JP2596798B2 - Existing building seismic isolation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATIONS The present invention incorporates a seismic isolation device into a deep corner of an existing office building or a large store building such as a department store,
The present invention relates to a seismic isolation method for existing buildings, which is implemented to improve seismic resistance and seismic isolation in the event of an earthquake so that the building is not shaken by the earthquake.

2. Description of the Related Art Various types of seismic isolation buildings and seismic isolation devices are known to the public (for example, Japanese Patent Application Laid-Open Nos. 60-168875 and 61-151377, and
61-17984). There are also some examples of seismic isolation buildings.

However, these are all technical contents to be implemented for newly constructed buildings.

Problems to be Solved by the Present Invention Recently, office automation of offices (OA
Although it is remarkable, it has become an important condition that existing buildings do not shake significantly due to the earthquake.
Precision OA equipment is very sensitive to vibration.

Therefore, there is no concern about the office building of newly constructed base-isolated buildings, but it is urgently necessary to make existing buildings seismically isolated by some means.

With the recent development of the car society, parking spaces have become an indispensable condition in office buildings and store buildings, etc., and the expansion and expansion of these spaces has become an important business issue. However, abnormally high land prices and overcrowding of buildings in recent years in urban areas have made it extremely difficult to buy new land with good location and build buildings and parking lots. So, for example, if you try to add a new space above the existing building, there is a limit on the structural strength that the existing building has,
The issue of sunshine rights is also involved, so it is very difficult to realize it. In particular, when a new building is built on top of a building before June 1981, the new seismic design method is applied, and it is considered that it is almost impossible to meet the conditions (seismic diagnosis criteria) at first. .

Therefore, an object of the present invention is to provide a seismic isolation method for an existing building, which can safely and surely make the existing building seismically isolated, and can improve its structural safety and seismic resistance.

Means for Solving the Problems (First Invention) As a means for solving the above-mentioned problems of the prior art, the seismic isolation method for an existing building according to the present invention employs a method in which the existing building is supported by supporting piles. As shown in the embodiment in FIGS. 1 to 13 of the drawings, a) excavating the basement of the existing building 3 and exposing the support piles 2 to the support layer ground 1. Steps: b) Build the required number of temporary support supports 8 on the outer periphery of the exposed support pile 2, and install hydraulic jacks on each temporary support 8.
12) Installing the hydraulic jack 12 between the underground structure 3A of the existing building 3 and the hydraulic jack 12 to change the load on the support pile 2 to the temporary support 8 ... c) Change the axial force After that, the supporting pile 2 is dismantled, and instead, a permanent steel column 18 is constructed at the same position. D) A seismic isolation device 19 is installed between the permanent steel column 18 and the underground structural frame 3A of the existing building 3. After that, the axial force of the temporary support 8 is re-arranged to the permanent steel column 18, and the temporary support 8 and the like are removed (FIGS. 1 to 8).
Figure).

Operation Since the axial force borne by one support pile 2 is changed as the axial force of several temporary support supports 8 and hydraulic jacks 12 built around its periphery, the worker enters and exits between the temporary support supports 8. Thus, the work of dismantling the support pile 2 can be easily and safely performed.

Since the support pile 2 is dismantled and rebuilt to the permanent steel column 18,
The soundness and seismic resistance of the existing building 3 are never impaired. Then, it becomes possible to easily incorporate the seismic isolation device 19 into the position between the permanent steel column 18 and the underground structure skeleton 3A of the existing building 3, and the building can be made seismically isolated. In addition, the seismic isolation greatly improves the seismic resistance and structural safety of the existing building 3. Basement with excavation to expose support pile 2
It is also possible to add an additional 20. Anchors for beam and column joints required for skeleton construction of the added basement 20 (underground extension) can be provided on the main steel column 18 in advance, facilitating joining. Can be performed reliably.

(Second Invention) Similarly, as means for solving the problems of the prior art,
The seismic isolation method of an existing building according to the present invention is carried out when the existing building is directly supported by the ground of the support layer and there is no supporting pile, which is also shown in FIGS.
As shown in the embodiment in the figure, a) A main horizontal tunnel 7 extending underground of the existing building 3 is dug in the support layer ground 1 supporting the existing building 3, and the horizontal tunnel 7 A step of digging a branch tunnel 21 passing directly below the column 3B; and b) a vertical shaft 22 is dug vertically upward from the branch tunnel 21 toward the lower end of the column 3B in the existing building 3, and a steel column is formed along the shaft 22. C) The seismic isolation device 19 is installed between the top of the steel column 24 and the column base of the column 3B of the existing building 3, and the hydraulic jack 25 is further installed. And the step of introducing an axial force to the steel column 24 to change the support of the existing building 3 from the support layer ground 1 to the steel column 24 and the seismic isolation device 19.

In the case of the existing building 3 which is constructed directly on the supporting layer ground 1 and has no supporting pile, the steel column 24 is constructed through the branch tunnel 21 dug at a sufficiently deep position in the supporting layer ground 1.
The soundness and seismic resistance of the existing building 3 are not impaired,
It is easily possible to incorporate the seismic isolation device 19 when building 24. The support of the existing building 3 is changed from the support layer 1 to the steel column 24 and the seismic isolation device 19. Then, the basement 20 can be newly added by cutting off the surrounding ground 1, and the steel column 24 can be finally formed as a part of the structural frame of the added basement 20.

Next, an embodiment of the present invention shown in the drawings will be described.

First, FIG. 1 to FIG. 8 show a case where an existing building 3 supported by support piles 2...

FIG. 1 shows a stage in which a mountain retaining wall 4 also serving as a water stop is constructed on the outer periphery of the existing building 3. This retaining wall 4
For example, as shown in FIG. 9A, it has a planar shape surrounding the existing building 3 and is formed at a depth reaching the support layer ground 1 from the ground. The retaining wall 4 is constructed by driving a sheet pile or by a chemical liquid injection method using a solidifying material such as Tax (trademark).

FIG. 2 shows that a shaft 5 is dug near the existing building 3, a grab hopper 6 is installed on the ground, and a horizontal tunnel 7 connected to the shaft 5 is formed in a plane shape of the existing building 3. Dig along the outside (Fig. 9A), and
This shows the stage where materials and excavated soil are carried in and out using, and the underground part (beam foundation) of the existing building 3 is cut off to completely expose the support piles 2 to the depth of the support layer 1. ing.

The excavation work in this case is performed on the plane of the existing building 3 as illustrated in steps in FIGS.
A quadrangular shape including, for example, four support piles 2... In order from the end along the horizontal tunnel 7 is defined as one unit of root cutting section, and this cutting section is partially advanced in every other unit. In the unlikely event that a problem occurs, a procedure that does not have any adverse effect on the earthquake resistance and soundness of the existing building 3 is adopted. Of course, as the next construction procedure, the roots of the construction sections skipped every other step are first advanced and contacted laterally as shown in FIG. 9B, and the same procedure is repeated to repeat FIGS. It spreads horizontally to the construction of all planes like this.

Next, FIG. 3 shows a stage in which temporary supports 8 are erected on the outer periphery of each support pile 2 exposed by the root cutting.

FIG. 4 shows a stage in which an axial force is introduced into each temporary support 8 to change the load support of the existing building 3 from the support pile 2 to the surrounding temporary support 8.

The concrete means is, as shown in detail in FIGS. 10 and 11, four temporary supporters 8 are erected at four positions at right angles to the outer periphery of the support pile 2 (however, the number and positions are limited Not). First, as shown in FIG. 10, a shaft 9 is preliminarily excavated at a predetermined position of the support layer ground 1 at a depth of, for example, about 2 meters, and an H-shaped steel serving as a temporary receiving support 8 is inserted into the shaft 9 and vertically. build. The temporary receiving supports 8 built in the vicinity of the support piles 2 inevitably support the column bases or the vicinity thereof in the underground structure skeleton 3A, which is advantageous in terms of strength. The four temporary supporting supports 8... Which work in common with respect to one supporting pile 2 are joined to each other by a horizontal connecting member 10 and further stiffened by incorporating a brace 11. One hydraulic jack 12 is installed at the upper end of each of the temporary receiving supports 8, and the load is changed by jack-up.

As shown in FIGS. 12A to 12C, details of the load changing operation are as follows. First, a hydraulic jack having an axial force capacity of 200 tons and a stroke of about 220 mm is placed on the top end plate 17 attached to the upper end of the temporary support 8. 12 is installed, and the tip of the ram is brought into contact with a plate 13 fixed to the lower surface of the underground structural frame (foundation beam) 3A of the existing building 3 with a hole-in anchor or the like. The plate 13
And the upper end of the temporary support 8 are connected by a diagonal member 14.
In addition, a bracket 15 is provided in advance on the temporary support 8. Then, by driving the hydraulic jack 12, an axial force that is appropriately larger than the axial force necessary for the load change is initially introduced into the temporary support 8, thereby requiring the temporary support 8 after the load change. An end supporting force enough to withstand the applied axial force is generated in the supporting layer ground 1 in advance. After confirming the predetermined axial force with the hydraulic jack 12, the frame receiving gantry made of steel is inserted between the bracket 15 and the plate 13.
Assemble 16 (Fig. 12B). Thereafter, the hydraulic jack 12 is loosened and removed, and the work of changing the load burden is completed. When the rearrangement of all four temporary receiving supports 8 is completed in this way, the load burden on the support pile 2 becomes zero and the support pile 2 can be dismantled.

Next, FIG. 5 shows a stage in which the support pile 2 released from the load burden as described above is completely dismantled and the load of the existing building 3 is supported by the temporary receiving supports 8.

FIG. 6 shows a stage in which a permanent steel column 18 has been erected at the position where the support pile 2 was located.

FIG. 7 shows a stage in which the load is changed from the temporary support 8 to the permanent steel column 18 and the temporary support is removed.

In order to change the axial force of the temporary support 8 to the permanent steel column 18, a seismic isolation device 19 is installed between the top end of the permanent steel column 18 and the underground structural frame 3A of the existing building 3, as shown in FIG. Install.
The seismic isolation device 19 is a laminated rubber column formed by alternately attaching iron plates 19a and rubber sheets 19b to form a columnar body, and has an excellent effect of absorbing horizontal input.

Also, a bracket 26 protrudes below the main steel column 18,
A base plate 28 is fixed on a column foundation 27 cast on the support layer ground 1, and a hydraulic jack 25 erected on the base plate 28 is acted on a bracket 26 to introduce an axial force to the permanent steel column 18. Foot plate at the lower end of the permanent steel column 18
A stud bolt 30 is screwed into 29 and fixed with a lock nut 31.

A predetermined amount of axial force is introduced into the permanent steel column 18 by the hydraulic jack 25 to change the axial force from the temporary support 8 to the permanent steel column 18. The axial force of the steel column 18 is transmitted from the stud bolt 30 to the base plate 27 by adjusting the stud bolt 30 and the lock nut 31. Thereafter, the hydraulic jack 25 is loosened and removed, and the permanent steel frame 18 is finished into, for example, a steel reinforced concrete column.

The seismic isolation of the existing building 3 is performed as described above, and as a result, the seismic resistance and structural safety of the building 3 are greatly improved. Therefore, construction of the new seismic design method (Showa 56
Buildings before June) are not necessarily required to have seismic reinforcement as a result of the expansion, greatly improving economic efficiency and creating an environment suitable for the use of OA equipment.

Next, FIG. 7 shows a stage in which the basement 20 is expanded by extending the root excavation incorporating the seismic isolation device 19 to the whole ground as described above for all the support piles 2. This shows a stage where the skeleton construction of a part has been performed and the extension of the basement 20 has been completed.

The process up to the construction of the underground extension is described in Section 12.
It is completed for each unit of the construction section shown in FIGS.
Then, by connecting the adjacent construction sections sequentially, the seismic isolation device 19 is incorporated and the basement 20 is expanded while the seismic resistance and soundness of the existing building 3 are secured. With regard to the beam-column joints in the frame construction of the added basement 20, joints can be easily and reliably performed by projecting anchors for column and beam joints in advance on the permanent steel columns 18.

Second Embodiment Next, FIGS. 14 to 18 show that an existing building 3 is directly supported by a support layer ground 1 such as a Dotan layer or a Tokyo gravel layer, and a deep foundation portion such as a support pile is provided. If there is no construction method, the existing building 3 is seismically isolated.

FIG. 14 shows a stage in which a mountain retaining wall 4 also serving as a water stop is constructed on the outer periphery of the existing building 3.

This retaining wall 4 is, as in the case of the first embodiment,
It is constructed in a planar shape surrounding the existing building 3 and is formed from the ground to a depth reaching the support layer ground 1. The retaining wall 4 is formed by driving a sheet pile or using a tax (trademark).
It is constructed by means such as a chemical liquid injection method using a solidifying material such as.

FIG. 15 shows that a shaft 5 is dug near the existing building 3, a grab hopper 6 is installed on the ground, and a main horizontal tunnel 7 connected to the shaft 5 is provided at a predetermined depth in the support layer ground 1. Dig to the position, that is, the level of the lower end position of the steel column to be installed later, carry out the loading and unloading of materials, excavated soil, etc. using this horizontal tunnel 7, and branch tunnel that passes immediately below the column 3B ... of the existing building 3 The stage where 21 was dug is shown.

FIG. 16 shows that a shaft 22 is dug vertically upward from the branch tunnel 21 dug as described above toward the lower end of each column 3B in the existing building 3, and a column foundation is located immediately below the shaft 22.
23, a steel column 24 built on it is set up along the shaft 22, and a seismic isolation device is installed between the lower end of the column 3B of the existing building 3.
19, the hydraulic jack 25 was installed under the steel column 24, the axial force was introduced to the steel column 24 by the jack-up, and the load of the existing building 3 was relocated from the support layer ground 1 to the steel column 24. Is shown.

As shown in Fig. 13, the means and method of incorporating the seismic isolation device 19 between the top end of the steel column 24 and the lower end of the column 3B of the existing building 3 are as follows. A hydraulic jack 25 is installed along the lower part of the
Is transmitted to the steel column 24 via the bracket 26. Then, the axial force that the steel column 24 bears is changed by changing the load by raising the stud bolt 30 and transmitting it to the base plate 28.

FIG. 17 shows a stage in which the basement 20 is formed by extending the roots of the surrounding ground 1 to the entire ground after changing the load support of the existing building 3.

Fig. 18 shows the construction work of the expanded basement,
This shows a stage where the extension of the basement 20 has been completed.

Also in the case of the present embodiment, a series of steps from the construction of the steel columns 24 to the ground excavation and the skeleton construction are performed on the plane of the existing building 3 in the plane of the existing building 3 as in the first embodiment. In order from the end along the tunnel 7, for example, the length of a square or branch tunnel 21 including several pillars 3B... Is defined as one unit of construction section, and the construction is partially advanced in alternate units. First of all, proceed with the construction of every other skipped section, and then adopt the method of horizontal development to the construction of the whole building as shown in Figs. 9A to 9D by repeating the same procedure, and in case of emergency However, it is said that the existing building 3 will not have any adverse effect on the earthquake resistance and soundness.

Advantageous Effects of the Present Invention As described in detail in conjunction with the embodiment above, according to the seismic isolation method for an existing building according to the present invention, the existing building 3
Can be implemented safely and reliably without damaging the soundness and seismic resistance of the existing building, and without interrupting the use of the existing building. The structural safety and seismic resistance of the existing building 3 In addition to greatly improving the environment, it is possible to provide an environment suitable for use of OA equipment and the like.

Therefore, existing buildings before the enforcement of the New Seismic Design Law in June 1981 can be constructed economically without necessarily requiring seismic strengthening accompanying the expansion.

In addition, in conjunction with the seismic isolation of the existing building 3, the basement 20 (floor area) will be safely expanded without any problems with the structural strength and sunshine rights inherent in the existing building 3. By using the basement 20 for a parking lot, a warehouse, a sales floor, etc., a great economic effect can be obtained. In particular, the recent rise in land prices to an unusually high level means that even if the huge cost (unit price per tsubo) required for underground construction for seismic isolation is deducted, there is still enough available space for the expanded basement 20 It brings benefits and added value.

[Brief description of the drawings]

1 to 8 are cross-sectional views showing essential steps of a basement extension method of an existing building according to the present invention, and FIGS. 9A to 9D are views showing progress of construction when the building is viewed in a plan view. Fig. 10, Fig. 10 is an elevation view showing a means for changing the load between the support pile and the temporary support, Fig. 11 is a sectional view taken along line 11-11 of Fig. 10, and Fig.
To C are explanatory views showing the jack-up means of the temporary support in the order of steps, FIG. 13 is a front view showing the structure for incorporating the seismic isolation device, and FIGS. It is sectional drawing which showed the important process of the basement extension construction method of a certain existing building. 3 ... existing building 4 ... retaining wall 2 ... support pile 1 ... support layer 8 ... temporary support, 12 ... hydraulic jack 3A ... underground structure frame 18 ... permanent steel column, 19 …… Seismic isolation device 7 …… Main horizontal tunnel, 21… Pit shaft 24 …… Steel column, 25… Hydraulic jack

Continued on the front page (72) Inventor Masao Miyaguchi 8-21-1, Ginza, Chuo-ku, Tokyo Inside the Tokyo Head Office of Takenaka Corporation (72) Inventor Hiromichi Yamada 8-2-1-1, Ginza, Chuo-ku, Tokyo Stock Company Takenaka Corporation (Tokyo) (72) Inventor Susumu Yamashita 8-21-1, Ginza, Chuo-ku, Tokyo Inside Tokyo Takenaka Corporation (Tokyo) (72) Inventor Tadao Murano 8-2-1-1, Ginza, Chuo-ku, Tokyo (72) Inventor Katsushi Uchimura 8-21-1, Ginza, Chuo-ku, Tokyo Tokyo, Japan (72) Inventor Yoshio Suzuki 2-5-2 Minamisuna, Koto-ku, Tokyo No. 14 Inside Takenaka Corporation Technical Research Institute (72) Inventor Shunsuke Sugano 2-5-1 Minamisuna, Koto-ku, Tokyo Inside No. 5 Takenaka Corporation Technical Research Institute (72) Inventor Hiroshi Hayami 2-Chome Minamisuna, Koto-ku, Tokyo No. 5-14 Inside of Takenaka Corporation Technical Research Institute

Claims (2)

(57) [Claims] (1) A step of excavating the basement of an existing building to expose the supporting piles, and (b) A required number of temporary supporting supports are erected around the exposed supporting piles, and jacks are installed on each temporary supporting support. Then, the jack is applied to the underground structure of the existing building to change the axial force of the supporting pile to the temporary support. C) After the axial force is changed, the supporting pile is dismantled and the book is replaced at the same position. And d) installing a seismic isolation device between the main steel column and the underground structure of the existing building, and then relocating the axial force of the temporary support to the main steel column. A method of seismic isolation of existing buildings, characterized by the following steps: 2. A main tunnel extending underground to the existing building is dug in the support layer ground supporting the existing building, and a branch tunnel passing from the horizontal tunnel to a position directly below the pillar of the existing building. Digging; and b) digging a vertical shaft vertically upward from the branch tunnel toward the lower end of the pillar of the existing building, and constructing a steel column along the shaft; c) the top of the steel column and the existing building. A seismic isolation device and a jack are installed between the underground structural frame and a jack, and this jack is used to introduce the axial force into the steel column, and to replace the support of the existing building with the steel column and the seismic isolation device. A seismic isolation method for existing buildings, characterized by the following: