How many bridge construction methods does ZZHZ have?
ZZHZ mainly use below methods to construct bridge.
1. Balanced cantilever method. It uses movable suspended scaffolding (hanging basket) to pour concrete symmetrically from two ends to the middle span at the same time and impose pre-stressing force. It demands balanced temporary loads at both ends, construction at the same time and concreting at the same time.
2. Cast-in-situ concrete method. It mainly refers to construct bridge by overhead or underslung movable scaffolding system bridge building machine. After the movable scaffolding system is installed, cast-in-situ concrete for one span is done, then tension and maintain the span, when all the process is finished, next span cast-in-situ concrete will begin.
3. Full span method. It means to install one span precast or cast-in-situ concrete girder at one time by launching crane.
4. Segments installation method. It means to lift, suspend and install one precast segment at one time, then next segment, till all segments are installed in one span, the launching gantry will move to next span.