Simple seismic isolation structure

Abstract

Improved seismic isolation performance at a relatively low cost Simple seismic isolation structure to provide. [Solution] The simple seismic isolation structure 2 supports a building BL and comprises a ballast 10 containing crushed stone or gravel, a foundation 20 provided on the ballast 10, a collapse prevention structure 30 covering the periphery of the ballast 10, and a frame body 40 provided around the collapse prevention structure 30. The ballast 10 is formed in a target area A1 set on a reference ground surface GL. The collapse prevention structure 30 is provided around the ballast 10. The collapse prevention structure 30 contains soil, pebbles, and sand. It is preferable that the soil be capable of penetrating into the gaps in the crushed stone or gravel that constitutes the ballast 10. The frame body 40 is provided around the ballast 10 on the reference ground surface GL. It is preferable that the material forming the frame body 40 is concrete.

Description

[Technical field]

[0001] The present invention relates to Simple seismic isolation structure This is regarding. [Background technology]

[0002] A recent common construction technique for seismic isolation is to install seismic isolation devices using laminated rubber or bearings between the building and its foundation, preventing earthquake tremors from being transmitted directly to the building.

[0003] However, with construction methods that use seismic isolation devices, earthquake motion is less likely to be transmitted directly to the building, and although they are known to be effective in reducing the toppling of furniture and fixtures, the initial investment (design and construction costs) required for seismically isolated detached houses is high, and regular maintenance is required to maintain the functionality of the isolation devices, as well as regular replacement work. As a result, seismic isolation devices have not been widely adopted in the detached house market.

[0004] As a solution to this problem, there is a simple seismic isolation structure that uses crushed stone or gravel to impart seismic isolation capabilities to lightweight structures such as detached houses, equipment, and devices (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication 2011-184984 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the simple seismic isolation method of Patent Document 1 can be implemented at a relatively low cost, the seismic isolation performance is insufficient.

[0007] Therefore, the present invention provides a structure that improves seismic isolation performance at a relatively low cost. Simple seismic isolation structure The purpose is to provide. [Means for solving the problem]

[0008] The simple seismic isolation structure of the present invention comprises ballast, a foundation provided on the ballast, a collapse prevention structure covering the periphery of the ballast, and a frame body surrounding the ballast, wherein the collapse prevention structure is filled between the ballast and the frame body, and a mixed structure is formed between the ballast and the collapse prevention structure which is more likely to be destroyed by the energy of an earthquake than the collapse prevention structure, and wherein the mixed structure is composed of gravel or crushed stone which constitutes the ballast, and components contained in the collapse prevention structure which have penetrated into the gaps in the gravel or crushed stone, and wherein the components contained in the collapse prevention structure include at least one of soil, sand, or pebbles which can penetrate into the gaps in the gravel or crushed stone which constitutes the ballast.

[0009] The components of the collapse prevention structure preferably consist of at least one of soil, sand, and pebbles that can penetrate into the gaps in the gravel or crushed stone that constitutes the ballast.

[0010] The collapse prevention structure is preferably formed in a frustum shape.

[0011] Furthermore, it is preferable that the ballast and the frame are provided on the ground surface or on a common underground level. Effect of the Invention

[0012] According to the present invention, seismic isolation performance is improved at a relatively low cost. Simple seismic isolation structure can be provided. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is an explanatory diagram showing an overview of a simple seismic isolation structure. [Diagram 2] FIG. 1 is a flow chart showing an outline of a simple seismic isolation method. [Diagram 3] FIG. 1 is an explanatory diagram showing an overview of a simplified seismic isolation structure (modification). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] As shown in Figure 1, the simple seismic isolation structure 2 supports a building BL, and comprises ballast 10 containing crushed stone or gravel, a foundation 20 provided on the ballast 10, a collapse prevention structure 30 covering the periphery of the ballast 10, and a frame body 40 provided around the collapse prevention structure 30.

[0015] The ballast 10 is formed in a target area A1 set on the ground surface GL, which serves as a reference. The ballast 10 is formed in a frustum shape. The dimensions of the target area A1 in a plan view may be the area of ​​the ballast 10 required to support the target building BL and foundation 20.

[0016] The ballast 10 includes crushed stones or gravel. The size of the stones constituting the crushed stones or gravel is not particularly limited as long as it is not contrary to the spirit of the present invention, but is, for example, 30 mm or more and 60 mm or less. The thickness of the ballast 10 is not particularly limited as long as it is not contrary to the spirit of the present invention, but is, for example, preferably 200 mm or more and 500 mm or less, and more preferably 250 mm or more and 300 mm or less.

[0017] The foundation 20 is a slab foundation. Steel bars and concrete are used as materials for forming the foundation 20. The thickness of the foundation 20 is not particularly limited as long as it is not contrary to the spirit of the present invention, but is preferably 100 mm or more and 200 mm or less, and more preferably 100 mm or more and 150 mm or less. Here, the thickness of the foundation 20 refers to the vertical thickness for the part extending in the horizontal direction, and refers to the horizontal thickness for the part extending in the vertical direction.

[0018] The collapse prevention structure 30 is provided around the ballast 10. The collapse prevention structure 30 contains soil, pebbles, and sand. It is preferable that the soil is capable of penetrating into the gaps between the crushed stone or gravel that constitutes the ballast 10. It is also preferable that the collapse prevention structure 30 covers the slope 10NM of the ballast 10. It is more preferable that the collapse prevention structure 30 covers not only the slope 10NM of the ballast 10 but also the upper surface 10UM.

[0019] The frame 40 is provided around the ballast 10 on the ground surface GL, which serves as a reference. Concrete is preferably used as a material for forming the frame 40. The size of the frame 40 is not particularly limited as long as it is not contrary to the spirit of the present invention, but is preferably 120% or more and 140% or less of the dimensions of the ballast 10 in a plan view, for example.

[0020] Next, the simple seismic isolation method will be explained.

[0021] As shown in FIG. 2, the simple seismic isolation method 100 includes a frame body forming process 110, a ballast forming process 120, a collapse prevention structure forming process 130, and a foundation forming process 140.

[0022] In the frame body forming step 110, a frame body 40 is provided around a target area A1 set on a reference ground surface GL. When performing the frame body forming step 110, it is preferable that the reference ground surface GL is flat.

[0023] In the ballast formation step 120, the ballast 10 is provided in the target area A1. The ballast 10 is preferably formed in a frustum shape.

[0024] In the collapse prevention structure forming process 130, the collapse prevention structure 30 is provided so as to cover the periphery of the ballast 10. It is preferable that the soil as the collapse prevention structure 30 is filled between the frame 40 and the ballast 10.

[0025] In the foundation forming step 140, the foundation 20 is provided on the ballast 10. After the foundation 20 is provided in the foundation forming step 140, the collapse prevention structure 30 may be provided in the foundation forming step 140 so as to cover the periphery of the foundation 20.

[0026] In this manner, the simple seismic isolation structure 2 is formed by the simple seismic isolation method 100.

[0027] Next, according to the simple seismic isolation structure 2, since the foundation 20 is built on the ballast 10, the vibration energy of the earthquake is converted into the flow and friction energy of the crushed stone or gravel that constitutes the ballast 10, and the energy transmitted to the building BL is small.

[0028] In addition, because the collapse prevention structure 30 is provided around the ballast 10, the shape of the ballast 10 is maintained in the state it was in when it was constructed. As a result, the vibration energy absorption performance of the ballast 10 can be maintained as intended. Furthermore, because the collapse prevention structure 30 maintains the shape of the ballast 10 in the state it was in when it was constructed, it is possible to suppress deviations (horizontal and vertical) in the position of the building BL constructed on top of it.

[0029] Furthermore, since the soil contained in the collapse prevention structure 30 can enter the gaps between the crushed stones or gravel that constitute the ballast 10, after the simple seismic isolation method 100, the soil hardens over time in a state where the soil has entered the gaps between the crushed stones or gravel that constitute the ballast 10. As a result, a mixed structure K in which the soil is filled into the gaps between the crushed stones or gravel is formed near the slope 10NM and the top surface 10UM of the ballast 10. When the vibration energy of an earthquake is transmitted to the mixed structure K, the soil portion that fills the gaps between the crushed stones or gravel in the mixed structure K and integrates them is more likely to be destroyed than the collapse prevention structure 30 other than the mixed structure K. In other words, the vibration energy of the earthquake is used as energy to destroy the mixed structure K. Furthermore, since the mixed structure K has fluidity thereafter, the vibration energy of the earthquake becomes the flow and friction energy of the crushed stones or gravel that constitute the soil and the ballast 10. It is preferable that the horizontal length of the mixed structure K is 5% or more and 15% or less of the length of the target area A1.

[0030] In this way, the simplified seismic isolation structure 2 has a high performance of absorbing the vibration energy of an earthquake, so that the vibration energy transmitted to the building BL can be suppressed. The mixed structure K can be formed in the vicinity of the slope 10NM and the upper surface 10UM of the ballast 10 in a short time.

[0031] In the collapse prevention structure forming step 130, the collapse prevention structure 30 filled between the frame 40 and the ballast 10 may be compressed from the upper surface thereof, or water may be sprinkled on the upper surface of the collapse prevention structure 30. This allows the mixed structure K to be formed in a short time.

[0032] In the above embodiment, the ballast 10 is provided in the target area A1 set on the ground surface GL serving as a reference, but the present invention is not limited to this, and a hole GL may be formed in the ground surface GL, the ballast 10 may be provided on the bottom surface GM of the hole GL, and the foundation 20 may be provided on the ballast 10 (FIG. 3). In this case, if the wall surface of the hole GL fulfills the same function as the frame body 40, the frame body 40 may be omitted.

[0033] In the above embodiment, the ballast 10 is formed in a frustum shape, but the present invention is not limited to this, and the ballast 10 may be formed in a rectangular parallelepiped shape.

[0034] In the above embodiment, the foundation 20 is a slab foundation, but the present invention is not limited to this, and the foundation 20 may also be an independent foundation, a strip foundation, a deep foundation, or a pile foundation.

[0035] Incidentally, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0036] 2. Simple seismic isolation structure 10 Ballast 20 Basics 30 Anti-collapse structure 40 Frame 100 Simple seismic isolation method 110 Frame formation process 120 Ballast formation process 130 Prevention structure formation process 140 Foundation formation process K mixed structure

Claims

1. Ballast and a foundation provided on the ballast; A collapse prevention structure that covers the periphery of the ballast; A frame body surrounding the ballast, The collapse prevention structure is filled between the ballast and the frame body, A mixed structure is formed between the ballast and the collapse prevention structure, which is more likely to be destroyed by the energy of an earthquake than the collapse prevention structure, The mixed structure is Gravel or crushed stone constituting the ballast; A component contained in the collapse prevention structure that has penetrated into gaps in the gravel or crushed stone, A simple seismic isolation structure, characterized in that the components contained in the collapse prevention structure include at least one of soil, sand, and pebbles that can penetrate into the gaps in the gravel or crushed stone that constitutes the ballast.

2. 2. The simple seismic isolation structure according to claim 1, wherein the components of the collapse prevention structure are at least one of soil, sand, and pebbles capable of penetrating into the gaps in the gravel or crushed stone that constitutes the ballast.

3. 2. The simplified seismic isolation structure according to claim 1, wherein the collapse prevention structure is formed in a frustum shape.

4. The simplified seismic isolation structure according to claim 3, wherein the ballast and the frame are provided on the ground surface or on a common underground surface.

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