JP5965703B2 - Building - Google Patents

Description

  The present invention relates to a building constructed by building a building on a base plate installed on a bedrock through a seismic isolation device.

  Conventionally, as this kind of building, for example, a configuration as disclosed in Patent Literature 1 and Patent Literature 2 has been proposed. In these conventional configurations, a foundation plate is installed on the ground, and a building is constructed on the upper surface of the foundation plate via a seismic isolation device. And at the time of the occurrence of an earthquake, the vibration transmitted to a building is reduced by a seismic isolation apparatus, and a building is protected.

JP 2001-288930 A JP 2011-95173 A

  In these conventional constructions, a plurality of rubber layers are generally laminated with steel plates interposed as a seismic isolation device. This seismic isolation device has higher vertical rigidity than horizontal rigidity. For this reason, with respect to seismic force (horizontal vibration), the laminated rubber of the seismic isolation device can be greatly deformed to obtain the seismic isolation effect, but the vertical vibration tends to increase rather. And when the ground is made of hard rock, the vertical vibration of the rock and the peak of the resonance period of the structure (building) appear on the short period side, and the equipment inside the building may resonate greatly. .

  By the way, an earthquake-resistant building such as a nuclear power plant has high rigidity and strength, and it is considered that the deformation of the building is in an elastic region even if it receives a strong earthquake. On the other hand, such a building is installed on a solid bedrock having a high bearing strength, and the supporting ground and the foundation are brought into close contact with a solid foundation, and such a supporting ground is considered to be in an elastic region. Accordingly, as shown in FIGS. 6A and 6B, the vibration model of the rock mass 30 under the building 21 and the surface layer 22 of the ground is represented by a series including a ground spring 23, a base plate 24, a seismic isolation spring 25, and a building 26. It is common to express it by a model. Reference numeral 27 shown in FIG. 6B represents a concentrated mass of the floor of each floor of the base plate 24 and the building 26. In this coupled model, during an earthquake, the amplitude of the ground vibration 28 in the vertical direction increases as the vibration propagates to the upper floor 29 as shown in FIG.

  In order to cope with such problems, recently, seismic isolation devices have been proposed in which the vertical rigidity of laminated rubber and springs is reduced to enable vertical isolation. However, when the vertical rigidity is set to be small, the laminated rubber and the spring of the seismic isolation device are greatly contracted by the weight of the building and the building sinks. For this reason, it is necessary to further secure the expansion / contraction allowance during the earthquake, with the initial value of the seismic isolation device being in a state of shrinking in proportion to the weight of the building, and it is necessary to use thick laminated rubber or a vertically long spring. It was. Therefore, it is difficult to secure a space for installing the thick laminated rubber and spring, and the construction of the building progresses with the slow contraction of the thick laminated rubber and long spring, which makes the construction difficult. It was a thing.

  In order to cope with such circumstances, new technologies such as a three-dimensional seismic isolation device using an air spring that floats a building by the force of air pressure have been proposed. In this three-dimensional seismic isolation device, seismic force (horizontal vibration) and vertical vibration can be reduced at the same time, but the structure of the device is complicated and expensive. In addition, there are problems of running costs associated with air pressure management inspections and regular maintenance, as well as dealing with troubles and unexpected situations.

  The present invention has been made paying attention to the problems existing in the conventional inexpensive technology. The object is to provide a building that is simple in structure and can achieve low cost, and that can simultaneously reduce the vertical seismic force.

In order to achieve the above object, the present invention comprises a recess formed on the lower surface of the foundation plate in a building that supports the building via a seismic isolation device on the foundation plate installed on the bedrock , According to the hardness of the bedrock, comprising a vibration blocker that prevents vertical vibration from the bedrock from being transmitted to the foundation plate by not contacting the bedrock and the foundation plate directly , It is characterized by comprising an area determined so as to shift the resonance period of the vertical vibration of the building to the long period side .

  Therefore, in the building of the present invention, the horizontal force of the earthquake is reduced by the seismic isolation device, and the vertical vibration is reduced by suppressing the transmission of vibration by the vibration blocking unit. For this reason, compared with the structure provided with the three-dimensional seismic isolation apparatus containing an air spring, while being simple and cheap, a horizontal vibration and a vertical vibration can be reduced simultaneously.

Furthermore, a resonance period that is convenient for a building can be obtained simply by changing the area of the concave portion, which is the vibration blocking portion, according to the hardness of the ground (rock).

The said structure WHEREIN: You may provide a member softer than a base plate in the said recessed part.
The said structure WHEREIN: It is good to remove the position which supports the said housing body of a building, and to provide the said vibration isolating part.

  As described above, according to the present invention, the structure can be simple, and the effect of reducing the vibration transmission of the earthquake to the building can be exhibited.

The longitudinal cross-sectional view which shows the building of 1st Embodiment. Sectional drawing in the 2-2 line of FIG. The fragmentary sectional view which expands and shows the vibration isolating part in the building of FIG. The perspective view which decomposes | disassembles and shows the mold which comprises the vibration interruption | blocking part. The fragmentary sectional view which shows the vibration isolating part of the building of 2nd Embodiment. (A)-(c) is a schematic diagram which shows the coupled vibration model at the time of an earthquake.

(First embodiment)
Below, 1st Embodiment of the building 10 which actualized this invention is described according to FIGS. 1-4.

  As shown in FIGS. 1 and 2, a foundation slab 12 made of reinforced concrete is installed on a hard bedrock 30 composed of a Tertiary layer below the surface layer 22 of the ground or a layer of an earlier period. A building 14 is constructed on the base plate 12 via a plurality of seismic isolation devices 13 having a known structure. The seismic isolation device 13 corresponds vertically to the frame parts such as columns and walls in the building 14 so that the load of the building 14 is effectively supported by the base plate 12 and the seismic isolation effect is exhibited. Placed in position.

  As shown in FIGS. 1 to 3, a plurality of vibration blocking portions 15 are formed on the lower surface of the foundation plate 12. This vibration isolating portion 15 is constituted by a concave portion such as a plane quadrangle, and the inside of the concave portion is a gap, and a position corresponding to a vertical portion of a building such as a column or a wall in the building 14, that is, an arrangement position of the seismic isolation device 13 Is arranged. The contact area of the lower surface of the foundation plate 12 with respect to the bedrock 30 is reduced by these vibration blocking portions 15 so that transmission of vibration from the bedrock 30 to the foundation plate 12 side is suppressed.

In addition, the space | gap of the vibration isolator 15 may be any shape as long as the edge of the ground is cut.
As shown in FIGS. 3 and 4, when the base plate 12 is formed from reinforced concrete, a flat box-shaped formwork 16 made of a steel plate on the upper surface of the rock mass 30 and opened at the bottom is rocked by the anchor bolts 17. 30 is fixed. In this state, the concrete of the foundation slab 12 is placed so as to bury the formwork 16 together with the reinforcing bars (not shown). In this way, the vibration isolating portion 15 composed of the concave portion is formed on the lower surface of the base plate 12.

  The mold 16 is formed by welding a lower plate 18 having a plurality of bolt insertion holes 18a, a long rectangular frame-shaped side frame 19, a reinforcing plate 19a in the side frame 19 and an upper plate 20. .

Next, the operation of this embodiment will be described.
In the building 10, the seismic isolation device 13 is disposed between the base plate 12 and the building 14 at a position corresponding to the vertical portion of the building 14 such as a column or wall of the building 14. For this reason, the vertical support load from the building 14 and the horizontal load at the time of the occurrence of the earthquake are effectively transmitted from the foundation plate 12 to the rock mass 30 via the seismic isolation device 13.

  And when an earthquake occurs, the horizontal response of a building is significantly reduced by deforming each seismic isolation device 13. On the other hand, since the contact area of the base plate 12 with respect to the rock mass 11 is reduced by forming the vibration isolating portion 15 formed of the concave portion on the lower surface of the base plate 12, the vertical response is reduced because the spring rigidity of the ground spring 23 is reduced. The vibration system in the coupled models 6 (a) to (c) changes, and the peak of the resonance period becomes longer. Thereby, it can prevent resonating with the natural vibration of the equipment or the like inside the building 14.

Therefore, according to this embodiment, the following effects can be obtained.
(1) In this building 10, since the vibration shielding part 15 which consists of a recessed part is formed in the lower surface of the base plate 12 in the interface with the rock mass 30, the ground which acts on the building shown in FIG.6 (b). The spring rigidity of the spring 23 is lowered, and the resonance period of the vertical vibration of the building 10 can be shifted to the long period side. Therefore, it is possible to avoid resonance and maintain the soundness and safety of important equipment and the like arranged in the building. And since only the recessed part was formed as a structure of the vibration isolation | separation part 15, compared with the conventional structure of the complicated mechanism provided with the three-dimensional seismic isolation apparatus containing an air spring, a structure is simple and construction and maintenance are easy. Cost reduction is possible.

  (2) In the building 10, the vibration isolating portion 15 is provided by removing a position corresponding to the housing portion of the building 14. Therefore, the lower surface of the foundation plate 12 is supported by the rock mass 30 at a position corresponding to the frame portion of the building 14, and the vertical support load of the building 14 and the horizontal load when an earthquake occurs are received from the foundation plate 12 to the rock mass 30. And the building 14 can be appropriately supported by the bedrock 30.

  (3) By appropriately setting the area of the concave portion of the vibration isolating portion 15, even if the design of the building is not changed, the vertical vibration resonance period toward the long period side in the ground (rock) conditions of different construction sites Transition can be obtained.

(Second Embodiment)
Next, a second embodiment of the building 10 embodying the present invention will be described with a focus on differences from the first embodiment.

  In the second embodiment, as shown in FIG. 5, the vibration isolating portion 15 is formed by embedding a cushioning material 15 a such as polystyrene foam as a softer member than the base plate 12 on the lower surface of the base plate 12. . Therefore, transmission of the vertical vibration of the rock mass 30 is suppressed by the deformation of the cushioning material 15a.

  Therefore, in this second embodiment, it is possible to obtain an effect substantially equivalent to the effect in the first embodiment, and in this embodiment, the following effect can be obtained.

  (4) In this embodiment, since the vibration shielding part 15 is formed only by installing the cushioning material 15a such as polystyrene foam, the mold is not necessary, and the cost can be further reduced.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
-The vibration isolator 15 should have a planar shape other than a rectangle such as a circle or triangle.

-The mold 16 for forming the vibration isolator 15 is made of a wooden board.
-By embedding wood such as square wood as a softer member than the base plate on the lower surface of the base plate 12, that portion should be used as the vibration isolating portion 15.

  -Studs and plates are erected on the upper surface of the upper plate 20 or the like of the mold 16 for more reliably forming the vibration isolating portion 15 to enhance the reinforcement and integrity of the mold 16 with respect to the cast concrete To do.

  DESCRIPTION OF SYMBOLS 10 ... Building, 12 ... Base version, 13 ... Seismic isolation device, 14 ... Building, 15 ... Vibration isolation part, 30 ... Bedrock.

Claims (3)

In a building that supports the building via a seismic isolation device on the base plate installed on the bedrock,
It comprises a recess formed on the bottom surface of the foundation plate, and includes a vibration isolating portion that prevents vertical vibration from the rock mass from being transmitted to the foundation plate by not directly contacting the bedrock and the foundation plate ,
The said recessed part was comprised with the area determined so that the resonance period of the vertical vibration of the said building might be shifted to a long period side according to the hardness of the said rock mass . The building according to claim 1 , wherein a member softer than a base plate is provided in the recess. The building according to claim 1 or 2, wherein the vibration isolating portion is provided by removing a position for supporting a building frame.