Research On The Cantilever Construction And Control Of Concrete Continuous Beam Of Punan2#Bridge Over Highway

Railway transportation plays an important role in our national economy. However,According to relevant public data, the railway network just meets40%of domestic demand.Railway transportation, facing heavy pressure, has an obvious bottleneck. Chinese railway hasoperated overloadedly which needs to improve better and faster.The proportion of bridge construction occupies a lot in transportation infrastructureconstruction. For example, bridge comprises about36percent of the high speed railwaypassenger dedicated line. And more long-span bridges are in urgent need to span highway,railway, gulf and rivers. With the continuous development and innovation of bridgeconstruction technology, the important role of construction monitoring is being known bymore and more people. Each bridge construction can be regarded as a systematic engineering,so particularly the long-span continuous beam bridge can. In this system, there exist theinterferences of inherent and external factors along with the whole construction process. Thesystem parameter of the influence error should be identified effectively and the reasonablevalue should be attained. Each construction should comply with the design requirement. Sowe need to conduct a whole-process monitor and rectify a deviation to the constructionprocess.Combining the whole process of continuous cantilever-construction of Punan No.2Bridge over Express Highways, the present paper analyzes the continuous beam control fromfollowing aspects.(1) The development and current situation at home and abroad and relevant content ofconstruction control, the structural calculation method are generalized. The characteristic andimportance of cantilever-construction of prestressed concrete continuous beam bridge aresummarized.(2) Analog simulation analysis is conducted for cast-in-cantilever work process ofcontinuous beam by finite element software MIDAS/Civil. With the help of element model,stress and elevation of major control section are obtained under different construction stages.Dead load of beam, material elasticity modulus, thermal expansion, concrete shrinkage andcreep, construction load, prestress, structural system conversion and boundary conditionschange are considered comprehensively.(3) Through the contrastive analysis among design value, predicted value and measuredvalue in the process of monitoring, some calculating parameters are amended accurately. Greysystem theory is used for build GM (1,1) model. Construction errors are analyzed andcontrolled by self-built procedure of MATLAB. Formwork uprighting camber of next beam ispredicted and adjusted validly.(4) Zero block of continuous beam have stressed complicated that it may crack in partswhich affect the structure safety when poorly controlled.3D entity model is built for zero block using MIDAS/FEA. Then we calculate different stresses of zero block in maximumcantilever-construction state and bridge using state, and construction details are optimized.By studing and summarizing cantilever-construction moitoring of2#Bridge overHighway, one can be provided theoretical and practical support on the bridgecantilever-construction controlling aspect in the future. Meanwhile, both construction andbridge can be guaraneed to safe and reliable structure.