Pier - Span Rigid Frame - Continuous Girders Key Technology Research

With the development of science technology and communication project, the construction of highway and bridge have been advanced rapidly in our country. Long-span bridges,especially long-span prestressed reinforced concrete continuous bridges and continuous rigid-frame bridges, have been used widely through the great river as well in our county. Prestressed reinforced concrete rigid-frame—continuous combination bridges have the advantages of continuous bridges and continuous rigid-frame bridges,and it is used rapidly because of simple construction , economical, good mechanical property, comfortable travel. At present, the theoretics of continuous bridges and continuous rigid-frame bridges have been researched deeply, design theoretics has matured and the experience of construction has been abundant. But, the research about rigid-frame—continuous combination bridge is still not enough. So, it is still necessary to do some researches on this aspect.Youshui River Bridge was used as project sample in the paper. By one of MIDAS family program,Civil structure analysis & design for windows, a lot of finite element models are created and calculated for the structure,and compared with continuous bridges and continuous rigid-frame bridges. Some internal forces and deformations's tendency of high-pier long-span rigid-frame—continuous combination bridge has been found through the calculated results. The results are as follows: When the pier of side span is low or continuous length is too long, rigid-frame—continuous combination bridge is economic and reasonable choice in order to satisfy the need of superstructure's displacement; Compared with continuous rigid-frame bridges, its stress can decrease remarkably; Compared with continuous bridges, its spanning ability is greater. The shrinkage and creep effects on the internal forces and deformations of the structure are large, especially on the deformations.The results of the paper gives some experiences and advises to the design and construction and provide foundation for construction control.