Experimental behavior of flange-welded/web-bolted steel tubular connections under post-earthquake fire

Extreme events such as earthquake and fire can cause severe damage to building structures. Besides the extreme events themselves, the coupling of multiple extremes such as earthquake followed by fire is more destructive. As fire is a common event appeared in or subsequently after earthquakes, it is necessary to capture the behavior of building structures subjected to post-earthquake fire (PEF) for buildings with high-level safety requirement. This study aims to investigate the behavior of steel connections subjected to the PEF scenario. In the experimental investigation, a group of flange-welded and web-bolted steel connections was tested in fire by using transient state method after subjected to various seismic loadings. It was found that the duration time of the connections with pre-damage decreased significantly under fire, which indicated the time available for evacuation, search and rescue become shorter than the original buildings without pre-damage. The findings are useful for engineering practice when PEF needs to be considered.