普通城门洞形断面
Common City-opening Shaped Cross-section
城门洞形隧洞
Arch cross-section tunnel
隧洞断面形状
tunnel cross-section form
朝天门断面
Chaotianmen cross section
特大断面洞室
tunnel with especially large-size section
串列双矩形断面
two rectangular cylinders in tandem
大曲率球面面形检测
Testing of large curvature spherical surface