Study On Key Techniques Of Concrete Box-section Bridge Casted By Movable Scaffolding System

Mobilesupport system method has the advantages of simple procedure, short construction period, operation standardization, integrity of the beam body good, high repeated utilization rate, reasonable economy, low requirement for the foundation, does not affect the bridge navigable traffic advantages, particularly in the construction of city viaduct, bridge with high piers in the application of mobile scaffolding widely. However, from the engineering practice at present, mobile support system construction method in force, economy, construction process, construction monitoring is still exists many shortcomings, particularly prominent especially in variable construction technology of mobile section problem. In addition, also appeared in the mobile construction safety accidents, these problems have seriously restricted the promotion and application of MMS in middle and small span bridge in the construction.Application for MMS construction method in this paper, taking the Quanzhou Bay Bridge as the engineering background, the "MMS force analysis, key construction technology and construction monitoring", by collecting a lot of literature, and the scope of application for MMS construction method, simulation, process and key construction technology, construction monitoring, launched a series of research, through research, get some conclusion and innovation of practical significance:(1)On the basis of the existing MMS design and practice, comparative study of the structure, characteristics of MMS, the applicability and advantages with other method. The design requires the application of mobile construction of box girder bridge construction and the construction of mobile formwork construction method is reasonable.(2)Combined with the steel structure design theory and the related standard, using the finite element software MIDAS CIVIL to mobile is mainly affected by the main beam, bridge of the nose, corbel structure are analyzed and calculated, the bracket and its support system simulation: additional stress is concentrated, the design is close to Q345 steel stress, indicating to these parts of the steel at the most disadvantageous load prone to plastic state. Girder in the casting state, bridge of the nose in walking component state of stress in the process of value is relatively small, that member strength to meet the design requirements.(3)The mobile construction process and steps of uniform and variable construction method, comparison of mobile section difference in main body structure and process, assembling, debugging MSS, mold body structure adjustment difficulties, the key technology of concrete pouring sequence are studied, the Department of the wrong station measures mobile construction bridge combination of new and old concrete. And the safety control and the girder of transition section construction formwork structure shape control and other technical problems are summarized.(4)The MMS process and steps of uniform and variable construction method, comparison of mobile section difference in main body structure and process, assembling, debugging MSS, mold body structure adjustment difficulties, the key technology of concrete pouring sequence are studied, the Department of the wrong station measures mobile construction bridge combination of new and old concrete. And the safety control and the girder of transition section construction formwork structure shape control and other technical problems are summarized.