附加质量模型在渡槽抗震计算中的适用性研究

Research on Additional Mass Model's Applicability in the Seismic Calculation of Aqueduct

针对南水北调中线某大型渡槽结构,分别基于流固耦合理论和附加质量方法建立了数值分析模型,对其自振频率和地震响应进行了分析。结果表明,两种模型的自振频率比较接近;附加质量模型的地震响应要大于流固耦合模型。因此,在渡槽抗震研究中,采用较简单的附加质量模型代替复杂的流固耦合模型考虑水体的影响是偏于安全的,适用于渡槽结构抗震的定性分析。

With an aim at a large-scale aqueduct structure in the Middle Line of the South-to- North Water Diversion Project,a numerical analysis model is established on the basis of the dynamic fluid-structure coupling theory and the additional mass method,and also,the self-vibration frequency and the seismic response of the aqueduct structure are analysed. The results indicate that the two models＇ self-vibration frequency is approximately the same and that the seismic response with additional mass is larger than corresponding result with the fluid-structure coupling. Therefore, in the aqueduct sructure＇s seismic research, it is comparatively safe to adopt the simple additional mass model instead of the complex fluid-structure coupling model, so that the additional mass model is practical for the qualitative analysis in the seismic research of the aqueduct structure.