Application Of Construction Control For Prestressed Concrete Continuous Rigid Frame Bridge

On the background of Shi Wang River prestressed concrete continuous rigid-framebridge, which located in Shaanx Province, to aiming at the actual situation of the balancedcantilever installation for long span continuous prestressed concrete continuous rigid-framebridge，in order to ensure the consistency of practical alignment of structure and idealalignment, deflection and internal force within the allowable limit, a systematic study on theconstruction control for prestressed concrete continuous rigid frame bridge is conductedthrough the theory of modern predictive control methods.1) Status quo, mechanical characteristics, purpose and significance of the bridgeconstruction control work, was introduced. Construction monitoring theory and methods forprestressed concrete continuous rigid frame bridges, including the theory of structuralsimulation analysis, construction monitoring methods, theories and monitoring systems wasreviewed in this paper;2) Contents, principles and methods of construction control for the prestressed concretecontinuous rigid frame bridge was described, and the main factors affecting the constructionmonitoring work was analyzed. According to characteristics and construction process of ShiWang River prestressed concrete continuous rigid frame bridge, the construction monitoringsystem was established, to carry out on-site monitoring of concrete structure stress (strain),deflection and temperature.3) A spatial beam element model of Shi Wang River prestressed concrete continuousrigid frame bridgewas established to analyse the internal force and deformation of thestructure during and after the construction stage. Structural strength, stiffness and stress waschecked. These work provided technical reference for bridge construction control.4) Monitoring data collected during construction process was analysis and comparedwith the results of finite element model. It is shown that deflection and alignment of the mainbeam and the height difference of the closure section meet the requirements of thespecification; the compressive stress in the each section did not exceed the design strength ofthe concrete materials.5) A parameter sensitivity analysis was conducted to study influence of shrinkage andcreep of concrete, enviroment temperature, temperature gradient of box girder and the unevensettlement of foundation on static load performance of prestressed concrete continuous rigidframe bridge. The results showed that: vertical displacement and longitudinal stress of mainbeam caused by shrinkage and creep of concrete were more sensitive to the changes ofenvironmentally relative humidity, sevice time, overall warming and cooling and the unevensettlement of foundation than to the loading age and the positive temperature gradient.