A Study Of Several Questions In Construction Control Of PC Continuous Beam Bridge

Recent years, prestressed concrete continuous beam bridges develop vigorously in our country. PC continuous box girder bridge has been wildly used in bridge construction for its excellent performance in structure. The design and construction of continuous bridge request highly coordinates, and construction method and installment procedure not only influences initial structure stress, but also determines ultimate stress and bridge profile, so construction control of continuous bridge is vitally necessary for structure safety, reasonable error range, bridge profile and stress requirement in course of construction.This paper bases on the instance of canltilever continuous bridge construction on one express way, and main jobs as following: First of all, because of the bad heat conduction of the concrete materia1, prestressed concrete bridges are subject to varied of temperature actions, which can make notable influence on the stress of bridge structures, according to the themal conduction theory and finite element method, the model of zero block is built to analyze the effect of cementitious hydration heat. The solution is done to conclude the rules of temperature development for this structure and to predict the temperature distribution unde1 field conditios. Then some measures are commmended to control the structural temperature and ensure the quality of the casting concrete. Secondly, using the bridge structure analysis software MIDAS/Civil to establish the bridge structure simulation model, this paper researchs how the internal force and deformation will change when the system transforms, and provides a reasonable order of closure. Thirdly, based on the construction practise of a PC bridge for grounting the connecting gap of the continuous girders, there are two restricted locking measures, i.e. the internal locking method and external. This paper introduces the basic principles, calculating methods and the constructing procedure of these measures. They are valuable as references for construction works.