Construction Control And Optimization Of High-Speed Railway T-Shape Bridge

T-shape bridge as a kind of bridge structure has many advantages like convenient,safe and reliable,These features makes the T-shape bridge not only been widely used in highway engineering,and also the high speed railway construction project which has the higher stiffness and accuracy requirements.The high speed railway T-shape bridge structure always been built by the cantilever method.T-shape bridge construction already had some mature methods and many studies of T-shape bridge construction control have already made.In recent years construction's precision requirement is higher and higher,the high-speed railway T-shape bridge construction control method still exists a lot of optimization space.The key problems of T-shape bridge's linear control and stress control still need to be research further and clearer.This paper Based on the project of(80+80)m prestressed concrete T-shape bridge construction control studied and optimized several problems in the bridge construction control,includes.(1)First,to summarize the recent construction control methods,according to the three ways to classify all kinds of construction control method,according to the classification of the construction control.Analysis the characteristics of each method.Make the suited structure clear of each control method.(2)Then,established the numerical model of T-shape bridge by using Midas Civil software.Using both of measured data and numerical calculation date,with linear supplemented stress control concept,to make the control more effective.(3)Focus on the linear changing rules by the influence of sunshine radiation.Get the vertical displacement date with influence from sunshine radiation Through the numerical model which has been brought to bear the temperature gradient that based on the experiment of inner beam temperature,combined with measured data of measuring points,the linear variation law of the bridge are summarized.Through the calculation results of the numerical model to modify measurement value of measuring points in each time period,put forward the corresponding correction formula of each measuring data.(4)Monitor bridge construction stress by the stress increment method,to ensure the whole cross section under compression state during the bridge construction process.summarized the advantages of stress increment method in the mastery of stress change rule and testing of the prestressed tension effect.Design the temporary locking forms of the closure construction,calculated the stress of the temprary locking forms under the influence of the sun,put forward the reasonable construction sequence of temporary locking.(5)in order to speed up the construction progress and avoid winter construction,puts forward two strategy to solve this problem.One solution has shorter cantilever length,and the other one make the cantilever shorter and remove the closure segments.This paper analysis and compares the various solutions,discusses these two solutions ‘s influence of bridge on many aspects,and optimized the solutions to make them better,to choose safe and effective way of T constitute a bridge,provides experience and reference to find a safe and effective way of T-shape bridge's construction.