Influence of site conditions on structural vulnerability of a super high three-tower cable-stayed bridge

Abstract The sensitivity of vulnerabilities for a super high three-tower cable-stayed bridge to site conditions is examined. A finite element model for a cable-stayed bridge with a total length of 2135 m is established on the basis of OpenSEES. Then, a suit of seismic records matching the response spectrum under three soil types is selected, and components and systems vulnerabilities curves are generated by conducting incremental dynamic analysis (IDA). The results indicate that with the soil softening, the damage probability of the structure increase, while the sensitivity to the site type is different among components, among which the bearings are the most sensitive and the upper tower are the least sensitive. For the design response spectrum, compared with the maximum acceleration of the spectrum, the extension of the characteristic period significantly improves the failure probability of the structure, which needs special attention in the design.