JP3656452B2 - Seismic isolation method for existing buildings - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a construction method for isolating an existing building.
[0002]
[Prior art]
As is well known, conventionally, when an existing building is to be seismic isolated, the existing building is supported using a temporary receiving jig while excavating the ground below the existing building, and then the foundation is placed below the existing building. Concrete was constructed, and a seismic isolation device was installed between the foundation concrete and the existing building, and then the temporary support jig was removed.
[0003]
[Problems to be solved by the invention]
However, when performing seismic isolation in this way, there was a problem that the construction period was prolonged because the ground below the existing building had to be excavated for each part while installing the temporary receiving jig. .
[0004]
In addition, if the existing building to be seismically isolated has a large weight, the provisional jig must be made large in accordance with this, so as to secure the installation space for the provisional jig. However, the amount of excavated soil had to be increased, and there was a problem in construction. Further, in this case, the cost required for the temporary receiving jig itself is increased.
[0005]
Furthermore, when the number of basement floors of the existing building to be seismically isolated is large, the installation position of the temporary receiving jig becomes deep, so that the installation work of the temporary receiving jig is troublesome.
[0006]
The present invention has been made in view of such circumstances, and the construction period can be shortened compared to the conventional case, and the existing building to be seismically isolated has a large weight or has a large number of underground floors. Even in the case, it is an object to provide a seismic isolation method that can be applied well.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following means.
That is, the seismic isolation method for an existing building according to claim 1 is a method for isolating an existing building,
On the ground below the existing building, a pile is constructed such that the pile head is positioned below a predetermined dimension from the bottom slab of the existing building, and at the time of the construction, a column material is provided to the pile head, Embed it in a state of protruding from the top of the pile head to the position reaching the bottom plate of the existing building,
The bottom plate of the existing building and the upper end of the pillar material are integrally joined,
Excavating the side and lower ground of the existing building,
Under the bottom slab of the existing building, the foundation slab is built in a state integrated with the pile head, and is separated from the bottom slab,
A seismic isolation device is interposed between the foundation slab and the bottom plate,
Thereafter, a portion of the pillar material located between the bottom slab of the existing building and the foundation slab is removed.
[0008]
With such a configuration, when the seismic isolation device is interposed below the existing building, the existing building can be supported from the pile via the pillar material.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an existing building 1 that has undergone seismic isolation work and its lower structure 2.
[0010]
As shown in FIG. 2, this existing building 1 does not have a portion corresponding to the lower structure 2 (see FIG. 1), and its bottom slab 3 is directly on the ground G, as shown in FIG. As shown in Fig. 1, the lower structure 2 is newly constructed and seismically isolated by performing seismic isolation work.
[0011]
The substructure 2 includes a pile 4 constructed in the ground G, a foundation slab 6 constructed integrally with a pile head 5 of the pile 4, and a bottom slab of the existing building 1 arranged on the foundation slab 6 3 is provided with a seismic isolation device 7 made of laminated rubber that supports 3.
[0012]
In order to make the existing building 1 seismic isolation into the state shown in FIG. 1, first, as shown in FIG. 3, the pile 4 is constructed on the ground G below the existing building 1. In this case, the through hole 8 is provided in the bottom slab 3 of the existing building 1, and the pile 4 is constructed below the through hole 8. Alternatively, when building the pile 4, the pile head 5 is positioned below the bottom plate 3 of the existing building 1 by a certain dimension, and a built-up column (column material) 9 made of steel is embedded on the top surface of the pile head 5. Keep it. At this time, the upper end 9a of the stem column 9 is arranged so as to reach substantially the same level as the bottom plate 3.
[0013]
Next, as shown in FIG. 4, the reinforcing beam 10 is installed on the bottom slab 3 of the existing building 1. At this time, the upper end 9 a of the frame column 9 is embedded in the reinforcing beam 10, and thereby the bottom plate 3 and the upper end 9 a of the frame column 9 are integrated via the reinforcing beam 10.
[0014]
Subsequently, as shown in FIG. 5, the ground G located on the side and below the existing building 1 is excavated to form a gap between the ground G and the bottom slab 3 of the existing building 1. As a result, the existing building 1 is provisionally received by the construction pillar 9. Further, the ground G on the side of the existing building 1 is supported by providing a retaining wall 11 and a beam 12.
[0015]
Thereafter, as shown in FIG. 6, the foundation slab 6 is provided on the excavated ground G below the existing building 1, and the side wall 13 is provided inside the retaining wall 11. In this case, the foundation slab 6 is formed integrally with the pile head 5 of the pile 4.
[0016]
Then, as shown in FIG. 7, seismic isolation devices 7 are attached between the bottom slab 3 and the foundation slab 6 of the existing building 1, and among the construction pillars 9, between the bottom slab 3 and the foundation slab 6. By removing the portion located at, the seismic isolation of the existing building 1 is completed as shown in FIG.
[0017]
In the seismic isolation method for the existing building 1 described above, when the existing building 1 is provisionally received when the seismic isolation device 7 is attached, the pile 4 is constructed in advance under the existing building 1 and the existing building 1 and the pile 4 Are integrated with each other through the structural pillar 9, so that the existing building 1 can be supported from the pile 4 through the structural pillar 9 before excavating the ground G. Therefore, unlike the conventional seismic isolation method, it is not necessary to install a temporary receiving jig while excavating the ground for each part, and the construction period can be shortened.
Moreover, since the temporary receiving jig is not used, the cost for installing the temporary receiving jig can be reduced. In particular, when the weight of the existing building 1 is large, the temporary receiving jig is different from the conventional one. Since it is not necessary to increase the amount of excavated soil in order to secure the installation space, it is possible to reduce the construction cost and labor. Moreover, since the temporary receiving jig is not used, even when the existing building 1 has a large number of underground floors, the construction labor is not complicated.
[0018]
【The invention's effect】
As described above, in the seismic isolation method for an existing building according to the present invention, when temporarily installing the existing building when installing the seismic isolation device, a pile is constructed in advance under the existing building, and the existing building and the pile are also constructed. Are integrated through the pillar material, so that the existing building can be supported from the pile through the pillar material before excavating the ground. Therefore, unlike the conventional seismic isolation method, it is not necessary to install a temporary receiving jig while excavating the ground for each part, and the construction period can be shortened.
In addition, since the temporary receiving jig is not used, it is possible to reduce the cost for installing the temporary receiving jig. Since it is not necessary to increase the amount of excavated soil in order to secure a space, it is possible to reduce the construction cost and labor. Moreover, since a temporary receiving jig is not used, even if the existing building has a large number of underground floors, the construction labor is not complicated.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an embodiment of the present invention, and is a vertical sectional view of an existing building subjected to a seismic isolation method.
FIG. 2 is a vertical sectional view of an existing building before the seismic isolation method is applied.
FIG. 3 is a diagram showing a step of the seismic isolation method for an existing building according to the present invention.
4 is a diagram showing the next step of FIG. 3 in the seismic isolation method for an existing building of the present invention.
FIG. 5 is a diagram showing a step subsequent to FIG. 4;
6 is a diagram showing a step subsequent to FIG. 5. FIG.
FIG. 7 is a view showing the next step of FIG. 6;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Existing building 3 Bottom plate 4 Pile 5 Pile head 6 Foundation slab 7 Seismic isolation device 9 True column (column material)
9a top

Claims (1)

A construction method for seismic isolation of existing buildings,
On the ground below the existing building, a pile is constructed such that the pile head is positioned below a predetermined dimension from the bottom slab of the existing building, and at the time of the construction, a column material is provided to the pile head, Embed it in a state of protruding from the top of the pile head to the position reaching the bottom plate of the existing building,
The bottom plate of the existing building and the upper end of the pillar material are integrally joined,
Excavating the side and lower ground of the existing building,
Under the bottom slab of the existing building, the foundation slab is built in a state integrated with the pile head, and is separated from the bottom slab,
A seismic isolation device is interposed between the foundation slab and the bottom plate,
After that, the seismic isolation method for the existing building is characterized in that a part of the pillar material located between the bottom slab of the existing building and the foundation slab is removed.

Images