Analysis Of Structure Behavior Of Continuous Multi-box Girder Bridges And Its Experimental Study

Because of the advantages such as less precast beams, easier construction and lower cost, simply-supported continuous multi-box girder bridges with the span about 25-40 meters are being built on highway. At present, the design of multi-box girder bridges is based on classical load transverse distribution calculation method, rigid connected beam method as a T-beam multi-girder bridge due to the limit of research technology. In fact, multi-box girder bridge is different from T-beam multi-girder bridge. First, transverse distribution of load is influenced quite with the closed box beam; Secondly, as a simply-supported—continuous system, its 3-d structure behavior is remarkable, especially for a continuous skew bridge. So it is significative and valuable to research and discuss structure behavior and calculate method of multi-box girder bridges.Based on the behavior of this type structure, and by finite element analysis, organic glass model experimental analysis and field bridge test, the structure behavior and load transverse distribution are researched and analyzed on bridges different from span or types such as multi-box girder bridges such as simple sported right bridges, simple sported skew bridges, continuous right bridges and continuous skew bridges. In this paper, based on rigid connected beam method, a revised method applied to calculate load transverse distribution coefficients of simple sported skew bridges and a reduced method applied to calculate load transverse distribution coefficients of continuous right bridges are offered and been validated with 3-d finite element method and experimental research. And some other problems are analyzed and discussed such as load transverse distribution influenced by different style load, transverse distribution coefficients of single girder influenced by transverse beam, transverse distribution coefficients of single girder changed along the lengthways location and structure law between transverse distribution coefficients of single girder and structure parameters(span, skew angle),etc. Finally, a real bridge is studied as a research object, its design schemes is studied on corresponding demonstration analysis from the aspects such as technology and economy, and the advantage of prestressed multi-box girder bridges is elaborated.