Precautions against excessive deflection of long-span PC rigid-frame bridges

In order to prevent the excessive mid-span deflection commonly existing in the long-span prestressed concrete (PC) continuous rigid-frame bridges, some effective approaches and measures have been put forward according to different causes leading to the excessive deflection, including the closure aided by temporary stay cables, the mid-span closure by the incremental launching and tensioned temporary external tendons during construction etc. Furthermore, the effectiveness of the proposed measures to reduce the excessive mid-span deflection was analyzed in detail by developed finite element models of a long-span PC continuous rigid-frame bridge. The results show that the mid-span deflection of the bridge is significantly reduced in completed stage and the predicted long-term creep for ten years stage, and the excessive deflection can be prevented or the rate of deflection is slowed down sharply.