The Analysis Of Horizontal Seismic Response And Engineering Application Of Large Span Aqueduct

Aqueduct is a kind of conveyance structures widely used to across obstacles in water transfer project; and multitudes of aqueducts are constructed in major hydraulic projects including South-to-North Water Transfer Project. On account of delivering water, aqueduct needs to possess severe seepage-proof and leak-proof performances. If the aqueduct shell damage in one place, the whole delivery line stretching thousands of miles may become paralyzed. Hence, a large-scale aqueduct often becomes the key work in water delivery project. As an earthquake-prone country, lots of aqueducts are constructed in high seismic intensity area; and several aqueducts are damaged or even destroyed because of earthquake. Presently, there is no relevant norm for aqueduct seismic design; and it can lead to serious consequences by the ignorance of seismic action or improper calculation. In the dissertation, the study are carried out around aqueduct seismic calculation.In aqueduct seismic calculation, the key, as well as the difficulty, is the dynamic calculation of fluid-structure interaction. For an aqueduct, the fluid-structure interaction dynamic response under transverse seismic action is mainly studied, for it is not obvious under longitudinal(along the flow direction) seismic action. To systematically study the fluid-structure interaction mechanism of aqueduct under earthquake action, and to provide theoretical basis for relevant norm-setting, the following aspects of research work have been done:(1) The aqueduct seismic theories and relevant theories are reviewed and summarized. Based on an actual aqueduct project, a comparative study on the computation accuracy of the common simplified calculation models of dynamic water pressure are conducted by using response spectrum method and time-history analysis method, respectively.(2) Take water tower seismic design code as a relevant, for the fluid-structure interaction mechanism of water tower is similar to aqueduct, then the derivation process of the calculation formula of horizontal seismic force in water tower seismic code is reconstructed based on the theory of fluid coupling dynamics.(3) By modeling an ALE dynamic calculation model of fluid-solid interaction, the aqueduct dynamic response is obtained by time-history method, followed by an analysis of fluid-structure interaction mechanism. The results obtained by the ALE dynamic calculation model are contrasted with the simplified model to demonstrate the reliability of the simplified model and corresponding formula.Finally, research contents are summarized briefly and further research work is prospected.