Seismic Response Analysis of Cable-stayed Bridges with Cable Forces Optimized Parameters based on a New Type of Strongly Sub-feasible SQP Method

Abstract

A new type of strongly sub-feasible SQP (Strong Quadratic Programming) method is used to establish a nonlinear model to realize the automatic search of the rational cable force of the cable-stayed bridge. The objective function is established based on the stress and displacement of the main girder and the bridge tower. The cable force of the stay cable is the design variable, the stress and displacement of the main girder and the bridge tower are the constraints, and the numerical model of the earthquake force is analyzed under different cable loading conditions. The results show that the new type of strongly sub-feasible SQP method is suitable for the complicated cable force optimized parameters of large-scale cable-stayed bridges, the calculated results are in good agreement with the designed cable force, and the bending moment of the main beam in the bridge state is uniform. The main tower is close to the axial compression force, and structural deformation is much smaller than the specification limits. Under the excitation of earthquake, the optimized cable force can effectively improve the uneven distribution of bending moment of the main beam, limit the longitudinal mid-span deformation and the lateral deformation of the main tower, so that the whole structure is safer in the earthquake.