furthermore, since the infiltration area is higher than the muddy water that seeps in from the same location when the sliding window 17 is damaged by water pressure, etc., it is believed that the inflow of soil (mud) can be kept to a minimum. After that, as the water subsides, the water inside the building is discharged outside through the flood water intake 2 up to the height of the intake 2.

[0051] Next, the indoor exhaust port 3 will be described. This is used to drain water from inside the building that is not discharged through the floodwater intake 2, and is installed below the floodwater intake 2. The shape of the pipe is that of a drainage pipe equipped with an operating valve 3a to prevent backflow, and the valve 3a prevents water from entering from the outside, but when the water around the building recedes, the valve opens due to the water pressure inside the building and the water can be discharged outside. Figure 3 shows the state in which the valve 3a is operating and discharging water from inside the room. The installation position is below the flood water intake 2 as shown in Figure 2, for example, at a height that touches the floor, so that all flood water above the floor can be drained. The number of units to be installed depends on the floor area, layout, etc. of the building and the size of the indoor exhaust outlet 3. For example, if the diameter is about 10 cm, several or more units may be installed throughout the building. In the case of an existing building, a method may be used in which a circular hole is made through the wall, the outer pipe is fixed inside the wall, and the indoor exhaust port 3 is fixed inside the outer pipe. The same applies to a newly constructed building. In this way, as long as the water has not infiltrated inside the floor structure 16 and the wall structure 15 after the water has been drained, recovery work such as cleaning, disinfecting, drying, etc. of the surfaces of the floor etc. can be carried out relatively smoothly.

[0052] An embodiment of aspect 8 will be described. This is the building described in aspect 7, characterized in that it is equipped with an introduction path body 4 that temporarily introduces floodwater that has entered through the floodwater intake 2 into under the floor. The introduction path body 4 is made of resin or metal that is water-resistant and weather-resistant, and has a tubular, hose-like shape and a bellows-type construction that is convenient for storage and the like. As shown in FIG. 3, this introduction path body 4 is connected and fixed to a water inlet 2 such as a window, and one end is placed and fixed under the floor. Water seeping in through a water inlet 2 such as a window would enter above the floor if left as is, but it passes through the inside of this introduction path body 4 and seeps under the floor. When the water that has flooded under the floor becomes full, it sprays out onto the floor through several underfloor inspection hatches 14 that have been left open. Also, if the floodwater drops below floodwater intake 2 (the water recedes) before the space under the floor is filled up, flooding above the floor can be avoided.

[0053] Furthermore, as shown in FIG. 3, by providing an accumulation section 5 for accumulating soil and fine floating debris in the middle of the introduction path body 4, it is possible to minimize the amount of soil and other debris that flows under the floor. The accumulation section 5 may be, as shown in Fig. 3, a part of the inner diameter of the cylindrical introduction path body 4 enlarged. When provided at the end, it may be a net-like or mesh-like one, or an accumulation frame 5a for accumulation may be installed under the floor (see Fig. 3). The accumulation section 5 reduces the inflow of soil under the floor, and by accumulating the soil in the accumulation frame 5a, the spread of soil over the entire surface of the floor can be reduced. The shape of the part of the introduction path body 4 that connects to the flood water intake 2 is formed to match the shape of the flood water intake 2. For example, a square tube structure is used for connection to a square window, and a cylindrical structure is used for connection to a cylindrical ventilation port. The part is fixed to the flood water intake 2 by conventional techniques such as a hook type or waterproof double-sided tape adhesion. As shown in FIG. 3, the main body of this introduction path body 4 is placed on the floor, and the other end is placed under the floor and fixed here as well by a suitable method such as a hook type or waterproof tape adhesion. If the introduction path body 4 is of a bellows type, the accumulation section 5 is the valley of the bellows. Sediment accumulates in this section due to its weight. Therefore, if the valley is enlarged or a bag-shaped object is connected to the middle of the introduction path body 4, sediment will accumulate in that section. Like the floodwater intake 2, both the introduction path body 4 and the accumulation section 5 can be retrofitted to an existing building.

[0054] In addition, underfloor inspection hatches 14 are provided in several places in conventional buildings. As these are important for taking in floodwater as mentioned above and for cleaning and disinfecting the underfloor area after the water has subsided, it is best to install them in several places on all four sides of the building and one near the center of the building, taking into consideration the location of the floodwater intake 2. If it is installed near the center of a building, tap water can be sprayed from that location to clean the underfloor area in all four directions. The underfloor inspection hatch 14 can be added even to an existing building if there is a suitable location for installation. Furthermore, if a sterilization and purification filter or the like with high processing capacity capable of keeping up with the water infiltration speed is developed in the future, it may be installed midway through the introduction path body 4, at the end (under the floor).

[0055] An embodiment of aspect 9 will be described. This is a building described in any one of aspects 1 to 9, and is characterized in that a water infiltration prevention function 1 such as caulking is provided at the joints of the flooring material 12, the joints of the floor underlayment material 11, the joints between the flooring material 12 and the threshold, the joints between the flooring material 12 and the wall structure 15, the joints of the wall underlayment material 15a, the outlet equipment installation area in the wall, the switch equipment installation area in the wall, the area around the underfloor inspection hatch 14, the joints between the toilet bowl and the flooring material 12, etc., to prevent water from infiltrating into the floor structure 16 and the wall structure 15. In this way, existing buildings should be waterproofed by caulking or the like at all joints, and electrical outlets should be replaced with waterproof, watertight ones. Furthermore, it is a good idea to apply a water-repellent, waterproof coating 1c or the like to wooden flooring materials 12, etc. In newly constructed buildings, the joints between each component are glued with a waterproof adhesive, and the joints of each component are caulked, etc., to enhance the water ingress prevention function1.

[0056] An embodiment of aspect 10 will now be described. This is a building according to any one of aspects 1 to 9, and a building equipped with a device to prevent water from entering the building from the underfloor ventilation openings above the foundation 6, which prevents water from entering the floor structure 16 and the wall structure 15. In the event of water entering the building, after the water has subsided, if there is no water in the floor structure 16 and the wall structure 15, it is possible to restore the building without having to completely remove the floor structure 16, etc., by cleaning and disinfecting the wall and floor surfaces, washing and disinfecting the area under the floor from the underfloor inspection hatch 14, draining the water from the underfloor drain opening 6a, and finally drying the entire building.

[0057] An example of an embodiment of the procedure etc. will be specifically described. First, in existing buildings, First, a water ingress prevention device for the building will be installed from the underfloor ventilation layer (the part where the foundation gasket 7 is installed above the foundation 6), as has been proposed in the past. In addition, a water ingress prevention device will be installed in the ventilation layer on the inside of the exterior wall, and an underfloor drain 6a will be installed to drain water ingress from under the floor to the bottom of the foundation 6. Secondly, a water ingress prevention function 1 such as a waterproof sheet 1a is installed in appropriate locations to prevent water from infiltrating into the floor structure 16 and wall structure 15 of the building (modes 1 to 3). Thirdly, a water ingress prevention function 1 is provided for the underfloor material 11 in the area where the tatami mats are laid (mode 4). Fourthly, the height of the floodwater intake 2 is determined based on the strength of the connection between the base 8 and the foundation 6, the flow rate of water around the building in the event of a flood, etc. (Mode 7). Fifth, if there are no windows or ventilation openings at the determined height, water inlet ports 2 are installed in several places through the wall, and indoor exhaust ports 3 with anti-backflow valves 3a are also installed in several places (mode 7). Sixthly, an introduction path body 4 for introducing floodwater under the floor, an accumulation section 5 for accumulating soil and sand, and an accumulation frame 5a under the floor are prepared (embodiment 8). Seventh, when a flood or other occurrence forecast is received, the first flood prevention device is set to a flood prevention state, the fifth flood intake 2 is opened, and the sixth introduction path body 4 and accumulation section 5 are fixed to the fifth flood intake 2. Furthermore, all underfloor inspection hatches 14 are opened. Furthermore, the shutters 18 of the sweep window 17 are closed, and water stops, etc. are set up. Eighth, if the building is flooded, all the flooded water inside the building is drained from the indoor drainage outlet 3 on the floor and the underfloor drainage outlet 6a of the foundation 6, and the walls, floors, etc. are washed, disinfected, and dried. Next, the underfloor area is washed from the underfloor inspection hatch 14. In this way, if the water ingress prevention device and waterproof sheet 1a are not damaged by a direct hit from drifting debris, etc., it is possible to reduce damage caused by water pressure and buoyancy to the building structure, etc., and damage caused by erosion of the floor structure 16, etc. In addition, as long as the glass of the sliding window 17 is not broken and a large amount of soil (muddy water) does not flow under the floor, etc., restoration work and restoration costs can be reduced.

[0058] New buildings are almost the same as the specific embodiment examples for existing buildings described above, but for new buildings, it is important to use construction methods and measures to prevent the foundation 6 from being washed away, such as by enlarging the buried part of the foundation 6, and to increase the connection between the foundation 6 and the base 8 so that the part above the base 8 does not wash away. It is also important to use waterproofing for each component and to fully ensure the watertightness of the joints between each component.

[0059] The present invention is effective when combined with technologies such as building flood prevention devices. [Explanation of symbols]

[0060] 1 Flood suppression function (flood suppression layer) 1a Tarpaulin 1b Breathable waterproof sheet 1c Waterproof coating 1d Water-repellent and breathable coating 1e Waterproof and breathable coating 2 Water intake 3 Indoor outlet 3a Actuated valve 4. Introduction pathway 5. Accumulation section 5a Accumulation Frame 6 Basics 6a Underfloor outlet 7 Basic packing 8. Foundation 9. Bridge 10 Joists 11 Floor underlayment 12 Flooring materials 13 bundles 14 Underfloor inspection hatch 15 Wall structure 15a Wall base material 16 Floor structure 17 Sweeping Window 18 Shutter

Claims

1. A building having a wall portion above a foundation, The wall portion is provided with a flood water intake for taking in flood water from the outside into the building, The device further includes an indoor exhaust port provided below the water inlet of the wall portion, and a check valve provided at the indoor exhaust port. building.

2. A building having a wall portion above a foundation, The wall portion is provided with a flood water intake for taking in flood water from the outside into the building, Further, an introduction path body is provided which is connected to the flood water intake port and introduces the taken in flood water into a space under the floor structure. building.

3. A building having a wall portion above a foundation, The wall portion is provided with a flood water intake for taking in flood water from the outside into the building, Further comprising an introduction path body connected to the flood water intake port and introducing flood water; and a collection section provided on the introduction path body. building.

4. The building has a floor space, and a floor structure is provided above the floor space, A water infiltration suppression layer is provided between the floor structure and the underfloor space. The building according to claim 1.

5. The building has a floor space, and a floor structure is provided above the floor space, A water ingress prevention layer is provided on the indoor side of the floor underlayment included in the floor structure. The building according to claim 1.

6. The building has a floor space, and a floor structure is provided above the floor space, A water infiltration suppression layer is provided at the joints of the members included in the floor structure. The building according to claim 1.

7. A water infiltration suppression layer is provided on the indoor side of the wall base material of the wall portion. The building according to claim 1.

8. A method for reducing flood damage to a building having a wall portion above a foundation, comprising: Taking in floodwater from the outdoors into the building through a floodwater intake provided in the wall portion for taking in floodwater from the outdoors into the building; The flood water is discharged by an indoor discharge port provided below the flood water intake port of the wall portion and a check valve provided at the indoor discharge port. How to reduce flood damage to buildings.

9. A method for reducing flood damage to a building having a wall portion above a foundation, comprising: Taking in floodwater from the outdoors into the building through a floodwater intake provided in the wall portion for taking in floodwater from the outdoors into the building; An introduction path body connected to the flood water intake introduces the taken in flood water into a space under the floor below the floor structure. How to reduce flood damage to buildings.

10. A method for reducing flood damage to a building having a wall portion above a foundation, comprising: Taking in floodwater from the outdoors into the building through a floodwater intake provided in the wall portion for taking in floodwater from the outdoors into the building; Water is introduced from an introduction path body connected to the water inlet into a collection section provided in the introduction path body. How to reduce flood damage to buildings.

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