Abstract:  Based on beam-type aqueduct structures‚the arbitrary Lagrangian-Eulerian （ALE） method was used to study the dynamic characteristics of large-scale rectangular and U-shaped aqueduct -water coupling systems．The vibra-tion reactions of the aqueduct structures with different water levels to the harmonic excitation and earthquake action were then investigated‚as well as the action of water to the aqueduct．The results indicate that the sloshing of water in the aqueduct is remarkably nonlinear‚and that the sloshing action is very remarkable under certain external excitation．Meanwhile‚the hydraulic pressure aroused by water sloshing will change the stress distribution in the aqueduct struc-ture‚without losing the transverse stability of the aqueduct structure if the ratio of depth to width of the aqueduct cross section is reasonable．By making a comparison of dynamic characteristics‚it is found that the sloshing action of waterin the U-shaped aqueduct is commonly more significant than that in the rectangular aqueduct‚which greatly affects the behaviors of high frame-supported aqueduct structures to which great attention should be paid in the aseismic design of aqueduct structures．

Key words: aqueduct structure, arbitrary Lagrangian-Eulerian, fluid-solid coupling, dynamic characteristic