Abstract: A seismic isolator is provided in a building and maintains the horizontalness of the building. The isolator includes a foundation base plate in contact with the ground surface, and a foundation top plate on which a building is mounted, the foundation base plate and the foundation top plate being in intimate contact with each other leaving no space and being individually directly formed with a curved surface symmetrically facing each other; and a spherical body positioned at the center of the curved surfaces, when the foundation base plate moves as a result of horizontal vibrations caused by an earthquake, the spherical body rotates and rolls along the curved surfaces to raise the foundation top plate; thereby the vibrations are hindered from being transmitted to the foundation top plate to perform seismic-isolation action on the building; and after the earthquake subsides, the spherical body returns to the center of the curved surfaces.

Abstract: The object of the present invention is to obtain a seismic isolator which is provided in a building and maintains the horizontalness of the building, characterized by including: a foundation base plate arranged in contact with the ground surface, and a foundation top plate on which a building is mounted, the foundation base plate and the foundation top plate being in intimate contact with each other and being individually directly formed with a curved surface symmetrically facing each other, for example, in the four corners of the building; and a spherical body positioned at the center of the curved surfaces, characterized in that: as a result of horizontal vibrations caused by an earthquake, the spherical body smoothly rotates and rolls along the curved surfaces; thereby the foundation top plate rises to perform seismic-isolation action on the building; and after the earthquake subsides, the spherical body returns to the center of the curved surfaces.

Abstract: A method for designing a structure or the like is provided in which an arbitrary curve is approximately drawn using a circular segment. This method includes the steps of: setting a straight line which connects one end of a desired curve and the other end thereof; setting an intersection point of the curve and a perpendicular to the straight line at a middle point thereof; obtaining a distance between the intersection point and the middle point, and a length of a straight-line segment from each of the one end and the other end of the curve up to the middle point; setting a curvature radius of a circular segment which approximates the desired curve in association with these distance and length, and acquiring a radius center point of the circular segment; and setting a circular segment from the one end up to the other end of the curve by using this center point as the center thereof.

Abstract: A method for designing a structure or the like is provided in which an arbitrary curve is approximately drawn using a circular segment. This method includes the steps of: setting a straight line which connects one end of a desired curve and the other end thereof; setting an intersection point of the curve and a perpendicular to the straight line at a middle point thereof; obtaining a distance between the intersection point and the middle point, and a length of a straight-line segment from each of the one end and the other end of the curve up to the middle point; setting a curvature radius of a circular segment which approximates the desired curve in association with these distance and length, and acquiring a radius center point of the circular segment; and setting a circular segment from the one end up to the other end of the curve by using this center point as the center thereof.

Abstract: A method for designing an elliptical structure with an outline of an approximate elliptic curve, which is generated by connecting circular segments to one another, and an elliptical structure created on said method.

Abstract: A method for designing an elliptical structure with an outline of an approximate elliptic curve, which is generated by connecting circular segments to one another, and an elliptical structure created on said method.