JP6161979B2 - 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 is composed of a flat part and a receiving part formed to be recessed downward from the flat part and having a bottom surface and a side wall surface. The at least the lower part is accommodated in the accommodating portion, and a predetermined interval is provided between the side wall surface, and the seismic isolation material is installed on the bottom surface and made of an elastic material that supports the lower surface of the structure. And the entire container is filled so that at least the lower part of the structure is surrounded. A shock absorber that can be elastically deformed is attached to the entire circumference of the upper end of the storage portion, and the shock absorber retains the enclosed state of the envelope within a predetermined range of fluctuation caused by an earthquake. To do.

  If comprised in this way, while the enclosure will be in the state always enclosed, the impact with respect to the accommodating part of the structure at the time of inclination is relieve | moderated.

  According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the shock absorber has a box-shaped cross section in the circumferential direction of the structure.

  If comprised in this way, injection | pouring and enclosure of an enclosure will become easy.

  According to a third aspect of the present invention, in the configuration of the first aspect of the present invention, the shock absorber has a cross section in the circumferential direction of the structure, the upper end portion being fixed to the structure or the housing portion, and the lower end portion being the housing portion or the structure. It has a skirt shape that contacts an object.

  If comprised in this way, a structure will be simple and design will become easy.

  According to a fourth aspect of the present invention, in the configuration of the first aspect of the invention, the shock absorber has a cross section in the circumferential direction of the structure, the upper end portion and the lower end portion are fixed to the structure or the accommodating portion, and the central portion is accommodated. It has an Ω shape that comes into contact with a part or structure.

  If comprised in this way, contact force will be exhibited stably.

  According to a fifth aspect of the present invention, in the configuration of the first aspect of the present invention, the cushioning body is filled with compressed air, and the circumferential section of the structure is in contact with the structure and the accommodating section at the center. It has a ring shape.

  If comprised in this way, the contact force stable in all directions will be exhibited.

  According to a sixth aspect of the present invention, in the configuration of the first aspect of the present invention, the shock absorber has a cross section in the circumferential direction of the structure, the upper end is fixed to the structure or the housing, and the lower end is the housing or the structure. It has a bellows shape that is fixed to the object.

  If comprised in this way, an upper end part and a lower end part will always be fixed to an accommodating part or a structure.

  As described above, according to the first aspect of the present invention, the enclosure is always enclosed, and the impact on the housing portion of the structure at the time of inclination is reduced, so that the seismic resistance of the structure increases. At the same time, the risk of damage to the structure is reduced.

  In addition to the effect of the invention of the first aspect, the invention of the second aspect improves the usability because it becomes easy to inject and enclose the enclosure.

  The invention according to claim 3 is advantageous in terms of cost since the structure is simple and the design is easy in addition to the effect of the invention according to claim 1.

  In addition to the effect of the first aspect of the invention, the abutting force is stably exhibited, so that the reliability is improved.

  In addition to the effect of the first aspect of the invention, the invention according to the fifth aspect improves the reliability because a stable contact force is exhibited in all directions.

  In the invention described in claim 6, in addition to the effect of the invention described in claim 1, since the upper end portion and the lower end portion are always fixed to the housing portion or the structure, the enclosed state of the enclosure is ensured and the reliability is improved. improves.

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. FIG. 5 is an enlarged view of a portion “X” shown in FIG. 4. FIG. 5 is a schematic end view showing a state where the seismic isolation structure according to the embodiment of FIG. 4 has received a tsunami caused by an earthquake. It is a schematic sectional drawing of the buffer in the seismic isolation structure by 3rd Embodiment of this invention, and is a figure corresponding to FIG. 5 by 2nd Embodiment. It is a schematic sectional drawing of the buffer in the seismic isolation structure by 4th Embodiment of this invention, and is a figure corresponding to (1) of FIG. 7 by 3rd Embodiment. It is a schematic sectional drawing of the buffer body in the seismic isolation structure by 5th Embodiment of this invention, and is a figure corresponding to (1) of FIG. 7 by 3rd Embodiment. It is a schematic sectional drawing of the buffer in the seismic isolation structure by 6th Embodiment of this invention, and is a figure corresponding to (1) of FIG. 7 by 3rd Embodiment.

  FIG. 1 is a plan view showing a schematic structure of a seismic isolation structure according to a 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, which corresponds to FIG. 2 of the first embodiment, and FIG. 5 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 first embodiment except for the upper end portion of the accommodating portion, the different portions will be mainly described.

  Referring to the drawing, the seismic isolation material 19 is installed on the entire bottom surface 25 of the accommodating portion 24, and includes a support body 37 made of an elastic material such as synthetic rubber that supports the lower surface 20 of the structure 18, and the structure 18. The container 24 is filled so that at least the lower part is surrounded, and is composed of an enclosure 38 made of, for example, an asphalt polymer-based viscous material having fluidity. 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.

  Further, an elastically deformable buffer body 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 housing 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. 6 is a schematic end view showing a state where the seismic isolation structure according to the embodiment of FIG. 4 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 37 is deformed by the behavior of the lower surface 20 of the structure 18, and the shock absorber 35 is further 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. 7 is a schematic cross-sectional view of the buffer body in the seismic isolation structure according to the third embodiment of the present invention, and corresponds to FIG. 5 according to the second embodiment.

  Since the structure of the seismic isolation structure other than the shock absorber is the same as that of the second embodiment, the shock absorber will be mainly described here.

  Referring to (1) in the figure, the shock absorber 35 installed between the structure 18 and the foundation concrete 17 is a deformation composed of fiber reinforced rubber in which synthetic fibers are embedded in ethylene propylene rubber (EPDM). It consists of a possible elastic body, and the cross section in the circumferential direction of the structure 18 has a skirt shape in which the upper end is fixed to the structure 18 and the lower end is in contact with the side wall surface 26 of the foundation concrete 17 (accommodating part). is there. In this state, the enclosure 38 is sealed below the buffer body 35.

  The shape is set so that the lower end portion of the buffer body 35 always presses the side wall surface 26 of the foundation concrete 17 (accommodating portion) even when the structure 18 is inclined due to the occurrence of an earthquake. That is, as shown in (2) of the figure, when the distance between the structure 18 and the foundation concrete 17 becomes the minimum width due to the earthquake, the shock absorber 35 is deformed in the elastic region and the enclosure 38 is enclosed. When the state is maintained and the interval returns to the original width, the characteristic (form maintainability) is set so as to return to the initial state of (1) in the figure.

  On the other hand, when the distance between the structure 18 and the foundation concrete 17 reaches the maximum width due to the earthquake, the shock absorber 35 is deformed so as to spread by the elastic force applied in the initial state (the state (1) in the figure). The contact state with the side wall part 26 is maintained, and the enclosure state of the enclosure 38 is maintained. And the characteristic (form maintenance property) of the buffer 35 is set so that when the space | interval returns to the original width | variety, it will return to the initial state of (1) of a figure.

  Thereby, since the structure of the buffer 35 becomes simple, the design according to a use place becomes easy. The buffer 35 may be attached to the structure 18 after filling the enclosure 38.

  FIG. 8 is a schematic cross-sectional view of a shock absorber in a seismic isolation structure according to the fourth embodiment of the present invention, and corresponds to (1) of FIG. 7 according to the third embodiment.

  Since the structure of the seismic isolation structure other than the shock absorber is the same as that of the third embodiment, the shock absorber will be mainly described here.

  Referring to the figure, a shock absorber 35 installed between the structure 18 and the foundation concrete 17 is a deformable elastic body made of fiber reinforced rubber in which synthetic fibers are embedded in ethylene propylene rubber (EPDM). The cross section in the circumferential direction of the structure 18 has an Ω shape in which the upper end portion and the lower end portion are fixed to the structure 18 and the central portion is in contact with the side wall surface 26 of the foundation concrete 17 (accommodating portion). . In this state, the enclosure 38 is sealed below the buffer body 35.

  And like the buffer body by 3rd Embodiment, even if the space | interval of the structure 18 and the foundation concrete 17 changes with an earthquake, the buffer body 35 always presses the side wall surface 26 of the foundation concrete 17, so that The shape (form maintainability) is set.

  In addition, since both the upper end part and the lower end part are fixed to the structure 18 as for the buffer body 35 by this embodiment, the contact force with respect to the side wall surface 26 is exhibited stably.

  FIG. 9 is a schematic cross-sectional view of the buffer body in the seismic isolation structure according to the fifth embodiment of the present invention, and corresponds to (1) of FIG. 7 according to the third embodiment.

  Since the structure of the seismic isolation structure other than the shock absorber is the same as that of the third embodiment, the shock absorber will be mainly described here.

  Referring to the figure, a shock absorber 35 installed between the structure 18 and the foundation concrete 17 is a deformable elastic body made of fiber reinforced rubber in which synthetic fibers are embedded in ethylene propylene rubber (EPDM). The circumferential cross section of the structure 18 has a ring shape and is filled with compressed gas. In order to prevent the buffer body 35 from moving up and down, a pair of L-shaped first fixtures 39 a and 39 b are provided on the structure 18 side above and below the buffer body 35, and a pair of side walls 26 of the foundation concrete 17. L-shaped second fixtures 40 a and 40 b are respectively attached to the upper and lower sides of the buffer body 35. In this state, the enclosure 38 is sealed below the buffer body 35.

  As a result, like the buffer according to the third embodiment, even if the distance between the structure 18 and the foundation concrete 17 varies due to an earthquake, the buffer 35 is always freely deformed by the pressure of the internal compressed gas, The shape (form maintainability) of the buffer 35 is set so as to always press the side wall surface 26 of the structure 18 and the foundation concrete 17.

  Since the buffer body 35 according to this embodiment is ring-shaped and filled with compressed gas inside, the abutting force against the side wall surface 26 of the structure 18 and the foundation concrete 17 is stably exhibited in all directions. The

  FIG. 10 is a schematic cross-sectional view of a buffer body in a seismic isolation structure according to a sixth embodiment of the present invention, corresponding to (1) of FIG. 7 according to the third embodiment.

  Since the structure of the seismic isolation structure other than the shock absorber is the same as that of the third embodiment, the shock absorber will be mainly described here.

  Referring to the figure, a shock absorber 35 installed between the structure 18 and the foundation concrete 17 is a deformable elastic body made of fiber reinforced rubber in which synthetic fibers are embedded in ethylene propylene rubber (EPDM). The circumferential cross section of the structure 18 has a bellows shape in which the upper end is fixed to the structure 18 and the lower end is fixed to the side wall surface 26 of the foundation concrete 17 (accommodating portion). In this state, the enclosure 38 is sealed below the buffer body 35.

  As in the case of the shock absorber according to the third embodiment, the bellows structure of the shock absorber 35 expands and contracts even when the distance between the structure 18 and the foundation concrete 17 changes due to an earthquake, and the enclosure 38 is maintained in the enclosed state. Thus, the shape of the buffer 35 is set.

  In addition, since both the upper end part and the lower end part are fixed to the structure 18 and the foundation concrete 17, the buffer body 35 by this embodiment can maintain the enclosure state of the enclosure 38 more reliably.

  In each of the above embodiments, the body shape of the structure has a cylindrical shape, but may be other shapes.

  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.

  Further, 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 may be a flat surface or a simple protruding shape. It may be. In this case, in any 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.

  Further, in each of the above-described embodiments, a synthetic rubber material having a specific configuration is used as the elastic material of the buffer body. However, a natural rubber material may be used, or alternatively, a synthetic rubber and fiber laminate or a synthetic rubber material may be used instead. A resin material may be used.

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

  Furthermore, in said 3rd or subsequent embodiment, although the buffer body is attached to the specific object of a structure or foundation concrete, an attachment object may be reverse. For example, the shock absorber according to the third embodiment may be fixed to the foundation concrete side.

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 (6)

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,
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,
The seismic isolation material is
A support body made of an elastic material installed on the bottom surface and supporting the lower surface of the structure;
An enclosure made of a viscous material filled in the entire housing portion so that at least the lower part of the structure is surrounded,
A shock absorber capable of elastic deformation is attached to the entire circumference of the upper end of the housing portion,
The seismic isolation structure, in which the buffer body maintains the enclosed state of the enclosure in a fluctuation range of the predetermined interval caused by an earthquake.   The seismic isolation structure according to claim 1, wherein the shock absorber has a box-shaped cross section in the circumferential direction of the structure.   2. The shock absorber has a skirt shape in which a cross section in a circumferential direction of the structure has an upper end fixed to the structure or the housing and a lower end abutted against the housing or the structure. The seismic isolation structure described in 1.   The shock absorber has a cross section in the circumferential direction of the structure, and has an Ω shape in which an upper end portion and a lower end portion are fixed to the structure or the housing portion, and a central portion is in contact with the housing portion or the structure. The seismic isolation structure according to claim 1.   2. The seismic isolation structure according to claim 1, wherein the shock absorber has a ring shape in which a compressed gas is sealed inside, and a cross section in a circumferential direction of the structure has a central portion that contacts the structure and the housing portion. body.   The shock absorber has a bellows shape in which a cross-section in the circumferential direction of the structure has an upper end fixed to the structure or the housing and a lower end fixed to the housing or the structure. Item 1. The seismic isolation structure according to item 1.

Images