七、初期衬砌所有用盾构开挖的隧道必定有一层初期衬砌来支护围岩,并承受推进千斤顶的推力。传统方法是用铸铁管片衬砌块。其它的方法是拱肋加木板,装配式的钢衬砌块,压制衬砌钢板及预筑混凝土衬砌块。1、铸铁衬砌块。将衬砌块铸成多管片形式,一般为760mm到810mm宽。有些铸造厂能铸造22mm宽、150mm深的翼缘。所有四个翼缘面都经机械加工处理,确保密贴吻 Seven, the initial lining All tunnels with shield excavation must have an initial lining to support the surrounding rock, and to withstand the thrust of jacking. The traditional method is to use cast iron pipe lining block. Other methods are rib-and-board, fabricated steel lined blocks, pressed lining steel and precast concrete blocks. 1, cast iron lined block. The lining blocks are cast in the form of multiple tubes, typically 760 mm to 810 mm wide. Some foundries can cast 22mm wide, 150mm deep flanges. All four flange faces are machined to ensure kissing