Research On The Seismic Erformance Of Deck Type Rib Arch Aqueduct

Aqueduct is one of constructions which is most widely used in long distance watertransfer project and irrigation area. We China is country with lots of earthquakes. Aqueductused in the earthquake area is distinct from general constructions. Except bearing waterpressure, self weight and certain static load else, it still needs to sustain dynamic load fromwind and earthquake. So the anti-earthquake analysis of its structure is difficult to carry out.Up till now, our country hasn’t issued related design specifications yet. Seismic Resistanceresearch of aqueduct mainly focuses on type select of the body structure, water sloshing underdynamic load and so on, while studies on supporting structure is rare and let alone do thesame seismic resistance study with time-history analysis.This paper had referred to research achievements of bridges, aqueduct structure,time-history analysis and seismic wave at home and abroad. Make time-historical dynamicanalysis with ANSYS by taking Donghuayu as an example. Using different experimentaldesigns (single factor, orthogonal test) to change the rise span ratio, arch axis form,arrangement mode, density of bent frame and made dynamic time-historical analysis underconditions that the water flow, span, seismic fortification intensity and the foundation bearingcapacity are all fixed. Finally, get the structure parameters which can meet the requirements ofsecurity and harvest outstanding economic benefits as well as construction value. Main workcontents are as follows:(1)Researching the simplified method of bridge and the structure model of aqueduct athome and abroad to decide the structure of the body, supporting structure, element type ofsimplified water model, boundary constrains as well as node coupler of the supporting bentframe and the body. Make static and modal analysis of Donghuayu aqueduct under its emptyand working conditions separately. On this basis, exerting transverse and straightforwardseismic excitation and continuing related analysis with time-history method. By static analysis,research the distribution of internal forces (axial force, shear, bending the inner surface andouter surface moment) along the main arch.By dynamic analysis, research the distribution ofdisplacement and internal force on the main arch to determine the cross-sectional position ofmaximum displacement and internal forces.(2)Arranging the experiment with single factor method, Changing the rise span ratio, the arch axis form, arrangement mode and density of bent frame, Building finite element modelsto conduct static analysis, modal analysis and time-historical dynamic analysis. Then,superposing the result of static analysis and dynamic analysis, comparing the maximuminternal force (axial force, shearing force, in-plane bending movement, out-plane bendingmovement) and the stress of the arch foot. Ultimately, deciding the optimal rise span ratio,arch axis form, arrangement mode and density of bent frame.(3)Arranging the experiment with orthogonal test method and building finite elementmodel to make static analysis, modal analysis and dynamic time-historical analysis;Superposing the result of static analysis and dynamic analysis and using SPSS software tomake variance analysis of the maximum internal forces and the stress of the arch foot. Then,deciding the primary and secondary order of the factors. Ultimately, ascertain the optimallevel of the factor, namely the optimal combination of the structure parameters.With simplified method the final outcomes were obtained: The optimal rise span ratio is1/6; The optimal arch axis form is catenary; The optimal arrangement mode is vault withoutbent; The optimal bent density is the same as the original. With orthogonal test method thefinal outcomes were obtained: In addition to transverse seismic excitation, the optimalarrangement mode is vault with bent, Other optimal structure parameters is the same to theresults of simplified method.