Multi-parameter seismic resilience assessment framework for large-span spatial structure emergency shelters

Large-span spatial structures are widely adopted in emergency shelters due to their high occupancy capacity, functional adaptability, and structural reliability. The post-earthquake functionality loss and activation efficiency of such structures critically influence emergency shelter performance. This study proposes a multi-parameter seismic resilience assessment method integrating system functionality loss, repair time, and casualty rates, establishing a hierarchical evaluation framework. A logic tree model is developed to quantify shelter system functionality loss, based on the damage states of 36 critical components, incorporating Maslow's hierarchy of needs and normal-to-disaster functional transition. A component-floor-building repair process model is developed to represent the staged post-earthquake recovery and functional transition process. A total of 216 incremental dynamic analysis (IDA) cases are conducted on a K6-type single-layer spherical reticulated shell-steel frame structure under various seismic inputs and structural parameters, extracting four key resilience parameters. The resilience levels are classified based on repair time, and the calculation formula for the resilience index (R_S) is calibrated. The critical thresholds for each level are determined to be 0.255, 0.5, 0.725, and 1.0, with variances below 3%. Corresponding threshold intervals for the four resilience parameters are also established. Further, three extended models are established using widely applied structural forms in engineering for analysis. The R_S values for all cases fall within or close to the theoretical range based on resilience parameter grading, indicating that the resilience index formula has good engineering applicability, providing theoretical support and reference for shelter resilience levels and post-earthquake activation decision-making of large-span spatial structure emergency shelters.