The Key Technology Research Of Seqmental Precasted Box Girder Assembly

Accompanied the urban transportation problem becoming serious increasingly, the road and bridge construction projects increase rapidly and the bridge form is constantly updated and its structure is more complicated as well as its diversified line. For the above reasons, in construction it is necessary to invent a new, high-speedy, convenient and economic technique all the time. And the technology of assembling prefabricated section of box girder in situ is applied extensively. This technology relaxes interfere with the urban traffic by the bridge construction. It raises the viaduct project technology level too. For its better economic benefit and aesthetic effect, the assembly technology of segmental precasted reinforced concrete box girders has been gradually extended to all over the world.In this thesis, several aspects of research are done based on the XIAMEN BRT bus rapid transit engineering project:(1) Two prefabrication methods of bridge section assembly technology are introduced systematically in this thesis, namely the long line method and short line method of precasting and matching construction. According to the analysis of their respective features as well as advantages and disadvantages, the two pre-casting techniques are combined in this thesis, namely long and short line of precasting and matching process. And the new technology of construction method is discussed in detail.(2) Because the linear control technology can control the beam bridge line shape well, ensure the whole line shape smooth and accurate, and satisfy the requirements of the construction quality, so it is necessary to research the linear control for segmental precasted girders assembly construction. According to the characteristics of long and short line method of precasting and matching technology, the linear control technology has been analyzed thoroughly in the thesis.(3) The upper structure model of XIAMEN BRT segmental pre-cast and assemble bridge is set up by the finite element software "MIDAS", in order to prove the adaptability of the long and short line method of matching and prefabrication technology to bridge capability. According to the comparison of bridge self-vibration characteristics, internal force and displacement with or without geometry nonlinear, the influence of geometric nonlinear to the bridge dynamic characteristics are analyzed by the initial internal force of dead load of bridge in this paper.