arch ring 隧道拱圈 ; 桥涵拱圈

closure of arch ring 拱圈封顶

arch ring stress adjustment 拱圈应力调整

construction joint for arch ring 拱圈施工缝

Arch Ring Slabs 拱圈底板

horizontal arch ring 水平拱圈

inner arch ring 内套拱圈

stone arch ring 石拱圈