Abstract: The site of the Central Yunnan Water Diversion Project is earthquake-prone with high seismic intensity. To ensure the safety of aqueduct facilities against earthquakes, the seismic performance of an elevated large-span beam-supported aqueduct of the Central Yunnan Water Diversion Project was analyzed. ABAQUS was utilized to establish a model of single-span aqueduct in consideration of fluid-structural interaction. Ground motion inputs were selected based on the site’s geological conditions. The elastic-plastic time-histories of aqueducts with pot-type elastomeric pad bearings (PEPBs), lead rubber bearings (LRBs), and friction pendulum bearings (FPBs) were analyzed. Results demonstrate that aqueducts with isolation bearings exhibit a 25.5% lower maximum displacement and a 24.3% smaller maximum bending moment at bottom of the pier compared to aqueducts with PEPBs. Thus, the seismic isolation performance of isolation bearings surpasses that of PEPBs, and the damages in PEPB aqueducts are more severe, primarily concentrated in the areas where the aqueducts come into contact with the bearing and at variable section of the aqueduct wall as well as at the bottom of the piers. Regarding empty aqueducts, those with LRBs experience a 10.4% larger maximum displacement than full aqueducts, accompanied by a 21.4% smaller maximum bending moment at pier bottom. On the other hand, aqueducts with FPBs demonstrate a 20.9% smaller maximum displacement and a 32.2% smaller maximum bending moment at pier bottom compared to full aqueducts. The seismic isolation period of LRBs is significantly affected by the mass of upper structure, while the period of FPBs remains independent of the mass of upper structure. Considering these factors, FPBs are found to be more suitable for aqueducts.

Key words: aqueduct, finite element analysis, elastic-plastic time history analysis, seismic isolation bearing, seismic performance