JP6075953B2 - Seismic isolation structure - Google Patents

Description

  The present invention relates to a seismic isolation structure, and more particularly to a seismic isolation structure that alleviates the effects of various phenomena associated with earthquakes.

  With Japan as a country with frequent earthquakes, after the Great Hanshin Earthquake, the development of earthquake-resistant structures has progressed in conjunction with recent high-rise buildings, and various earthquake-resistant measures have been applied to various buildings, resulting in moderate effects. Yes.

  The seismic structure as described above is effective and reliable for earthquakes in inland structures.

  However, the actual situation is that the coastal area was hit hard by the double impact force accompanying the tsunami in response to earthquakes such as the Indonesia Sumatra Earthquake and the Great East Japan Earthquake.

  In particular, among coastal structures, structures that require continuous space between the ground and underground, such as sewerage treatment facilities, were found to have insufficient wave resistance against liquefaction phenomena and tsunamis.

  On the other hand, the current situation is that separate measures have been taken for seismic isolation and wave isolation (wave resistance). That is, steel laminated rubber or the like is used as the seismic isolation structure, and there are few structures for which direct countermeasures are taken for the structure as a seismic isolation structure. In this case, the area required for the countermeasure becomes excessive, and the cost is not advantageous.

  This invention was made in order to solve the above subjects, and it aims at providing the seismic isolation structure provided with seismic isolation performance and wave isolation performance.

In order to achieve the above object, the invention according to claim 1 is a seismic isolation structure, and a seismic isolation material disposed on the foundation concrete, and a structure installed on the seismic isolation material, The lower surface of the structure has a shape that protrudes downward, and the center of gravity of the structure is perpendicular to the vertical line that passes through the center of gravity of the structure and the vertical generated from the seismic isolation material that acts on the lower surface when the structure is tilted Located below the intersection with the extension line of the reaction force in the direction, the foundation concrete consists of a flat part and a receiving part that is formed to dent downward from the flat part and has a bottom surface and a side wall surface, and is seismically isolated. The material is disposed on at least the bottom surface of the housing portion, and at least the lower part of the structure is housed in the housing portion, and a predetermined interval is provided between the side wall surface and the structure is oscillated within the range of the predetermined interval. The seismic isolation material is installed on the bottom surface and the bottom surface of the structure It includes a support made of a plurality of elastic materials that are supported at regular intervals, and an enclosure made of a viscous material filled in the entire accommodating portion, and the entire upper end of the accommodating portion can be elastically deformed to abut against the structure. A shock absorber is attached , and the enclosure is enclosed in the housing portion by the shock absorber .

  If comprised in this way, when a structure inclines with an earthquake or a tsunami, the moment of the direction which returns to the original position will generate | occur | produce. Moreover, the inclination range of the structure is limited. Furthermore, the structure returns to the initial position within a predetermined interval. In addition, when the structure is tilted, the support and the enclosure produce resistance. Further, the enclosure is enclosed in the accommodating portion.

  According to a second aspect of the present invention, in the configuration of the first aspect of the invention, the lower surface of the structure has a spherical shape.

If comprised in this way, the same resistance will arise with respect to all the directions of a structure.
According to a third aspect of the present invention, in the configuration of the first aspect of the invention, the lower surface of the structure has a cylindrical side shape.
If comprised in this way, the influence of the force added to the direction orthogonal to the axial direction of a cylinder will be relieved.
According to a fourth aspect of the present invention, in the configuration of the first aspect of the invention, the lower surface of the structure is configured by a curved surface having a constant curvature radius, and the upper surface of the seismic isolation material is configured in a shape along the lower surface. Is.
If comprised in this way, a structure and a seismic isolation material will be in the state which always contacts over the whole surface.

  The invention according to claim 5 is a seismic isolation structure, comprising a seismic isolation material disposed on the foundation concrete and a structure installed on the seismic isolation material, the lower surface of the structure being lower The center of gravity of the structure has a vertical line passing through the center of gravity of the structure and an extension line of the vertical reaction force generated from the seismic isolation material acting on the lower surface when the structure is inclined. Located below the intersection, the lower surface of the structure has a stepped shape made up of a plurality of concentric circles.

If comprised in this way, when a structure inclines with an earthquake or a tsunami, the moment of the direction which returns to the original position will generate | occur | produce. In addition, the structure can be easily manufactured and the same resistance is generated in all directions.

The invention according to claim 6 is the structure of the invention according to claim 5, wherein the basic concrete includes a flat portion and a receiving portion formed so as to be recessed downward from the flat portion, and having a bottom surface and a side wall surface, The seismic isolation material is disposed on at least the bottom surface of the accommodating portion, and the structure is configured such that at least a lower portion thereof is accommodated in the accommodating portion and a predetermined interval is provided between the side wall surface.
If comprised in this way, the inclination range of a structure will be restrict | limited.
According to a seventh aspect of the present invention, in the configuration of the sixth aspect of the present invention, the seismic isolation material is installed on the bottom surface and is made of a plurality of elastic materials that support the lower surface of the structure at a predetermined interval, and the structure. And an enclosure made of a viscous material filled in the housing portion so that at least the lower part of the housing is surrounded.
If comprised in this way, when a structure will incline, a support body and an enclosure will produce resistance.
According to an eighth aspect of the present invention, in the configuration of the seventh aspect of the present invention, an elastically deformable shock absorber that abuts against the structure is attached to the entire circumference of the upper end of the accommodating portion, and an enclosure is provided in the entire accommodating portion. It is to be filled.

  If comprised in this way, while it will be in the state with which the enclosure was enclosed, the impact with respect to the accommodating part of the structure at the time of inclination will be relieved.

  As described above, according to the first aspect of the present invention, when a structure is tilted by an earthquake or tsunami, a moment is generated in a direction to return to the original position. Reduce the impact. In addition, since the inclination range of the structure is limited, the structure is prevented from overturning and the reliability is improved. Furthermore, in the range of the predetermined interval, the structure returns to the initial position, so that no extra work is required for the return. Further, when the structure is inclined, the support and the surrounding body generate resistance, so that the seismic resistance of the structure increases. Furthermore, since the enclosure is enclosed in the accommodating portion, there is no risk that the enclosure will inadvertently flow out of the accommodating portion even if it is swung by an earthquake or the like.

In addition to the effect of the invention of the first aspect, since the same resistance is generated in all directions of the structure, the reliability of the seismic resistance is improved.
In addition to the effect of the invention described in claim 1, the effect of the force applied in the direction orthogonal to the axial direction of the cylinder is mitigated, so that the invention can be applied to limited applications.
In addition to the effect of the invention described in claim 1, the structure according to claim 4 is in a state where the structure and the seismic isolation material are always in contact with each other over the entire surface. Is more stable.

  According to the fifth aspect of the present invention, when the structure is tilted by an earthquake or a tsunami, a moment is generated in a direction to return to the original position. In addition, since the structure is easy to manufacture and the same resistance is generated in all directions, the cost is advantageous and the reliability of the seismic resistance is improved.

According to the sixth aspect of the invention, in addition to the effect of the fifth aspect of the invention, the inclination range of the structure is limited, so that the structure is prevented from falling and the reliability is improved.
According to the seventh aspect of the invention, in addition to the effect of the sixth aspect of the invention, when the structure is inclined, the support body and the surrounding body generate resistance, so that the seismic resistance of the structure increases and Filling is easy.
In addition to the effect of the invention described in claim 7, the invention described in claim 8 is in a state in which the enclosure is enclosed, and the impact on the housing portion of the structure during tilting is mitigated. The seismic resistance is further increased and the risk of damage to the structure is reduced.

It is a top view which shows schematic structure of the seismic isolation structure by 1st Embodiment of this invention. It is the end view of the II-II line shown in FIG. It is the schematic side view which showed the behavior of the structure 18 shown in FIG. 2 when a tsunami generate | occur | produces. It is a schematic end view of the seismic isolation structure by 2nd Embodiment of this invention, and respond | corresponds to FIG. 2 of 1st Embodiment. It is a schematic end view of the seismic isolation structure by 3rd Embodiment of this invention, and respond | corresponds to FIG. 2 of 1st Embodiment. It is a general | schematic end elevation of the seismic isolation structure by 4th Embodiment of this invention, and respond | corresponds to FIG. 2 of 1st Embodiment. It is a schematic end view of the seismic isolation structure by 5th Embodiment of this invention, and respond | corresponds to FIG. 6 of 4th Embodiment. FIG. 8 is an enlarged view of a portion “X” shown in FIG. 7. FIG. 8 is a schematic end view showing a state where the seismic isolation structure according to the embodiment of FIG. 7 has received a tsunami caused by an earthquake. It is a schematic end view of the seismic isolation structure by 6th Embodiment of this invention, and respond | corresponds to FIG. 7 of 5th Embodiment.

  FIG. 1 is a plan view showing a schematic structure of the seismic isolation structure according to the first embodiment of the present invention, and FIG. 2 is an end view taken along line II-II shown in FIG.

  With reference to these drawings, the structure 18 has a cylindrical shape extending in the vertical direction, and its lower surface 20 has a spherical shape. The lower part of the structure 18 is accommodated in an accommodating part 24 formed in the foundation concrete 17. The accommodating portion 24 is formed so as to be recessed downward in a cylindrical shape from the flat portion 23 of the foundation concrete 17 and has a bottom surface 25 and a side wall surface 26.

  A seismic isolation material 19 mainly composed of an elastic material such as synthetic rubber is disposed on at least the bottom surface 25 of the housing portion 24. A side surface of the structure 18 is not restrained, and a predetermined interval 28 is provided around the side wall surface 26 of the housing portion 24 to allow the structure 18 to swing within a certain range. Thereby, the seismic isolation material 19 exhibits the seismic isolation function when an earthquake occurs as usual, and the shape of the lower surface 20 of the structure 18 also exhibits the seismic isolation function.

  Next, the wave isolation function will be described.

  FIG. 3 is a schematic side view showing the behavior of the structure 18 shown in FIG. 2 when a tsunami occurs.

  Referring to the drawing, when the structure 18 whose side surfaces are not restrained is subjected to a tsunami impact, the lower surface 20 is inclined as shown in the figure because it has a spherical shape. At this time, the lower surface 20 receives a reaction force F equal to the magnitude of gravity W from the seismic isolation material 19 at the contact position between the lower surface 20 and the surface of the seismic isolation material 19. On the other hand, the center of gravity G of the structure 18 is set to be positioned below the intersection point O between the vertical line 31 passing through the center of gravity G and the extension line 32 of the reaction force F.

  Then, downward gravity W acts on the position of the center of gravity G of the structure 18, and a reaction force F having the same magnitude as the gravity W is generated on the lower surface 20 of the structure 18 in parallel with a distance L therebetween. As a result, a moment that is a couple (W · L) is generated to return the structure 18 to the original position. Therefore, the impact force of the tsunami is alleviated by the tilting motion of the structure 18, and when the impact force is reduced, the structure 18 returns to the original position. In this case, the tilting motion of the structure 18 changes according to the impact force of the tsunami. Further, since the distance L increases as the degree of inclination of the structure 18 increases, the value of the couple acting on the return also increases. As a result, the risk of the structure 18 being destroyed or damaged by the impact force of the tsunami is reduced.

  Further, in this embodiment, a part of the structure 18 is accommodated in the accommodating portion 24 via the predetermined interval 28. Therefore, the structure 18 swings in the range of the predetermined interval 28, and when the tsunami impact force exceeding the range of the predetermined interval 28 is received, the structure 18 comes into contact with the side wall surface 26 of the accommodating portion 24, and the inclination further increases. Be bound. Thereby, the possibility of the structure 18 falling is avoided and the reliability of the seismic structure is improved.

  FIG. 4 is a schematic end view of the seismic isolation structure according to the second embodiment of the present invention, and corresponds to FIG. 2 of the first embodiment.

  Since this embodiment has the same structure as that of the first embodiment except for the upper end portion of the accommodating portion, the different portions will be mainly described.

  Referring to the figure, an elastically deformable shock absorber 35 that is in contact with the side wall of the structure 18 is attached to the entire periphery of the upper end of the accommodating portion 24. Thereby, even when the structure 18 is largely inclined by an impact force such as a tsunami, damage can be prevented without directly contacting the foundation concrete 17. Further, since the buffer body 35 has elasticity, the magnitude of the reaction force against the structure 18 via the buffer body 35 can be adjusted to a desired value by adjusting the elastic characteristics. .

  FIG. 5 is a schematic end view of the seismic isolation structure according to the third embodiment of the present invention, and corresponds to FIG. 2 of the first embodiment.

  Since this embodiment has the same structure as that of the first embodiment except for the shape of the upper surface of the seismic isolation material, different portions will be mainly described.

  Referring to the figure, the upper surface of seismic isolation material 19 is formed in a shape along the lower surface of lower surface 20 of structure 18. Therefore, the weight of the normal structure 18 is dispersed in the seismic isolation material 19 as compared with the first embodiment in which the top surface of the seismic isolation material 19 is flat, and the installation state is stabilized. On the other hand, as described above, the lower surface 20 of the structure 18 has a spherical shape. That is, the radius of curvature M for all locations on the lower surface 20 does not change from the center O. Therefore, when the structure 18 tilts due to the impact force of the tsunami, the seismic isolation material 19 has no fear of obstructing its movement in terms of shape other than slip resistance. In addition, even when tilted, the bottom surface 20 of the structure 18 and the top surface of the seismic isolation material 19 are maintained in contact with the entire surface. Therefore, the installation state is more stable even in an earthquake. Even in this case, when the impact force of the tsunami is reduced, the structure 18 returns to the original position.

  FIG. 6 is a schematic end view of the seismic isolation structure according to the fourth embodiment of the present invention, and corresponds to FIG. 2 of the first embodiment.

  Since this embodiment has the same structure as that of the first embodiment except for the structure of the seismic isolation material, different parts will be mainly described.

  Referring to the drawing, the seismic isolation material 19 is installed on the bottom surface 25 of the accommodating portion 24 and is made of a support made of an elastic material such as a plurality of synthetic rubbers or specific fiber materials that support the lower surface 20 of the structure 18 at a predetermined interval. The body 37 and an enclosure 38 made of, for example, an asphalt polymer-based viscous material that has fluidity and is filled in the accommodating portion 24 so as to surround at least the lower part of the structure 18. As a result, the weight of the structure 18 is mainly handled by the support body 37, and the enclosure 38 is mainly responsible for the resistance force against the tilting motion of the structure 18 due to the impact force of the tsunami. Therefore, it becomes possible to adjust desired earthquake resistance with respect to an earthquake.

  In addition, since the structure 18 is raised from the bottom surface 25 of the accommodating portion 24 by the support body 37, the enclosure 38 including the portion below the lower surface 20 of the structure 18 can be easily filled. In addition, although it is possible to use the existing seismic isolation material for the support body 37 and to give high damping property, in this embodiment, the support body 37 is constrained by the surrounding body 38. Therefore, the conventional underground structure for the base isolation system is not required without using the conventional steel sheet laminated rubber. As a result, significant cost reduction is possible.

  FIG. 7 is a schematic end view of the seismic isolation structure according to the fifth embodiment of the present invention, which corresponds to FIG. 6 of the fourth embodiment, and FIG. 8 shows the “X” shown in FIG. It is an enlarged view of a part.

  Since this embodiment has the same structure as that of the fourth embodiment except for the upper end portion of the accommodating portion, different portions will be mainly described.

  Referring to the figure, an elastically deformable shock absorber 35 that is in contact with the side wall of the structure 18 is attached to the entire periphery of the upper end of the accommodating portion 24. Specifically, a concave portion 41 is formed at a corner portion between the upper end of the side wall surface 26 of the foundation concrete 17 and the flat portion 23, and the buffer 35 closes a space between the concave portion 41 and the structure 18. is set up.

  The buffer body 35 is made of an elastic material of fiber reinforced rubber in which synthetic fibers are embedded in ethylene propylene rubber (EPDM), and is made of a rubber that fits detachably into a concave groove portion 42 that is opened upward and an upper surface of the groove portion 42. And a lid portion 43. Injection holes 44 are formed at predetermined intervals in the circumferential direction at the bottom of the recess 41 and facing the space between the side wall surface 26 of the foundation concrete 17 and the side wall surface of the structure 18. As a result, the enclosure 38 can be filled up to the position of the buffer 35 in the accommodating portion 24 through the injection hole 44 of the buffer 35.

  Thus, since the enclosure 38 is enclosed in the accommodating part 24, even if it receives rocking | fluctuation by an earthquake etc., there is no possibility of inadvertently flowing out from the accommodating part 24 outside.

  FIG. 9 is a schematic end view showing a state where the seismic isolation structure according to the embodiment of FIG. 7 has received a tsunami caused by an earthquake.

  Referring to the drawing, when receiving a tsunami 47 caused by an earthquake, the structure 18 is inclined by the impact force as described above. In this case, the support body 37 is deformed by the behavior of the lower surface 20 of the structure 18, and the shock absorber 35 is deformed by the inclination of the side wall of the structure 18 to alleviate the impact. Even if the buffer 35 is deformed, the enclosed state of the enclosure 38 is maintained, so that the enclosure 38 does not flow out and the enclosure 38 flows according to the movement of the structure 18 with respect to the accommodating portion 24. . This increases the flow resistance of the enclosure 38 against the inclination of the structure 18. Further, due to the change in the pressure receiving angle from the tsunami due to the inclination of the structure 18, it can be expected that the flowing water pressure of the subsequent tsunami (push wave and pull wave) will be reduced.

  Even if the tsunami 47 covers the upper surface of the foundation concrete 17, the shock absorber 35 does not cause the tsunami 47 to enter the housing portion 24. Therefore, there is no possibility of the structure 18 being lifted due to the intrusion of seawater, so that the reliability of the installation of the structure 18 is improved. Furthermore, since the lower part of the structure 18 is filled and surrounded by the enclosure 38, the possibility of inflow of groundwater through the ground below the foundation concrete 17 is reduced.

  When the earthquake is stopped and the tsunami 47 is drawn, the restoring force of the structure 18 restores to the original position as described above, the support body 37 in the accommodating portion 24 also returns to the original shape, and the enclosure 38 is also restored to the original shape. It will be in the state of filling, and will be able to demonstrate the initial seismic performance.

  FIG. 10 is a schematic end view of the seismic isolation structure according to the sixth embodiment of the present invention, which corresponds to FIG. 7 of the fifth embodiment.

  Since this embodiment has the same structure as that of the fifth embodiment except for the shape of the lower surface of the structure, different portions will be mainly described.

  Referring to the figure, the lower surface of the structure 18 protrudes downward and has a shape, but it does not have a spherical shape as in the fifth embodiment. That is, the lower surface of the structure 18 has a horizontal plane, and is composed of a first step portion 49, a second step portion 50, and a third step portion 51 each having a concentric outer edge. A support 37 having different vertical lengths is installed between each of the first step portion 49, the second step portion 50, and the third step portion 51 and the bottom surface 25 of the housing portion 24. If the shape of each of the first step portion 49, the second step portion 50, and the third step portion 51 is approximated to the curved surface shape corresponding to the arc of the two-dot chain line in the figure, the radius of curvature M is constant from the center O. Can be assumed. Then, the position of the center of gravity G of the structure 18 may be similarly set to a position below the center O. As a result, the lower surface of the structure 18 can have a simple stepped shape, and the same seismic isolation effect as that of the base isolation structure according to the fifth embodiment can be expected.

  In each of the above embodiments, the housing portion is provided. However, the housing portion is not necessarily provided, and the body portion of the structure has a cylindrical shape, but has other shapes. Also good.

  Further, in each of the embodiments described above, about half of the structure is accommodated in the accommodating portion, but it is sufficient that at least the lower part of the structure is accommodated.

  Furthermore, in each of the embodiments described above, the lower surface of the structure has a spherical shape, but may be a shape other than a spherical shape such as a cylindrical side surface shape, or a simple protruding shape. Also good. In this case, the position of the center of gravity may be set so that it can return to the original position when tilted.

  Furthermore, in each said embodiment, although the accommodating part is made into the recessed part formed in the basic concrete, you may form the part corresponded to the side wall surface of an accommodating part with steel sheet piles.

  Furthermore, in each of the above embodiments, a synthetic rubber material is used as the elastic material. However, a natural rubber material may be used, or a synthetic rubber and fiber laminate or a synthetic resin material may be used instead. good.

  Furthermore, in the above-described fourth and subsequent embodiments, an asphalt polymer-based viscous material is used for the enclosure, but instead, a mixture of synthetic rubber and asphalt may be used. Preferably, a viscoelastic material having not only viscous performance but also elastic performance is more effective.

  Furthermore, in the fourth and subsequent embodiments, the lower surface of the structure has a spherical shape, but may be a flat surface.

DESCRIPTION OF SYMBOLS 15 ... Base isolation structure 17 ... Foundation concrete 18 ... Structure 19 ... Base isolation material 20 ... Lower surface 23 ... Flat part 24 ... Storage part 25 ... Bottom part 26 ... Side wall surface 28 ... Predetermined space | interval 31 ... Vertical line 32 ... Extension line 35 ... Buffer body 37... Support body 38... Enclosure The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (8)

A seismic isolation structure,
Seismic isolation material placed on the foundation concrete,
A structure installed on the seismic isolation material,
The lower surface of the structure has a shape projecting downward, and the center of gravity of the structure acts on the vertical line passing through the center of gravity of the structure and the seismic isolation acting on the lower surface when the structure is inclined. Located below the intersection with the extension line of the vertical reaction force generated from the material,
The foundation concrete is formed of a flat portion and a receiving portion formed to be recessed downward from the flat portion, and having a bottom surface and a side wall surface,
The seismic isolation material is disposed on at least the bottom surface of the accommodating portion;
At least a lower part of the structure is accommodated in the accommodating portion, and a predetermined interval is provided between the side wall surface,
In the range of the predetermined interval, the structure is installed to be swingable,
The seismic isolation material is
A support made of a plurality of elastic materials installed on the bottom surface and supporting the lower surface of the structure at a predetermined interval;
An enclosure made of a viscous material filled in the entire housing portion,
An elastically deformable shock absorber that contacts the structure is attached to the entire periphery of the upper end of the housing portion ,
The seismic isolation structure , wherein the enclosure is enclosed in the housing portion by the buffer .   The seismic isolation structure according to claim 1, wherein a lower surface of the structure has a spherical shape.   The seismic isolation structure according to claim 1, wherein a lower surface of the structure has a cylindrical side shape. The lower surface of the structure is configured by a curved surface having a constant curvature radius,
The seismic isolation structure according to claim 1, wherein an upper surface of the seismic isolation material is configured in a shape along the lower surface. A seismic isolation structure,
Seismic isolation material placed on the foundation concrete,
A structure installed on the seismic isolation material,
The lower surface of the structure has a shape projecting downward, and the center of gravity of the structure acts on the vertical line passing through the center of gravity of the structure and the seismic isolation acting on the lower surface when the structure is inclined. Located below the intersection with the extension line of the vertical reaction force generated from the material,
The bottom surface of the structure is a seismic isolation structure having a stepped shape including a plurality of concentric circles. The foundation concrete is formed of a flat portion and a receiving portion formed to be recessed downward from the flat portion, and having a bottom surface and a side wall surface,
The seismic isolation material is disposed on at least the bottom surface of the accommodating portion;
The seismic isolation structure according to claim 5, wherein at least a lower part of the structure is accommodated in the accommodation portion and a predetermined interval is provided between the side wall surface and the structure. The seismic isolation material is
A support made of a plurality of elastic materials installed on the bottom surface and supporting the lower surface of the structure at a predetermined interval;
The seismic isolation structure according to claim 6, further comprising an enclosure made of a viscous material filled in the housing portion so that at least a lower portion of the structure is surrounded. An elastically deformable shock absorber that contacts the structure is attached to the entire periphery of the upper end of the housing portion,
The seismic isolation structure according to claim 7, wherein the entire enclosure is filled with the enclosure.

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