ASEISMIC BASE ISOLATION DEVICE, AND CRANE WITH ASEISMIC BASE ISOLATION DEVICE

PROBLEM TO BE SOLVED: To make it possible to base-isolate a structure by a simplified and inexpensive configuration.SOLUTION: An aseismic base isolation device comprises: an oscillation support mechanism 7 including a horizontal support surface 2 provided at an end part 1b' of a lower side leg 1b, and a curved member 3 provided at an end part 1a' of an upper side leg 1a such that a curved projection surface 4 formed by upward curving the left and right ends contacts the horizontal support surface 2; a trigger device 14 including left and right wedge members 9 which are located in left and right wedge-shaped gaps 8 formed between the horizontal support surface 2 and the curved projection surface 4 of the curved member 3 to contact the curved projection surface 4 to thereby hold the upper side leg 1a and the lower side leg 1b vertically in a straight line, and pressing means 13 which supports the left and right wedge members 9 such that any one of the wedge members 9 retracts from the respective wedge-shaped gaps 8 when the lower side leg 1b moves in a left-right direction at an acceleration equal to or greater than a preset value; and coupling means 17 for coupling oscillatably in a left-right direction the curved member 3 and the lower side leg 1b comprising the horizontal support surface 2 so that the horizontal support surface 2 does not separate from the curved projection surface 4.