Abstract:
Aiming at the impact of bridge deck crane on bridge structure during cantilever construction of long-span cable-stayed bridge, taking a long-span single tower hybrid girder cable-stayed bridge as the background, the response surface method(RSM) was used to study the influence of structural parameters of bridge deck crane on main beam alignment, internal force and cable force during cantilever construction. The weight of the bridge deck crane, the front and rear reaction ratio, the front and rear support span and the elastic modulus of the steel box girder were taken as the main design parameters, and the deflection of the main girder under the maximum cantilever state and the stress, alignment and cable force of the main girder under the bridge completion state were taken as the response parameters. The explicit response equation was constructed to solve the influence degree of each design parameter on the structural response, and the sensitivity analysis of the structural parameters was carried out. The results showed that the self-weight of bridge deck crane, the front and rear reaction ratio and the front and rear support span had significant effects on the deflection, internal force and bridge cable force of steel main girder. Under the same conditions, for every 10 t increase in the weight of the crane, the deflection of the cantilever end increased by 42.46 cm, and the cable force of the bridge increased by 3.16 kN. Using the response surface method to analyze the influence of structural parameters, the research results are scientific, accurate, simple and practical, which can provide scientific basis for the optimization design of bridge deck crane structure and the monitoring of key control parameters in construction, and also have reference significance for the same type of bridge engineering.