Balanced Cantilever method of Bridge Construction:
Balanced cantilever method of bridge construction is chosen where a bridge has few spans which range from 50 to 250m. Construction begins at each bridge pier. Special formwork is positioned and cast-in-situ pier segment is begun. The complete pier segment is then used as an erection platform and launching base for all subsequent travelling formwork and concrete segment construction. Cast-in-situ segments range between 3mm to 5m in length with formwork moving in tandem with each segment. Segment construction is continued until a joining midpoint is reached where a balanced pair is closed.
Stability of the end cantilever is maintained by using temporary pier supports as the end span is begun. The length of the end spans is equal to between 0.55 and 0.65 times the length of the typical span in the bridge.
Although this is a flexible method with its repetitive construction cycle improving efficiency it is still relatively slow. This restriction was improved in 1962 with the introduction of precast segments.