Seismic response and natural frequencies analysis of large-span aqueduct considering pile-soil and fluid-structure interaction

Large-span aqueduct is a key hydraulic structure for building a national water network and realizing the spatial balance of water resources, and its safety under the action of earthquakes has become the focus of trans-basin water transfer projects. Taking the Adoucun Aqueduct as the research object, this study considers the soil-structure-fluid interaction and uses the finite element software ANSYS to conduct modal analysis and seismic response analysis of the overall aqueduct structure. The results show the following: The presence of fluid in the aqueduct can effectively reduce the structural frequency. The natural frequency of the structure changes nonlinearly with the increase of fluid mass and has little impact on the high-order frequencies of the structure. Compared with the empty aqueduct, under the designed water depth condition, the relative displacement between the troughs increases, and the influence of water on the structural response cannot be ignored. Different pile-soil models have a significant impact on the fundamental frequency of the structure but almost no effect on the high-order frequencies. The contact model, which simulates pile-soil interaction, shows stable calculation results and is more consistent with engineering practice.