Abstract: An upper board fixed to a lower part of a structure; a lower board fixed to a foundation at the same position in a plan view with respect to the upper board; and four seismic isolation plates fixed to the upper and lower boards and extending in a cross direction in a plan view. The seismic isolation plates are U-shaped members obtained by bending a long steel sheet, and include an upper fixing part parallel to a lower fixing part, an upper inclined part and a lower inclined part that are closer to each other while separated from the upper and lower fixing parts, and a connecting part that connects the upper and lower inclined parts. The four seismic isolation plates are fixed to upper board at position where upper fixing parts do not overlap and are fixed to lower board at position where lower fixing parts do not overlap.

Abstract: A pin joint type structural member, made of double steel pipe consisting of a main pipe and a stiffening pipe, restrains buckling so as to be stable under axial compressive force. A clearance between the stiffening pipe 2 and the reinforcing member is determined so that a ratio (Pc2/Pc2) of the reinforcing member contact force with the stiffening pipe inner surface at the end 4b of a counter-clevis side, to the reinforcing member contact force with the stiffening pipe inner surface at the end 4a of the clevis side may be 0.40 to 0.65 when the reinforcing member 4 inclines to the main pipe 1 due to the axial force acting on the main pipe 1. In addition, a length Lin that the stiffening pipe 2 overlaps with the reinforcing member 4 is at least 1.1 times as large as the reinforcing member outer diameter at the overlapping portion.

Abstract: A brace member includes a plastically deformable core member, a buckling restraining member through which the core member extends, a cap sleeve in which a first end portion of the core member and a first end portion of the buckling restraining member are disposed, a cap-sleeve crevice disposed on the cap sleeve so as to protrude toward a side opposite to a side on which the core member and the buckling restraining member are disposed, a reinforcing member in which a second end portion of the core member is disposed, and a reinforcing-member crevice disposed on the reinforcing member so as to protrude toward a side opposite to a side on which the core member is disposed. The reinforcing member surrounds a predetermined area of the buckling restraining member extending from a second end surface on the second side in the longitudinal direction.

Abstract: A bridge pier structure includes a damper having damping characteristics, a substructure joined with a lower end portion of the damper, and a pillar member provided upright on the substructure, a side surface of the pillar member being joined with an upper end portion of the damper. The damper is substantially parallel to the side surface of the pillar member.

Abstract: A bridge pier structure includes a damper having damping characteristics, a substructure joined with a lower end portion of the damper, and a pillar member provided upright on the substructure, a side surface of the pillar member being joined with an upper end portion of the damper. The damper is substantially parallel to the side surface of the pillar member.

Abstract: A pin joint type structural member, made of double steel pipe consisting of a main pipe and a stiffening pipe, restrains buckling so as to be stable under axial compressive force. A clearance between the stiffening pipe 2 and the reinforcing member is determined so that a ratio (Pc2/Pc2) of the reinforcing member contact force with the stiffening pipe inner surface at the end 4b of a counter-clevis side, to the reinforcing member contact force with the stiffening pipe inner surface at the end 4a of the clevis side may be 0.40 to 0.65 when the reinforcing member 4 inclines to the main pipe 1 due to the axial force acting on the main pipe 1. In addition, a length Lin that the stiffening pipe 2 overlaps with the reinforcing member 4 is at least 1.1 times as large as the reinforcing member outer diameter at the overlapping portion.

Abstract: A buckling stiffening brace member eliminates welding time. Readily available components such as a steel rod and a steel pipe can be used as an axial force member and a stiffening member. The axial force member and the stiffening member can be easily connected in a dry manner by threads. A thread for screwing with a joint is formed at an end of an axial force member. At an end of a stiffening pipe that does not have a retaining ring, a sleeve for suppressing neck bending of the axial force member is joined to the outer surface of the axial force member. The axial force member and the stiffening pipe are joined together with the retaining ring therebetween by inserting an end of the axial force member that does not have the sleeve into the inner peripheral surface of the retaining ring and joining it to the retaining ring.

Abstract: A buckling stiffening brace member eliminates welding time. Readily available components such as a steel rod and a steel pipe can be used as an axial force member and a stiffening member. The axial force member and the stiffening member can be easily connected in a dry manner by threads. A thread for screwing with a joint is formed at an end of an axial force member. At an end of a stiffening pipe that does not have a retaining ring, a sleeve for suppressing neck bending of the axial force member is joined to the outer surface of the axial force member. The axial force member and the stiffening pipe are joined together with the retaining ring therebetween by inserting an end of the axial force member that does not have the sleeve into the inner peripheral surface of the retaining ring and joining it to the retaining ring.