JP2010024764A - Foundation base-isolating method for existing building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foundation base-isolating method for an existing building comparatively low in cost, easily executed and contributing to the formation of a resource circulating type society for the purpose of minimizing material damage and human damage caused by an earthquake. <P>SOLUTION: A base-isolating repair of a foundation of the existing building is carried out by excavating and removing a foundation work portion T of rubble or the like existing at the lower part of existing foundation concrete N, and placing a base-isolating board A on expansive concrete I in that portion R. An elastic material L-M is used as a backfilling material. Propagation of seismic energy is suppressed in case of an earthquake, and the foundation of the existing building is base-isolated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a basic seismic isolation method for an existing building for the purpose of suppressing propagation of horizontal seismic energy to the building.

When building a new building, the technology of various seismic isolation devices is widely known, but it takes a lot of construction costs to make an existing building seismic isolation. In addition, although technology for seismic isolation of large-scale buildings is known, technology for seismic isolation of the foundations of general medium and low-rise buildings has been demanded.
JP-A-11-256596 JP2008-104511

  The object of the present invention is to protect the lives and property of people from earthquake damage by renovating the bases of existing buildings that have not been seismically isolated at low cost.

  As a means for achieving the above object, the present invention mounts the seismic isolation board so that it abuts the lower surface of the existing foundation concrete after excavating and discharging a groundwork such as quarry stone applied under the existing foundation concrete. By placing the expansive concrete in the cavity that appears between the generally seismic isolation substrate and the supporting ground, the generally seismic isolation substrate is pushed up directly above and makes contact with the bottom surface of the foundation concrete without any gaps. Next, the excavation and earth removal portions around the existing foundation concrete on the indoor side and the outdoor side are backfilled using an elastic material, thereby reducing the force transmitted to the existing foundation concrete by the seismic energy propagating through the ground. Also, even if an earthquake of a magnitude greater than expected occurs and strong seismic energy propagates to the existing building, a substantially semi-spherical protrusion is slidably in contact with the bottom surface of the existing foundation concrete on the top surface of the base isolation board. As a result, the seismic isolation effect is exhibited.

  The seismic isolation method for an existing building according to the present invention does not require repair of the main structure such as the foundation, frame, floor, wall, and roof of the existing building, and can be seismically isolated at low cost. .

  It is also possible to adopt the seismic isolation method using this seismic isolation board when building a new building.

It is possible to contribute to the formation of a resource recycling society by recycling waste materials etc. using seismic isolation boards and elastic backfill materials.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  A is a seismic isolation substrate, and a seismic isolation substrate recess D is provided on the upper surface B of the substrate by exposing a substantially semispherical protrusion C. The base isolation board A is placed on the expanded concrete I placed after excavating and discharging the ground industry such as quarry stone. Moreover, the indoor backfill material M and the outdoor backfill material L are backfilled in the excavation / soil removal portion R around the existing foundation concrete N.

  A basic seismic isolation method for an existing building having the above configuration will be described based on one construction embodiment.

  The basic seismic isolation method for an existing building according to the present invention can be applied to a relatively low-rise and lightweight building such as a one-story building, two-story building, and three-story building.

  First, carefully examine the construction method of the existing building including its surroundings, such as the frame, structure, finishing material, and the compaction strength and soil quality of the local board. decide.

  As one construction embodiment, the supporting ground J of an existing building is intruded under the floor from the indoor side O through the underfloor inspection port or the like and excavated and discharged. Next, excavate and evacuate the existing quarry stone T. At this point, excavation and soil removal will be carried out within a range where safety can be confirmed while providing temporary support so as not to cause uneven settlement of the existing building Q.

  In parallel with the excavation and earthing of the indoor side O, the ground J is excavated and earthed from the outdoor side P to remove the existing ground industry, and then the existing foundation concrete lower surface S is polished smoothly.

  Next, the seismic isolation substrate A is inserted and provisionally placed in the horizontal direction from the outdoor side P so that the substantially semispherical protrusion C contacts the lower surface S of the existing foundation concrete.

  A cavity H appears between the bottom surface E of the base isolation board and the ground J after excavation. Expanded concrete I is placed in the cavity H, and the seismic isolation board A is brought into contact with the existing foundation concrete lower surface S.

  Next, the indoor side backfill material M and the outdoor backfill material L are backfilled in the excavation / soil removal portion R on the indoor side O and the outdoor side P of the existing foundation concrete N, and are rolled with a tamper or the like.

  Both expanded concrete I and seismic isolation board A should be of quality including the hardness required by various laws and regulations including the Building Standard Law.

  In order to repeat the above construction in sequence, the next base isolation substrate notch F is engaged with the base isolation substrate notch F and connected. Temporary placement of the seismic isolation substrate A is facilitated by sequentially engaging the notches F.

As long as the indoor backfill material M and the outdoor backfill material L have elasticity, they may be used regardless of whether they are spheres, squares, cuboids, powders, or gels.

Schematic sectional view showing an embodiment of the present invention The perspective view which shows one Example of a seismic isolation board Side view of long side direction showing one embodiment of seismic isolation board Side view of short side direction showing one embodiment of seismic isolation board

Explanation of symbols

A Seismic isolation board B Upper surface of seismic isolation board
C Almost semi-spherical protrusion
D Seismic isolation substrate recess
E Bottom surface of seismic isolation board
F Notch
G Seismic isolation board side
H cavity
I Expanded concrete
J ground
K drilling line
L Outdoor backfill material
M Interior backfill material
N Existing concrete foundation
O Indoor side
P Outdoor
Q Existing building frame
R excavation and earth removal part
S Bottom surface of existing foundation concrete
T Existing local industry

Claims (1)

In the foundation seismic isolation method for existing buildings, the area around the existing foundation concrete is excavated from the surface, and the existing foundation ground such as quarry stone that supported the existing foundation concrete is excavated and discharged, Insert and place the seismic isolation board horizontally in the gap between the bottom of the cavity and temporarily support it, and then place expanded concrete in the gap between the base isolation board and the bottom of the cavity, and place the bottom surface of the existing foundation concrete and the top surface of the base isolation board. Make contact. The generally seismic isolation board has a shape such as a rectangular parallelepiped, and a plurality of semi-spherical protrusions or protrusions protrude from the upper surface of the base isolation board that abuts the lower surface of the existing foundation concrete, and both ends or each end. Is provided with a notch having a joint function.
In addition to making the entire surface stepped as shown in the figure, there is a method of providing unevenness on the side surface and connecting the cutout portions in combination, and it can be determined from the viewpoint of use and construction.
A substantially hemispherical protrusion formed on the upper surface of the base isolation board, which is constructed by laying multiple adjacent base isolation boards with asymmetrical notches, and using an elastic material for backfilling. Alternatively, the base seismic isolation method for existing buildings is characterized by the fact that the ridges are slidably in contact with the bottom surface of the existing foundation concrete, and when the seismic energy propagates from the surrounding ground, it exhibits a seismic isolation effect.