Analytical Study of Seismic Demand and Fragility of Piping Systems in the Reticulated Shell Structures

The large-span spatial hub structure is an important urban lifeline project with complex structure form and many types of internal non-structural components. As one of the main non-structural components, the safety of the piping system is important to ensure the normal use of the overall function of the large span hub structure. Once damage occurs to the piping system under the action of earthquake, it will affect the traffic operation and urban rescue, resulting in incalculable casualties and property damage. To assess the impact of diverse connection locations on the piping system’s response, this study investigates acceleration and response amplification factors at various positions within the reticulated shell structure. Through this analysis, we underscore the critical need to consider the spatial coupling effect for the piping system within the reticulated shell structure. In this study, the seismic response and damage modes of the internal piping system in a prevalent type of reticulated shell structures are investigated. This is achieved by establishing a coupled finite element model of the reticulated shell structure and the piping system. Three distinct damage modes of the piping system and their corresponding computational signs are identified, facilitating the creation of fragility curves for the piping system. The results highlight significant variation in the damage degree of the piping system at different locations. Additionally, past studies have shown a notable probability of damage to piping systems, even under very slight ground shaking, emphasizing the necessity for careful consideration.