JPH0333527A - Damping sand for high external force - Google Patents

Abstract

PURPOSE:To improve damping function against external force and reduce vibration of a building by providing an asphalt layer on the surface of sand, and making weight of the asphalt layer equal to 1-7% weight of the sand. CONSTITUTION:An asphalt layer is provided on the surface of sand. Weight of the asphalt layer is equal to 1-7% weight of the sand. Accompanying with increase of the asphalt quantity, area drawn by shearing stress - strain hysteresis curve becomes larger, damping constant becomes larger, and remarkable improvement of damping function against external force is recognized. At the same time, rigidity characteristic is nearly same as that of ordinary sand. This damping sand for high external force 1 is spreaded all over, on the bottom of a building 2 and around its lower end part, or between the bottom of a building 2 and a base 3 supported with piles. Thus, the damping function against external force is improved and vibration of the building can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to high external force attenuating sand that is spread over the foundations of structures, etc. to attenuate external forces such as earthquakes and wind, and to alleviate external forces acting on the structures.

[Problem to be solved by the invention]

Various methods have been proposed as methods for reducing the response to external disturbances such as earthquakes and wind that act on structures.

The purpose of this invention is to propose high external force attenuation sand that has a rigidity comparable to that of sand, has a high external force attenuation function, and can be used in a wide range of applications, such as laying on the foundations of structures.

[Means to solve the problem]

This high external force attenuation sand is characterized in that a thin asphalt film layer is provided on the surface of the sand, and the asphalt layer has a weight of 1 to 7% of the weight of the sand.

This high external force damping sand has the same rigidity as the main material, sand, and the thin asphalt layer on the sand surface provides an external force damping function that sand does not have. Increasing the amount of asphalt improves the damping function, but creep characteristics become noticeable. Usually, the amount of asphalt is 1-7%
is within the range of If it is less than 1%, the damping function is poor, and if it is more than 7%, creep characteristics become noticeable. More preferably 1
~5%, and the percentage is selected depending on the purpose of use.

〔Example〕

1%, 2%, 3%, 4% of the sand weight on the surface of the sand.

A 5% asphalt thin film layer (using a straight asphalt layer with an angle of 60° to 80°) was created to create high external force attenuation sand, and placed on top of the specimen (φ108 x h 30mm).
Place the plate load σ, = ],, Okg f/cnI,
A horizontal dynamic shear force with a frequency of f-4,011z was applied.

Shear strain r=0.001%, r=0.01%,
The shear center Kerr strain history curve for the case of 7001% is the first
Shown in the figure. Furthermore, FIG. 2 shows a correlation graph between the shear deformation coefficient, damping constant, and shear strain.

As the amount of asphalt increases, the area covered by the hysteresis curve in FIG. 1 becomes wider, the damping constant in FIG. 2 becomes larger, and a significant improvement in external force damping performance is recognized. but,
Regardless of the increase in the amount of asphalt, the slope of the curve in Figure 1 and the shear deformation coefficient G in Figure 2 hardly change.
It shows that the stiffness properties are almost the same as normal sand.

[For production]

This high external force damping sand 1 is, for example, shown in FIG. 3(a) or (
As shown in b), it is used by laying around the bottom and lower end of the building 2, or between the bottom of the building 2 and the foundation 3 supported by piles. Further, as shown in FIG. 3(C) or (d), it is used by filling inside the box column 4 of the building 2, the steel pipe column 6 of the tower 5, etc.

As mentioned above, high external force damping sand has the same rigidity as sand and can stably support the building above. Furthermore, since it has a high external force damping function, external forces such as earthquakes and wind that act on buildings, etc. can be weakened, and vibrations of buildings, etc. can be significantly reduced.

〔Effect of the invention〕

The present invention is as described above, and this high external force attenuation sand has the characteristics of sand in terms of rigidity, and at the same time has an excellent external force attenuation function. vibration can be reduced. In addition, it is low cost, easy to construct, and can be used for various objects in various ways.

[Brief explanation of drawings]

Figures 1 and 2 are the hysteresis curve and shear deformation coefficient of the high external force damping sand of the example, and the correlation graph between the damping constant and shear strain. Figure 3 (a), (b), (C), and (d) are FIG. 3 is a schematic diagram showing a mode of use of this high external force attenuation sand. 1... High external force attenuation sand, 2... Building, 3
...Foundation, 4...Box column, 5...
...Tower, 6... Steel pipe column.

Claims (1)

[Claims] (1) High external force attenuation sand, characterized in that an asphalt layer is provided on the surface of the sand, and the asphalt layer has a weight of 1 to 7% of the weight of the sand.