Stairs TL1, TL2, TL3, respectively, which parts
2, the stairs and ladder stairs: , Beam staircase: arranged on both sides of the stairs and platform, used to support the ladder beam and platform plate. As for the TL after the value of the layout of the entire staircase structure with different cross-sectional size, different reinforcement, etc. to classify and number.
Table 3 staircase: ladder beam (TL) arranged in the platform, for supporting the plate staircase and platform plate;
In the structure diagram, the staircase beam is represented by the character TL
