JPH11323960A - Aseismatic underground structure for structural body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb a relative deformation caused by the difference in natural period even when it occurs at an underground portion by substituting part of the ground region spread between adjacent structural bodies with the prescribed deformation absorbing region. SOLUTION: The soft ground 3 in the ground region spread between a structural body 1 and a structural body 2 is dug down, and a buffer material 8 of foam styrol is filled in the removed space 11 to form a deformation absorption region 4. Even when the structural bodies 1, 2 are vibrated at their natural periods in natural phases and a relative deformation occurs between both underground portions, the relative deformation is absorbed by the deformation absorption region 4, and the soil pressure caused by the relative deformation is not applied to the underground portions of the structural bodies 1, 2. The underground portions of the structural bodies 1, 2 are not broken at the time of an enormous earthquake, and healthiness is maintained. The vibration by the earthquake is damped by the deformation absorption region 4 and is quickly converged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earthquake-resistant underground structure of a structure mainly applied when structures having different vibration properties are installed adjacent to each other.

[0002]

2. Description of the Related Art In constructing a structure, for example, when the ground strength near the surface layer is relatively large compared to the weight of the structure, a direct foundation is adopted, and conversely, when the ground strength near the surface layer is relatively high. When the foundation is small, a pile foundation is used so that it can be supported by a high-quality support layer, and by appropriately selecting the foundation type according to the ground strength of the location while considering the characteristics of the superstructure, It is necessary to ensure sufficient stability of the entire structure during an earthquake.

[0003]

Here, the vibration characteristics of the structure greatly depend on the weight and rigidity of the upper structure even when there is not much difference in the ground characteristics. Even if there is no difference in rigidity, there is a large difference in the vibration characteristics between the two when, for example, different foundation types are adopted depending on the difference in the degree of seismic importance of the superstructure.

[0004] Therefore, when two structures are constructed adjacent to each other, due to the difference in the weight and rigidity of the superstructure or the difference in the basic form, the vibration characteristics, especially the natural period, differ between the two structures. Relative deformation occurs. And when such relative deformation occurs in the underground part, a large earth pressure occurs in the ground region sandwiched between adjacent structures, and in the worst case, collapse of the foundation and eventually collapse of the upper structure It is also a concern.

The present invention has been made in view of the above-mentioned circumstances, and the base of the structure collapses due to the relative deformation in the underground part generated between the adjacent structures, and the upper structure is accordingly formed. It is an object of the present invention to provide an earthquake-resistant underground structure of a structure capable of preventing collapse.

[0006]

In order to achieve the above object, an earthquake-resistant underground structure of a structure according to the present invention has at least one of a ground area extending between adjacent structures. A part is replaced with a predetermined deformation absorption region.

In the earthquake-resistant underground structure of a structure according to the present invention, a part of the ground region extending between adjacent structures is replaced with a predetermined deformation absorbing region, so that vibration characteristics, especially differences in natural period, are different. Even if the relative deformation caused by underground occurs in the underground part, the relative deformation is absorbed in the deformation absorbing region, and there is no concern that excessive earth pressure acts on the underground part of the structure.

For constructing the deformation absorbing region, a buffer material having a high deformation absorbing ability, for example, styrene foam, asphalt-based material, silicon or urethane-based material, soft clay,
Place saturated loose sand, light soil, rubber, gravel, crushed stone, etc. around the structure, fill such a groove in the ground extending between the structures, and also spread the ground between the structures For example, a method of injecting a foaming agent into the foam and foaming the foamed material internally is conceivable.

The location where the deformation absorbing area is provided is arbitrary, but in the depth direction, for example, it is considered that the area is mainly placed near the ground surface where the relative deformation between adjacent structures is most likely to be the largest. Can be Further, in plan view, it is conceivable to provide a deformation absorbing region on one or both opposing side surfaces of adjacent structures, or to form a deformation absorbing region entirely between adjacent structures. In such cases,
The former corresponds to replacing a part of the ground region extending between adjacent structures with the deformation absorbing region, and the latter corresponds to replacing all of the ground region with the deformation absorbing region.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of an earthquake-resistant underground structure of 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 will be omitted.

FIG. 1 is a sectional view and a plan view showing an earthquake-resistant underground structure of a structure according to this embodiment. As can be seen from these figures, the seismic underground structure of the structure according to the present embodiment is a soft ground 3 which is a ground region extending between the adjacent structures 1 and 2, and has a structure near the ground surface. It is replaced by the deformation absorption region 4.

Here, the structure 1 is constructed in a so-called direct foundation form in which a foundation plate thereof is directly mounted on a support base 6 in a state of being buried in the soft ground 3, and LNG as shown in FIG. In addition to tanks, reactor buildings with high seismic importance are often constructed on such direct foundations.

On the other hand, the structure 2 is constructed in the form of a so-called pile foundation in which a pile 7 is penetrated into the soft ground 3 and its tip is driven into the support base 6, such as a nuclear reactor auxiliary building or a turbine building. Is often constructed with such pile foundations.

The deformation absorbing region 4 can be formed of a cushioning material 8 such as styrene foam having a high deformation absorbing ability.

In order to construct an earthquake-resistant underground structure of a structure according to this embodiment, first, as shown in FIG.
The soft ground 3, which is the ground area extending between the ground and the structure 2, is dug down, and then the space 11 excavated and removed is filled with a cushioning material 8 such as styrene foam as shown in FIG.
Is defined as the deformation absorption region 4.

In the seismic underground structure of the structure according to the present embodiment, the structures 1 and 2 vibrate mainly in the direction of the arrow in FIG. 3 during an earthquake, but the vibration characteristics are different depending on the basic type. , The natural periods and phases do not coincide with each other, and a relative deformation occurs between the two.

Therefore, in the related art, there is a concern that a large earth pressure may act on the underground portions of the structures 1 and 2 due to the relative deformation, and the underground portions may be damaged. Since the deformation absorbing region 4 as shown in the figure is provided between the structures 1 and 2, the structure 1 and the structure 2 inherently vibrate at respective periods and phases. Even if relative deformation occurs between the portions, such relative deformation is absorbed in the deformation absorbing region 4, and no earth pressure due to the relative deformation is applied to the underground portions of the structures 1 and 2.

As described above, according to the earthquake-resistant foundation structure of the structure according to the present embodiment, the vicinity of the ground surface of the soft ground 3, which is the ground area extending between the adjacent structures 1 and 2, is deformed and absorbed. 4 so that the relative deformation caused by the vibration property, particularly the difference in the natural period, is caused by each structure 1, 2
Even if it occurs in the underground part, such a relative deformation is absorbed in the deformation absorption region 4 as shown in FIG.
Excessive earth pressure does not act on the underground part of 2.

Therefore, even in the event of a huge earthquake, the underground portions of the structures 1 and 2 are not damaged, and the soundness is maintained.
It is to be noted that the vibrations of the structures 1 and 2 due to the earthquake are damped by the deformation absorbing region 4 and the vibrations are quickly converged.

Here, a dynamic response analysis was performed to confirm the operation and effect of this embodiment, and the results are shown in FIG.

The graph shown in FIG.
How the horizontal earth pressure and member shearing force acting on the structure change when the deformation absorbing area 4 made of the cushioning material 8 is not provided between the two (left end) and when it is provided (right end) It is shown.

It can be seen from FIG. 1 that the provision of the deformation absorbing region 4 significantly reduces the horizontal earth pressure acting on the structures 1 and 2 during an earthquake and the shear force generated in the members due to the earth pressure.

In this embodiment, the entire ground area extending between the structures 1 and 2 on the ground surface is replaced with the deformation absorbing area 4. However, the present invention is not necessarily limited to such a configuration. As shown in FIG. 5, the deformation absorbing regions 24 may be provided on the side surface of the underground buried portion of the structure 1 and the side surface of the underground buried portion of the structure 2, respectively. In such a modification, any of the deformation absorption regions 24 may be omitted. Also, as shown in FIG. 6, a groove 31 formed between the structure 1 and the structure 2
The deformation absorbing region 32 may be formed by filling the inside with the cushioning material 8.

In this embodiment, the structure 1 is a cylindrical structure and the structure 2 is a rectangular structure. However, the present invention is not limited to such a shape. It should be noted that the basic form of the can be the same.

[0025]

As described above, according to the quake-resistant underground structure of the structure according to the first aspect of the present invention, the underground portion of the adjacent structure suffers from the vibration properties, particularly the relative deformation caused by the difference in the natural period. Even if it occurs, the relative deformation is absorbed in the deformation absorbing region, and there is no concern that an excessive earth pressure acts on the underground portion of each structure. Therefore, even in the event of a huge earthquake, the underground portion of the structure is not damaged, and its soundness is maintained.
It is to be noted that the vibration of the structure due to the earthquake is damped by the deformation absorbing region, and the effect of rapidly converging the vibration is obtained.

[0026]

[Brief description of the drawings]

FIG. 1 is a diagram of an earthquake-resistant underground structure of a structure according to the present embodiment, (a) is a cross-sectional view, and (b) is a plan view as seen from the direction of line AA.

FIG. 2 is a sectional view showing a construction procedure of the earthquake-resistant underground structure of the structure according to the embodiment.

FIG. 3 is a sectional view showing the operation of the earthquake-resistant underground structure of the structure according to the embodiment.

FIG. 4 is a graph showing a result of a dynamic response analysis for confirming an operation effect of the seismic basement structure of the structure according to the embodiment.

5A and 5B are diagrams showing an earthquake-resistant underground structure of a structure according to a modification, in which FIG. 5A is a cross-sectional view, and FIG. 5B is a plan view as viewed from the line BB.

6A and 6B are diagrams showing an earthquake-resistant underground structure of a structure according to another modification, wherein FIG. 6A is a cross-sectional view, and FIG. 6B is a plan view as viewed from the line CC.

[Explanation of symbols]

 1, 2 Structure 3 Soft ground (ground area) 4, 24, 32 Deformation absorption area

Claims (1)

[Claims] 1. An earthquake-resistant underground structure for a structure, wherein at least a part of a ground region extending between adjacent structures is replaced with a predetermined deformation absorbing region.