Construction-control technique for PC bridge with cantilever casting method

摘要

Adaptive control theory, structural parameter identification and error analysis are used to control the construction of PC cantilever casting bridge in the paper. The construction camber for main beam can be determined by BP artificial neural network. The deflection of main beam should be tested persistently. Strain sensors are previously located in beam to determine the concrete strain. The paper analyze some infection factors of strain test, such as concrete shrinkage, creep, temperature influence, and the strain correction method is proposed. So the stress and deflection of main beam in construction period can be controlled. Practical application approved that adaptive control theory combining with ANN could forecast appropriate camber. The factor of concrete shrinkage and creep could not be ignored on strain test of main beam. Measured value should be corrected to make us obtain objective stress status of structure. The correction method on measured strain which the paper proposed is feasible and accurate.