Technique of Cutting-Pushing Closure for North Main Bridge of Xiazhang Sea-Crossing Bridge

The north main bridge of the Xiazhang Sea-Crossing Bridge is a steel box girder cablestayed bridge with double pylons and double cable planes. The main girder of the bridge was erected by the cantilever assembling method and the central span was closed by the technique of cutting and pushing. Before the span was closed,the closure gap was continuously observed and the closure gap width ～ temperature curves were fitted. In the light of the predicted width of the closure gap,the material for the closure block was laid off and also at the temporary fixity of a pylon and the girder,the girder was pushed towards one side and / or withdrawn a little amount. Practice proves that the technique of the cutting and pushing closure applied to the bridge not only ensures the closure block to be smoothly lifted into the closure gap and but also achieves the ideal width of the welding seams. With the technique,the reliability of the closure is improved and the structural safety risk is decreased.