Dynamic Analysis For Prestressed Aqueduct With Fluid-structure Coupling

In middle and west route project of south-north water transfer, aqueduct is a sort of important water conveyance structure. There are more than 40 aqueducts in middle route, and their flow rate, water depth and span length all occupying the front rank in the world, most of which located in high earthquake intensity and high incidence regions. Water is concentrated at top of structure, during earthquake large sloshing of water in aqueduct is a disadvantage factor to aqueduct security. recent years with the far-ranging application of this new type of aqueduct, aqueduct structure seismic response considering water pressure under earthquake load has been a research hotspot. Since at present the nonlinear shake research on flow-structure interactive is limited in 2-D plane analysis, so it is quite necessary to establish a linear shake dynamic analysis model to calculate modal results and seismic response. This is the first key problem in the research.Normally prestressing technique is not used in small aqueduct, limited changes of hydrodynamic pressure and stress in the aqueduct will not affect the safety of aqueduct structure, and the design method used in the codes can meet the requirement of design aqueduct. While for large aqueduct, prestressing technique is always used; large amplitude sloshing effect of water will significantly change the value and distribution of hydrodynamic pressure and stress in the aqueduct, which greatly affect the reasonableness and effectiveness of arrangement of prestressing bars. Therefore with the construction of large aqueducts and the appearance of new types of aqueduct structure, the problems that basic theoretical researches abided by aqueduct design have been lagging behind practice projects are very prominent, and then a system of design theory of aqueduct must be fulfilled urgently, this is the second key problem in the research.In this text, aiming at these two problems above, the main research content is as follows: (1) By dint of the calculation method about hydraulic motive pressure on rigid liquid storage tank , calculate the effect of water on aqueduct structure. With an aim at aqueduct structure features, considering the flow-structure interactive effect, establish a dynamic analysis model; (2) Put forwards a conception of "whole model division" to mesh complex structure with irregular shape; accurately realize the prestressed stranded wire by APDL program; (3) According to dynamic analysis model, compiled analytical program, run the program to analysis the whole model. By run the program, calculate the Natural Vibration characteristics of Ming He aqueduct under several conditions, analysis the dynamic characteristics affection by water pressure and prestressed bars; (4) According to dynamic analysis model, compiled analytical program, calculate the response under synchronous invigorative function about Ming He aqueduct to ensure the seismic behavior.The analysis of an example shows that the dynamic analysis model put forward in this paper is simple modeling, you can get accurate results by relatively short time, can be applied to the practical engineering. The thesis opens a new approach for large prestressed aqueduct considering flow-structure interaction dynamic analysis.