Research On Control Technique Of Cantilever Truss Cast Construction Of Long-span RC Arch Bridge

The cantilever cast construction methods of reinforced concrete arch bridge aredivided into the tower cable-stayed suspension cantilever cast and cantilever truss cast.It has the advantages such as no restricted by terrain conditions, convenient construction,favorable unity, less maintenance and easier repair reduce damage to environment andso on. So it will get fast development in China. However, the hanging basket cantilevercast construction research in our country started very late. Especially, the study ofcantilever truss cast method is in a blank state in our country, by contrast, it has beenwidely utilized to construct RC arch bridges abroad since1960s. Especially, in recentyears, many some of these bridges create the new arch span records of the nations.Based on the research of the key techniques of concrete arch bridge design andconstruction with cantilever cast method which belongs to the Guizhou department oftransportation science and technology project, Focus on long-span reinforced concretearch bridge construction technology of cantilever truss cast method. The main work areas follows:①Cantilever truss cast method is adopted in place of tower cable-stayed suspensioncantilever cast method under the project background of Mupeng Bridge，design ofCantilever truss cast construction scheme is studied.②Using birth-death element technique in ANSYS, the analysis program thatcantilever truss cast construction stage of Reinforced concrete arch bridge is writtenbased on the APDL language in ANSYS. To carry out the research of the variation ofcable force, linear and stress in the process of construction.③Base on the analysis of one-off tension method, to carry out the research of acable tension adjustment method which adjusting the vertical displacement deviationtimely and fixing column horizontal longitudinal deviation in the construction processand reduce the additional internal force.④From three aspects of cable force, linear and stress, the comparative analysis ofdifferences between one-off tension and several adjustments for cable in the cantilevertruss cast construction, and differences between cantilever truss cast construction andtower cable-stayed suspension cantilever cast construction.⑤Based on collecting and studying correlative information about the spandrelstructure in the cantilever truss cast method at home and abroad. The commonly usedtypes of column, bent cap, bridge deck are sumarized from materials, cross section form and structure system. according to the characteristics of the mechanics in the cantilevertruss cast method, research on spandrel construction design which is suitable for theconstruction method is to be carried out，proposing the reasonable design suggestions ofspandrel structure and corresponding construction control method.