What’re the advantages for the flame straightening method of bridge girder launcher ?
1. Good correction result, especially on harder crook;
2. Simple construction technology of bridge girder launcher
Disadvantages:
1. As using flame straightening method, to achieve compression molding, main girder correction part must be jacked up, or it has no effect, which increases the work difficulty
2. Even though flame heating is at the position of baffle plate, it can still cause a large shape wave on the web plate and cover plate
3. Main girder strengthening must be done after flame correction, or it will cause a more serious distortion.
According to analysis above, ZZHZ does not use flame straightening method in general condition. While the method is most appropriate as aligning and make pre-deformation on the large joint steel, U-bar and other materials. Large press machine or too capacious area is not necessary. Just properly choose size, numbers and position of heating points according to structural steel bending and deformation degree, the correction can be done, convenient and simple.
