SEGMENT

To enhance the load resistance of a segment, as well as, to reduce costs required for manufacturing.SOLUTION: A segment 1 comprises: a circular arc-shaped steel frame 2 which is formed into a box shape being open toward an inner peripheral side; and concrete 3 disposed on an inner side of the steel frame 2. The steel frame 2 comprises: a skin plate 4 arranged on an outer peripheral side, and extending in a peripheral direction; a pair of main girders 5 arranged on both sides of the skin plate 4 in a width direction; a pair of joint plates 6 arranged on both sides of the skin plate 4 in the peripheral direction; ribs 7 extending in a width direction, and connecting a pair of the main girders 5; first reinforcing ribs 8 extending in the peripheral direction and each connecting the rib 7 and the joint plate 6; and second reinforcing ribs 10 for each connecting the first reinforcing rib 8 and the joint plate 6 at a corner part between the first reinforcing rib 8 and the joint plates 6.SELECTED DRAWING: Figure 2 【課題】セグメントの耐荷性能を向上させると共に、製作にかかるコストを削減することを目的とする。【解決手段】セグメント１は、内周側が開口した箱型に形成された円弧状の鋼枠２と、鋼枠２の内側に打設されたコンクリート３と、を備え、鋼枠２は、外周側に設けられると共に、周方向に延びたスキンプレート４と、スキンプレート４の幅方向両側に設けられた一対の主桁５と、スキンプレート４の周方向両側に設けられた一対の継手板６と、幅方向に延び、一対の主桁５同士を接続するリブ７と、周方向に延び、リブ７と継手板６とを接続する第１の補強リブ８と、第１の補強リブ８と継手板６との角部において、第１の補強リブ８と継手板６とを接続する第２の補強リブ１０と、を備える。【選択図】図２