Research On Design Optimization Of Pedestal And Precast Techniques Of Prestressed Box Girder

Prestressed concrete box girder bridge as one of the main bridge of prestressed concrete bridge,has good mechanical performance,large stiffness,driving a smooth,beautiful modelling,less expansion joints,easy maintenance,etc.Because the construction space limitation,quality control,small box girder usually use workshop prefabrication.In this paper,based on the guangfo highway origin first C small blocks of 3#,4#,plant on small box girder precast pedestal and precast technology to carry out the specific research work as follows:1,prefabricated pedestal scheme design and optimizationThis study point#3,on the basis of traditional small box girder precast beam field pedestal design optimization,a new type of concrete piers steel pedestal through calculating the stress of checking pedestal,and applied to the 4#beam field,the success of the new pedestal,comparing with traditional pedestal is more easy to use,economic and environmental protection.2,small prestressed box girder prefabrication quality control techniquesPoint of this research from the pedestal construction of membranes,template installation,steel reinforcement cage,concrete pouring,to the intelligent tensioning,intelligent grouting,spray curing,finally to move the beam,carry out a small box girder the precast process summarized a set of quality control method.3,small prestressed box girder concrete strength and durability of control technologyThis research points from optimization of mixture ratio of raw materials,to the field management of raw materials,and then is the mixing of concrete,the last is the transportation and casting of concrete,puts forward the small box girder concrete strength and durability of the control of key indicators and control measures.4,intelligent tensioning abnormal cause analysis and prevention and treatment measuresPoint of this research is mainly to zhang tensile length value and the tension stress anomaly as a starting point,the cause of abnormal tension calculation,equipment,construction,and puts forward the corresponding prevention and treatment measures,thus guiding the guangfo highway bid first C small box girder tensioning construction,and under the small box girder anchor prestress test qualified.In this study,a small site binding prestressed precast box girder construction process heavy and difficult project to carry out the measures and resource allocation analysis and research about construction projects,the proposed management measures and precast beam field to adapt effectively to ensure the construction quality and safety.