Continuous Prestressed Concrete Beam Bridge Deflection Controlling Methods

Continuous prestressed concrete beam bridges as continuous beam structures of great stiffness and ability to cross the bridge, have seen significant development in the last few decades. Pouring consecutive cantilever beam bridge construction process is complicated, which involves not only main beam forming process at "T" - pouring stage of rigid frame cantilever, but also system conversion process.Construction control, an important way of enabling internal force to meet the design requirements, is a complex dynamic system engineering, which also helps to achieve linear. The construction process may be affected by many factors, which will cause deviation of the internal forces and displacements at sections of continuous girder bridge, resulting in full-bridge closure difficulties, or bridge alignment with the state of internal forces not meeting the design requirements, eventually influencing construction safety, appearance, driving conditions to varying degrees. Hence it is necessary to carry out strict control over the entire construction process of bridges.At present, there are many bridge construction control methods, but they are all based on feedback data error analysis, calculation, adjusting control over the target state of the structure and the implementation state of construction to achieve the construction error control purposes. China is not so strong as some foreign countries in the field of construction control and therefore, deep researches of construction control theories and their practical application in the future construction of bridge construction are what should be done immediately.Based on the author's study and others' research results, combining continuous prestressed concrete cantilever beam bridge construction control practice, the paper mainly conducts the following areas of study: considering the various influencing factors in continuous girder bridge construction control, it puts forth a specific approach; Through the continuous girder bridge cantilever construction of the structure and evolution of the internal forces of progress and regression analysis of the advantages and disadvantages compared to the use of iterative approximation of Construction Control Structure Analysis Method, it suggests continuous girder bridge construction monitoring systems, the construction of the bridge during the actual state of tracking observation, to provide basis for calculation in the construction control; the paper also uses the finite element analysis software, Dr. Bridge, throughout the construction process simulation analysis of the main bridge, calculating pre-parabolic high value; predicting the construction segment deviation in both measured state and ideal state by using grey system, and making timely adjustments.The measured data of a complete bridge show that the consideration of the main factors in the bridge construction control is comprehensive, calculating parameters are reasonable and grey predictive control system can carry out long-span continuous beam bridge construction control simply and effectively.