土木方面一句话? bs 5911-114 porous precast concrete pipe, with rebated joints, with non-porous invert extruded for the full length of the pipe and to a height up to the pipe equal to not less than one-third of the internal diameter, pipe diameter(s) as indicated 多孔预制混凝土管,槽舌榫接合,沿管子全长有挤压成型的无孔内底,内底高程不低于管内径三分之一,管径如所示。 不知道是不是内底高程,请高手指正一下! [ ]查看更多