桩—土—渡槽—水相互作用动力特性分析

Dynamic Characteristics Analysis of Aqueduct Structure of Pile-soil Interaction and Fluid-solid Coupling

目前,对渡槽抗震性能的研究多集中在槽身与水体的流固耦合问题上,对桩土间的动力相互作用则研究较少,然而桩土相互作用会影响渡槽结构对动荷载尤其是地震荷载的反应。为探究桩土相互作用对渡槽结构动力特性的影响,采用大型有限元软件ABAQUS对南水北调中线工程双洎河渡槽建立了同时考虑流固耦合和桩土相互作用的桩—土—渡槽—水三维仿真力学模型,并进行了不同工况下的自振频率及振动模态分析。结果表明,与固结模型相比,考虑桩土相互作用的渡槽结构在地震荷载作用下自振频率减小,桩土相互作用改变了渡槽结构动力特性。

At present,aseismic research of aqueduct mostly focus on the fluid-solid coupling between aqueduct and water body and gives less attention to pile-soil dynamic interaction.However,the pile-soil interaction affects the aqueduct structure response to dynamic load especially seismic load.In order to study the impact of pile-soil interaction on dynamic characteristics of aqueduct structure,the large-scale finite element software ABAQUS is used to establish three-dimensional mechanical simulation model of pile-soil-aqueduct-water by taking into account fluid-solid coupling and pile-soil interaction in middle route of South-to-North Water Diversion Project.At the same time,the natural frequencies and vibration is obtained with modal analysis under different operating conditions.Compared with the consolidation model,the results indicate that the pile-soil interaction reduces the natural frequency of aqueduct under the action of earthquake load,and it changes the dynamic characteristics of the aqueduct.