JPH11223028A - Base isolation device setting method for existing building deep foundation pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To incorporate a base isolation device between the deep foundation pile and the foundation part of an existing building by cutting and removing both the side parts of the head part of the deep foundation pile, arranging an oil jack and transferring the load of the deep foundation pile. SOLUTION: In a building comprising a deep foundation pile 1, a foundation part 2, an underground beam 3 or the like, and both the side parts of the head part of the deep foundation pile 1 is cut and removed to support the load of the existing building by a central part 1b. A plurality of oil jacks 5 are arranged through a concrete frame 4 on both the side parts, the load of the central part 1b is transferred to the oil jack 5 to cut and remove the central part 1b, concrete is placed on the head of the deep foundation pile 1 to form a pressure- resistant board, a base isolation device is set, concrete is injected in the upper part of the base isolation device to be integrated with the foundation part 2, and the load of the oil jack 5 is transferred to the base isolation device to remove the oil jack 5. Thereby the base isolation device can be incorporated between the deep foundation pile 1 and the foundation part 2 of the existing building.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of installing a seismic isolation device on an existing building deep foundation pile.

[0002]

2. Description of the Related Art As a countermeasure against earthquakes, there is an increasing need to install a seismic isolation device at the foundation of a building. However, in the case of an existing building, it is not easy to incorporate the seismic isolation device into the foundation. In the case of a small building with a lower floor, for example, it is possible to adopt a construction method in which the building is separated from the foundation and pushed up, the seismic isolation device is installed on the foundation, the building is lowered, and the building is integrated with the seismic isolation device. In a high-rise building, such a construction method cannot be applied. For this reason, means for repairing the wall portion and incorporating an earthquake-resistant mechanism such as a damper is usually employed.

[0003]

However, with the above-mentioned conventional construction method in which an earthquake-resistant mechanism is incorporated in a wall portion, there is a problem that a sufficient earthquake-proof effect cannot always be expected for a large earthquake. The present invention has been made to solve such a conventional problem, and even in the case of a large-scale, high-rise existing building having a deep foundation pile, the earthquake-resistant mechanism is used for the foundation using the deep foundation pile. The purpose of the present invention is to provide a method of installing a seismic isolation device on a deep foundation pile of an existing building so that the seismic isolation device can be incorporated.

[0004]

As a means for achieving this object, according to the present invention, in an existing building having a deep foundation pile, excavation is performed so that the head of the deep foundation pile is exposed, and Cut and remove leaving the central part, install a jack at the cut point to receive the foundation of the existing building, then cut and remove the central part, and form a pressure-resistant plate at the upper end of the deep foundation pile The gist is to install a seismic isolation device in the central part where it has been cut and removed, integrate it with the foundation, transfer the load of the existing building to this seismic isolation device, and remove the jack. In addition, in this seismic isolation device installation method, when forming a pressure-resistant version, a lower anchor plate that serves as a seismic isolation frame is installed, and a seismic isolation device is installed on the lower anchor plate. The gist is that concrete is press-fitted into the gap and integrated.

[0005]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1 (a), reference numeral 1 denotes a deep foundation pile of an existing building (not shown), on which a foundation 2 is formed, and underground beams 3 intersect in a cross shape as shown in (b). Attached. In the first step of the method of the present invention, a predetermined depth L (about 1.5 m to 2.0 m) is excavated from the bottom surface of the foundation 2 to expose the head of the deep foundation pile 1. This excavation can be performed by machine or human power from outside the building.

In the second step, a part of the exposed head of the deep foundation pile 1 is removed. As shown in FIGS. 2 (a) and 2 (b), a predetermined portion of the deep pile 1 is cored to form a wire set hole 1a, and a central portion 1b of the deep pile 1 is left. Part 1
c and 1d are removed by cutting C with a wire saw (not shown). At this time, the remaining cross section of the central portion 1b has an area necessary and sufficient to support the load of the existing building.

The third step is to cut and remove both sides 1c,
As shown in FIGS. 3 (a) and 3 (b), a plurality of oil jacks 5 are arranged via a concrete frame 4 in 1d, and preloading (releasing of axial force) is performed. That is, a plurality of oil jacks 5
To stably receive the base part 2 and temporarily support the existing building.

The fourth step is removal of the central portion 1b of the deep foundation pile 1, which is left at the head of the deep foundation pile 1 as shown in FIGS. 4 (a) and 4 (b). The upper and lower sides are cut by a wire saw C 'and removed.

In the fifth step, as shown in FIGS. 5 (a) and 5 (b), a pressure-resistant plate 6 is placed on the deep foundation pile 1 including the concrete base 4.
To form The pressure-resistant plate 6 is provided by arranging a reinforcing bar and casting concrete. At that time, a lower anchor plate 7 serving as a base isolation base is installed, and a base isolation device 8 is installed thereon.
Further, concrete is press-fitted into a gap between the seismic isolation device 8 and the foundation 2 to form an upper anchor plate 9 and integrated with the foundation 2.

In the sixth step, the seismic isolation device 8
And remove the temporary receiving material. That is, FIG.
As shown in (b), the oil jack 5 is unloaded, and after transferring the building load to the seismic isolation device 8, all the oil jacks 5 are removed. The concrete gantry 4 is left as it is, or the protrusion is removed to make the same surface as the upper surface of the pressure-resistant plate 6.

Through the above steps, the foundation 2 of the existing building
A seismic isolation device 8 can be incorporated between the base pile 1 and the deep foundation pile 1. In this case, since the seismic isolation device 8 is interposed in the foundation 2 of the existing building, a sufficient seismic isolation function can be exerted in the event of a large earthquake.

[0012]

As described above, according to the present invention,
The seismic isolation device can be installed between the foundation of the existing building and the deep foundation pile using the deep foundation pile of the existing building, and in the installation process, the existing building is maintained as it is, The construction is simple because it is completed by renovating only the upper end of the pile. Therefore, it can be applied to a large-scale, high-rise existing building.

[Brief description of the drawings]

FIG. 1 shows a first step of a method of installing a seismic isolation device according to the present invention, wherein (a) is a cross-sectional view and (b) is a plan view.

FIG. 2 shows a second step, in which (a) is a cross-sectional view and (b) is a plan view of the upper part of the deep foundation pile.

FIG. 3 shows a third step, in which (a) is a cross-sectional view and (b) is a plan view of the upper part of the deep foundation pile.

FIG. 4 shows a fourth step, in which (a) is a cross-sectional view and (b) is a plan view of the upper part of the deep foundation pile.

FIG. 5 shows a fifth step, in which (a) is a cross-sectional view and (b) is a plan view of the upper part of the deep foundation pile.

FIG. 6 shows a sixth step, in which (a) is a cross-sectional view and (b) is a plan view of the upper part of the deep foundation pile.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Deep foundation pile 2 ... Foundation part 3 ... Underground beam 4 ... Concrete stand 5 ... Oil jack 6 ... Pressure-resistant version 7 ... Lower anchor plate 8 ... Seismic isolation device 9 ... Upper anchor plate

Claims (2)

[Claims] In an existing building having a deep foundation pile, excavation is performed so that the head of the deep foundation pile is exposed, cut and removed while leaving a central portion of the head, and a jack is installed at the cut location to install an existing jack. Receiving the foundation of the building, then cutting off the central part,
A pressure-resistant version is formed at the upper end of the deep foundation pile, and a seismic isolation device is installed at the central part where it has been cut and removed, integrated with the foundation, and after transferring the load of the existing building to this seismic isolation device, the jack is installed. A method of installing seismic isolation devices on existing foundation piles, which is to be removed. 2. When forming a pressure-resistant version, a lower anchor plate serving as a seismic isolation frame is installed, and a seismic isolation device is installed on the lower anchor plate, and concrete is pressed into a gap between the seismic isolation device and a foundation. The method for installing a seismic isolation device on an existing building deep foundation pile according to claim 1, wherein the seismic isolation device is integrated.