JP2009097185A - Vibration reducing structure of structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure capable of effectively reducing the vibration of a structure on which there is the possibility of vibration since structure support ground is soft. <P>SOLUTION: An underground wall body 5 extending to the periphery of the structure is formed in the support ground 1 for the structure 4, and the upper part of the underground wall body is joined to the underground outer wall surface of the structure. The underground wall body is so formed as to function as a buttress to restrain the side displacement of the structure and the support ground and the relative rotation thereof in a vertical plane during an earthquake. In a flat or rectangular structure, the underground wall body functioning as a buttress is formed at both ends in the longitudinal direction in the state of extending sideways along the short side direction. An annular underground wall for restraining the twist deformation by surrounding the underground outer wall surface of the structure all therearound is formed and joined to the underground wall body. The structure and a hard ground are connected to each other through the underground wall body. A plurality of structures are connected to each other through the underground wall body. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a structure for reducing the vibration of a structure during an earthquake, and more particularly to a structure for reducing the vibration of a structure suitable for application to a case where a supporting ground is soft.

When the supporting ground of the structure is soft, the structure 4 is generally supported by a pile 3 that reaches a stable and solid supporting layer 2 in the deep part of the supporting ground 1 as shown in FIG. When the pile length is long because the support layer 2 is deep, or when the aspect ratio of the structure 4 is large (when the height is high with respect to the width of the structure 4, that is, in the case of a tower-shaped structure) Therefore, a sway vibration in which the structure 4 is displaced in the horizontal direction with respect to the support ground 1 and a rocking vibration that rotates in a vertical plane are likely to occur.
In particular, when the aspect ratio of the planar shape of the structure 4 is large (when the length of the long side is considerably larger than the width in the short side direction, that is, in the case of a rectangular shape elongated in a plane), Not only sway vibration and rocking vibration occur remarkably, but also vibration due to torsional deformation in the horizontal plane as shown in FIG.

  As a vibration reduction measure for the structure 4 in which such a vibration is expected, the pile 3 is strengthened (increase of pile diameter and number of piles) to make a sufficiently strong pile foundation, or the structure 4 It is common to install seismic reinforcement members such as braces.

In addition, as a measure for preventing liquefaction of sand ground that is liable to liquefy during an earthquake, Patent Document 1 discloses that a cemented solidified material is mixed and stirred with the original ground soil to form a wall-like solidified body. There is a disclosure about a liquefaction prevention method that surrounds the target ground by ligation.
Furthermore, as a reinforcement measure for existing pier foundations built in the ground where there is a risk of ground fluidization, Patent Document 2 describes the improvement of the ground for the pier foundation and its surrounding liquefaction area, There is a disclosure of surrounding a pier foundation with an anti-earth pressure structure such as a medium continuous wall or providing a fluidization pressure dispersion wall or a fluidization deterrence wall around the pier foundation.
Japanese Patent Laid-Open No. 2-311613 JP 9-310360 A

  As described above, the reinforcement of the pile foundation and the installation of the seismic reinforcement member as a countermeasure for reducing the vibration of the structure 4 that is likely to generate vibration due to the soft support ground 1 is therefore However, depending on the ground conditions and the size and form of the structure 4, there may be cases where a sufficient effect is not always obtained.

Moreover, instead of performing the reinforcement | strengthening with respect to a pile foundation or structure itself as mentioned above, as shown in patent document 1 and patent document 2, a solidified body and continuous in the support ground 1 of the structure 4 are shown. It is also considered to reduce the vibration caused to the structure 4 by reinforcing the supporting ground 1 by providing an underground wall.
However, since the construction methods shown in Patent Document 1 and Patent Document 2 are originally intended to prevent ground liquefaction (fluidization), such a construction method is not a countermeasure against liquefaction. In order to obtain a sufficient effect by applying it as a measure for reducing vibration in (4), it is necessary to develop a specific, effective and appropriate method for enabling it.

  In view of the above circumstances, the present invention is intended to provide an effective and appropriate structure that can sufficiently reduce the vibration for a structure that is worried that vibration will occur due to the soft support ground. It is aimed.

  In order to achieve the above object, according to the present invention, an underground wall body projecting around the structure is provided in a supporting ground of the structure, and an upper portion of the underground wall body is opposed to an underground wall surface of the structure. By joining together, the underground wall body functions as a buttress to restrain the lateral displacement of the structure with respect to the supporting ground and the relative rotation in the vertical plane during an earthquake.

In particular, when applied to a structure having a rectangular planar shape, an underground wall functioning as a buttress is provided along the short side direction of the structure at both ends in the long side direction of the structure. It is preferable to provide it in a state of projecting to the side of the structure.
In that case, an annular underground wall is provided to restrain the torsional deformation of the structure by being joined to the underground outer wall surface so as to surround the entire underground wall surface of the structure. It is more preferable to join the underground wall functioning as a buttress to the intermediate wall.
Furthermore, another underground wall that similarly functions as a buttress may be provided between the underground walls provided to function as a buttress at both ends in the long side direction of the structure.

  In addition, when the hard ground exists at a position away from the right side of the structure to the side, the tip of the underground wall body that is provided in a state of projecting around the structure and functions as a buttress is connected to the hard ground. It is conceivable that the structure and the hard ground are connected via the underground wall body by being disposed inside.

  Further, when a plurality of structures are independently constructed at a predetermined distance, the underground wall that functions as a buttress for each structure is provided integrally in a state of projecting around each structure. It is also conceivable to provide a body and to connect the structures by the underground wall.

According to the present invention, since the underground wall functions as a buttress (holding wall) for supporting the structure, the structure is supported by the underground wall from obliquely below, so that the structure at the time of the earthquake is obtained. Lateral displacement and relative rotation in the vertical plane of the object are naturally constrained, and the reinforcement effect on the support ground can also be expected by providing an underground wall, which can cause sway and rocking vibrations of the structure. Is effectively reduced.
In particular, in the case of a structure having a rectangular planar shape, the width of the structure is substantially reduced by providing the underground wall body so as to project in the short side direction at both ends in the long side direction. It is enlarged by the overhanging dimension of the wall body, so that the apparent aspect ratio and aspect ratio are substantially reduced, so that vibrations and torsional deformations in the short side direction are not easily generated.

“First Embodiment”
The most basic first embodiment of the present invention is shown in FIG. This is intended to reduce the vibration (sway vibration and rocking vibration) to the side (short side direction) of the structure 4 constructed on the soft support ground 1 as shown in FIG. In addition, the underground wall body 5 that extends to at least one side (right side in the illustrated example) of the structure 4 in the supporting ground 1 at both ends in the long side direction of the structure 4 extends along the short side direction. The upper part of the underground wall body 5 is joined to the underground outer wall surface of the structure 4.

According to the first embodiment, the underground wall body 5 functions as a buttress (holding wall) for supporting the structure 4. That is, the lateral displacement of the structure 4 and the vertical plane in the event of an earthquake are supported by the structure 4 supported from obliquely below by the underground wall 5 provided in the support ground 1 on the side of the structure 4. The relative rotation at is naturally constrained, thereby effectively reducing sway and rocking vibrations.
Particularly, since the underground wall body 5 is provided so as to protrude in the short side direction at both ends in the long side direction, the width dimension in the short side direction of the structure 4 is substantially equal to the protruding dimension of the underground wall body 5. Therefore, the apparent aspect ratio and aspect ratio are substantially reduced, and as a result, vibration in the short side direction and vibration due to torsional deformation in the horizontal plane as shown in FIG. It will be difficult.
And the effect which strengthens the support ground 1 by providing the underground wall body 5 can also be anticipated, and according to the structure of this 1st Embodiment, the vibration of the structure 4 is reduced effectively by the synergistic effect by the above each effect | action. be able to.

The structure of the underground wall body 5 is not particularly limited as long as it can function as a buttress. For example, a ground improvement wall by a deep mixing treatment method or a continuous underground wall can be suitably employed.
In addition, as the thickness dimension and width dimension of the underground wall body 5 (the dimension projecting to the side of the structure 4) and the length dimension (depth dimension) are increased, the supporting force is enhanced. The shape and dimensions of the body 5 may be appropriately designed according to various conditions such as the assumed earthquake scale, the form and scale of the structure 4, the structure thereof, and the required vibration reduction effect. In particular, the bottom of the underground wall 5 may be provided so as to reach the support layer 2, but this is not necessarily the case, and it may be kept at a position shallower than the support layer 2 as shown in the example of the drawing.
Moreover, the structure for joining the upper part of the underground wall body 5 with the underground wall surface of the structure 4 protrudes joining means, such as an anchor and a connecting line, from the underground wall or underground beam of the structure 4, for example. Then, it can be considered to be structurally integrally joined by fixing it to the underground wall 5. However, in short, it is only necessary that the underground wall 5 supports the structure 4 and restrains the displacement and rotation thereof, and as long as the structure and type of joining are arbitrary, more simply, a cotter or It is also possible to just abut after roughening.

The underground wall 5 may be provided so as to protrude to one side at least at both ends in the long side direction of the structure 4 as in the illustrated example, but the structure as shown by the broken line in FIG. Of course, it may be provided so as to project on both sides of the object 4, or another underground wall 5 may be provided in parallel between the underground walls 5 provided at both ends in parallel. Furthermore, it does not preclude the provision of the same underground wall body 5 in the direction along the long side direction from both ends of the structure as required, and the planar shape and vibration characteristics of the structure 4 are particularly complicated. In some cases, the underground wall 5 may be provided along an arbitrary direction in which vibration is assumed to occur.
Furthermore, although it is realistic to support the structure 4 with the pile 3, you may abbreviate | omit when the pile 3 is unnecessary by the ground condition etc.

“Second Embodiment”
A second embodiment of the present invention is shown in FIG. This is because the annular underground wall 6 is provided so as to surround the underground wall surface of the structure 4 over the entire circumference, and the annular underground wall 6 is joined to the underground wall surface of the structure 4. The underground wall body 5 that functions as a buttress is joined to the annular underground wall 6 as in the embodiment. As the annular underground wall 6, similarly to the underground wall body 5, for example, a ground improvement wall by a deep mixing treatment method or a continuous underground wall can be suitably employed.
In the second embodiment, such an annular underground wall 6 is structurally integrated with the bottom of the structure 4 so that the torsional deformation of the entire structure 4 is effectively restrained. As the structure 4 is supported by the underground wall 5 via the ground, the vibration is reduced more effectively.
FIG. 2 shows an example in which three underground walls 5 are provided on both sides of the structure 4, but in the second embodiment as well, as described in the first embodiment. What is necessary is just to design the number of installation surfaces and installation positions of the middle wall body 5 suitably.

“Third Embodiment”
A third embodiment of the present invention is shown in FIG. This is when there is a facility such as a road on the side of the structure 4 and immediately below it is a stable hard ground 7, that is, when the hard ground 7 exists at a position away from the bottom of the structure 4 to the side. This is an application example.
In the third embodiment, the structure 4 and the hard ground 7 are connected via the underground wall 5 by disposing the tip of the underground wall 5 functioning as a buttress in the hard ground 7. It is connected. And the underground wall body 5 which supports the structure 4 will be supported by the hard ground 7 from the back, Therefore, the structure 4 is more reliably made by these whole underground wall body 5 and the hard ground 7 more reliably. It can be supported and the vibration reduction effect can be further enhanced.
In the illustrated example, the underground wall 8 is provided on one side surface of the structure 4. However, such an underground wall 8 may be omitted, or the underground wall 8 may be replaced with the second embodiment. Similarly, an annular underground wall 6 surrounding the structure 4 may be provided. Of course, it is the same as that of the said embodiment that the surface number and position of the underground wall 5 are arbitrary.

“Fourth Embodiment”
A fourth embodiment of the present invention is shown in FIG. This is an application example in the case where a plurality (two in the illustrated example) of the structures 4 are independently constructed with a predetermined distance, and the underground functions as a common buttress for both structures 4. A wall 5 is provided. In other words, at least both ends in the long side direction of each structure 4 are provided with underground wall bodies 5 projecting toward the other structure 4 side. Thus, both structures 4 are connected.
In this case, both the structures 4 are supported by the underground wall 5 at the same time and the vibrations are reduced, and both the structures 4 are substantially integrated in the supporting ground 1. It behaves as a structure of one building, and therefore, as a whole, the planar shape is greatly enlarged, the aspect ratio and aspect ratio are substantially improved, and the vibration due to the lateral vibration and torsional deformation can be effectively reduced. it can.

"Analysis result"
FIG. 5 shows the results of dynamic nonlinear analysis performed by FEM to verify the effectiveness of the second embodiment shown in FIG. In this analysis, as shown in (a), for the structure 4 having a length of 98.5 m in the long side direction and a width of 34 m in the short side direction, the underground wall body 5 is provided at both ends and the center part in the long side direction. It is provided with a side projecting dimension of 13 m (therefore, the total width of the underground wall 5 provided at both ends is 60 m). The underground wall 5 was a ground improvement wall (cement consolidated wall) by the deep mixing treatment method, and the depth was two types of 11.3m and 26.8m as shown in (b).
As a result of analyzing the acceleration distribution in the supporting ground 1 and the structure 4 (up to 5 m above the ground) in each case, significant acceleration reduction is achieved by providing the underground wall body 5 in each case as shown in (c). An effect is seen and it can confirm that it is effective enough even when the underground wall 5 is shallow.
FIG. 6 shows an analysis result in the case corresponding to the third embodiment shown in FIG. 3 (however, the underground wall 5 is installed only at both ends of the structure 4). As a result of the analysis when the planar shape and dimensions of the structure 4 are the same as above, the width of the underground wall 5 is 13 m, and the width of the hard ground is 17 m, an obvious vibration as shown in (c) Reduction effect is seen.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Of course, the present invention is not limited to the above-described embodiments. Needless to say, various design changes and applications can be made without departing from the gist of the present invention to support the structure.
It should be noted that the present invention is particularly preferably applied to tower-like buildings that are prone to vibrations and buildings that are prone to torsional deformation, but are not limited to such structures. In particular, it is effective to be applied to a structure for which vibration is not used, for example, a factory for manufacturing or handling precision equipment, but it does not limit the use of the structure.
Of course, the present invention is effective not only in the case of constructing a new structure but also as a repair method for reducing the vibration of existing structures. Conventional methods such as the mixed processing method and continuous underground wall method can be used as they are.

It is a figure which shows 1st Embodiment of this invention. It is a figure which shows 2nd Embodiment same as the above. It is a figure which shows 3rd Embodiment same as the above. It is a figure which shows 4th Embodiment. It is a figure which shows the analysis result about 2nd Embodiment. It is a figure which shows the analysis result about 3rd Embodiment. It is explanatory drawing about the vibration of a structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support ground 2 Support layer 3 Pile 4 Structure 5 Underground wall (buttress)
6 Ring underground wall 7 Hard ground 8 Underground wall

Claims (6)

  An underground wall body projecting around the structure is provided in a supporting ground of the structure, and an upper part of the underground wall body is joined to an underground wall surface of the structure, thereby the underground wall body A structure for reducing the vibration of a structure, which functions as a buttress to restrain the lateral displacement of the structure with respect to the supporting ground and the relative rotation in the vertical plane during an earthquake. A structure for reducing vibration of a structure according to claim 1,
For a structure having a rectangular planar shape, the underground wall functioning as a buttress is placed on the side of the structure along the short side direction of the structure at both ends in the long side direction of the structure. A structure for reducing vibrations of structures, characterized by being provided in an overhanging state. A vibration reduction structure for a structure according to claim 2,
An annular underground wall that restrains torsional deformation of the structure is provided by being joined to the underground outer wall surface so as to surround the entire underground wall surface of the structure, and functions as a buttress on the annular underground wall. A vibration reduction structure for structures, which is formed by joining underground walls. A vibration reduction structure for a structure according to claim 2 or 3,
A structure in which another underground wall is provided in parallel with the underground wall between the underground walls provided to function as a buttress at both ends in the long side direction of the structure. Structure for reducing vibration of objects. A structure for reducing vibration of a structure according to claim 1, 2, 3, or 4,
By placing the tip of the underground wall body that functions as a buttress overhanging around the structure in a hard ground that is located laterally away from just below the structure, A vibration reduction structure for a structure, wherein the structure and the hard ground are connected via a wall. A structure for reducing vibration of a structure according to claim 1, 2, 3, or 4,
Underground wall that functions as a buttress for each structure, which is integrally provided in a state of projecting around each structure in a supporting ground in which a plurality of structures are independently constructed at a predetermined distance. A structure for reducing vibrations of a structure, characterized in that each structure is connected by the underground wall.

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