And mold using a thin jack, seismic isolation device installation method and bridge bearing replacement method

摘要

PROBLEM TO BE SOLVED: To provide a thin jack which is usable as a concrete form and can be repeatedly utilized, and a seismic isolator installation method and a bridge bearing replacement method using the thin jack.SOLUTION: A thin jack includes a cylinder, a medium chamber capable of supplying and discharging a pressure medium, and a movable body. The medium chamber is expandable/contractable by supplying/discharging the pressure medium to adjust the amount of the medium in the medium chamber, and the movable body ascends/descends with the extension/contraction of the medium chamber. Two or more thin jacks are assembled annularly to form a placing space surrounded by the inside surface thereof. Thereby, this assembly can be used as a concrete form in which a placing material can be placed in its placing space, and can be used also as a support for supporting another concrete form when the assembly is arranged outside another concrete form. After use, the assembly is disassembled to be reusable.