JP2000170194A - Base-isolation construction of structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the effect of absorption of seismic energy by a buffer area for a long period, while preventing bad effects such as collapse of the peripheral ground, settlement of the ground or aged deterioration of buffer materials. SOLUTION: In a base-isolation construction of a structure, a dynamic earth pressure buffer area 4 is provided between an underground outer wall 2 and a pile 7 being underground buried parts of the structure 1 and the peripheral ground 3, and this area is constituted of a hollow support 5 supporting part of the earth pressure from the peripheral ground 3 and a filler 6 filled inside the hollow support and supporting the residual earth pressure at the back of the hollow support. The hollow support 5 is constituted of a tube body of a brittle material so that it may support, together with the filler 6 inside, ordinary static earth pressure and dynamic earth pressure in a medium or small earthquake and that it be destructed, on the other hand, by the dynamic earth pressure in regard to an earthquake of a prescribed scale or above, while the filler 6 be discharged outside the hollow support 5 by the earth pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation structure for a structure having an underground buried portion.

[0002]

2. Description of the Related Art A structure of a structure is appropriately selected from a direct foundation, a pile foundation, and the like according to its scale and strength of a supporting ground. In the case of a pile foundation, a pile is buried underground. However, even if it is a direct foundation, if it is a structure of a certain size or more, it is often constructed on a high-quality supporting ground below the surface layer, so that it often has an underground outer wall.

Underground buried portions of structures such as underground outer walls and piles are subjected to dynamic earth pressure based on dynamic interaction with the surrounding ground during an earthquake. It is necessary to anticipate a large seismic margin, but if a huge earthquake unexpectedly hits, the dynamic earth pressure during the earthquake will be excessively larger than the design external force,
The underground part of the structure may be damaged unexpectedly. In particular, sewage treatment plants must be located on soft ground because they are required to be close to rivers.However, in such soft ground, the underground structure of the ground is often complicated, and There is a limit in accuracy in accurately grasping the dynamic earth pressure acting on the part at the design stage.

[0004]

Under such circumstances, there is a concept that a buffer region is provided between the structure and the surrounding ground to absorb the dynamic earth pressure during an earthquake.

[0005] However, in a site composed of backfill soil or soft soil, if a buffer region is simply provided around the underground buried part, the buffer region may not be connected to the buffer region by a constant static earth pressure or by a dynamic earth pressure of a small or medium earthquake. The ground side wall, which is the boundary, collapses to the buffer area side, causing the subsidence of the surrounding ground, or the cushioning material arranged in the buffer area is compressed and hardened by the constant static earth pressure etc., and the deformation absorption capacity deteriorates over time, At the time of the great earthquake, there was a problem that the buffer effect was not exhibited.

The present invention has been made in consideration of the above-described circumstances, and has an effect of absorbing energy during an earthquake by a buffer region while preventing the adverse effects such as collapse of the surrounding ground, land subsidence, and aging of the cushioning material. It is an object of the present invention to provide a seismic isolation structure for a structure capable of maintaining the structure for a long time.

[0007]

In order to achieve the above-mentioned object, a seismic isolation structure for a structure according to the present invention is described in claim 1, wherein a moving soil is disposed between an underground portion of the structure and a surrounding ground. A pressure buffer area, wherein the dynamic earth pressure buffer area is provided with a hollow support for supporting a part of the earth pressure from the surrounding ground, and a soil filled inside the hollow support at the back of the hollow support. And a filler that supports the rest of the pressure, so that the hollow support is deformed with respect to a dynamic earth pressure of a certain level or more, and the filler is discharged by the dynamic earth pressure. .

Further, the seismic isolation structure of the structure according to the present invention comprises:
The hollow support is made of a brittle material such as concrete or glass.

Further, the seismic isolation structure of the structure according to the present invention comprises:
The filler is composed of a liquid such as water or muddy water.

In the seismic isolation structure for a structure according to the present invention, a hollow support for supporting a part of earth pressure from the surrounding ground and the hollow support between the underground portion of the structure and the surrounding ground. And a filling material for supporting the rest of the earth pressure at the back of the hollow support is provided, but such a hollow support has a dynamic earth pressure of a certain level or more. And the filler is discharged by the dynamic earth pressure.

For this reason, at all times or during a small or medium-sized earthquake, the static earth pressure or a relatively small dynamic earth pressure is supported by the hollow support and the filler filled therein. The hollow support is deformed by the large dynamic earth pressure, and the filler filled therein is discharged out of the hollow support by the dynamic earth pressure.

[0012] Therefore, at all times or during a small-to-medium-sized earthquake, the hollow support and the filler prevent the surrounding ground from collapsing or subsidence. Also, in the event of a large earthquake, large dynamic earth pressure deforms the hollow support and the internal filler is discharged out of the hollow support, absorbing the seismic energy and the relative displacement between the surrounding ground and the structure As a result, the seismic input to the structure is reduced, and the vibration of the structure also functions in the same manner as when the hollow support and the filler are subjected to dynamic earth pressure. Converges promptly upon receiving.

[0013] The dynamic earth pressure buffering area may be provided so as to be scattered around the underground portion of the structure, that is, around the underground outer wall or the pile, or to be continuously surrounded, but the arrangement thereof is arbitrary. is there. Further, it may be provided so as to be in contact with the underground buried portion, or may be provided in a state separated from the underground buried portion. The underground buried portion includes not only a case where a part is buried as in a high-rise building but also a case where it is almost or completely buried such as an LNG underground tank or a water storage pit.

The hollow support, together with the internal filler, supports static earth pressure and dynamic earth pressure during a small or medium-sized earthquake, while having a strength low enough to be deformed by an earthquake of a certain scale or more due to the dynamic earth pressure. If the hollow support is made of a brittle material such as concrete or glass, the hollow support will have a brittle fracture property when a dynamic earth pressure of a certain level or more is applied. And instantaneously fall apart, and its crushing makes it possible to absorb large seismic energy in an instant. Also, relative displacement between the surrounding ground and the structure can be quickly followed and absorbed without delaying the seismic motion.

On the other hand, the filler always supports the earth pressure or a small dynamic earth pressure together with the hollow support on the back side of the hollow support, and follows the deformation when the hollow support is deformed by the large dynamic earth pressure. Any structure or material can be used as long as it can be quickly discharged out of the hollow support, but if such a filler is composed of a liquid such as water or muddy water, it will squirt onto the ground, , It can be quickly discharged from the hollow support.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a seismic isolation structure for a structure according to the present invention will be described with reference to the accompanying drawings. It is to be noted that the same reference numerals are given to components and the like that are substantially the same as those in the conventional technology, and description thereof is omitted.

FIG. 1 is a view showing a seismic isolation structure of a structure according to the present embodiment. As can be seen from the figure, the seismic isolation structure of the structure according to the present embodiment provides a dynamic earth pressure buffering region 4 between the underground outer wall 2 and the pile 7 and the surrounding ground 3 which are the underground buried portion of the structure 1. The dynamic earth pressure buffer region is supported by a hollow support 5 that supports a part of the earth pressure from the surrounding ground 3, and the inside of the hollow support is filled to support the remaining earth pressure on the back surface of the hollow support. And a filling material 6 to be used.

As can be clearly understood from the horizontal sectional view of FIG. 2, a plurality of hollow supports 5 are provided so as to surround the underground outer wall 2, and each has a substantially cylindrical shape. Such a hollow support 5
Is supported together with the internal filling material 6 against the constant static earth pressure and the dynamic earth pressure during a small or medium-sized earthquake, while it is destroyed by the dynamic earth pressure when the earthquake exceeds a certain scale. It is composed of a tube made of mortar or concrete as a brittle material so that the filler 6 is discharged out of the hollow support 5 by pressure. The hollow support 5 can be made of precast.

The filler 6 is formed of liquid water, and is filled in the hollow support 5 in a state of being filled in a water-blocking bag 9 made of rubber, vinyl or the like. Here, the water-blocking bag 9 is configured such that when the hollow support 5 is broken and dynamic earth pressure acts on the filler 6, the vicinity of the top ruptures and the filler is ejected to the ground. Is good.

As described above, the constant static earth pressure and the dynamic earth pressure during a small-to-medium earthquake are not supported by the hollow support 5 alone, but the filling material 6 on the back side of the hollow support 5 also has a hydraulic pressure corresponding to the water depth. (Head), the hollow support 5
May be relatively thin, for example, about several cm.

In order to construct the seismic isolation structure of the structure according to the present embodiment, first, as needed, a retaining wall is constructed around the underground outer wall 2 of the structure 1, and thereafter, the retaining wall and the retaining wall are connected to each other. It is dug down in a groove between the underground outer wall 2.

Next, the hollow support 5 is suspended in the hollow space dug down, and the filler 6 is filled in the hollow support 5 in a state of being stored in the water-blocking bag 9.

In the seismic isolation structure for a structure according to the present embodiment, a hollow support 5 for supporting a part of the earth pressure from the surrounding ground 3 between the underground outer wall 2 of the structure 1 and the surrounding ground 3. A dynamic earth pressure buffering region 4 is provided, which is filled with the inside of the hollow support and a filler 6 that supports the rest of the earth pressure at the back of the hollow support. The structure is such that the filler 6 is discharged outside the hollow support 5, for example, onto the ground, by the dynamic earth pressure so as to be broken by the dynamic earth pressure of a certain level or more.

For this reason, the static earth pressure and the relatively small dynamic earth pressure are always supported by the hollow support 5 and the filling material 6 filled therein during a normal or small-to-medium-sized earthquake. In other words, the hollow support 5 is brittlely fractured by a large dynamic earth pressure, and the filler 6 filled therein is ejected from the ground or diffused into the surrounding ground by the dynamic earth pressure.
Is discharged outside.

As described above, according to the seismic isolation structure of the structure according to the present embodiment, the surrounding ground 3 collapses and the land subsidence is caused by the hollow support 5 and the filler 6 at all times or during a small or medium-sized earthquake. Can be prevented beforehand. In addition, in the case of a huge earthquake, a large dynamic earth pressure destroys the hollow support 5 and the internal filler 6 is discharged out of the hollow support 5. The relative displacement between the surrounding ground 3 and the structure 1 is absorbed, the seismic input to the structure can be reduced, and the vibration of the structure 1 is also reduced when the hollow support 5 and the filler 6 are at the dynamic earth pressure. In the same manner, the hollow support 5 is broken by the vibration of the structure 1 and at the same time the internal filler 6 is discharged to the ground, whereby the vibration energy of the structure 1 and the relative energy to the surrounding ground 3 are reduced. Displacement is absorbed,
Thus, the vibration of the structure 1 can be quickly converged.

Since the buffer material for absorbing the dynamic earth pressure is not required, there is no need to worry about the aging of the buffer material, and the energy absorbing function of the dynamic earth pressure buffer region 4 for absorbing energy during an earthquake can be maintained for a long time. Becomes possible.

Further, according to the seismic isolation structure of the structure according to the present embodiment, the hollow support 5 is formed of a brittle material such as concrete or glass. The body 5 exhibits brittle destructive properties and breaks apart instantaneously, and its crushing allows instantaneous absorption of large seismic energy. Further, the relative displacement between the surrounding ground 3 and the structure 1 can be quickly followed and absorbed without being delayed by the seismic motion.

Further, according to the seismic isolation structure of the structure according to the present embodiment, since the filler 6 is made of liquid water, the hollow support 5 is blown out to the ground and diffused into the surrounding ground due to damage of the hollow support 5. It can be quickly discharged in the form.
Also, if local groundwater is used, for example, the cost of procuring the filler 6 is almost negligible.

Although not specifically mentioned in the present embodiment, when filling the filler 6, the water-blocking bag 9 is first placed on the suspended hollow support 5 and the well is placed near the structure 1. And the groundwater may be pumped up from the well and injected into the water-blocking bag 9.

Although the present embodiment has been described as an example of application to an existing structure, when applied to a new structure, first, a dynamic earth pressure buffer is provided around a region where a structure is to be constructed. A structure may be constructed by constructing a region and then dug down into an inner region surrounded by the dynamic earth pressure buffer region. In such a configuration, the dynamic earth pressure buffer region is
It functions as a retaining wall for foundation work on structures.

In the present embodiment, the hollow support 5 is formed of a brittle material such as mortar or concrete. Instead, the hollow support 5 may be formed of soil cement, recycled glass, or a burned material such as incinerated ash or sludge. It may be.

Further, in this embodiment, the hollow support 5 is made of a brittle material so that the hollow support is brittlely broken when a dynamic earth pressure of a certain level or more is applied. The hollow support 5 may be made of a material that does not need to be plastically broken, that is, gradually deforms.

Further, in this embodiment, after the hollow support 5 is suspended, the filler 6 is filled in the water-impervious bag 9 while filling the hollow support. The hollow support 5 may be constructed of cast-in-place concrete. In that case, the water-blocking bag 9 is suspended in a drilled hole excavated by an earth auger or the like, and the filler 6 is put into the bag. In this state, concrete or mortar is placed around the water-blocking bag 9. The hollow support can be constructed by injection. In such a construction method, the water-blocking bag 9 also functions as an inner frame when the hollow support is cast in place.

In the present embodiment, the hollow support 5 is filled with the filler 6 in the water-blocking bag 9, but the hollow support 5 itself is watertight so as not to leak water. If so, the water blocking bag 9 may be omitted, and the hollow support may be directly filled with the filler 6. Also,
If the local groundwater level is high, the groundwater may be introduced into the hollow support 5 by connecting the inside of the hollow support 5 to the surrounding ground, and this may be used as the filler 6.
Even in such a configuration, the water-blocking bag 9 is not required.

In the present embodiment, the hollow support 5 is formed in a cylindrical shape. However, the present invention is not limited to such a shape, and may be formed in a rectangular tube shape. It may be formed in a groove shape so as to surround the periphery.

In this embodiment, the dynamic earth pressure buffering region 4 is provided so as to be in contact with the underground outer wall 2 of the structure 1.
Instead, the dynamic earth pressure buffer region may be provided in a state separated from the underground outer wall.

FIGS. 3 and 4 show such modifications. In the seismic isolation structure of the structure shown in the same figure, a dynamic earth pressure buffering region 4a is provided between the underground outer wall 2 and the pile 7 and the surrounding ground 3, which are the underground buried portion of the structure 1, as in the above-described embodiment. The dynamic earth pressure buffer region is provided with a hollow support 5a for supporting a part of the earth pressure from the surrounding ground 3, and filled inside the hollow support to support the remaining earth pressure on the back surface of the hollow support. In this modification, the hollow support 5a is spaced apart from the structure 1 in the form of a plurality of pillars around the structure in the present modification. different. Here, as in the above-described embodiment, the filler 6 is filled in the hollow support 5a while being filled in the water-blocking bag 9.

In this configuration, the same operation and effect as described above can be obtained. Note that other configurations, construction methods, and operational effects are almost the same as those of the above-described embodiment, and thus description thereof is omitted here.

In this embodiment, a normal building is assumed as the structure 1. However, the present invention can be applied to all structures that require seismic isolation. For example, the well base may be a structure, and the dynamic earth pressure buffering region 4 or the dynamic earth pressure buffering region 4a may be provided between the well base and the surrounding ground 3.

In this modification, the same operation and effect as described above can be obtained, but the description is omitted here because it is the same as the above description.

[0041]

As described above, according to the seismic isolation structure of the structure according to the first aspect of the present invention, the hollow ground and the filler cause the surrounding ground to collapse or collapse at all times or during a small or medium-sized earthquake. Land subsidence can be prevented beforehand. In addition, in the event of a huge earthquake, large dynamic earth pressure deforms the hollow support and the internal filler is discharged out of the hollow support. Relative displacement with the structure is absorbed, seismic input to the structure can be reduced, and vibration of the structure also functions in the same way as when the hollow support and the filler work under dynamic earth pressure. The vibration energy of the object and the relative displacement with respect to the surrounding ground are absorbed, and thus the vibration of the structure can be quickly converged.

Further, according to the seismic isolation structure of the structure of the present invention according to the second aspect, when a dynamic earth pressure of a certain level or more acts, the hollow support exhibits brittle destructive properties and falls apart instantaneously. At the same time, the fracturing can instantaneously absorb large seismic energy, and the relative displacement between the surrounding ground and the structure can follow the ground motion quickly without delay. The effect of being able to absorb is also exerted.

Further, according to the seismic isolation structure of the structure according to the third aspect of the present invention, since the filler is composed of liquid, the hollow support is deformed so that it is ejected to the ground and diffused to the surrounding ground. Thus, it is also possible to discharge quickly.

[0044]

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a seismic isolation structure of a structure according to an embodiment.

FIG. 2 is a horizontal sectional view of the seismic isolation structure of the structure according to the embodiment.

FIG. 3 is a diagram of a seismic isolation structure of a structure according to a modification;
(a) is a vertical sectional view, (b) is a horizontal detailed sectional view along the line AA.

FIG. 4 is a horizontal sectional view of a seismic isolation structure of a structure according to a modification.

[Explanation of symbols]

Reference Signs List 1 Structure 2 Underground outer wall (underground buried part) 3 Peripheral ground 4, 4a Dynamic earth pressure buffering area 5, 5a Hollow support 6 Filler 7 Pile (underground buried part) 9 Water-blocking bag

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Matsuda 4-640 Shimoseito, Kiyose-shi, Tokyo Inside the Obayashi-gumi Technical Research Institute, Inc. (72) Inventor Yozo 4-640 Shimoseito, Kiyose-shi, Tokyo, in the Obayashi-gumi Technical Research Institute F Term (reference) 2D046 DA12 DA15

Claims (3)

[Claims] 1. A dynamic earth pressure buffering region is provided between an underground buried portion of a structure and a surrounding ground, and the dynamic soil pressure buffering region is provided with a hollow support for supporting a part of earth pressure from the surrounding ground. A filler that fills the interior of the hollow support and supports the rest of the earth pressure at the back of the hollow support, so that the hollow support is deformed against a dynamic earth pressure of a certain level or more. A seismic isolation structure for a structure, wherein the filling material is discharged by the dynamic earth pressure. 2. The seismic isolation structure for a structure according to claim 1, wherein said hollow support is formed of a brittle material such as concrete or glass. 3. The seismic isolation structure of a structure according to claim 1, wherein said filler is made of a liquid such as water or muddy water.