APPLICATION OF THE ENDURANCE TIME METHOD TO SEISMIC-INDUCED POUNDING ANALYSIS FOR LONG-SPAN EXTRADOSED CABLESTAYED BRIDGES CONSIDERING WAVE PASSAGE EFFECTS

The endurance time method (ETM) is a novel dynamic analysis procedure in which artificially intensified accelerograms are used as loading inputs. In this method, various dynamic responses under seismic excitations of different intensity levels are estimated with a reduced simulation effort. Based on these merits, this paper investigated the accuracy and effectiveness of ETM in predicting the pounding responses of long-span extradosed cable-stayed bridges considering wave-passage effects. A typical extradosed cable-stayed bridge with two-side abutments in the valley was selected as the analyzed target, and the incremental dynamic analysis (IDA) results with natural earthquake records were obtained to make a comparison. Parametric analyses on the wave-passage effect with different apparent wave velocities were carried out by ETM. The concerned responses included the pounding force, the displacement of bridge deck and towers and the curvature ductility factors of bridge piers. The results indicate that ETM can efficiently predict the seismic-induced pounding response of long-span extradosed cable-stayed bridges with the inclusion of wave-passage effects. In addition, the dual effects of wave-passage on seismic-induced pounding response, which are related to structural nonlinearity, seismic amplitude and apparent wave velocity, were observed.