STATIC MECHANICAL PROPERTIES EVOLUTION ANALYSIS OF A LONG-SPAN TRACK CABLE-STAYED BRIDGE

To analyse the static mechanical properties evolution law of long-span track cable-stayed bridges, an evaluation mode based on the parameter time-dependent effect change rate was proposed to evaluate a twin-tower and double-cable plane concrete cable-stayed bridge with a main span of 250 m. Finite element method (FEM) analysis was performed, considering the time-dependent change effect (including concrete shrinkage and creep, material strength, and cable elastic modulus) after 2 years of service since bridge completion. The results of the analysis were compared to the measured data detected by the structural health monitoring (SHM) system. The results show that the mechanical parameters of the long-span track cable-stayed bridge, including cable force, internal force of girder, deformation of girder, and displacement of main tower, constantly change with time and are stable with increasing service time. The FEM model can be modified using the measured parameters obtained from the SHM system, so the static mechanical evolution can be effectively predicted. The measured data can objectively describe the static mechanical properties evolution law based on the change rate index of the parameter time-dependent effect.