Structure for seismic isolation, steel support structure, and method for seismic isolation of existing steel support structures

A method for providing a structure for seismic isolation in an intermediate layer of an existing steel support structure including an object to be supported, and a support steel frame that has a plurality of columns standing on a foundation via column bases and a plurality of beams connecting adjacent columns and that suspends and supports the object to be supported, the structure for seismic isolation being provided on a structure plane including a pair of left and right columns spaced apart in a horizontal direction, and a pair of upper and lower beams spaced apart in a vertical direction, each of the upper and lower beams bridging between the pair of columns,

• wherein the structure for seismic isolation comprises:
• a seismic isolation device provided in a middle of each of the columns;
• and
• a horizontal tie beam connecting the pair of columns,
• wherein the seismic isolation device is provided to be displaced closer to one of the upper and lower beams, and
• the horizontal tie beam is provided between the area in which the seismic isolation device is provided and the other of the upper and lower beams,
• wherein the structure for seismic isolation is provided on the structure plane including the pair of left and right columns and the upper and lower beams,
• the method comprises at least the steps of:
• connecting the pair of columns using the horizontal tie beam;
• providing a support member between the horizontal tie beam and one of the upper and lower beams and then cutting an area of at least one of the pair of left and right columns between the horizontal tie beam and the one of the upper and lower beams;
• providing the seismic isolation device in the cut area;
• and
• removing the support member.