JPH11124863A - Spread foundation practice having damping function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spread foundation practice having a damping function, in which horizontal force energy at the time of earthquake can be absorbed and damped effectively. SOLUTION: When low-medium-rise buildings are constructed, the base mat 3 of reinforced concrete is placed on the surface of an excavating ground 1, PC slabs 4 coated with frictional adjusting materials 5 are spread all over the top face of the base mat 3, and the PC slabs 4 are welding-joined and unified mutually. The top face of the base mat 3 on the base section of a ground beam is also coated with the frictional adjusting material 5, and a specified metallic sheet 10 is spread all over the frictional adjusting material 5 and the ground beam 9 and a bearing slab 11 are driven. An elastic molded form 8 functioning as a damper is installed between the outside section of the PC slabs 4 and the lower section of the inside section of the ground beam 9, and a foundation has the damping function to the horizontal energy of an earthquake by the sliding action of the frictional adjusting material 5 and the metallic sheet 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention provides a seismic isolation function to absorb and attenuate horizontal force energy such as earthquakes when building low-, medium- and high-rise buildings directly on a relatively good supporting ground by a foundation method. On the method of construction.

[0002]

2. Description of the Related Art When designing and constructing a low-, medium-, and high-rise building, a relatively good supporting ground is used, and when the building load is not so uneven, a direct foundation method (solid foundation).
Is often adopted.

When an earthquake occurs, its seismic force is directly input to the building from the bottom and side surfaces of the building foundation.

[0004] Usually, buildings are designed structurally with respect to seismic force stipulated by laws and regulations, and there is no problem in seismic design. However, when an unexpected and strong earthquake occurs, cracks occur and joints are cut off. Damage, destruction of the piloti, collapse of furniture, and other various damages are expected.

As means for absorbing and reducing the energy of seismic force, a considerable number of various construction methods have been proposed and partially implemented. As an example, a method of constructing a strong artificial ground or base and incorporating seismic isolation devices (isolators and dampers) between the ground and the upper main structure is often used. Various types of seismic isolation devices, including laminated rubber, lead, steel plates, springs, etc., those that apply air pressure, water pressure, and hydraulic pressure, those that are mechanical, or those that combine or combine them have been proposed and evaluated. Implementation has been done.

[0006]

However, in any case, a high level of analysis, calculation and technical skills are required, and the adoption thereof requires a large increase in cost, and long-term maintenance must be considered. There is a problem that is.

[0007] Therefore, an object of the present invention is to reduce the input of horizontal force by providing a seismic mitigation function to the foundation of a building, so that even if a legally designed structural design is adopted, the safety of the building's seismic resistance is reduced. The degree of improvement can be expected to reduce the sensitivity of the human body to seismic motion, and the construction cost is significantly lower than other proposed and implemented construction methods, and the construction management is also easier. An object of the present invention is to provide a direct foundation method having a vibration reduction function which is easy and requires little maintenance.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention places a reinforced concrete base mat on an excavated ground surface and places an underground beam pressure-resistant plate on the base mat. At the position of the part, a PC plate coated with a friction adjusting material on the upper surface is laid, the PC plates are integrated with each other, and the friction adjusting material is coated at the position where the underground beam on the concrete base mat is provided, and then the friction is applied. Underlay the metal sheet on the part coated with the adjustment material and the PC plate and place the underground beam and pressure-resistant plate on it,
An elastic molded body acting as a damper is provided between an outer peripheral portion of the PC plate and an inner portion of the underground beam.

The friction modifier has a structure in which a ceramic particle or a glass particle having an arbitrary particle diameter is kneaded and mixed with a bituminous chemical solvent which cures at room temperature.

[0010] Here, the horizontal seismic force energy input from the ground is absorbed and reduced by a friction adjusting material coated on the upper surface of the PC plate, and an elastic molded body provided between the inner surface of the underground beam and the outer surface of the PC plate. In this way, horizontal vibration is mitigated, and excessive displacement prevention and return to original position are considered.

It is also conceivable to design the structure such that the ground reaction force against the building load is borne by the underground beam pressure resistant version and the PC version in combination.

[0012] Seismic vertical motion (UD) has not been taken into account. As for the reason, many reports have been made on high-rise buildings, such as breakage of steel pipe columns, breakage of pile heads, buckling of columns and brace materials, etc. in the Great Hanshin Earthquake. This is because there is no case of damage due to vertical movement (UD) unless the construction is defective.

The friction-adjusting material can adjust the coefficient of friction so as to cope with the load of the building and the set seismic force, and the elastic molded body is made of a synthetic rubber-based material which does not cause deterioration in the alteration strength. By adjusting the amount of elastic deformation and thickness, it has a role as a cushioning material and a damper. The specifications of both materials are determined by theoretical and experimental values.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a necessary portion on which a direct foundation having a vibration reduction function is constructed, and FIG. 2 is a plan view of the same.

The crushed stone layer 2 is compacted on the ground 1 excavated to a predetermined depth, and a reinforced concrete base mat 3 having a predetermined thickness is cast thereon.

The PC plate 4 manufactured at the factory is coated with a friction adjusting material 5 on the upper surface. The PC plate 4 is spread on a reinforced concrete base mat 3 using a mortar 6, and the PC plate 4 is coated with a cotter. The part 7 is welded and integrated.

The integrated PC plate 4 corresponds to the portion where the underground beam pressure-resistant plate is formed, and the elastic molded body 8 is attached to the outer periphery of the PC plate 4 in an appropriate arrangement.

The surface of the base mat 3 on which the undersurface of the underground beam 9 rests is coated with a friction adjusting material 5 on site, and a metal sheet 10 such as stainless steel is spread over the friction adjusting material 5 and the PC plate 4.

The PC plate 4 is provided with level adjusting means which is operated from the upper surface at the four corners, so that the horizontal accuracy of the PC plate 4 to be laid is raised to the utmost.

The friction modifier 5 is manufactured by kneading and mixing porcelain particles or glass particles of an arbitrary particle size with a bituminous chemical solvent which cures at room temperature, and is applied to the surface of the PC plate 4 manufactured at the factory. At the same time, it is applied and used on the base mat 3 at the site.

In the illustrated embodiment, the elastic molded body 8 is a cylindrical body having a porous structure using rubber or the like, but a coil spring, a leaf spring, or the like may be used.

As described above, when the preparation is completed by laying down the metal sheet 10, the reinforcing bars and the formwork are assembled on the metal sheet 10, concrete is poured into the formwork, and the pressure-resistant plate 11 and the underground beam are assembled. Build 9.

A cushion member 12 is interposed between the underground beam 9 and the ground 1 to maintain a space.

On the direct basis constructed as above,
The horizontal seismic force energy input from the ground is PC version 4.
Absorbed and attenuated by the friction adjusting material 5 and the metal sheet 10 coated on the upper surface and the base mat 3, and the horizontal vibration is caused by the elastic molded body 8 provided between the inner surface of the underground beam 9 and the outer surface of the PC plate 4. In addition to reducing displacement, it is possible to prevent excessive displacement and return to the original position. In this way, by adding a seismic reduction function to the foundation of the building, the input of horizontal force is reduced and exempted. Even if it is adopted, the safety level of the building's earthquake resistance is improved, and the sensitivity of the human body to earthquake motion is reduced.

[0026]

As described above, according to the present invention, a friction adjusting material is applied on a base mat and a PC plate, a metal sheet is laid thereon, and an underground beam and a pressure-resistant plate are further constructed thereon. Then, since the elastic molded body was provided between the outer circumference of the PC plate and the inner circumference of the underground beam, the horizontal seismic force energy input from the ground was absorbed and attenuated by the sliding of the friction adjusting material and the metal plate,
In addition, the elastic molded body reduces horizontal vibrations, prevents excessive displacement and returns to the original position, reduces the input of horizontal force, improves the safety of the building's earthquake resistance, and reduces the sensitivity of the human body to earthquake vibrations. can do.

In terms of cost, construction costs are significantly lower than those of various other proposed and implemented methods, construction management is easy, and almost no maintenance is required.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a direct foundation having an earthquake mitigation function.

FIG. 2 is a cross-sectional plan view of the above.

FIG. 3 is a perspective view of an elastic molded body.

FIG. 4 is an enlarged cross-sectional view of a friction adjusting material and a metal sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ground 3 Concrete base mat 4 PC version 5 Friction modifier 6 Mortar 8 Elastic molded object 9 Underground beam 10 Metal sheet 11 Pressure-resistant version

Claims (2)

[Claims] 1. A reinforced concrete base mat is cast on the excavated ground surface, and a PC plate coated with a friction adjusting material on the upper surface is laid on the base mat at a position where the underground beam pressure resistant plate is to be cast. Then, the PC plates are integrated with each other, and the position where the underground beam is provided on the concrete base mat is coated with a friction adjusting material, and then a metal sheet is spread over the portion coated with the friction adjusting material and the PC plate. Place an underground beam and a pressure-resistant plate on top of it and
A direct foundation method having a vibration reduction function characterized by providing an elastic molded body acting as a damper between an outer peripheral portion of a plate and an inner portion of an underground beam. 2. A friction modifier for use in a direct foundation method having an anti-vibration function according to claim 1, wherein ceramic particles or glass particles having an arbitrary particle size are kneaded and mixed with a bituminous chemical solvent which hardens at room temperature.