Large Span Continuous Rigid Frame Bridge Construction Monitoring And The Cause Of Web Cracks

Prestressed concrete continuous rigid frame bridge is one of the major long-span bridge girder bridges,which combines continuous beam bridge with rigid frame bridge strengths,it has reasonable force,economical,driving comfort and many other advantages;In recent years,with the the development of China’s transportation construction of prestressed concrete continuous rigid frame bridge in engineering construction practice has become increasingly widespread.In engineering construction,usually symmetrical method Cantilever Construction Method to construction of long span prestressed concrete continuous rigid frame bridge,since there are many controllable and uncontrollable factors will bridge elevation,stress and other on-site construction process to produce impact,and these effects often lead to bridge differences between the state and the state of design,such as the elevation error,stress less than the design state and other issues,thus affecting the construction of the bridge closure,practicality,safety;so long span prestressed continuous rigid frame bridge construction concrete,through a finite element model of the bridge,and linear field measurement,stress and other data in the bridge construction process,monitor and analyze the data optimization,optimization of construction to provide advice to minimize construction errors,control of the construction process,so that the bridge into the state as much as possible consistent with the ideal design,therefore,construction monitoring long-span continuous rigid frame bridge construction process is particularly important.Prestressed concrete continuous rigid frame bridge is an engineering web crack common problem,there is a web of cracks will affect the appearance of the bridge quality,durability,structure,use function.Although these diseases at an early state of the bridge does not affect the overall security structure,but over time,can cause steel corrosion will lead to the gradual decline in the carrying capacity of the bridge,or even serious quality accidents.Therefore,continuous rigid frame bridge design and construction process,the web crack problem must be taken seriously enough.Taking Guangxi Liu Wu highway Panlong Liujiang large prestressed concrete continuous rigid frame bridge as the engineering background.Researched the bridge construction monitoring technology and the web cracks which were found during the construction monitoring.The main contents are as follows:1,Read long span prestressed concrete continuous rigid frame bridge construction monitoring and related articles cracks in the webs,summed prestressed concrete continuous rigid frame bridge construction monitoring and research status web cracking,research methods and trends.2,Give a brief introduction of finite element methods and principles.Build the finite element model of the bridge with the Midas/Civil finite element software,preparation of construction monitoring program will monitor the construction of the measured data with theoretical data were compared,conclusions drawn construction monitoring.3,Using the ANSYS finite element software finite element model of the bridge space 8 # of 10 # Piers segment to the web reinforcement ratio,the top longitudinal prestress,prestress longitudinal web,web vertical pre stress,changes in web tension sequence of prestressed longitudinal and vertical,web thickness change as a susceptibility factor,sensitivity analysis to determine the sensitivity of the factors generating web cracking,and propose targeted improvement measures and suggestions.4,Construction monitoring summary of conclusions,conclusions and recommendations as well as prospects crack crack prevention analysis.