Seismic performance evaluation of single-layer reticulated dome and its fragility analysis

In order to have a better understanding of the failure mechanism of a single-layer reticulated dome under seismic load, parametric analyses through increment dynamic analysis (IDA) are conducted on the dome. The results of the analyses indicate that the limit load of the structure significantly increases together with the plastic development with the decreasing rise-span ratio, roof mass and initial defects prior to the failure to collapse. The plastic development reduces and the structural ductility gets worse as the cross-section area of a structural member decreases. The failure of a single-layer reticulated dome under a strong seismic load is due to the failure in dynamic strength resulting from the excessive damage of material. A structural damage model which can estimate different degrees of damage of the dome is defined. Then, the fragility curves of the different values of the structural damage model with the corresponding different degrees of damage under seismic records are obtained through IDA analysis which can be used for seismic performance evaluation and risk assessment for its loss or fatality acceptability. A theoretical guidance is thus provided for the engineering application of this kind of structure.