Design And Construction Of The Simply Supported-to-Continuous Box Girder Bridge

In this paper,with the background of Jing-Jin Highway, we researched the effect of the Simply Supported-to-Continuous Box Girder Bridge under the construction and operation stage and introduced the construction technology and points for attention and emphasized on that the tension of steel strand, the connection of the new and old concrete, the installation of the temporary support and the steel bar welding of the middle cross beam were the key problems in the construction quality control.First,there was an introduction of the researching background and current situation about Simply Supported-to-Continuous Box Girder Bridge.Second,two kinds of effect about internal force of construction stage in two construction methods were compared. On the one hand,the stress on both edge were homogeneous when by the construction sequence of transform the structure system into continuous beam bridge after bridge desk pre-pouring. Contrarily, the stress on both edge were larger difference. The paper analysed the effect about internal force of construction during service stage, temperature change, shrinkage and creep and support settlement.Furthermore, systematically, the construction technology and points for attention of Simply Supported-to-Continuous Box Girder Bridge were discussed. At the same time, we used the vacuum grouting, roughening on the faying surface of the new and old concrete, flask method temporary support the first time.Last,the loading test of the Simply Supported-to-Continuous Box Girder Bridge under the serviceability limit state were done. Under the loading, the strain of the mid-span section and the deflection were linear growth with the loading.In summary,we analysed the effect of the Simply Supported-to-Continuous Box Girder Bridge with the various factors under the construction and operation stage. The research results will be very valuable for design and construction of this kind of bridges in the future.