Abstract：
The roof of Beijing Traffic Control Center is of a plane steel truss structure, whose total weight is 4 000 t. Welding process is established with consideration of such difficulties as crack defect generated during thick plate welding, many nodes, small cross section of column which is difficult for welding, tight construction period, etc. Quality control measures are put forward for welding sequence, welding environment and deformation prevention, and favorable effects are realized.
