How many kinds of launching girders in ZZHZ are used to contruct simply supported span bridge?
In ZZHZ, there are 6 kinds of launching girders to construct simply supported span bridge:
1. upstroke movable support system for cast-in-situ bridge
2. downstroke movable support system for cast-in-situ bridge
3. walking type launching girder for highway bridge (lift one span at a time)
4. highspeed railway launching girder (lift one span at a time)
5. segmental assembly launching girder (lift segment by segment, then glue and tension the one span together)
6. launching girder for highway and railway
All launching girders above are manufactured and exported to foreign countries, whose range is:
1. span (20m-60m)
2. lifting weight (30t-900t) (segment assembly launching girder is not included, because weight of all segments in one span is uncertain, it may be above 1000t)