Probabilistic Multi-Hazard Fragility Analysis of High-Rise Concrete Structures Under the Combined Effects of Earthquake and Wind Loads

In recent years, multi-hazard engineering has garnered increasing interest and recognition for its growing importance. High-rise concrete structures may be affected by one or more disasters (such as earthquakes, wind loads, etc.) during their long design life. Existing codes, industry standards, and research reports on high-rise concrete structures primarily focus on single disasters and do not account for the combined effects of multiple disasters. To investigate the multi-disaster fragility of high-rise concrete structures under the separate and combined effects of earthquake and wind loads, a reinforced concrete (RC) TV tower has been selected for analysis. The numerical models considering uncertainties are established, and nonlinear time history analyses (NTHA) are carried out based on considering the uncertainties of input loads. Combined with the results of NTHA, the probabilistic fragility curves and multi-hazard fragility surfaces of RC-TV tower under different load conditions are established. The results show that the main body of the tower has good toughness under the separate effects of earthquake and wind loads, while the mast is significantly affected. Compared with the single hazard, the combined effects of earthquake and wind loads result in more serious damage to the structure. At the same time, the response and damage under the combined effects of multi-hazard is not a simple superposition of response and damage under the effects of a single hazard, which needs to be studied specially. The analysis results can provide useful references for designers in safety design and decision-makers in daily maintenance.